5 Concrete and Reinforcement: 5.1 General

5 Concrete and Reinforcement
5.1 General
5.1.1 Definitions
The following terms and definitions shall apply;
'NEOM" NEOM Company (NEOM).
"The Contractor" The party defined in the contract documents.
"The Engineer" The party or person assigned by NEOM to supervise the Contractor's
performance.
"The Designer" The party who is responsible for the various stages of design
services.
"BS" British Standard
"ASTM" American Society for Testing and Materials
"ACI" American Concrete Institute
"Particular Amendments to the Standard Specification":
A document which shall be issued by the Designer in order to cover any special requirements
which are not covered by this Standard Specification.
"Acceptance" and "Approval":
A statement from NEOM or the Engineer which acknowledges that a certain documentation has
been submitted. The statement shall not relieve the Contractor of any responsibility for the
completeness or correctness of the documentation or the quality of the works.
"Quality Assurance":
The overall organization, planning, and documentation needed to establish confidence that the
desired quality will be achieved.
"Quality Control":
The sampling, testing and reporting needed to prove that the desired quality has been achieved.
5.1.2 Minimum requirements and additional requirements

The Standard Specification covers minimum requirements to materials, workmanship, and
quality control during execution. It shall not in any way reduce the relevant contract parties'
responsibility for designing and constructing safe and durable structures
5.1.3 Applicable Standards

The specification refers to selected standards and guides which are identified in the relevant
sections. They comprise:
BS 14188-1 Hot-applied joint sealant system for concrete pavements: Methods of

tests
11-152120-4800000519-RWF-CIV-SPC-000001 R E V I S I O N CODE : A PAGE 48 OF 171

BS 2571 Specification for general-purpose flexible PVC compounds for moulding
and extrusion
BS 6093 Design of joints and jointing in building construction. Guide
BS 6213 Selection of construction sealants. Guide
BS 8666 Scheduling, dimensioning, bending and cutting of steel reinforcement

for concrete
BS EN 196 Methods of testing cement
BS EN 480 Admixtures for concrete, mortar and grout - Test methods
BS EN 933 Tests for geometrical properties of aggregates
BS EN 1097 Tests for mechanical and physical properties of aggregates
BS EN 12620 Aggregates for concrete
BS EN 1367 Tests for thermal and weathering properties of aggregates
BS EN 1744 Tests for chemical properties of aggregates
BS EN 1992-1-1 Eurocode 2. Design of concrete structures - General rules and rules for
buildings
BS EN 1992-3 Eurocode 2. Design of concrete structures - Liquid retaining and

containing structures
BS EN 12350 Testing fresh concrete
BS EN 12390 Testing hardened concrete
BS EN ISO 11600 Building construction - Jointing products - Classification and

requirements for sealants
ASTM C33/C33M Standard specification for concrete aggregates
ASTM C40/C40M Standard test method for organic impurities in fine aggregates for
concrete
ASTM C117 Standard test method for materials finer than 75 µm (no 200) sieve in
mineral aggregates by washing
ASTMC127 Standard test method for specific gravity and absorption of coarse
aggregate
ASTMC128 Standard test method for specific gravity and absorption of fine
aggregate
ASTM C131/C131M Standard test method for resistance to degradation of small size coarse
aggregates by abrasion and impact in the Los Angeles Machine
ASTM C142/C142M Standard test method for clay lumps and friable particles in aggregates
ASTM C150/C150M Standard specification for Portland Cement
ASTM C191 Standard Test methods for Time Setting of Hydraulic Cement by Vicat
Needle
ASTM C403/C403M Standard test method for time of setting of concrete mixtures by
penetration resistance

ASTM C1064/C1064M Standard test method for temperature of freshly mixed Portland Cement
concrete
ASTM C1202 Standard test method for electrical indication of concrete's ability to
resist chloride ion penetration
ASTM A615/A615M Standard specification for deformed and plain carbon-steel bars for
concrete reinforcement
ASTM A775 Standard specification for epoxy-coated reinforcing steel bars
ACI 301 SI Specifications for Concrete Construction
ACI 304 Guide for measuring, mixing, transporting, and placing concrete
ACI 305R Guide to Hot weather concreting
ACI 506R Guide to shotcrete
ACI 506.2 Specification for shotcrete
Contractor shall supply two sets of all standards and codes referred in this specification and
elsewhere in the project for the Employer and the consultant prior to the commencement of the
contract.
5.1.4 Exposure Classes

This Specification refers to three exposure classes. If there is any doubt about what class to use
for a given structure, the strictest shall always apply, even if e.g. the levels of chlorides or
sulphates in soil may seem moderate.
5.1.4.1 Class A, Aggressive, with Chlorides and Sulphates

This includes:
Any structure in contact with sea water, or discharge water such as cooling water, brine, etc.
Typical examples are intakes, pump-houses, foundations, shafts, basins, and channels.
Any structure exposed to occasional spray or splash from seawater or discharge water.
Any structure in the ground or in contact with the ground up to 0.5 m above station elevation
(ground elevation).
5.1.4.2 Class B, Aggressive, With Risk of Chlorides, but no Sulphates

This includes for example the following unless they belong to Class A:
Any out-door structure more than 0.5 m above station elevation (ground elevation) located in a
coastal region. Typical examples are columns, walls and roofs outdoor in costal areas.
Any area subject to water spillage or washing
Tanks and other structures containing product water.
5.1.4.3 Class C, Moderate, With no Risk of Chlorides or Sulphates

This includes for example the following unless they belong to A or B. Typical examples are
columns, walls and roof not located in costal areas and 2 m above ground.
• In-door structures in dry buildings, if isolated from the ground or more than 2 m above
ground, and not exposed to frequent water spillage or washing.

• Out-door structures more than 2 m above ground in dry buildings in dry inland locations
(not in a coastal region), and not exposed to frequent water spillage or washing.
A dry building shall mean an administration building, residential building, warehouse, or factory
without any wet or aggressive processes which may put the building in a stricter exposure class.
5.1.5 As-Built Documentation and Maintenance Manual

As-built documentation and maintenance manuals shall as a minimum include complete as-built
drawings, complete design calculations, a complete list of materials used, and a manual for re-
coating of surfaces and replacement of items with a design life less than the project to which
they belong.
The maintenance manual shall state the expected interval between re-coating and
replacements, and shall list any inspection procedures which are necessary as part of a well
planned maintenance scheme.
5.1.6 Quality Assurance and Quality Control
5.1.6.1 General
The Contractor shall establish, document and maintain an appropriate Quality Assurance system
for his works. The system shall be clearly documented and submitted to the Engineer for
approval within eight weeks from the Contractor's taking over of the site.
During the performance of the work, the Contractor shall document that he adheres to the system
and that it is adequate to ensure a consistent and acceptable quality throughout the works.
The Contractor shall hold regular quality assurance meetings at not more than one month's
interval, with participation of all senior key staff. The meetings shall be used to monitor the quality
assurance performance and identify any need for improvement of the system. The meetings
shall be minuted with copy to the Engineer.
The Contractor's quality assurance shall comprise but not be limited to the following which is to
be read in conjunction with all other contract documents.
5.1.6.2 Quality Assurance System and Organization

The Contractor shall in the Quality Assurance System define and document his policy and
objectives for quality.
The System shall show an organization diagram and job descriptions which shall clearly define
responsibility, authority and inter-relation of all key staff.
All Quality Assurance functions shall be kept separate from the quality control functions: the
Contractor shall appoint one senior person as Quality Assurance Manager for this particular job;
this person shall be authorized to liaise with the Engineer in any Quality Assurance matter. The
Quality Assurance Manager shall have direct access to the Contractor's top management, and
such access shall not be interfered with by the Contractor's project management.
The System shall include adequate plans for document handling, ensuring that all necessary
documents on site are properly identified, planned, distributed and filed, keeping track of any
revisions. The purpose is to ensure that necessary documents are available in time, reach the
people concerned, are kept up-to-date, are easily retrievable, and that no obsolete documents
are used on site.
5.1.6.3 Quality Plans

The Contractor shall prepare a Quality Plan and submit it for approval by the Engineer not less
than two weeks before commencement of the related activities; it may be subdivided into several

plans, each covering work on one or more of the structures to be built. No work must commence
until the Quality Plan for the work has been approved.
The Quality Plan shall include:
• the scope of work which they cover;

• method planning with identification of all work sequences, procedures, and identification
of all equipment needed for the work, including stand-by spares; the method planning
shall be consistent with the approved method statements submitted with the tender;
• identification of staff responsibilities;
• Control Plan as specified in 5.1.6.4.
5.1.6.4 Control Plans

For each Quality Plan, the Contractor shall prepare a Control Plan clearly identifying each and
all Contractor's supervision, inspection, sampling and testing to be performed. The Control Plan
shall be specific, and terms like "as per the relevant specification" will not be accepted. The main
contents in the Control Plan shall be:
• definition of control sections;

• listing of Contractor's supervision duties and all required quality control documentation;
• hold-points for inspection by Contractor's supervision;
• type and number of all tests in each control section;
• sampling and testing method identified by Code and No;
• responsibilities for inspection, sampling, testing;
• responsibility for assessing the test results and taking initiative to corrective action
wherever required;
• reporting procedures, including the agreed format of all required documentation.
The Control Plan shall clearly define the control sections. Each control section shall coincide
with one or more casting sections.
If the Contractor's Quality Control in any one control section reveals non-conformity with the
specified requirements, all the works in that control section are not approved. The Contractor
shall immediately inform the Engineer about the non-conforming results; and he shall propose
appropriate corrective action which may be re-test, re-work, or remove the non-conforming
section.
The Engineer shall decide if re-testing or re-working Is acceptable; otherwise, the Contractor
shall remove the non-conforming section at his own cost.
5.1.6.5 Independent Testing Contractor and Laboratory Facilities

Unless specifically stated in the Contract Documents or agreed later in writing, all frequent
testing shall be done in a properly equipped site laboratory.
The Contractor shall engage an approved independent testing laboratory to perform all tests
which are not done on site; such testing shall always be done in the presence of the Engineer.
All test results shall be submitted in duplicate to the Engineer at the same time as they are
submitted to the Contractor.
The Contractor shall submit his request for approval of the independent testing contractor and
the laboratory facilities with a complete description of capabilities, experience, equipment, staff
and organisation. NEOM reserves the right not to approve or to withdraw approval of the testing
contractor and/or the facilities if they in the opinion of NEOM do not perform at an acceptable
level.

5.1.6.6 Planning and Quality Control
The Contractor shall be responsible for the comprehensive quality assurance and quality control
in accordance with this chapter. The responsibility shall include but not be limited to the
submission of the individual method statements and the specific quality control actions
mentioned in other chapters of this Specification.
5.1.6.7 Engineer's Approvals or Acceptance

Acceptance or approval by the Engineer shall not in any way relieve the Contractor of any part
of his full responsibility for all design, methods, materials, workmanship, etc.
5.2 Concrete Constituent Materials
5.2.1 General
Concrete constituent materials shall mean the materials which are used in the concrete mix, as
specified in this chapter or as otherwise agreed in writing. The materials shall be obtained from
approved sources known to produce the required quality and with no adverse effect on the
durability of the concrete.
The Contractor shall obtain the approval of NEOM in writing for all materials before they are
brought to site. To obtain the approval of a proposed material, the Contractor shall submit a fully
documented request stating;
• type of material;
• for which mix it is intended to be used;
• to which part of the specification it refers;
• name and address of source, manufacturer, and supplier;
• representative samples;
• reference list for similar application;
• relevant test results.
The samples will be kept for reference for the duration of the project. The test results shall include
the outcome of the tests specified in this chapter. Where more than one test has been performed,
the results shall be presented as average, minimum and maximum values.
NEOM has the right at any time to withdraw approvals and/or to reject any material if the
subsequent production test values deviate from the approved pre-test values, or if in their opinion
the material does not meet the objective of the works. NEOM shall have access to all sources
of supply and to transport and storage facilities for the purpose of inspection and sampling.
All reference to %-values in this chapter shall mean mass percentage (percentage by weight)
unless otherwise stated.
5.2.2 Cement
5.2.2.1 Requirements
5.2.2.1.1 Reinforced Concrete
Cement for all reinforced concrete shall be Portland cement complying with ASTM C150/C150M,
Type I, and fulfilling the following additional requirements:
• the equivalent alkali content (Na2O + 0.658K2O) shall not exceed 0.6%

• time of initial set (Vicat test, ASTM C191) shall not be less than 120 min;
• the fineness (air permeability) shall not exceed 400m2/kg;
• C3A contents, in concrete shall be as specified in Section 5.3.6;
5.2.2.1.2 Un-reinforced Concrete
Unless otherwise approved by the Engineer, cement for un-reinforced concrete shall be a
Portland cement complying with ASTM C150/C150M, Type V, and fulfilling the following
additional requirements:
• the equivalent alkali content (Na2O + 0.658K2O) shall not exceed 0.6%;
• time of initial set (Vicat test, ASTM C191) shall not be less than 120 min;
• the fineness (air permeability) shall not exceed 400 m2/kg.
Cement Type V will generally develop less heat during hardening than Type I, and is used
without silica fume in the mix. It shall therefore be used for un-reinforced mass concrete
structures if low heat of hydration in the opinion of the Engineer is required for an adequate
control of the thermal forces.
Cement Type V has an increased sulphate resistance, and shall therefore be used for all un-
reinforced structures in Exposure Class A.
If approved by the Engineer, cement for un-reinforced concrete may alternatively be as specified
in 2.2.1.1 for reinforced concrete, waiving the lower limit of 5% on the C3A content.
5.2.2.1.3 Delivery
Bulk delivery trucks shall be provided with clear markings of the cement type at the outlet pipe.
Cement in bags and big bags shall be delivered to the concrete production site in original
moisture-proof sealed packing, clearly labelled to show weight, manufacturer, brand, type and
production date. Cement shall be stored and handled as specified in section 3.2.
5.2.2.1.4 Quality Control
Approval and quality control of cement manufactured in Saudi Arabia will be based on
manufacturer's certificates. However, chloride contents shall always be determined either by the
manufacturer or by independent testing in accordance with BS EN 196.
Approval of imported cement will be based on the manufacturer's certificates supported by

independent testing of samples selected by the Engineer. The independent testing shall be
performed for the Contractor by laboratories approved by NEOM; the frequency of independent
testing shall be at least one test during pre-testing and one test from each shipment; the
independent testing shall comprise all properties stated on the manufacturer's certificate plus
chloride contents determined in accordance with BS EN 196.
The number and frequency of manufacturer's certificates shall be as follows:
• certificates covering the manufacturer's production of the preceding half year shall be
submitted with the Contractor's request for approval;
• a certificate representing the production period where the cement was manufactured shall
be submitted with each shipment arriving to site.
The manufacturer's certificate shall state place and date of manufacturing. It shall give
all test values for the chemical composition and physical properties which are specified
as standard requirements in ASTM C150/150M and as additional requirements in this
specification.

5.2.3 Silica Fume
5.2.3.1.1 Type and Composition
Silica fume (microsilica) shall comply with the following additional requirements when tested in
accordance with BS EN 196:
• SiO2 content shall not be less than 90%;

• Loss on ignition shall not exceed 4.0%;
• SO3 content shall not exceed 2.0%;
• MgO content shall not exceed 5.0%
• Alkali content (Na2O + 0.658K2O) shall not exceed 1.5%;
• Chloride content shall not exceed 0.10%;
• Free CaO content shall not exceed 1.0%;
• Free Si content shall not exceed 0.40%
• Specific surface shall notbe less than 15 m2/g
• Max. grain size 0.1 mm
The density shall be measured and reported in the certificates.
Silica fume shall always be homogenized before mixing, whether it is delivered as slurry or
powder in loose or compacted form. Powder shall not contain lumps which cannot be easily
broken down when rubbed in a hand.
5.2.3.1.2 Delivery
Silica fume in bags and big bags shall be delivered to the concrete production site in original
moisture-proof sealed packing clearly labelled to show weight, manufacturer, brand, type and
production date.
Silica fume in the form of slurry shall be delivered in original sealed containers with same marking
as required for bagged products, plus information about the solids/water ratio.
5.2.3.2 Quality control

Approval and quality control of silica fume will be based on manufacturer's certificates. The
number and frequency of manufacturer's certificates shall be as follows:
• certificates covering the manufacturer's production of the preceding half year shall be
submitted with the Contractor's request for approval;
• a certificate representing the production period where the silica fume was manufactured
shall be submitted with each shipment arriving to site.
• The manufacturer's certificate shall state place and date of manufacturing. It shall give all
test values for the specified chemical composition and physical properties.

5.2.4 Fine Aggregates
Fine aggregate shall be from natural sources in compliance with ASTM C33/C33M or BS EN
12620 and shall have the following properties, measured by the test methods shown in brackets
after the specified value:
a) Clay lumps and friable particles: max 1.0% (ASTM C142/C142M)
b) Material finer than 75 micron

(washing and sieving): max 2.0% (ASTM C117)
c) Organic impurities: lighter than standard (ASTM

C40/C40M)
d) Water absorption: max 1.5% (ASTM C128)
e) Chloride ion content (Cf): max 0.050% acid soluble

(BS EN 12390)
f) Sulphates (SO3): max. 0.40% acid soluble (BS EN

1744)
g) Magnesium sulphate soundness: max. 10%, 5 cycles (ASTM C 88)
h) Potential alkali-silica reactivity: innocuous (ASTM C289)
i) Drying shrinkage: max 0.075%(BS EN1367)
j) Specific gravity (unit weight) ASTM C 128
5.2.4.1.2 Grading
The average grading of each type of fine aggregate shall be determined in accordance with BS
EN 933 and shall be stated by the supplier.
The permissible deviation from stated grading is as follows, expressed as percentage by the
mass passing the sieve:
Sieve (mm) 0/4 mm 0/2 mm 0/1 mm
5 ± 5% - -
2.36 - ± 5% -
1.18 ± 20% ± 20% ± 5%
0.300 ± 20% ± 25% ± 25%
0.150 ± 10% ± 10% ± 10%
5.2.4.1.3 Moisture Content
The maximum free water content of the fine aggregate shall be 5%. The free water content is
the difference between the total moisture content determined in accordance with BS EN 1097
and the water absorption determined in accordance with ASTM C 128.

Water used for washing, if any, shall fulfil the requirements in Section 5.2.6.
5.2.4.1.4 Delivery
Each load of fine aggregates shall be delivered to the concrete production site with a delivery
note stating name of supplier plus type and source of aggregate.
5.2.4.2.1 Initial Approval
Initial approval will be based on the supplier's test reports which shall include all. items
mentioned in 5.2.4.1 above. The test reports shall cover the supplier's production in the
preceding half year, and shall show that the testing has been performed on a regular basis.
However, one test report shall be considered sufficient for the following tests, provided it is not
more than six months old:
• 2.4.1.1 g), magnesium sulphate soundness;

• 2.4.4.1 h), potential alkali-silica reactivity;
• 2.4.4.1 i), drying shrinkage.
5.2.4.2.2 Testing During Production
Testing during the production shall be done by an approved independent laboratory with the
testing frequency specified in Table 2.4.2.2. The frequency of testing may be reduced as stated
if the latest six consecutive tests have values below 60% of the specified max limits.
The grading and the moisture of the Coarse aggregates can be tested in a adequately equipped
on-site laboratory.
Table 1: Test Frequencies for Fine Aggregates
Property At beginning of pro duction When latest six consecutive

and when latest test value tests are documented to be
exceeds 60% of limit below 60% of the specified
limit.
2.4.1.1 Each day of production Each week of production

a) clay, etc
b) fines
d) absorption
e) chlorides
f) sulphates
2.4.1.1 Every six months Every 12 months
c) organic
g)soundness
h) reactivity
i) shrinkage
j) unit weight
2.4.1.2 Each production day Each week of production
grading

2.4.1.3 Two times every day of No relaxation
moisture production, or once every four
hours of production, whichever
is the lowest number of
tests.
5.2.5 Coarse Aggregates
Coarse Aggregates shall be from natural sources or from crushing plants (double broken)
obtained from an approved source in compliance with ASTM C 33 or BS EN 12620. They shall
be selected, re-crushed, finish screened and washed if necessary, to be free from adherent
coatings and complying with the following further requirements, measured by the test methods
shown in brackets after the specified value;
a) Clay and friable particles: max 1.0% (ASTM C142/C142M)
b) Material finer than 75 micron

(washing and sieving): max 1.0% (ASTM C117)
c) Water absorption
Concrete grade A and B: max 1.5% (ASTM C127)
Concrete grade C and D: max 2.5% (ASTM CI27)
d) Chloride ion content (CI): max 0.03% acid soluble (BS EN 12390)
e) Sulphates (SO3): max 0.40% acid soluble (BS EN 1744)
f) Magnesium sulphate soundness: max 10.0%, 5 cycles (ASTM C 88)
g) Potential alkali-silica reactivity: innocuous (ASTM C289)
h) Los Angeles loss (500 rev)

Concrete grade A and B: max 30% (ASTM C131/C131M)
Concrete grade C and D: max 35% (ASTM C131/C131M)
i) Drying shrinkage: max 0.075% (BS EN 1367)
j) Flakiness index: max. 25% (BS EN 933)
k) Elongation index: max 35% (BS EN 933)
l) Specific gravity (unit weight) ASTM C 127
5.2.5.1.2 Grading
Coarse aggregates shall be delivered as single sized coarse aggregates in accordance with BS
EN 12620. All-in aggregates (i.e. mixes with all sizes) are not allowed. Grading curves shall be
selected in accordance with ASTM C33/C33M unless other gradings have been proved to give
a dense well compacted concrete without segregation.

5.2.5.1.3 Moisture Contents
The free water content is the difference between the total moisture content determined in
accordance with BS EN 1097 and the water absorption determined in accordance with ASTM
C127.
Water used for washing shall fulfil the requirements in Section 5.2.6.
5.2.5.1.4 Delivery
Each load of coarse aggregates shall be delivered to the concrete production site with a delivery
note stating name of supplier plus type, source and nominal size of aggregate.
5.2.5.2.1 Initial Approval
Initial approval will be based on the supplier's test reports which shall include all items mentioned
in 5.2.5.1 above. The test reports shall cover the supplier's production in the preceding half year,
and shall show that the testing has been performed on a regular basis.
However, one test report shall be considered sufficient for the following tests, provided it is not
more than six months old:
• 2.5.1.1 f), magnesium sulphate soundness;

• 2.5.4.1 g), potential alkali-silica reactivity ;
• 2.5.4.1 h), Los Angeles loss
• 2.5.4.1 i), drying shrinkage.
5.2.5.2.2 Testing During Production
Testing during the production shall be done by an approved independent laboratory with the
testing frequency specified in table 5.2.5.2.2.
The frequency of testing may be reduced as stated if the latest six consecutive tests have values
below 60% of the specified max limits.
The grading and the moisture of the Coarse aggregates can be tested in a adequately equipped
on-site laboratory.
Table 2: Test Frequencies for Coarse Aggregates
Property At beginning of pro duction When latest six

and when latest test value consecutive tests are
exceeds 60% of limit documented to be
below 60% of the
specified limit.
a) clay, etc
b) fines
c) absorption
d) chlorides
e) sulphates
2.5.1.1 Each week of production Every two weeks of
j) flakiness production
k) elongation

2.5.1.1 Every six months Every 12 months
f) soundness
I)unit weight
2.5.1.1 Every 12 months No relaxation
g) reactivity
h) Los Angeles
i) shrinkage
grading
2.5.1.3 Two times every day of No relaxation.
Moisture production, or once every four
hours of production, whichever is
the lowest number of tests
5.2.6 Water
Water for concrete mixing and for curing shall be potable, clean, fresh, free from injurious
amounts of oil, acid, alkali, organic matter or other deleterious substances and shall be obtained
from an approved source. The water shall not affect the strength and durability of the concrete
or the mortar and shall not create discoloration of the hardened concrete or affect the
reinforcement. The water shall comply with the following:
a) pH 7-8
b) Total dissolved solids max 2,000 ppm
c) Suspended solids max 500 ppm
d) Chloride as Cl ions max 500 ppm
e) Sulphates as SO3 max 1,000 ppm
f) Alkali carbonate and bicarbonate max 1,000 ppm

As documentation for initial approval, the Contractor shall submit such documentation as may
be required by the Engineer in order to document that the source of supply will fulfil the above
requirements.
Unless otherwise agreed with Engineer, the sampling and testing frequency during the
production period shall be minimum 1 per production day, but not less than 1 test per week.
5.2.7 Admixtures
All admixtures shall conform to BS EN 480 or equivalent ASTM.
Admixtures shall not impair the durability of the concrete nor combine with the constituents to
form harmful compounds nor increase the risk of corrosion of the reinforcement. Calcium
chloride shall not be used. Chloride and sulphate contents in admixtures shall be stated by the
manufacturer and taken into account when checking the total limits for the mix.
If two or more admixtures are to be used in the same concrete mix, data shall be obtained and
documentation submitted by the manufacturer to assess their interaction and to ensure their
compatibility.
For each admixture the contractor shall submit the following information:
• product name;
• manufacturer and supplier;

• active components;
• density, kg/I;
• content of dry material, weight %;
• alkali content (Na2O + 0.658K2O);
• total chloride content;
• total sulphate content;
• pH-value;
• colour;
• normal side effects;
• side effects by over dosing;
• expiry date;
• max./min. storage temperature;
• any precautions to be taken before usage, if relevant;
• max./min. dosage as weight % of cementitious materials.
Each consignment of admixtures shall be delivered to the Contractor with a delivery note stating
name of manufacturer and supplier, product name and consignment identification.

For approval of admixtures the Contractor shall submit data sheets and test reports proving
conformity to BS EN 480 together with the information listed in cl. 5.2.7.1.
During the production period admixtures shall be retested whenever doubt arises about the
performance of an admixture. The retesting shall be performed in accordance with BS EN 480
and shall include the properties for which doubt has been raised.
For all deliveries arriving the site of the batching plant, the delivery notes have to be checked.
5.2.8 Other Materials

Other constituent materials (e.g. fly-ash, blast furnace slag cement, high-reactivity metakaolin,
etc) shall be used only if specifically agreed or stated in the contract documents.
5.3 Concrete Production
5.3.1 General for Ready Mixed Concrete and Site Mixed Concrete
All requirements whatsoever in this specification are minimum requirements which shall apply
equally to concrete mixed off site by a third party (ready mixed concrete) and to concrete mixed
at site under the direct control of the contractor (site mixed concrete).
Ready mixed concrete will be acceptable only from suppliers who have been approved in writing
by NEOM. Such approval shall specifically mention the project or projects for which the supplier
has been accepted; the approval may be withdrawn at any time in case of non-conformity with
the requirements. Readymix suppliers will be approved only if they can document that they
maintain and follow an adequate quality management system and have a proven ability and
capacity to produce concrete in accordance with these specifications.
Transportation time from the concrete mixing plant to the location of placing shall be carefully
planned and rigidly enforced; planning of ready-mix supplies shall include allowance for traffic
conditions en route to site.
The Contractor shall submit all relevant details of the concrete production facilities and quality
systems, and the Engineer shall have access for inspection of the facilities and systems at any
time.

5.3.2 Storage and Handling of Materials
5.3.2.1 General
Materials for use in concrete production shall be stored and handled in a way that does not
change their properties or expose them to contamination, cross-mixing, or harmful influence from
the environment. No materials shall be brought to the concrete plant unless they have been
tested and accepted in accordance with the requirements to the constituent materials.
5.3.2.2 Fine and Coarse Aggregates

Stock-piles of fine and coarse aggregates shall be placed on concrete hardstands with good
drainage and under a shade which prevents direct exposure to sunlight; necessary precautions
shall be taken to avoid contamination with blowing dust. Each fraction shall be kept separate by
ample space or suitable partitions, and the fractions shall not be mixed until they have been
measured.
Handling shall be with methods and equipment that ensure a uniform grading of the material
throughout the stockpile. No traffic is to be allowed on the stockpiled material.
If coarse aggregates are watered before mixing, it shall be demonstrated that the amount of free
water in the aggregates remains within uniform limits throughout the stockpile; the variation shall
not exceed +/- 1 litre of water per m3 concrete. Due allowance shall be given to the actual amount
of free water in the aggregates to ensure compliance with the specified free water/cement ratios
for different concrete mixes specified in clause 5.3.6.2 and calculated in accordance to clause
5.3.6.3. Proper drainage of the watered aggregates is important.
5.3.2.3 Cement
Cement shall be supplied and stored in bulk. All transport and storage shall be in closed systems.
The storage bins shall provide necessary protection against the weather. If several types of
cement are used, the necessary number of storage bins shall be reserved exclusively for each
type. Each bin shall be clearly marked for its intended use.
Freshly delivered cement may be hot and should not be used in production until it has cooled
down to ambient temperature; cement with temperatures above 65° C shall not be used in the
mix under any circumstances. Storage capacity shall be planned to allow for the necessary
cooling off.
The cement shall not be kept in stock for extended periods, and the stock shall be rotated on the
first in - first out principle. Storage bins shall be drawn down and cleaned regularly, at least once
per six months, to prevent old cement from building up in the bin.
Bagged cement shall be used in exceptional cases only, and always subject to prior approval in
writing from the Engineer. If bagged cement is used, delivery shall be in sealed bags which shall
be stored on pallets not more than 7 sacks high. Bagged cement shall be stored indoors in
weatherproof, dry, and well ventilated stores.
Cement older than six months from its production date shall not be used.
5.3.2.4 Silica Fume

Handling and storage of silica fume (microsilica) shall take into account the same considerations
as specified for cement, together with the additional recommendations of the manufacturer.
5.3.3 Batching and Mixing
5.3.3.1 Measuring, Batching, Charging

Batching shall be by equipment with adequate facilities for checking and calibrating the
measuring mechanisms. Ice and all constituent materials shall be measured by weight, except

water and admixtures which shall be measured either by weight or by volume, as practical. The
actual weights and volumes of each material shall be recorded for each batch.
The batching plant shall be equipped with separate weighing machines for cement and
aggregates.
The batching plant shall furthermore be furnished with a micro-processor monitoring system with
a automatic moisture control for the fine aggregates.
The combined accuracy of the measuring equipment and the dosage controls of the batching
equipment shall be such that the actual quantity of each constituent material in the mix is within
the following tolerances when compared to the theoretical weights and measures stated on the
mix recipe:
• Cement: ±3%
• Microsilica ±3%
• Fine and coarse aggregates: ±3%
• Water, inci ice: ±3%
• Admixtures: ±5%
The equipment shall be marked with a plate stating the largest and the smallest batch which can
be mixed in compliance with these tolerances, and batches shall be mixed only within the range
thus stated.
The weight of fine and coarse aggregates shall be adjusted for their moisture contents, using
the "saturated surface-dry" weights from the mix recipes as reference basis.
The equipment shall be cleaned, checked, and adjusted regularly in accordance with the
manufacturer's recommendations, the contractor's quality management system, and these
specifications, whichever is the strictest requirement.
Measuring equipment shall be checked at monthly intervals by using designated standard

weights which shall be kept available for this purpose at all times; calibrated containers shall be
used to check the accuracy of water and admixtures measuring if they are measured by volume.
The results of these monthly checks shall be entered in a log-book at the plant, and they shall
be notified to the Engineer each time they have been made.
A full calibration shall be made when the plant is commissioned for operation; it shall be repeated
every three months, plus whenever doubts arise about the accuracy of the weighed quantities.
The calibration shall include a check of scales over their entire range and a check on the
combined accuracy of the measuring equipment and the controls of the batching equipment; the
calibration shall always be performed by an authorised independent laboratory.
The certificate of calibration, stating the accuracy, shall be kept at the plant, and the result of the
calibration shall be notified to the Engineer.
Controls shall be provided to prevent weighed materials from entering the mixer before the
previous batch has been completely discharged. Weighed materials shall be discharged into the
mixer without loss.
Water measuring shall be accurate and safe. Reliable design and control devices shall ensure
that the inlet and the outlet can never be open or partially open at the same time, that no overflow
can enter the mix, and that no water is lost through leaks or incomplete charging of the measured
water.
The weighed materials shall be charged into the mixer over a period which shall not exceed the
first 25% of the specified mixing time.

Addition of retarding admixtures shall be completed in the time recommended by the
manufacturer's procedure. The required dosage has to be verified by trial castings obtaining the
necessary extension of setting time.
If two or more admixtures are used, they shall be added separately to avoid any interaction which
might interfere with their efficiency.
5.3.3.2 Mixing, Discharging

The concrete shall be mixed in a forced action batch mixer. Truck mixing (transit mixing) is not
allowed.
The mixer shall be capable of thoroughly combining the constituent materials into a uniform
mass within the specified mixing time, and of discharging the concrete without harmful
segregation. The mixer shall bear the manufacturer's rating plate indicating the rated capacity,
and it shall be operated in accordance therewith.
To avoid excessive heat development, the mixing time shall be kept to the minimum required for
producing a uniform mass. The minimum mixing time shall be as specified by the equipment
manufacturer, but never less than 90 seconds.
Controls shall be provided to ensure that the batch cannot be discharged until the required
mixing time has elapsed. At least 75% of the required mixing time shall take place after the last
of the mixing water has been added.
The interior of the mixer shall be free of accumulations that will interfere with mixing action. Mixer
blades shall be replaced when they can no longer be adjusted to their correct position within the
tolerances specified by the manufacturer. Mixer blades shall always be replaced when they have
lost 10% of their original height.
Mixers shall be thoroughly cleaned if they have been out of use for more than 30 minutes or if
they are to be used for a mix of a higher grade or for a mix with a different cement type.
5.3.4 Transport and Delivery
5.3.4.1 Transporting Equipment

Concrete shall be transported to the point of placing either in a truck agitator or in a truck mixer
operating at agitating speed. The transporting equipment shall prevent contamination,
segregation, and loss of constituent materials during transport and delivery. Water hoses and
pipes for cleaning shall not be fixed in a way that allows water to be injected directly into the
mixer drum.
The transporting equipment used for ready-mixed concrete should have a counter which will
record the total number of agitating revolutions, counting from loading at concrete mixer to
discharge at point of delivery. Transporting equipment shall be thoroughly cleaned and
completely emptied of water after each delivery.
5.3.4.2 Handling of Mix During Transport and Delivery

No further materials shall be added to the mix after it has been discharged from the mixer.
During concrete transportation from batching plant to the site (discharging point) the rotation
speed of the drum is min. 1/min. Before discharging the truck mixer the concrete must be
remixed by rotating the drum - at least 3 minutes - with the full rotation speed (6 rotations per
minute).
Retempering of concrete by addition of cementitious materials, aggregates, or water for

whatever reason is not allowed. Concrete which has exceeded the specified time limits,

temperature limits, or workability limits shall be rejected at the point of delivery, and must under
no circumstances be placed in the permanent works.
5.3.4.3 Transport Time and Temperature Limits

The transport time from leaving the concrete mixer to arriving at the point of placing shall be
planned and documented in detail for the Engineer's acceptance.
Unless special precautions are taken and prior agreement is given in writing by the Engineer,
the transport time shall be kept so short that the concrete will be placed in its final position within
the following time limits from mixing:
• 90 minutes for concrete at 20 C temperature or less.

• 50 minutes for concrete at 30 C temperature.
The concrete temperature refers to the temperature measured in the fresh concrete at arrival to
the point of placing. Time limits for concrete temperatures between 20 and 30 C shall be found
by linear interpolation between 90 and 50 minutes.
Concrete shall not be warmer than 30 C when placing it in its final position.
If trials have been made on site to show that the above time limits can be safely extended, e.g.
by use of retarders in the mix, such extension may be granted but always subject to the
Engineer's acceptance of the trials and specific conditions of quality control. As a minimum, the
trials required before accepting any extension to the time limits shall mimic in every detail the
actual mix, transport method, transport time, placing method such as pumping distance, and
temperature of the mix; it shall be shown that the desired workability is maintained without
segregation or other change in the mix until the concrete has been placed, and that the
temperature has not increased above the permitted limit.
If the workability of the concrete drops below acceptable limits before placing is completed either
the transportation and the placing time shall be reduced or the setting time of concrete shall be
extended by adding a regarding agent - or the adding of retarding admixture shall be increased.
5.3.5 Hot weather Precautions
5.3.5.1 General Requirements

Hot weather precautions under this section shall mean any precaution required at the concrete
mixing plant in order to comply with the specified temperature limits of fresh concrete at any time
of the year. CIRIA Special Publication 31 and ACI 305R are applicable for examples of good
practice, always subject to stricter requirements which may be stated in this Specification or in
other contract documents.
The overall maximum temperature limit for fresh concrete when starting to place it in its final
position is 30 C. To ensure compliance with this, and taking into account the variations in ambient
conditions, transport time, waiting time, etc, the target max temperature for fresh concrete at the
mixing plant shall be set lower than this overall maximum limit.
Lower temperature limits may also be necessary in order to comply with the specific temperature
requirements during hardening, or in order to maintain an adequate workability (prolonging the
effect of mixing water and admixtures). The mixing plant must have the capability of complying
with the relevant concrete temperature limits during any period of concrete production.
5.3.5.2 Specific Measures

The plant shall routinely take the following precautions in whatever combination necessary to
fulfil the above general requirements:

• maintain all plant clean and with suitable reflective surfaces (light colours) and heat
insulation where relevant;
• keep the batching and mixing plant under shade;
• maintain all mixer trucks clean and with a light-coloured reflecting shade covering the drum,
or continuously wet hessian cover on the drum;
• keep waiting trucks under shade
• keep constituent materials fully protected against sun radiation at all times;
• avoid the use of warm cement;
• use cooled or chilled water;
• substitute part of the water with flake-ice or well crushed ice which must be shown to melt
completely during the mixing;
• cool the aggregates;
• mix and deliver at an appropriate time during day or night, considering exposure conditions
during placing as well as the heat development in the young concrete and its coincidence
with ambient temperature variations.
Cooling of materials or mix by use of liquid nitrogen may be considered if suitable equipment is
available and proper procedures with quality control are documented and tested, subject to the
Engineers acceptance.
5.3.6 Minimum Requirements to Concrete Mix
5.3.6.1 Durability and Structural Design Requirements

The durability requirements to the mix (mainly the w/c ratio) are expected to give a higher
strength than required from a structural design point of view.
This expected strength shall be used to monitor the contractor's ability to manage and control
his concrete production process. Fluctuations in strength indicate a fluctuation in quality, such
as variations in w/c ratio; therefore, strength fluctuations must be kept within pre-planned limits
in order to have confidence in the production control.
Structural design considerations shall not be used to relax any requirements in this specification.
Strength requirements stated on construction drawings shall always be complied with if they are
higher than the strength requirements to grades in this Specification.
5.3.6.2 Concrete Grades

The following standard range of grades refers to reinforced structures. Exposure Classes are
defined in Chapter 1. Distinction between reinforced and unreinforced structures is made in
terms of cement types and the additional requirements to cement, as explained in Note 1) and
2) below.
• Grade "A"
To be used for all concrete in Exposure Class A.
Minimum characteristic strength =50 MN/m2
Cement ASTM Type I, see Note 1), 2) : 6% < C3A< 9%
Minimum cement content =350kg/m3
Maximum cement content =420 kg/m3
Microsilica content, see Note 2) = 7% of cement weight
Max. free water/cementitious material = 0.40
Admixtures, see Note 3), 4), 5).
Chloride penetrability measured by ASTM C1202 shall be Very Low (100 1,000
coulombs).
Water penetrability measured by BS EN 12390 shall be max 10 mm after 3 days with 5
bars.

• Grade "B"
To be used for all concrete in Exposure Class B.
Minimum characteristic strength = 50 MN/m2
Cement ASTM Type I, see Note 1), 2) : 8% < C3A
Maximum cement content =420 kg/m3
Microsilica content, see Note 2) = 7% of cement weight
Admixtures, see Note 3), 4), 5).
Chloride penetrability measured by ASTM C1202 shall be Very Low (100 1,000
coulombs).
Water penetrability measured by BS EN 12390 shall be max 10 mm after 3 days with 5
bars.
• Grade "C"
To be used for all concrete in Exposure Class C.
Cement ASTM Type I, see Note 1), 2) : 5% < C3A
Maximum cement content =390kg/m3
Admixtures, see Note 3), 5)
• Grade "D”
To be used only for blinding layers (mud-mats)
Cement ASTM Type V, see Note 2)
NOTE 1) Cement for reinforced structures shall be ASTM Type I in compliance

with the additional requirements stated in clause 5.2.2.1.1.
NOTE 2) Cement for un-reinforced structures shall be ASTM Type V (or TypeI)
in compliance with the additional requirements stated in section
5.2.2.1.2.
If Type V is used, there shall be no requirement for use of microsilica.
NOTE 3) With the specified limits on the water/cementitious ratio, plasticisers

and/or superplasticisers will generally be needed to produce a workable
mix. Plasticisers providing an entrained air content of about 1% are
generally found to increase the workability as well as reducing the
tendency of segregation. Retarders, e.g. in the form of retarding
superplasticisers may also be needed.
NOTE 4) High-range water-reducing admixtures shall always be used in mixes

containing microsilica.
NOTE 5) Admixtures shall fulfil the requirements specified for constituent

materials; furthermore, the compatibility and the effects of admixtures
shall be documented as part of the pre-testing of the concrete.

5.3.6.3 Free Water/Cementitious Material Ratio, w/c
The free water/cementitious material ratio, generally referred to as the w/c ratio, shall mean the
free water content divided by the cement content plus the microsilica content multiplied with an
activity factor of 2.0. This calculation is expressed in the following formula, referring to the weight
of each material:
w/c = free water/(1.0 x cement + 2.0 x microsilica)
In order to compensate for the deviations stemming from mixing tolerances, the target value (i.e.
the value on the mix recipe) for the w/c ratio shall be set lower than the specified maximum
value. Unless another value for mixing tolerances is documented to the satisfaction of the
Engineer (based on documented accuracy of the weighing and batching, see section 5.3.3.1),
the target value shall be 0.03 below the specified max value; in no event shall the target value
be less than 0.02 below the specified max value.
5.3.6.4 Free Water
5.3.6.4.1 General
Free water which is used in calculating the w/c ratio shall mean the amount of water which shall
be added to the mix if the aggregates are in a Saturated Surface Dry condition (SSD). It consists
of:
• any aggregate moisture contents in excess of SSD condition,

• any water added as part of admixtures,
• any water added as ice (or steam),
• the water added as mixing water.
The SSD moisture content shall be determined as the absorption measured in accordance with
ASTM C127 & C128. Actual moisture in aggregates shall be measured in accordance with BS
EN 1097 at the time of mixing. The difference between actual moisture and SSD moisture
content shall count as free water.
Water in admixtures shall be calculated by weight, based on documented contents of solids,

using the following formula:
added water = total admixture - total solids.
5.3.6.4.2 Procedures for Dry Aggregates
If the aggregates are not saturated to the SSD condition, the amount of mixing water shall be
increased to compensate for absorption into the aggregates.
For fine aggregates the increase in mixing water shall be calculated as the difference between
the SSD moisture content and the actual moisture content in the aggregates measured on the
day of mixing, using measuring methods as specified in section 5.3.6.4.1.
For coarse aggregates the increase in mixing water shall be calculated as 50% of the difference
between the SSD condition and the actual moisture content in the aggregates measured on the
day of mixing.
However, coarse aggregates with absorption of more than 1.5% shall not be used if they have
a moisture content of less than 1.5% at the time of mixing. This means that such aggregates
shall be used only if they are moistened before mixing.

5.3.6.5 Cement Contents
The Contractor shall design the concrete mixes with the lowest possible cement content
necessary to meet the requirement of the specified type of mix, but not below the stated
minimum.
5.3.6.6 Size and Grading of Aggregates

The concrete mixes shall be designed with a grading of the combined aggregates which is shown
to produce a homogeneous concrete without segregation and to give the required workability
within the specified water/cementitious ratio.
In general, the maximum nominal aggregate size shall be as large as possible but not larger
than:
40mm;
• specified nominal cover -10 mm;

• smallest nominal bar spacing -10 mm;
• 1/5 of the smallest nominal concrete dimension.
The maximum nominal aggregate size in the mix shall not be less than 20 mm except for local
areas with congested reinforcement, etc, where the Contractor may propose smaller aggregates
for the Engineer's approval.
Coarse aggregates shall be combined by minimum two fractions for all mixes with a maximum
nominal aggregate size larger than 10 mm.
5.3.6.7 Chloride Contents
5.3.6.7.1 General Limits
For reinforced concrete the total chloride content in the concrete expressed as percentage acid
soluble chloride by weight of cement shall not exceed 0.1%
5.3.6.7.2 Limits for Pre-stressed Concrete
For post-tensioned concrete where the post-tensioned tendons are either greased and sheathed
or placed in grouted ducts, the total chloride content in the concrete expressed as percentage
acid soluble chloride by weight of cement shall not exceed 0.1%.
For prestressed concrete where the pre-tensioned strands are in direct contact with the concrete,
the total chloride content in the concrete expressed as percentage acid soluble chloride by
weight of cement shall not exceed 0.10%.
5.3.6.7.3 Chloride Account
The Contractor shall keep a chloride account for each mix as specified in 5.3.7.2. The chloride
limits specified for individual materials shall be overruled by the chloride limits specified for the
mix, and the limits in Chapter 5.2 shall be tightened if necessary to comply with the limits
specified above.
The calculated chloride content shall be verified by measurement on trial mixes, ref cl. 5.3.7.3.1,
and during production, ref cl 5.3.8.7.
5.3.6.8 Sulphate Contents

The total sulphate content in the concrete expressed as percentage by weight of cement shall
not exceed 4.0% acid soluble SO3.

The Contractor shall keep a sulphate account for each mix as specified in 5.3.7.2. The sulphate
limits specified for individual materials shall be overruled by the sulphate limit specified for the
mix, and the limits in Chapter 5.2 shall be tightened if necessary to comply with the limit specified
above.
The calculated sulphate content shall be verified by measurement on trial mixes, ref cl. 5.3.7.2.
5.3.6.9 Content of Alkalis

The total alkali content in the mix, expressed as equivalent alkali (Na2O + 0.658K2O), shall not
exceed 3.0 kg/m3.
The calculation shall be based on the actual alkali contents in the constituent materials and the
actual mix design.
5.3.6.10 Strength
The specified characteristic strength shall mean the characteristic strength at 28 days of cube
specimens made, cured, and tested in accordance with BS EN 12390 (cured at 20 C +/- 1 C).
The characteristic strength is the value below which no more than 5% of the test results will fall.
The strength shall be documented by pretesting of the proposed mix and by production quality
control as specified in this chapter.
5.3.6.11 Workability
The workability of the concrete shall remain satisfactory until placing and compaction is finished.
Target workability and time limits shall be documented by the Contractor in his planning, and the
workability shall be demonstrated by trial mixes and production trials. The minimum slump
should be selected on basis of the following guidelines:
• Floors, etc., compacted by poker or beam vibrator: 50 mm

• Footings, foundations, blinding, normal slabs, beams, walls and columns, pumped concrete,
etc., compacted by poker or beam vibrator and/or tamping: 75 mm
• Concrete sections containing congested reinforcement, compacted by poker:
• 125 mm.
5.3.6.12 Drying Shrinkage

The drying shrinkage shall be tested in accordance with an approved standard (preferably using
DEMIC gauge points) and shall not exceed 0.05%.
5.3.6.13 Chloride Penetrability

For concrete in Grade A and B, chloride penetrability measured by ASTM C1202 shall be Very
Low (100 - 1,000 coulombs).
5.3.6.14 Water Penetrability

For concrete in Grade A and B, water penetrability measured by BS EN 12390 shall be max 10
mm after 3 days with 5 bars.
5.3.7 Design and Pretesting of Mix
5.3.7.1 General
The Contractor shall select constituent materials in compliance with Chapter 5.2 and design his
concrete mix in compliance with this Chapter 5.3. He shall through the specified sampling and
testing, including the specified documentation from trial mixing and production trials,
demonstrate that he has fulfilled these requirements.

The documentation shall be submitted to the Engineer for approval in adequate time before the
planned start of concrete production for permanent works. No concrete shall be placed in the
permanent \works until the pretesting has been completed, documented, submitted, and
accepted in writing by the Engineer. However, for blinding layers pretesting shall be limited to
documentation of materials and compressive strength.
The pre-tested and approved mix design shall not be changed without prior written approval from
the Engineer. However, the approved admixture dosage may be changed +- 25% as required to
ensure consistent concrete properties, without prior approval, but always subject to the condition
that the total amount of admixture shall be within the limits recommended by the manufacturer
and within limits documented by pre-testing to give an acceptable quality.
5.3.7.2 Mix Design

The Contractor's mix design shall be documented in a mix recipe for each mix. The mix recipe
shall be revised if there is any change in supplier, type, grading, size, or quantity of constituent
materials. The mix recipe which the Contractor shall submit for approval must as a minimum
include the following data:
• weight per m3 and specific gravity of all materials;

• volume per m3 of all materials;
• estimated air content and density of fresh concrete;
• estimated workability at 20° C and 30° C;
• grading for combined aggregates;
• calculation of free water and w/c ratio;
• calculation of alkali content;
• calculation of acid soluble chloride content;
• calculation of acid soluble sulphate content;
• estimated characteristic cube strength;
• estimated chloride penetration;
• estimated water permeability.
5.3.7.3 Trial Mixes

The following shall be documented by trial mix for each concrete grade and every proposed mix.
If the mix is to be produced as a well proven standard mix from a ready-mix supplier with a
reliable quality assurance system, equivalent existing documentation may be used instead of
performing new tests and trials, always provided such documentation is properly certified to the
satisfaction of the Engineer, and not more than three months old.
5.3.7.3.1 Chloride Contents
Test results of total amount of acid soluble chloride ions in the hardened concrete, for a minimum
of three samples taken and tested in accordance with BS EN 12390.
5.3.7.3.2 Sulphate Contents
Test results of total amount of acid soluble sulphate ions in the hardened concrete, for a
minimum of three samples taken and tested in accordance with BS EN 12390.
5.3.7.3.3 Workability
The target range of workability (e.g. maximum and minimum slump) shall be defined by the
Contractor considering the guidelines in 5.3.6.11, for the Engineer's acceptance. The workability
shall be tested on all trial mixes used for strength testing, see 5.3.7.3.6.

The workability shall be tested at 15 min intervals from 0 to 90 minutes from mixing, or longer if
placing is agreed to be permitted later than 90 minutes from mixing. The tests shall be made at
temperatures as expected on site, and the mix shall be agitated between each test to mimic the
specified agitation during transport.
The test results will be acceptable if workability is found within the target range in the six trial
mixes to the end of the agreed time interval representing the time from mixing to completion of
placing.
5.3.7.3.4 Drying Shrinkage
The drying shrinkage shall be tested as stated in5.3.6.12.
5.3.7.3.5 Time of Setting.
Time of setting shall be measured in accordance with ASTM C403/C403M, and the results shall
be plotted in a graph as shown in Appendix Fig. XI.1 of the standard, stating the time to initial
set and the time to final set.
5.3.7.3.6 Strength.
Strength shall be documented through trial mixing unless the mix is to be produced as a standard
mix from a ready-mix supplier who can document a consistent strength test record over a period
of minimum the latest three months before submission for approval.
For each proposed mix design, three trial mixes shall be made over three consecutive days.
From each trial mix six cube specimens shall be prepared, cured, and tested in accordance with
BS EN 12390. Each set of 6 cubes shall be tested for compressive strength as follows:
• 1 cube at 3 days age;

• 1 cube at 7 days age;
• 1 cube at 14 days age
• 3 cubes at 28 days age.
The individual and average strength for each of the three tests shall be recorded and the strength
development shall be plotted in a graph showing the strength at 3, 7, 14 and 28 days.
The specified strength will be deemed to have been achieved if the testing of the group of 9
cubes at 28 days shows (counting all 9 results from the mix):
• the standard deviation is 3.5 N/mm2 or less;

• the average ≥ specified Characteristic Strength +6.0 N/mm2
Based on the trials, the specified characteristic strength for the mix shall be reviewed in order to
establish a practical production control. The requirement shall be to achieve a uniform high
strength within the limits of what can be achieved with the approved constituent materials.
5.3.7.3.7 Chloride Penetrability
For concrete in Grade A and B, chloride penetrability shall be documented as per 5.3.6.13.
5.3.7.3.8 Water Penetrability
For concrete in Grade A and B, water penetrability shall be documented as per 5.3.6.14.

5.3.7.4 Production Trial
Production trials shall be made for the Engineers acceptance before any permanent works are
cast. They shall comprise a minimum of three separate castings, and they shall include at least
one trial with each relevant mix of grade
A, B, and C. Each casting shall comprise at least 3 concrete placed in a form with dimensions
and reinforcement similar to the dimensions and reinforcement in the structure to be built.
The production trials shall be done under site conditions with the actually planned
production equipment, including mixing and transport equipment, and they shall mimic
representative structures for the most difficult placing and compaction. The
time for placing, compaction, etc shall represent the expected longest concreting
operation, including time between casting of subsequent layers. If the Contractor
intends to add plasticiser on site, this procedure shall be included in the
production trial.
The following shall be recorded:
• complete batching and mixing record (weights, time, temperature of materials

and mix);
• transport time to point of placement;
• ambient temperature and fresh concrete temperature at point of placement;
• complete placing and compaction record (equipment, time, fresh concrete

temperature at completion of finished surface).
• After removal of form, the surface shall be inspected for honeycombs; three
horizontal cores D = 150 mm shall be taken to a depth of minimum 300 mm at
bottom, middle, and top of each production trial.
• The cores shall be inspected for pores and cavities, and shall be found to
have no excess void age (BS EN 12390).
• The cores shall be prepared with a length/diameter ratio of 1.0 and crushed
at 28 days. The average core strength in the three samples shall not be less
than the specified standard cube strength x 1.0.
5.3.7.5 Repetition of Trials

If trial mixes or production trials do not fulfil the requirements of this Specification, then necessary
changes shall be made, and new trials performed until the requirements have been fulfilled.
5.3.8 Quality Control during Production
5.3.8.1 General
The Contractor shall keep written records for all materials used in the works, to show that they
have been tested and found in conformity. This applies also to any ready-mix supply.
The Contractor shall furthermore keep records of the production quality control specified in the
following.

5.3.8.2 Weighing and Mixing
Mixing records shall be kept for each batch, showing actual dosage of constituent
materials and adjustment for aggregate moisture contents.
5.3.8.3 Delivery Notes for Ready-mix Concrete

Ready mixed concrete shall be accompanied by a delivery note with the following information:
• Name of purchaser/ contract

• Name of supplier
• Volume delivered
• Concrete grade
• Mix code number
• Maximum nominal aggregate size
• Cement type
• Workability
• W/c ratio
• Temperature at mixing
• Time and date of mixing
• Registration number or fleet number of trucks
• Delivery note number
• Signature of dispatcher.
The Contractor shall inspect the delivery note upon arrival and check that it Is in agreement with
his order; he shall sign off to show that he has satisfied himself that this is the case, and he shall
complete the delivery note by adding:
• Time of arrival
• details of admixture added at arrival, if any.
One copy of the completed delivery note shall be submitted to the Engineer immediately after it
has been signed off by the Contractor.
5.3.8.4 Temperature
The temperature of each concrete load shall be measured before the concrete leaves the mixing
plant, and again on site immediately before beginning of placing.
Measurements shall be made in accordance with ASTM C1064/C1064M using an appropriate

immersion thermometer inserted in the concrete to a depth of 100 mm. When steady conditions
have been obtained the temperature in the concrete shall be determined to the nearest 0.5°C.
The results shall be recorded in an agreed log format.
Concrete with temperature in excess of the specified max limits shall not be placed unless
approval is obtained from the Engineer, and only on the conditions which he may consider
appropriate.
5.3.8.5 Workability
The workability shall be measured for every load of concrete immediately before beginning of
placing. The test results shall be recorded in an agreed log format.
The test method shall be identical to the method used during pre-testing, and it may be any one
of the following:
Slump: BS EN 12390 or ASTM 0143

Flow: BS EN 12390
The maximum deviations from the established target values of workability from the pre-testing
is:
Slump: +25 mm
Flow: +30 mm
Concrete with workability outside the specified limits shall not be placed unless approval is
obtained from the Engineer, and only on the conditions which he may consider appropriate.
5.3.8.6 Compressive Strength
5.3.8.6.1 Control Sections
be larger than one week's production of the mix; smaller control sections may be used if it is
Strength testing shall relate to control sections as defined in section 5.4.1. The size of a control
section shall as a rule does not exceed 200 m 3 and not be less than 40 m3. A control section
shall not deemed desirable to minimise the consequences of a rejection
5.3.8.6.2 Sampling Plan
The concrete shall be sampled on site at beginning of placing in accordance with BS EN 12350.
Sampling within a control section shall be planned so that:
• only one sample shall be taken from any one truck mixer;
• minimum four samples shall be taken from any control section.
The minimum frequency of sampling shall be:
• at least one sample shall be taken each production day;
• at least one sample per 10 m3 of columns, beams, slabs;
• at least one sample per 20 m3 of other structures;
• never less than 4 samples per control section.
5.3.8.6.3 Preparation and Testing of Cubes
From each sample, four cubes 150 mm shall be made and cured at 20° C in accordance with
BS EN 12350.
The compressive strength of the cubes shall be determined in accordance with BS EN 12390 by
a compression testing machine.
Two cubes shall be tested at 7 days and two at 28 days. The test result at 7 days shall be used
to provide an early warning of a change in concrete properties. The test result at 28 days shall
be used for acceptance of concrete strength as specified in 5.3.8.6.4.
The average strength of the two cubes tested at the same age shall constitute one test result. If
the two cubes show individual test values more than 15% from the average of the two, then the
method of making, identification and marking, curing and testing cubes shall be checked. If the
difference exceeds 20% of the average value, then the concrete production shall be suspended
until the reason for the excessive deviations have been found and corrected.

5.3.8.6.4 Acceptance Criteria
The concrete in a control section shall be deemed to comply with the specified compressive
strength when both the following criteria are met:
a) The mean strength determined from the first two, the first three, and the rolling average of
any group of four consecutive test results, exceeds the specified characteristic compressive
strength by at least:
- first two test results: 1 N/mm2
- first three test results: 2 N/mm2
- any consecutive four test results: 3 N/mm2
b) No individual test result is less than the specified characteristic compressive strength minus
3 N/mm2.
5.3.8.6.5 Action in Case of Non-conformity
If the acceptance criteria for compressive strength is not met, then the control section is not
approved and the Contractor shall propose remedial action for the approval of the Engineer.
Such remedial action may include all or any of the following:
• additional testing in the non-approved control section;

• improving quality control;
• changing the mix design;
• removal and reconstruction of the control section.
5.3.8.7 Chloride Content

Chloride content of the fresh concrete mix shall be measured on one concrete sample taken
from the strength testing and tested in accordance with BS EN 12390.
Testing shall be done weekly if the chloride contents are above 60% of the limits specified in
5.3.6.7. If the chloride contents are below 60% of the specified limits, testing frequency may be
relaxed to once per month.
If the specified limit for chloride content is exceeded, then the control section is not approved,
and the Contractor shall propose remedial action for the approval of the Engineer. Such remedial
action may include all or any of the following:

• changing the constituent materials;
5.3.8.8 W/C Ratio

The W/C Ratio for the concrete grades A, 8, C shall be checked every single day at which
concreting works take place before placing of concrete by computing the ratio on basis of actual
measurements of water and cement contents at the plant, including the determination of
moisture contents and free water as per cl. 5.3.6.4.
If the spot-check show that the specified maximum w/c has been exceeded, taking the weighing
tolerances into account, then the check shall be extended to cover all batching in the period
since the last check.

If the specified limit for the w/c ratio is exceeded, then the control section is not approved, and
the Contractor shall propose remedial action for the approval of the Engineer. Such remedial
action may include all or any of the following:

• changing the mix design;
5.3.8.9 Chloride Penetrability

For concrete in Grade A and B, chloride penetrability shall be documented as per 5.3.6.13. The
testing shall be done once per month and after each change in any of the constituent materials.
5.3.8.10 3.8.10 Water Penetrability

For concrete in Grade A and B, water penetrability shall be documented as per 5.3.6.14. The
testing shall be done once per month and after each change in any of the constituent materials
5.4 Concreting Workmanship
5.4.1 Planning and Documentation
5.4.1.1 Prior Acceptance

Before any concreting is allowed to proceed, the following shall have been fully documented by
the Contractor, found compliant, and accepted by the Engineer, all in accordance with relevant
chapters of this Specification:
• concrete materials and pretesting of concrete production;
• a specific Method Statement with a comprehensive planning documentation for each

casting;
• inspection of excavations, construction joints, water stops, forms, reinforcement and

embedded items;
• Contractor's notice confirming that the above has been completed and that he intends to
cast the concrete.
5.4.1.2 Method Statement and Planning Documentation

The Contractor shall prepare a written Method Statement containing a comprehensive planning
specifically for each concrete pour. It shall describe in detail how he will comply with each
applicable requirement in this specification, demonstrating his understanding of the
requirements and his ability to fulfil them through a well-planned production, transport, placing,
compaction, finishing and curing, thus producing a compliant structure made of a dense,
homogeneous and uniform concrete free of honeycombs, cracks, and other casting defects.
The Method Statement shall be submitted to the Engineer for approval as early as possible and
not less than four weeks prior to the planned date of casting. The Engineer shall give his
comments to the Method Statement within two weeks from receiving it. The planned casting
shall not proceed until the Contractor has responded satisfactorily to the Engineer's comments,
if any, achieved approval of the Method Statement in writing from the Engineer, and
demonstrated that he is ready to implement the approved Method Statement.

When the Method Statement has been approved, it shall become binding for the Contractor who
shall not deviate from it unless prior written acceptance of a proposed change has been given
by the Engineer. Work which is not performed in compliance with an approved Method Statement
shall be rejected at the discretion of the Engineer.
The format of the Method Statement shall be proposed by the Contractor for the acceptance of
the Engineer; the contents shall always include the following minimum:
• The Contractor's line of responsibility for the casting shall be identified. This must include
the name of an engineer possessing the necessary experience and authority ho shall be
present on site during the entire casting and ensure that all works are performed in
accordance with the Method Statement.
• All plant and equipment must be identified by type and quantity. It must have been
demonstrated through prior testing and trials that it is capable of handling the concrete as
desired and specified.
• All personnel needed during the casting must be identified by grade, number of personnel
in each grade, and specific tasks or responsibilities assigned to each man; it must be
demonstrated that all involved personnel has been properly instructed and trained in their
individual tasks and responsibilities, and that they know the requirements of this specification
wherever relevant for their task.
• All applicable working drawings and any other relevant documents concerning the
construction of the structure which is to be cast must be listed.
• All inspections which are required before casting can proceed must be listed with
identification of time and responsibility for performing the inspections (e.g. inspection of
excavations, construction joints, water stops, forms, reinforcement and embedded items).
• The concrete grade, quantity, number of batches, planned delivery timing, and transport time
scenarios (high/low), must be stated.
• All relevant time and temperature limits during casting, finishing, and curing must be stated.
There must be enough reserves and back-up capacity available to ensure that these limits
are complied with even in case of a breakdown of any piece of plant or equipment.
• All required supervision, inspection, sampling and testing related to a subdivision into control
sections must be stated; it must be demonstrated that all necessary equipment is available
and that the responsibility for the sampling and testing has been assigned to persons with
necessary experience and skill. This shall be in agreement with the Control Plan specified
in Section 5.1.6.
• Specific hot-weather (and cold-weather) precautions must be identified wherever applicable.
• Specific safety precautions, including safe tagging of scaffoldings, access ladders, proper
light for night work, etc, must be identified and provided wherever applicable. The lighting
must illuminate the inside of the formwork as well as provide a safe workplace.
• A direct line of communication between the casting supervisor and the batching plant
supervisor must be demonstrated to exist so that any problems in the concrete production

or the casting can be immediately known and dealt with in an appropriate and coordinated
manner. If the plant is not within the site, telephone or radio connection must be established.
5.4.1.3 Control Sections

A control section shall mean the portion of the work which is accepted or rejected if the testing
of samples taken from the control section passes or fails when compared with the requirements
of this specification. A control section can contain only one grade of concrete.
The Contractor is responsible for selecting the size of the control sections as described in
Section 5.3.8. He shall propose the number and limits of control sections and keep exact records
for the sampling and testing for each control section.
The sampling and testing within a control section shall be in strict accordance with the
requirements in this specification.
5.4.1.4 Contractor's Notice and Engineer's Acceptance

The Contractor shall advise the Engineer as early as possible about his planned date for casting.
He shall give notice in writing 48 hours before the casting, confirming his intention to pour and
stating;
• structure, location and volume of concrete:
• planned commencement and completion time;
• reference to relevant accepted Method Statement and planning;
• confirmation that all required inspection of excavations, construction joints, water stops,
forms, reinforcement and embedded items, etc, have been performed and found
satisfactory.
• The Engineer will assess the information contained in the Contractor's notice and give his
comments or acceptance within 24 hours. No casting shall proceed without the Engineer's
written acceptance.
5.4.1.5 Daily Records

The Contractor shall maintain daily records for all work done, including but not limited to:
• type, location, and quantity of work;
• samples taken and inspections performed;
• results of inspection and testing;
• time for commencing and completing main operations;
• weather (wind, temperature, humidity).
5.4.2 Placing and Compaction
5.4.2.1 Delivery, Handling, Placing

Concrete shall be delivered as close to its final place of deposit as practically possible, as quickly
as possible, and always within the time limits and the temperature limits specified.

All handling of the fresh concrete into its final place of deposit shall be completed as quickly as
possible and always before the initial set, by methods which will prevent segregation and loss of
ingredients, and in a manner which will assure that the required quality of concrete is maintained.
ACI 304R cl 5.1 (General Considerations) shall apply unless otherwise stated or implied in this
specification.
Concrete shall not be allowed to drop into place from a height of more than 1 meter and dropping
concrete shall not be disturbed in its vertical fall by hitting reinforcement, etc, which may cause
segregation. Where necessary to limit drop heights or to avoid segregation, placing shall be by
means of trunks, chutes, buckets, hoppers, etc. ACI 304R cl 5.4 (Placing) shall apply unless
otherwise stated or implied in this specification.
Chutes shall be metal lined and their slope shall be steep enough to make the concrete flow (say
1:3) but not so steep that the flow becomes too rapid or disintegrated (say 1:2).
Pumping, if used, shall be controlled so that segregation does not occur in the discharged
concrete, and the loss of slump shall be within pre-determined limits.
Slip forming of concrete will not be accepted as a placing method.
At no time shall the fresh concrete be in contact with aluminium or aluminium alloys.
All equipment which is used in handling fresh concrete shall be kept clean and free of hardened
concrete. Under no circumstances shall spilled concrete or hardened concrete be allowed to
enter into the permanent works.
Concreting shall not take place during rain or during dust-storms, or until rainwater and dust has
been removed from the form after such events.
5.4.2.2 Casting Sequence

Fresh concrete in any structure shall be deposited in horizontal layers progressing from the lower
portion to the higher portion of the structure. The thickness of each layer and the time Intervals
between the layers shall be preplanner and monitored to ensure:
• a minimal horizontal movement of concrete during compaction;

• a proper compaction of each layer;
• a continuous pour without cold joints in or between layers.
Layers shall be limited to a thickness of 300 mm - 400 mm to ensure proper compaction. In no

event shall the depth of the concrete in one layer exceed 80% of the length of the poker vibrator
head, and the layer thickness shall always be determined after considering the compaction
procedure. Placing of the following layer shall not be commenced until the compaction of the
previously placed layer has been completed in the area where the next layer is to be placed.
In structures of significant horizontal dimensions, concrete shall furthermore be deposited in a

strip-wise horizontal progression which shall be planned and monitored to ensure a continuous
pour without cold-joints in or between strips.
5.4.2.3 Time to Completion of Compaction, Workability Limits

The following time and temperature limits shall apply from the time of mixing until the completion
of compaction, unless other limits have been documented by the Contractor and accepted in
writing by the Engineer:
• 90 minutes for concrete at 20 C temperature or less.

• 50 minutes for concrete at 30 C temperature.
• Always before the initial set.

The concrete temperature refers to the temperature measured in the fresh concrete at
completion of the compaction. Time limits for concrete temperatures between 20 and 30° C shall
be found by linear interpolation between 90 and 50 minutes.
These time limits shall be shortened if the workability drops below the agreed limits. Such
shortening shall be anticipated during periods of low relative humidity or high ambient
temperature or high winds, which will tend to increase the moisture loss from the fresh concrete.
5.4.2.4 Time Between Deposits, Avoiding Cold-joints

No concrete shall be placed against concrete which has dried or hardened sufficiently to cause
seams, planes of weakness, or cold joints.
The time between subsequent deposits within a pour shall always be as short as practically
possible. Concrete shall be deposited before the preceding layer or strip has reached the age
stated below, unless other limits have been documented by the Contractor and accepted in
writing by the Engineer:
• Max 180 minutes for concrete at 20° C temperature or less.

• Max 105 minutes for concrete at 30° C temperature.
• Always before the time of initial setting (ASTM C403/C403M).
The age shall be counted from the time of mixing. The concrete temperature refers to the
average temperature in the previously compacted layer measured at intervals from the time of
mixing. Time limits for concrete temperatures between 20 and 30°C shall be found by linear
interpolation between 180 and 105 minutes.
These time limits shall be shortened if any tendency of forming cold joints is noticed. Such
shortening shall be anticipated during periods of low relative humidity or high ambient
temperature or high winds, which will tend to increase the moisture loss from the fresh concrete.
5.4.2.5 Delay Between Vertical and Horizontal Components

If a monolithic placement of a deep beam, or a wall, or a column, together with a horizontal
component above is desired, it must be ensured that the concrete in the deep beam, wall, or
column is left to settle after it has been compacted, before casting the overlying horizontal
component. Failure to take adequate precautions may result in unacceptable plastic settlements
and cracking, in which case the structure will be rejected.
The necessary delay depends on temperature and characteristics of the mix, but will usually be:
• 90 minutes for concrete at 20° C temperature.

• 50 minutes for concrete at 30° C temperature.
However, it must always be ensured that the monolithic casting continues soon enough to allow
the two layers to be knitted together by compaction.
5.4.2.6 Sloping Surfaces

If concrete is placed with a sloping surface steeper than 1:4, a temporary or permanent holding
form shall be used to prevent sagging or flowing of the concrete during compaction.
Concrete may be placed in slopes less steep than 1:4 without a holding form only if the
Contractor can demonstrate that his mix and casting sequence will permit him to perform a
compliant compaction without sagging or flow.

5.4.2.7 Compaction
5.4.2.7.1 Requirements
Compaction shall be performed to ensure that the concrete becomes a dense, homogeneous
mass, completely filling the form and surrounding the reinforcement, thus achieving the desired
strength, appearance, and durability.
5.4.2.7.2 Equipment
All in-situ concrete except blinding layers shall be compacted by internal vibration using
immersion vibrators with a vibrating head and a flexible shaft ("spud" or "poker" vibrators).
However, slabs may be compacted by immersion vibrators used in combination with surface
vibrating equipment, subject to successful trials and prior approval in writing from the Engineer;
surface vibrating equipment will generally not be accepted as the only way of vibration for slabs.
Other types of vibrators (form vibrators, etc.) may be used only for precast elements
manufactured under industrialized conditions, subject to successful trials and prior approval in
writing from the Engineer.
The size and capacity of the vibrators shall be selected after considering the workability of the
mix, the geometry of the structure, and any congestion of reinforcement, etc, in the structure.
The effect of the vibrator depends on its size, amplitude, and frequency. A standard diameter of
head in poker vibrators is in the magnitude of 50 mm, but larger and smaller diameters shall be
used where appropriate, considering the dimensions of the structure, the spacing of
reinforcement, etc. Vibration in walls, columns and beams shall be done with vibrators of a
diameter not exceeding 1/6 of the smallest form width. The suit ability of the selected equipment
shall be demonstrated during relevant trials, considering workability, casting sequence, etc., and
changes shall be made if the trial results are not satisfactory.
The recommendations in this section are based on experience with electrically powered pokers
of about 12,000 Hz frequency.
A spare capacity of at least 50 % of the required compaction equipment shall be kept standby
during any pour, to avoid discontinuity in case of any breakdowns.
5.4.2.7.3 Procedures
The workers performing the compaction shall have been properly trained and instructed in this
work. They shall be supervised full time by an experienced foreman or engineer who is familiar
with the requirements to good workmanship, and who will ensure that these requirements are
followed:
• compaction shall not start until the placing operation has progressed to leave a level surface,
and the vibrator shall not be used to move the concrete horizontally;
• compaction shall always be through the freshly placed layer or strip into the preceding layer
or strip so that the two masses are worked together and becomes monolithic;
• compaction shall not be within 0.5 m from the un-restrained edge of newly place concrete
since this would make the concrete flow horizontally in an uncontrolled manner;
• the poker vibrator should not be inserted closer to the form side than 3 times its diameter,
and it must not be inserted in the cover layer (between the reinforcement and the form);

• the poker must not be used as a form vibrator, and it must not be used to vibrate the
reinforcement;
• the vibrator shall be inserted systematically in a regular grid with spacing of insertion points
depending on mix characteristics, structure and reinforcement characteristics and on the
effect of the vibrating equipment; the grid spacing shall be selected to ensure adequate
compaction of all parts of the concrete, without over-compacting it; the following guidelines
apply to spacing of insertion points (D is the diameter of vibrator head):
a) Mass concrete or lightly reinforced: 10 x D

b) Normal reinforced structure: 8 x D
c) Heavily reinforced structure: 6 x D
d) Heavily reinforced structure with
e) difficult access for pouring: 4 x D
f) Extreme cases (should be avoided): 2xd
• the vibrator shall be immersed vertically in its full length and through the entire thickness of
the concrete layer; a sloped immersion shall be made only if the thickness of concrete is
less than the length of the vibrator;
• compaction shall generally continue with the vibrator fully immersed until entrapped air has
been expelled, i.e. until no more air bubbles are seen to burst through the surface, but
compaction shall stop before the concrete shows signs of segregation or accumulating
mortar on the surface; the vibrator shall then be withdrawn at a slow rate (not more than
about 80 mm per second) so the hole will close after the vibrator without any entrapped air
in it;
• general guidelines for immersion time of standard type pokers are as follows, always subject
to adjustment based on trials with the actual equipment, mix, and work methods:
a) Slump 60 mm: 15-25 sec

b) Slump 90 mm: 10-15 sec
c) Slump 120 mm: 8-10 sec
d) Slump 150 mm: 5-8 sec
the above time limits refer to the effective vibration time not counting the time for inserting or
retracting the vibrator.
5.4.3 Un-formed surfaces
5.4.3.1 General
The finishing of un-formed surfaces shall be performed with necessary care in order to achieve
the desired strength, appearance, and durability of the concrete.
This includes protection against evaporation as specified in Section 5.4.6.
After completion of a thorough compaction, all subsequent operations of floating, towelling, etc.,
must be performed in such a manner that the concrete will be worked and manipulated as little
as possible and without bringing excessive fines and water to the surface. Floating and trowelling
must be delayed as long as possible in order to minimize the risk of over-working the surface.

If free water does accumulate, it must be removed before finishing works proceed. It is not
permissible to add any cement, sand, or other material to the surface, whether to absorb
accumulating water or for any other reason.
Mortar toppings shall not be used. All surfaces shall be finished as monolithic concrete without
mortar being worked into it.
5.4.3.2 Slab Surface Finishes

Where nothing else is specified in the contract drawings and documents, the following finishes
and level tolerance classes shall be used as applicable (tolerances are defined in 5.4.3.4):
Scratched finish: To be used for surfaces intended to receive bonded applied

cementitious applications.
Immediately after concrete placing and compaction a

retarding agent is to be sprayed onto the concrete. At the end
of the setting period, the grain structure may be exposed by
water jetting. This procedure results in a rough surface which
improves the bond between the old concrete and the
cementations application.
The 3 m straightedge tolerance shall be Class C.
Floated finish: To be used for surfaces intended to receive roofing,

waterproofing membrane, or sand bed terrazzo. The 3m
straightedge tolerance shall be Class B.
Trowelled finish: To be used for floor intended as walking surfaces or for

reception of floor coverings. The 3 m straightedge tolerance
shall be Class A.
Broom or belt finish: To be used for sidewalks and garage floors and ramps. The 3
m straightedge tolerance shall be Class B.
Non-slip finish: To be used for exterior platforms, steps, and landings; and for
interior pedestrian ramps. The 3 m straightedge tolerance
shall be Class A.
These finishes shall be made as specified in ACI 301 SI.
5.4.3.3 Finishes on Other Unformed Surfaces

Tops of walls, buttresses, horizontal offsets, and similar unformed surfaces occurring adjacent
to formed surfaces shall be struck smooth after concrete is placed and shall be floated to a
texture reasonably consistent with that of the formed surfaces.
Any final treatment of the formed surfaces shall continue across the unformed surfaces.
5.4.3.4 Surface Level Tolerances

Unless stricter limits are specified elsewhere in the contract drawings or documents, the
unformed finished level shall be within +/- 5 mm of the theoretical level, and the surface shall be
true planes within the following tolerances as determined by measuring from a 3 m long
straightedge placed anywhere in any direction:

• Slabs Class A: 1.5 mm
• Slabs Class B: 3 mm
• Slabs Class C: 5 mm
• Other (wall, beam): 5 mm
The tolerances as determined by the straightedge shall be modified as necessary where the
structure is placed with a pre-planned camber.
5.4.4 Making good of defects
5.4.4.1 General
While certain casting defects may occur in spite of all precautions, the Contractor shall do his
best to minimize such defects, and he shall adjust his methods if the number size or type of
defects in the opinion of the Engineer gives reasonable cause for concern.
All defects after casting shall be recorded by the Contractor and brought to the tension of the
Engineer before any making good is carried out.
The making good shall comply with the following minimum requirements which are intended for
normally occurring defects of limited and acceptable extent.
Any defect which in the opinion of the Engineer is frequent or large or unusual, including any
defect which is not covered by this Specification, shall be subject to a specific procedure to be
proposed by the Contractor for the Engineer's acceptance.
Repairs will be accepted only if they can bring the structure to the quality level of a well build
new structure. If this cannot be achieved and documented, the faulty work shall be replaced.
If it is found that a significant amount of voids, cavities, honeycombs, etc, is concealed behind a
surface skin of laitance or mortar, then the Contractor shall expose the full extent of the defects
by sweep-blasting or by a similar method to the approval of the Engineer.
5.4.4.2 Projections
Immediately after stripping the formwork, all surface fins, form offsets, form streaking, and other
projecting irregularities shall be removed and rubbed down with a carbonado brick or other
abrasive, taking care not to leave traces on the surface outside the removed irregularity.
5.4.4.3 Air bubbles (Bug-holes)

Where a noticeable amount of bug holes larger than 3 mm wide or deep appear, they shall be
filled with a ready mixed, resin modified sand-cement mortar of same colour as the concrete.
The mortar shall be applied on a wetted surface and scrubbed in with a float or stone to fill all
holes. All excess mortar, i.e. mortar outside the holes, shall be wiped off to leave the surrounding
surface without stains.
5.4.4.4 Honeycombs
Any honeycombed or incompletely filled area shall be cut back to sound concrete and made
good with a ready mixed, resin modified sand-cement mortar resembling the original concrete
as closely as possible.
The cutting out shall be by saw to a depth of 20 mm and shall follow regular boundary lines and
shall be made perpendicular to the surface so that featheredging is avoided. Bonding shall be
ensured by high-pressure water-jetting, grit blasting, or similar, and by wetting the concrete
before casting new.

The casting shall be made with formwork as necessary, and proper compaction of the repair
must be ensured; in some cases a "letter-box" form may be required, and the protruding part
shall then be cut off as soon as possible after striking the form. The making good shall be cured
as specified for the original concrete.
5.4.4.5 Cracks
A general occurrence of cracks will not be acceptable, and the Contractor shall revise his work
methods as required to minimize the risk of cracking if an unacceptable tendency in this respect
is observed.
Where cracks do occur in spite of such efforts, they shall be recorded by the Contractor and
submitted for the Engineer's attention. Unless otherwise directed by the Engineer, all cracks
wider than 0.15 mm shall be injected with an appropriate material.
All details of the injection (materials, pot-life, references from similar applications, equipment,
method, subcontractor) shall be subject to prior acceptance in writing from the Engineer.
5.4.4.6 Tie-holes
The tie holes are to be sealed with appropriate sealing caps on both sides.
5.4.5 Temperature during Hardening
The maximum temperature in the concrete during hardening shall not exceed 55 o, unless the
contractor can document to the satisfaction of the Engineer that a higher temperature will have
no detrimental effects on the strength and durability (crack-width due restraint forces) of the
structure. The documentation shall take into account that higher temperatures may cause larger
pores and lower durability in the concrete.
The Contractor shall always minimize thermal cracking by proper planning of the work and by
taking precautions to minimize temperature differences. Thermal cracks are likely to develop in
massive structures (smallest dimension more than 0.5 m) and structures with restrained
movement in the hardening phase (e.g. wall/slab) unless adequate measures are taken.
The Particular Amendment to the Standard Specification may state specific limits to the
acceptability of cracks in certain structures: the Contractor shall take all necessary precautions
to comply with such specified limits, including but not limited to precautions mentioned in the
following guidelines.
The Contractor's planning and methods for temperature monitoring and control shall be
submitted as a part of the relevant Method Statement. It shall be revised if experience on site
shows that the adopted methods do not lead to the desired results.
Any crack which occurs in spite of the planning shall be injected to the satisfaction of the
Engineer, or other measures shall be taken if in the opinion of the Engineer they are needed to
achieve an acceptable and compliant structure.
5.4.5.2 Guidelines on Temperature Differences

As a guideline, cracking will be minimal if the following is fulfilled:
• the maximum temperature differences between the coldest part and the warmest part of hardening
concrete should not exceed 20oC unless specifically approved on basis of the Contractor's detailed
documentation;

• the difference in mean temperature between the hardening concrete and adjacent hardened
concrete which will restrain the movement of the hardening concrete should not exceed 12°C unless
specifically approved on basis of the Contractor's detailed documentation.
Detailed documentation should include calculations or simulations demonstrating that the

thermally induced tensile stress in the concrete does not exceed the tensile strength which
develops in the hardening phase.
5.4.5.3 Guidelines on Temperature Control

As a guideline, means to control temperature differences include:
• planning of casting sequences to minimize temperature differentials;
• using low cement contents within the specified limits and low fresh concrete temperatures to slow
down the heat development;
• using insulating covers to control the loss of heat;
• using cast-in pipes for cooling of fresh concrete or heating of hardened concrete to control
temperature differentials. Material for cast-in pipes shall be polyethylene.
5.4.5.4 Monitoring
The Contractor shall as a minimum measure and record the following for all pours where the
smallest dimension exceeds 0.5 m:
• the maximum temperature in the hardening concrete;

• the difference in temperature between the centre of the cast structure and the surface of the
concrete
The measurements shall be made and recorded at intervals of 4 hours over the first 72 hours
after casting. As measurement device a thermocouple should be used for large pours.
5.4.6 Protection against evaporation
5.4.6.1 General
Concrete shall always be protected against evaporation during hardening. Particular care must
be exercised to implement the curing at the earliest possible stage during periods of high
temperature, low relative humidity, or strong winds which alone or in combination can cause
extremely rapid drying-out.
Curing shall be performed for a period of not less than 14 days. The Contractor shall keep a log
record with starting and completion dates plus dates of all specified curing operations.
5.4.6.2 Until Casting is Finished

Unformed surfaces shall be covered with close fitting polythene sheets as soon as the
compaction has been completed, and until other measures can be implemented as stated in
5.4.6.3.
This temporary protection shall be removed and re-installed as often as required for any
continued casting or for finishing operations, and the surface shall never be left unprotected
except when being worked on.
The effect of drying winds shall be minimized erecting necessary shelter to prevent the wind
from blowing over the concrete until moisture curing has been fully installed as specified in
5.4.6.3.

5.4.6.3 After Casting is Finished
As soon as the casting is finished the concrete can carry the traffic of the workers, but not later
than 4 hours, after completion of the casting, measures shall be implemented as follows:
• unformed surfaces shall be covered by hessian (burlap) with an overlying heavy duty polythene
sheet; the joints in the polythene shall have adequate overlap and be fully sealed; the hessian shall
be kept soaking wet during the specified curing period by adding water at frequent intervals; the
covering shall be in place as soon as practically possible and never later than four hours from
placing the concrete;
• ponding (curing with standing water) may be used on unformed horizontal surfaces instead of
hessian and polythene; the surface shall be kept water covered for the specified curing period by
adding water as necessary;
• form surfaces which are not 100% non-absorbing and water-tight shall be covered by tightly sealed
polythene sheets and kept moist by frequent sprinkling.
Wherever forms are loosened or removed, the hessian and polythene shall be applied, and
curing commence within one hour from loosening the form.
Necessary bracings shall be used on vertical faces so that the hessian is kept in direct contact
with the concrete without any air gap in between. In no event shall there be access for wind to
get under the polythene sheets.
Water for curing shall fulfil the requirements specified in Chapter 5.2. It shall have a temperature
in the same magnitude as the temperature of the concrete surface so that thermal chock is
avoided.
The unformed surfaces shall be kept covered with sealed polythene sheets for at least four days
after the completion of the specified curing period so that rapid drying out is avoided; it is
particularly important to implement this covering if ponding has been used.
5.4.7 Construction Joints

Construction joints are the joints between different pours. Such joints shall be pre-planned and
kept to the minimum for the execution of the work, and they shall consider structural
requirements as well as requirements to appearance.
Keys or other details may be specified in the Particular Amendments to the specification or in
the drawings and shall always take priority over the requirements specified in this Section.
Joints which are not shown on the drawings, but which are considered desirable for practical
reasons shall be proposed by the Contractor for the Engineer's approval.
If kickers are used at wall or column bases, it must be ensured that the concrete in the kickers
are compacted and cured in accordance with this specification.
Kickers at walls shall be poured in one go with the base slab.
The alignment of joints shall generally be straight, horizontal or vertical, parallel or perpendicular
to adjoining parts of the structure.
Vertical joint faces shall have a formed surface; horizontal joint faces shall be level and flat.
Reinforcement shall continue across joints.

In water retaining structures the construction joints must be sealed with water stops. For the
material to be used and the required information regarding dimensions reference is made to item
5.8.3.
5.4.7.2 Bonding at Joints

Bonding across the joint shall be ensured by thorough preparation of the joint before continuing
the casting. The preparation shall as a minimum include:
• grit blasting of the joint face to remove paste, etc so that coarse aggregate is exposed with a
roughness of not less than 6 mm depth;
• pre-wetting of the roughened surface so that the concrete is in a saturated surface-dry condition at
the time of continuing the pour.
5.4.7.3 Unplanned Joints

In case a casting cannot be completed as planned, the Contractor shall take all possible steps
to finish the interrupted casting with joints in compliance with the above, and he shall without
delay submit full details of such unplanned joints to the Engineer for decision.
If an unplanned joint in the opinion of the Engineer is not acceptable, then the Contractor shall
cut back to such limits and with such finish as instructed by the Engineer in order to achieve an
acceptable joint.
5.4.8 Hot weather concreting

The Contractor's Method Planning shall include precautions for hot weather concreting. These
precautions shall be implemented when concreting takes place in periods where the daily max
temperature on site may exceed 30° C. They shall ensure that the specification is fulfilled without
relaxation also during hot periods; concreting shall not take place in hot periods if the
temperature makes it impossible for the Contractor to comply with the specification.
The hot weather precautions on site shall be coordinated with the hot weather precautions during
production specified in Section 5.3.5, the temperature curing specified in Section 5.4.5, the
moisture curing specified in Section 5.4.6, and the general time/temperature limits specified
through Chapter 5.3 and 5.4.
The recommendations in ACI 305R are applicable as examples of good practice, always subject
to stricter requirements which may be stated in this Specification or in other contract documents.
Hot weather precautions shall include but may not be limited to;
• keeping a shade over the concrete from the day before casting until completion of the specified
curing period;
• cooling the form and the reinforcement by spraying with water immediately before the casting; water
shall fulfil the specification in Chapter 5.2, and it shall be drained away before concreting starts;
• casting at late or early hours where the ambient temperature during placing, compaction, and
finishing is at their lowest; always considering the time dependent heat development in the
hardening concrete vs. the day/night temperature fluctuations in order to avoid excessive thermal
stresses in the concrete;
• minimizing the time of all operations from mixing to finishing (including time between subsequent
layers) to the shortest possible.

5.4.9 Cold weather precautions
5.4.9.1 General
There are certain areas in Saudi Arabia where freezing temperatures may occur during winter
conditions, and there are many areas where day-time temperatures may be substantially below
20oC for extended periods. The contractor must take this into account, and he shall take all
necessary precautions to protect the concrete in its early life. Minimum requirements are stated
below.
5.4.9.2 Concreting at Low Temperatures

Unless specialist advice is taken, and appropriate measures are taken subject to the Engineer's
prior acceptance in writing, concreting works shall not be carried out in periods where there is a
risk of the ambient temperature during day or night being below 5°C.
Concreting must never take place against frozen ground, form, or reinforcement, or against
objects covered in ice or snow.
It must always be ensured that the concrete temperature does not drop below 10°C within the
first 72 hours from casting. This may require special precautions in the form of thermal insulation,
etc.
5.4.9.3 Curing and Hardening at low Temperatures

Minimum times given in this specification for curing and for removal of supports are stated with
a concrete temperature of not less than 20°C as a reference basis.
If concreting is done in periods with ambient temperatures less than 20°C as a combined day-
and-night average, the temperature in concrete during the first weeks must be recorded, and the
specified times for curing and for removal of supports shall be extended to adjust for the influence
of low temperatures.
The adjustment shall be based on a detailed calculation of accumulated maturity.
The maturity gain per time unit at a given concrete temperature is determined by a temperature-
dependent factor "H" which varies as follows:
▪ at 20°C H = 1.00
▪ at 15°C H = 0.75
▪ at10°C H = 0.50
▪ at 5°C H = 0.29
Linear interpolation may be made to find the maturity gain within these intervals. Maturity gain
below 5°C is negligible. No time reduction shall be made for increased maturity gain above 20°C
when considering curing or removal of supports.
5.4.10 Precautions against Saline Water

Un-coated concrete shall not be exposed to saline water (sea water, brackish water, etc) until it
has reached an age of 28 days.
Coated concrete may be exposed at an earlier date than 28 days from casting, but never earlier
than 14 days from casting, and only if the coating provides a substantial and well documented
protection against the ingress of chlorides under the actual conditions.

5.4.11 Crack-Width Limitation
5.4.11.1 General
For the suitability and durability of the concrete structures to be ensured, the cracks developing
as a result of static loads, restraint forces due loss of hydration heat and shrinkage act. are to
be reduced in width.
5.4.11.2 Reservoirs
The width of the cracks will have to be limited as follows for the individual structural elements:
5.4.11.3 Bottom slab
a) Separation cracks (rupture over entire cross-section)

Wm< 0.10 mm
b) Cross-section subject to bending, tensile zone top, compression zone bottom, min. thickness
5 cm
0.10 mm < Wm < 0.15 mm
c) Cross-section subject to bending, tensile zone bottom, compression zone top, min. thickness
5 cm
0.15 mm < Wm < 0.20 mm
5.4.11.4 Outer wall
a) Separation cracks (vertical cracks)

Height of reservoir ranging between 0 - 6 m Wm <0.10 mm
Height of reservoir ranging between 6-10 mm Wm = 0.10 mm
b) Cross-section subject to bending, tensile zone on the inside, compression zone on the
outside, min. thickness 5 cm
0.10 mm < Wm < 0.15 mm
c) Cross-section subject to bending, tensile zone on the outside, compression zone on the
inside, min. thickness 5 cm
0.15 mm < Wm < 0.20 mm
For reasons of water permeability, it is - in the case of separation cracks - necessary that
the maximum crack width his adhered to on both sides, i.e. the width of the crack may not
be widened on the dry side.
5.4.11.5 Roof slab
a) Separation cracks 0.10 mm < Wm < 0.15 mm
b) Cross-section subject to bending, tensile zone bottom, compression zone top

Wm < 0.15 mm
c) Cross-section subject to bending, tensile zone top, compression zone bottom

0.20 mm < Wm < 0.25 mm
5.4.11.6 Buildings and Structures in exposure classes A and B
a) Separation cracks, rupture over the entire

cross-section w < 0.10 mm
b) Cross-section subject to bending,

Tensile zone located on the outside of the structure
Compression zone thickness 5 cm 0.10 < w < 0.15mm
c) Cross-section subject to bending
d) Tensile zone located on the inside of the structure
e) Compression zone thickness 5 cm w < 0.17 mm
5.4.11.7 Buildings and Structures in exposure class C
a) Separation cracks w<0.20 mm
b) Bending cracks w < 0.25 mm
5.5 Protection Of Concrete
5.5.1 General
5.5.1.1 Scope of Protection Works

Protection of concrete as specified in this Chapter shall mean blinding, membranes, coating
systems, etc, which shall be applied for the purpose of protecting the finished concrete structure
against exposure to action or substances which may cause deterioration of concrete and/or
corrosion of reinforcement.
The Specification states minimum requirements which shall always be complied with. Additional
requirements to coatings and membranes may be stated In the Particular Amendments to the
Standard Specification, e.g. for the purpose of achieving a certain appearance, slip-proof
surfaces, abrasive-resistant surfaces, or increased protection in local areas where acids or other
aggressive chemical substances are to be used.
5.5.1.2 Materials
The Contractor shall propose brands of coatings and membranes which are suited for their
purpose and have a documented ability to resist the environmental, physical, and chemical
exposure. All materials shall be from recognized manufacturers with a well-documented
experience from similar applications in Saudi Arabia.
The Contractor's submittal for the Engineer's approval shall as a minimum includethe
manufacturer's latest data sheet with a full technical specification, and the manufacturer's list of
selected references from projects In Saudi Arabia.
For each type of coating, the submission shall furthermore include a written statement from the
manufacturer confirming the suitability and the service life of the
coating (time between re-coating), with a clear reference to the project, the area(s), and the
purpose for which it is proposed. The service life shall be stated as guaranteed minimum and an
expected average.
Materials which will be in contact with each other (e.g. primer and subsequent layers) shall be
considered part of a system; each part of one system shall be obtained from the same
manufacturer, and the compatibility of all parts in a system shall be documented in the
manufacturer's data sheets and reference lists.

Materials which may come in contact with intake water or product water shall have been
approved by recognized authorities for use in the areas where they are intended, e.g. intake
structures in desalination plants, water tanks, etc., and they shall not give any taste to the water.
Colour of materials which will be visible in the final works shall be subject to approval.
No material shall be brought to site unless approved in writing by the Engineer.
Storage and handling of materials shall be in strict accordance with the manufacturer's
instructions. Manufacturing date and expiry date shall be kept on record for each delivery.
Stock shall be used on a first-in-first-out basis; materials which have not been used before their
expiry date shall be rejected and removed from site without delay.
5.5.1.3 Workmanship
5.5.1.3.1 Methods and Crew
The Contractor's Method Statements for application of coatings and membranes shall include
and be in full agreement with the manufacturer's written recommendations for the actual
application. It shall describe all relevant requirements to substrate preparation, limitations on
temperature and moisture content of substrate, permissible ambient temperature and humidity
during work, tools and procedures to be used, maximum & minimum time between layers,
necessary protection and curing time before exposure to soil, water, direct sun, etc.
The application shall be done only by crews who have the necessary training and skill to comply
with the Method Statement, and who have successfully completed a trial panel.
Any work which has not been done by a properly skilled crew in compliance with an approved
Method statement may be rejected at the discretion of the Engineer.
5.5.1.3.2 Trial Panels for Coatings
Prior to carrying out any coating works, a representative trial panel shall be executed for each
coating system, in accordance with the Method Statement.
The size of the trial panel shall not be less than 10 m2 and shall represent not less than four
hours work (normal production rate for the planned crew) at the final layer. The execution shall
be witnessed by a qualified technical representative from the supplier/manufacturer who shall
certify in writing upon completion that he considers the application and quality of workmanship
to be in full accordance with the manufacturer's recommendations.
Tests shall be made on each trial panel as follows:
• check dry film thickness by cutting out samples in five places and measuring the thickness
in a laboratory. The dry film thickness of the total coat system shall be compared to the
thickness calculated from use of material per m2, and it shall not be less than the specified
thickness;
• check bond strength in all trial panels except for underground bituminous coatings. The
check shall comprise five pull-off tests with equipment and procedures to be approved by
the Engineer. Acceptance criteria shall be agreed on basis of the manufacturer's data
sheets, generally not less than 1.5 N/mm2.
The trial panel shall be accepted if it passes the testing and is certified by the supplier's
representative; it shall be used as a standard against which all subsequent work will be judged.

5.5.2 Structures in contact with the ground

A concrete blinding layer shall be provided under all structures; the thickness shall be at least
100 mm, and it shall extend so far outside the structure that formwork and membranes can be
installed without any difficulty. No concrete shall be cast directly against soil.
Concrete in contact with any soil or backfill shall be protected from ingress of moisture, chlorides
and sulphates from the ground. The protection shall be in the form of a coating or membrane
which shall continue to a level not less than 0.2 m
above final grade on all structures that extend above ground (station elevation).
All exposed underground coatings and membranes shall be protected to prevent
damage during backfilling. The protection material shall be proposed by the contractor and is to
be approved by the engineer.
Special attention has to be paid to structures in waterlogged areas, the protection membrane
must be selected accordingly.
5.5.2.2 Protection on Basements and Underground Ducts, etc
5.5.2.2.1 Torch-applied Preformed Sheets
Basements, underground ducts, and similar structures with a floor level below permanent grade
shall have the underground part completely encased in a tanking made from a prefabricated
heavy-duty waterproofing membrane of modified bitumen, minimum 4 mm thick, and with a
polyester non-woven fabric base.
The tanking on the sides and the tops of the structure shall be fully torch-applied on a bitumen-
primed surface.
The tanking under the structure shall be laid on a concrete blinding and protected by a concrete
overlay of minimum 50 mm thickness. All overlaps shall be minimum 100 mm and fully torch
welded.
Overlaps between horizontal and vertical faces shall be detailed in accordance with the
manufacturer's recommendations and to the satisfaction of the Engineer.
5.5.2.2.2 Self-adhesive Preformed Sheets
As an alternative to the membrane material specified in 5.5.2.2.1, tanking may be provided by a

flexible self-adhesive impervious composite sheeting of a total thickness not less than 1.5 mm
consisting of a sheet not less than 0.3 mm thick of three-layer cross-laminated high density
polyethylene, and a rubber-bitumen compound.
All preparation, priming, ancillary materials, accessories, details and workmanship for the
application shall be in strict accordance with the manufacturer's recommendations.
5.5.2.3 Protection on Foundations and Channels

Foundations and water-channels shall have a protection on all earth-covered faces of the
underground part as follows:
All sides and any earth-covered top of such structures shall be protected by a bituminous coating
system consisting of;

• a penetrating bituminous primer applied in one coat;
• a high build bituminous coating with a content of fibres, applied in minimum three coats.
The total dry film thickness of the coating shall be not less than 1.0 mm.
The bottom side of the structure shall be protected by a preformed membrane as specified in
5.5.2.2. The overlap between the membrane under the structure and the coating on vertical
faces shall be detailed by the Contractor to the satisfaction of the Engineer, making sure that all
faces remain protected.
The bottom-protection membrane (on the blinding concrete) shall be protected by a concrete
overlay - analogous to Item 5.5.2.2.1.
5.5.2.4 Protection under Slabs on Grade

Slabs on grade shall be cast on a blinding layer. Protection against upward migration of salts
from the soil shall be provided by laying a double layer of heavy duty polythene sheets with a
thickness of 1 mm each on the prepared surface of the blinding; each layer shall have at least
0.3 m overlap on joints, and the overlaps shall be secured by taping.
The concrete overlay shall be provided as stipulated in the item above.
5.5.3 Water retaining structures and channels

Water tanks, channels, pumping chambers and similar water retaining structures shall have a
waterproofing lining on all interior faces (i.e. faces towards the water), including roof soffits and
other areas above water level. The lining shall form an effective barrier to ingress of chlorides
and sulphates.
The material shall be proven to be stable and suited for submerged conditions and shall not
release any chlorides.
The guaranteed minimum service life shall be at least 10 years.
The system shall be at least equal to a two-component polymer modified cementitious

waterproofing slurry; it shall always be obtained from a well reputed manufacturer with a fully
documented record from similar applications. The work for a two-component polymer modified
cementitious system shall as a minimum include:
• sweep-blasted of the concrete surface to remove any loosely adhering matter;
• making good of casting defects or uneven surfaces after the sweep blasting, before applying the
lining;
• application in two layers of 2 kg/m2 (1 mm) each;
• application of additional layers with reinforcement of fibre mats if necessary, to resist abrasion
zones of high turbulence, etc.
5.5.4 Splash zone and tidal zone on marine structures

Splash zones and tidal zones of structures standing in the sea shall be coated from 2 m below
lowest low-water level and to the top of the splash zone. The extent of the splash zone shall be
defined in the design drawings but shall generally, not be less than 4 m above mean sea level.
Higher levels may be relevant where the structure is exposed to surf, large waves and/ or large
tidal variations.

Seawalls and similar shore-line structures directly facing the sea shall be considered as being
in a splash zone even if they are standing on the shore above the high-water level. Where such
structures are exposed to spray from the surf, it may be necessary to treat them as splash zone
in their full height.
The coating shall effectively seal the concrete from ingress of chlorides and sulphates, and it
shall have adequate flexibility to follow temperature movements on exposed faces without
cracking. The coating shall be durable and resistant to warm saline seawater, wave action, and
UV exposure; the coating should be easy to repair and re-apply and must be available in light
colours.
The successful performance of the complete coating system shall be documented on basis of
similar applications in marine structures under similar climatic conditions. The guaranteed
minimum service life shall be at least 15 years.
The system shall at least be equal to an epoxy-polyurethane system (solvent free epoxy base
coat followed by polyurethane topping). It shall always be obtained from a well reputed
manufacturer with a fully documented record from similar applications, and it must have
documented test results to show that it is effective
in stopping chloride ingress. The work for an epoxy-polyurethane system shall as a minimum
includes:
• sweep-blasted of the concrete surface to remove any loosely adhering matter;
• making good of casting defects after the sweep blasting;
• apply levelling layer of approved cementitious material;
• apply primer/sealer if recommended by the manufacturer, followed by minimum three applications

of high-build layers to a minimum total dry film thickness of 350 microns, or a thickness as stated
in the manufacturer's guarantee.
5.5.5 Areas with acid spillage, etc.

Spillage of hypochlorite and sulphuric acid occurs in certain plant areas. Concrete in such areas
shall be protected by heavy duty acid proof tiles laid on an acid proof membrane completely
protecting the concrete against any ingress of these or other similarly aggressive substances.
The materials used shall have a documented resistance to the concentrations of hypochlorite or
acid which is expected in the area.
5.5.6 Other areas to be protected

Exposed out-door concrete in other areas than described above shall be protected in
accordance with the following general guidelines:
• Reinforced concrete surfaces exposed to traffic shall always be covered with a wearing course of
asphalt, screed, tiles or other appropriate material in accordance with an approved detailed design.
• Reinforced concrete roof slabs shall always be covered with a waterproofing membrane in
accordance with an approved detailed design. Water shall be drained away from the structure
through properly designed gutters and downpipes.
Special protection shall be provided as part of the detailed design for concrete structures which
may be exposed to spillage of add or similar aggressive substances.

5.5.7 Quality control
The Contractor's control plan for protection of concrete shall include but not necessarily be
limited to the following:
• check all delivery notes on arrival of materials to site, and keep complete record;
• visually check the consistency when opening a can or a package from a new batch;
• Inspect each step of work before proceeding with the next step, and keep a complete Inspection
record;
• keep detailed records for each day's work showing work area, material type, batch identification,
and consumption of liquid material per m2;
• calculate theoretical dry film thickness based on consumption, and compare to the required
thickness;
• check and keep record of ambient temperatures, ambient relative humidity, surface temperature
and surface moisture condition wherever limits on temperature and humidity are stated in the
manufacturer's recommendation. Such measurements shall be performed on each day before
coating commences, each two hours during coating, and until the surface is dew-resistant according
to the manufacturer's specifications.
5.6 Reinforcement
5.6.1 General
This Chapter covers materials, fabrication, placement, and tolerances of reinforcement and
reinforcement accessories.
Types, grades, and details of reinforcement shall always be as shown on the construction
drawings and shall be in accordance with an approved design based on recognized international
design standards. The present Specification states minimum requirements which shall apply
where no stricter requirement is show or implied on the construction drawings.
Earthing of reinforcement is not covered by this Specification but shall be made as required in
accordance with applicable contract requirements.
5.6.2 Materials
5.6.2.1 Reinforcement Steel

Unless a higher quality is specified on the construction drawings or in other applicable contract
requirements, reinforcement shall be deformed bars conforming to ASTM A615/A615M Grade
60.
Reinforcement bars shall be free from loose mill scale, loose rust, deleterious amounts of salts,
oil, grease and other foreign matter which may destroy the bond.
Reinforcement bars shall be transported and handled in a manner to avoid bending or other
damage. They shall be bundled and tagged for unambiguous identification. Storage shall be on
firm supports at least half a meter above ground, on designated hardstand areas, and properly
sheltered against rain, dust, and other contamination.
Bars which are found to have reduced sections, visible transverse cracks at bends, or other
damage, shall be rejected.

Reinforcement shall be un-coated unless otherwise specifically stated in the contract or
approved in writing. Where coated bars are required, the coating shall be fusion bonded epoxy,
and the coated bars shall be from a manufacturer approved by NEOM for this purpose. All
materials, workmanship, handling, installation, and repair of damage shall be in accordance with
ASTM A775.
5.6.2.2 Binding Wire

Binding wire for fixing reinforcement shall be 1.5 mm annealed wire or similar approved.
Binding wire for fixing spacers shall be stainless steel or coated wire to be approved. The wire
shall be positioned as far from the exposed surface as practically possible.
5.6.2.3 Spacers
Spacers shall be made of concrete of same grade as the structure for which they are to be used.
The quality of spacers shall be equal to the specified quality of concrete, and particular attention
shall be given to;
• proper shape and dimensions, e.g. by using a well-designed casting mould for the spacers
• proper compaction of spacers;
• proper curing of spacers, e.g. by wet curing the spacers under hessian and polythene until they can
be removed from the form, and by keeping them submerged in curing water until they shall be used.
The thickness of spacers shall be the specified minimum cover layer thickness with a tolerance
of -0/+3mm.
Spacers of 70 mm x 70 mm x 70 mm shall have an absorption of not more than 3% water by

weight of concrete, measured on an oven-dry spacer submerged in water for 30 minutes.
5.6.2.4 Quality Control for Materials
5.6.2.4.1 Steel
Each delivery of reinforcement bars shall be accompanied by a test certificate from the
manufacturer, stating purchaser, order number, product, weight of delivery, diameter of bars,
cast number, yield strength, tensile strength, elongation, and chemical composition. Each
certificate shall show date, certificate number, and authorized signature of the manufacturer.
A visual check of conformity between order, certificate, and tagging shall always be done.
Three samples shall be taken at random from each month's delivery and tested for yield strength,
tensile strength, and elongation.
5.6.2.4.2 Spacers
Three random samples shall be taken from each batch of spacers after 14 days* curing and
tested for absorption. The size of batch shall be agreed for the purpose of testing but shall not
be more than 1000 units cast at the same time from the same mix. The batch shall be rejected
if any of the three samples fails to meet the absorption criteria specified in 5.6.2.3.
Each batch shall be checked for dimensional tolerances. Spacers shall be rejected if they have
a thickness outside the tolerance specified in 5.6.2.3.

5.6.3 Fabrication
5.6.3.1 Planning and Scheduling

The Contractor shall prepare detailed reinforcement plans and bar bending schedules in strict
accordance with approved construction drawings. Steel grades, bar diameters, bar spacings,
bending diameters, lap-lengths, lap spacings, etc, shall be stated on the construction drawings
in accordance with an approved design based on recognized international standards. All bars
shall be unambiguously identified by numbers on the plans and schedules.
The scheduling, dimensioning, cutting and bending shall be in accordance with BS 8666, except
where stricter requirements are specified or shown on drawings.
Copy of all reinforcement plans and bar-bending schedules shall be submitted to the Engineer
for information and for reference before commencing cutting and bending.
5.6.3.2 Bending
5.6.3.2.1 Cold Bending
Reinforcement shall be bent cold by use of approved tools with formers of the ap propriate
diameters. The bending force shall be applied as a continuous and uniform load.
The bending diameter shall be measured on the inside of the bar and shall be as stated on the
construction drawings. The following minimum diameter shall apply for hot-rolled mild steel if
nothing else is specified or shown:
The required bending diameter shall be derived from the very standard which has been used for
the structural design.
5.6.3.2.2 Pre-heating, Re-bending, Field-bending
Bars may be pre-heated for bending only if a detailed procedure has been prepared by the
Contractor for the approval of the Engineer.
Bent reinforcement shall not be re-bent or straightened except where specifically permitted by
the Engineer, and always subject to a detailed inspection for cracks or fractures after the
bending.
Partially embedded reinforcement shall not be field bent except where specifically shown on the
drawings in accordance with an approved design documentation.
As a guideline, heat-bending and re-bending of hot-rolled bars with a yield strength not
exceeding 450 N/mm2 may be permitted by the Engineer if;
• the carbon-content (0) does not exceed 0.26%;
• the equivalent carbon-content (Cw) does not exceed 0.52
• Cw = 0 + Mn/6 + (Cu + Ni)/15 + (Cr + Mo+ V)/5];
• the permissible design strength of the steel after heating or re-bending is reduced by not
less than 25% or as decided by the Engineer;
• the heating is done gradually to a temperature of 800°C - 1000°C, for a length not less than
100 mm outside the bending zone. The temperature must be kept for short time only, and
the cooling off shall be gradual and slow.

However, the Contractor shall in each case provide necessary documentation and perform trials
for the actual type and grade of reinforcement on which he proposes to perform heat-bending or
re-bending.
5.6.3.3 6.3.3 Welding

Reinforcement shall not be welded unless specifically shown on the drawings and documented
in an approved design. Site welding will be permitted only in exceptional cases, at the discretion
of the Engineer.
If welding is considered, the Contractor's Method Statement shall define the welding procedure,
the welder's qualifications and testing, the materials to be used, pre-trials, and welding quality
control tests, all in accordance with recognized international standards. It shall always be
documented by the Contractor that the steel is weldable in accordance with the approved design
and the Method Statement.
Welding of steel according to ASTM A615/A615M is generally not allowed since no specific
provisions have been included to ensure its weldability.
5.6.3.4 6.3.4 Laps and Splices

Lap-lengths and location of laps shall be shown on the construction drawings.
The minimum lap-length for deformed un-coated bars with a yield strength not exceeding 450
N/mm2 shall be 40 times the bar diameter if nothing else is indicated in the approved design.
Laps in slabs shall be staggered where possible so that not more than one half of the bars are
lapped in the same section. Laps in walls and beams shall be
staggered where possible so that not more than one third of the bars are lapped in the same
section. The specified lap-length shall be increased by 50% if these limitations are not fulfilled,
unless otherwise indicated in the approved design.
Mechanical couplings shall generally not be used. If mechanical couplings are considered for a
specific purpose, the Contractor shall submit his detailed documentation and proposal for
approval. The couplings may be approved at the discretion of the Engineer only if they are
produced under an acceptable quality assurance system by an approved manufacturer and do
not reduce the strength of the spliced bars.
5.6.4 Fixing
5.6.4.1 Placement, Tying, Supports

Reinforcement shall be accurately placed in accordance with the drawings and shall be firmly
secured and held in position so it will not move during steel fixing and concreting works.
Bars shall be tied together at all intersections; the ends of the tying wire shall be bent away from
the cover layer.
The spacing of supports shall always be close enough to maintain the specified cover layer
within the specified tolerances. The spacing of supports under reinforcement shall provide a rigid
system without deflection and without crushing of spacers.
Reinforcement shall be supported by spacers against all form sides.
Reinforcement layers shall be supported against each other by steel chairs. In no event shall
steel chairs or steel supports extend into the cover zone.
5.6.4.2 Cover Layer Thickness and Tolerances

The minimum cover layer on reinforcement steel shall be:

• Exposure Class A: 70 mm on any steel;
• Exposure Class B: 70 mm on any steel in civil or plant works; 50 mm on any steel in office
buildings, housing, etc.
• Exposure Class C: 40 mm on main bars; 30 mm on links and stirrups.
The tolerances on the cover layer measured at any point shall be -5/+5 mm on the above
dimensions.
5.6.5 Protection, cleaning

Reinforcement shall not be left exposed for an extended period before being cast in, and it shall
be kept covered by tarpaulins whenever it is not worked on.
If starter-bars, etc, have to be left exposed, they shall be given a protective coating of anti-
corrosion paint, or similar.
Immediately prior to casting, all rusty or temporary coated reinforcement shall be cleaned by grit-
blasting, and all reinforcement shall be thoroughly washed by a high-pressure water jet. Water
for washing reinforcement shall fulfil the requirements to water in the concrete mix.
5.6.6 Quality control for workmanship

The Contractor shall as a minimum perform and keep records for the following quality control;
• Visual inspection and check on dimensions, etc., during fabrication.

• Visual inspection and check on dimensions, spacing, laps, supports, and cover during fixing.
Final inspection of the completed reinforcement including final check by a competent person
prior to casting. The Contractor shall notify the Engineer as soon as a portion of reinforcement
has passed the final inspection.
No reinforcement shall be cast in until the Engineer has had an opportunity to do his own
inspection after the Contractor's final inspection. A detailed quality control shall be performed
wherever pre-heating, re-bending, or welding has been permitted; the type and extent of the
control shall be included in the relevant Method Statements.
5.7 Formwork
5.7.1 Planning and design
5.7.1.1 General
The Contractor shall design all formwork and all associated temporary works in accordance with
applicable codes and standards and the requirements in this Specification. The Contractor shall
submit his formwork design to the Engineer for information and reference before commencing
the fabrication and erection.
Formwork shall be designed, constructed, and maintained so as to insure that after removal of
forms the finished concrete members will
• have a true surface free of un-planned form marks, form offsets, waviness, bulges or mortar leaks
(form streaking);
• conform accurately to the indicated shapes, dimensions, lines, elevations, and positions within the
specified tolerances.

5.7.1.2 Details, Geometry
All openings, holes, box-outs, etc., shall be PRE-PLANNED, shown on form drawings, and
incorporated in the formwork.
All joints shall be horizontal or vertical in a pre-planned pattern, unless otherwise specified; joints
shall be as few as practically possible. Joints and other connections shall be designed to permit
easy loosening and removal of the formwork.
The anticipated deflection of the form and its supports under the fresh concrete load shall be
taken into account in the design of formwork so that the finished concrete member shall have
true surfaces conforming to lines, grades and levels shown on drawings.
The anticipated deflection of beams and slabs after removal of form and supports
shall be compensated by an up-ward camber which shall be calculated for the
individual structure. For normal simple spans, the camber in the middle of the span shall be not
less than 1/500 of the span-length unless otherwise shown or specified. For normal cantilevered
structures, the camber at the free end shall be not less than 1/250 of the cantilever length unless
otherwise shown or specified.
5.7.2 Form materials, surface quality
5.7.2.1 General
All concrete formwork shall be impervious in order to prevent moisture loss from the formed surface. All
formwork shall produce a uniform and consistent texture and pattern on the concrete surface.
Special requirements to form surfaces may be specified elsewhere, for the purpose of achieving
a desired architectural finish. The following types of materials will be acceptable unless
otherwise stated elsewhere in the contract documents:
• fibreglass formwork;
• plastic overlaid plywood forms (i.e. plywood with a resin-fibre overlay, heat fused to the panel face,
or equivalent).
Wood forms without an impervious overlay shall not be used.
5.7.2.2 Re-use of Forms

Form materials may be re-used only if the form surface remains impervious, smooth and clean
and the panels remain free from warping, twisting or other
deformation. Faces in contact with concrete shall be inspected after each use to ensure that they
are free from adhering grout, projecting nails, splits, or other defects.
Formwork which has become unsuitable for re-use shall be removed from the Site immediately.
Patch-repaired panels shall not be used.
5.7.3 Construction and erection
5.7.3.1 Openings
The formwork for walls, columns, and similar deep and narrow forms shall have openings placed
wherever needed for complying with the specification for concrete workmanship; this includes
openings for
• placing of concrete so the drop-height does not become excessive;

• for inspection during placing;

• for compaction.
Formwork shall always have openings at the lowest part which permits a thorough wash-out and
cleaning immediately prior to casting, after completing the fixing of steel.
The openings for inspection or drainage shall be made so that they can be conveniently and
quickly closed before the placing of the concrete reaches the opening.
5.7.3.2 Joints
Joints shall be arranged in accordance with the pre-planned pattern. They shall be tight to
prevent the leakage of cement grout and to avoid the formation of fins and other blemishes. The
joints shall be made watertight by fixing foam tape between the joints to prevent leakage of grout.
Faulty joints shall be caulked by approved methods, taking care not to leave visible marks on
exposed surfaces.
5.7.3.3 Chamfer
Chamfers 20 mm by 20 mm shall be formed by placing plastic moulding at the external form
corners of all concrete members, unless otherwise specified.
5.7.3.4 Ties
Form ties shall be factory-fabricated removable metal ties of a design which will not allow form
deflection and will not spall the concrete upon removal. Solid backing shall be provided for each
tie. The ties shall be provided with devices that will leave conic holes not deeper than 25 mm in
the concrete surface. The ties shall be set in a regular, pre-planned pattern, and holes after ties
shall be made good after casting as specified in Chapter 5.4.
In exceptional cases where cast in ties and anchors can not be avoided, they shall be of stainless
steel positioned at a distance from the reinforcement equal to the specified concrete cover
thickness.
Ties through the concrete shall not be permitted in structures which are subjected to a one-sided
water pressure.
All ties shall be subject to approval by the Engineer.
5.7.3.5 Form-release Agent

Forms for all concrete surfaces shall be coated with form-release agent before reinforcement is
placed.
The coating shall be commercially available formulations of satisfactory and proven performance
that will not bond with, stain, or adversely affect concrete surfaces, and will not impair
subsequent treatment of concrete surfaces depending upon bond or adhesion nor impede the
wetting of surfaces to be cured with water.
The coating shall be used as recommended in the manufacturer's printed instructions. It shall be
applied also on forms with plastic overlay. Re-application of form-release agent shall conform to
the manufacturer's instructions. Care shall be taken to avoid contact with the reinforcement or
previously cast concrete.
Surplus coating on form surfaces and any coating spilled on reinforcement steel or construction
joints shall be removed before placing the concrete.
5.7.3.6 Tolerances
Tolerances on formed dimensions shall conform to ACI 301 SI Table 4.3.1 except where
requirements are specified below or elsewhere in the contract documents:

a) Setting out dimensions: +/- 5 mm per 30 meters.
b) Sections through concrete member: +/- 3 mm.
c) Levels of slabs and beams +/- 3 mm.
d) Clear distance in openings: +/- 5 mm.
e) Plumb of vertical member: +/- 5 mm over any 3 m.

+/-10 mm over any 10 m.
+/- 20 mm over full height.
5.7.4 Protection, preparation before casting

Care shall be taken to avoid any damage to the form during the fixing of reinforcement, casting
of nearby structures, etc.
Forms shall be cleaned immediately before concreting by air jetting to remove sawdust,
shavings, metal from tie-wires, and all other foreign matter. The form shall be kept covered by
tarpaulins until the concreting starts.
5.7.5 Striking of formwork

The Contractor shall always ensure that formwork is removed in a manner to maintain the
complete safety and integrity of the structure after the following conditions have been met.
Forms shall have releasing devices so they can be loosened and removed without chock or
vibration, and without causing damage to exposed edges, etc.
Where the structure as a whole is supported on shores, then forms for beam and girder sides,
columns, and similar vertical structural members may be removed after 24 hours provided the
concrete has become sufficiently hard not to be injured thereby.
Supporting forms or shoring under slabs, beams, etc., shall not be removed until structural
members have acquired sufficient strength to support safely their own weight and any load to
which they may be subjected, and in no case shall the supports be removed earlier than:
• 15 days from casting beams and girders: -21 days from casting slabs.
Special care is necessary for structures which have to carry a large portion of their design load
immediately after removal of supports. Such structures may be exposed to unacceptable
combinations of excessive creep and shrinkage, and they shall be supported for their full load
until at least 28 days from casting.
Unusual structural elements such as large cantilevers, long-span beams, long span or thin slabs,
etc., may also require an extended time for hardening of the concrete before striking.
5.7.6 Quality control for formwork

The Contractor shall as a minimum perform and keep records for the following quality control;
• Review and check of formwork design.
• Visual inspection of materials upon delivery and before each re-use.
• Visual inspection on geometry, surface quality, application of release-agent, etc., during

construction and erection.

• Detailed control measurements of all geometry (setting-out, lines, levels, dimensions) of
finished formwork.
• Final inspection of the completed and cleaned form prior to casting. The Contractor shall
notify the Engineer as soon as a portion of the formwork has passed the final inspection.
• Documentation for minimum required and actually elapsed time from casting to removal of
form and supports.
• Inspection of concrete after removal, with record of any unusual observations.
• Level survey of major structures before and after removing the supports, if such levelling in
the opinion of the Engineer may be relevant for a future monitoring of the expected
deflections.
No concrete shall be cast in the form until the Engineer has had an opportunity to do his own
inspection after the Contractor's final inspection.
No supports shall be removed until the Engineer has received the Contractors documentation to
show that this will not result in overloading or excessive deflections.
5.8 Joints And Embedded Items
5.8.1 8.1 General

This Chapter covers normal movement joints and embedded items other than reinforcement.
Requirements to construction joints are specified in Section 5.4.7. Special joints for large
movements or with heavy bearing loads shall always be made in accordance with an approved
design and shown on large-scale drawings with all necessary additional specification of
materials and workmanship in accordance with the approved design.
The Specifications for concrete, formwork and reinforcement shall apply for movement joints and
embedded items wherever relevant, together with the detailed requirements specified in this
Chapter.
Materials shall be non-degradable and retain their specified properties under the prevailing
conditions. They shall be obtained from approved manufacturers, and must have a satisfactory
experience record from similar applications in Saudi Arabia.
Materials which may come into contact with sewage shall not be susceptible to chemical or
biological attack.
Materials which may come in contact with intake water or product water shall have been
approved by recognized authorities for use in the areas where they are intended, e.g. intake
structures in desalination plants, water tanks, etc., and they shall not give any taste to the water.
Documentation and samples shall be submitted for the approval of the Engineer. No material
shall be brought to site unless approved in writing by the Engineer.
Storage and handling of materials shall be in strict accordance with the manufacturer's
instructions. Manufacturing date and expiry date shall be kept on record for each delivery.
5.8.2 Movement Joints
5.8.2.1 Planning
Movement joints shall be positioned and detailed in accordance with an approved

design, taking into account the expansion and contraction forces which will be acting on the
structure, ensuring an un-restrained movement in the joint, and avoiding harmful consequences
from the forces and movements.
The joints shall be located with an aim to minimise the ingress of liquids or other undesirable
matters which may degrade the joints or cause harm to the structure Reinforcement and
embedded items shall not be permitted to extend across an expansion joint, and shall not be
placed with any part closer to the joints than the specified cover layer. However, dowels across
the joint shall be permitted if it is ensured by sleeves or similar arrangements that they remain
un-bonded at one side of the joint and that they do not prevent the free movement in the joint.
Contraction joints may be introduced by the use of crack inducers, if no expansion is to be

accommodated in the joint. Contraction joints shall always be sealed if the reinforcement
continues across the joint.
5.8.2.2 Materials
Movement joints shall contain pre-moulded expansion joint filler, and joint sealants of the type,
properties, and dimensions required In the approved design and shown on approved
construction drawings.
The joint filler shall be resilient and have high resistance to lateral deformation. Where nothing
else is specified by the designer, it may be of the following types in accordance with Table 5 of
BS 6093:
• bitumen impregnated fibreboard;

• self-expanding, resin bonded or natural bonded cork;
• closed cell polyethylene or rubber foam.
The joint sealant shall have enough bond and flexibility to follow the movements without breaking
and without de-bonding from the concrete surfaces. It shall be resistant to the actual exposure
and temperature ranges.
Where nothing else is specified by the designer, sealants shall be in accordance with BS 6213,
but always of the highest relevant grade, formulated for use in hot climates; the design life
expectancy shall be at least 15 years. Such sealants shall not be less than the equivalent of a
two-part polysulphide-based sealant conforming to BS EN ISO 11600, or a rubber-bitumen
pavement sealant con forming to BS EN 14188-1, whichever is the most appropriate in the
opinion of the Engineer.
Manufacturer's certificates shall be submitted which clearly state the proposed material is
suitable for the intended use and application environmental conditions and the required range
of movement, which shall be clearly stated.
5.8.2.3 Workmanship
5.8.2.3.1 Setting-out, Form, and Filler
All joints shall be accurately located, straight and well aligned, and truly vertical of’ horizontal or
parallel with the setting out lines of the building.
The width of the joint and the depth of sealant shall be in strict accordance with the design
drawings.
When forming movement joints, the joint filler must be fixed firmly to the first placed concrete. If
more than one length of filler is used in a joint, it is essential to butt the ends tightly together or
tape them together to prevent concrete or grout from entering into the joint.

The filler shall be kept at the specified depth from the surface so that the sealant will achieve the
design dimensions; a temporary plastic or wooden profile strip shall be placed to form the
necessary void for the sealant, and this strip shall be kept in place until the sealant is applied.
It is essential that concrete on both sides of the joint is thoroughly compacted to form a dense
uniform mass without any concrete penetrating into the joint.
Expansion joints shall extend for the full depth of the section or member to which they relate.
Joints which extend over only part of the depth of the section or member shall not be acceptable.
5.8.2.3.2 Sealant
Sealants shall not be applied until the concrete has been inspected and found free of faults and
with acceptable moisture content. The joint shall be thoroughly cleaned out before proceeding
with sealant work.
Concrete surfaces shall be primed in order to ensure the best possible adhesion of the sealant;
the primer shall be compatible with the sealant and shall be from the same manufacturer as the
sealant. The application of primer and sealant shall be in strict accordance with the
manufacturer's recommendations.
Should the sealant suffer any of the types of failure described in BS 6213, it shall be replaced
after the possible causes of failure have been investigated and appropriate remedial action has
been taken.
The sealant shall be separated from the filler by a bond-breaking tape or similar, in strict
accordance with the manufacturer's recommendations. Capping strips shall be used where
shown in the approved design drawings.
5.8.3 Water-Stops
5.8.3.1 Planning
Material, type, and location of water-stops shall always be provided in accordance with an
approved design and taking into account the exposure conditions and the working temperature
range.
The design shall specify the dimensions and physical properties which are required to resist the
design water-head and the design movement which will affect the joint.
For all underground structures especially waterlogged areas and where the water table is
perennial and high it is required to use externally fixed water stoppers. This will prevent water
ingress even from the developed joint in two stage pouring of the concrete.
At concrete structures such as dry manholes in dry areas, concrete structures at grade level
where the base slab and walls are constructed in dry areas internal water stopper shall be used.
5.8.3.2 Materials
5.8.3.2.1 Pre-moulded Materials
Water-stops shall be obtained as complete systems from one manufacturer, comprising all
necessary accessories for joining and fixing in accordance with the manufacturer's
recommendations.
Pre-moulded water-stops shall be delivered in the maximum practical length so that the number
of site joints will be held to a minimum.

Joints shall be made in accordance with the manufacturer's recommendations and shall ensure
an effective water-tightness fully equal to that of the continuous water-stop material. Joints shall
develop not less than 50% of the mechanical strength of the parent material and shall
permanently retain their flexibility.
Materials shall be from well reputed manufacturers with a proven track record for applications
under similar conditions. Samples and copy of relevant documentation shall be submitted to the
Engineer for approval. Unless otherwise specified, they shall fulfil the following requirements:
PROPERTY AT 25° Rubber PVC
Min tensile strength (N/mm2) 20 15
Minimum elongation at break (%) 450 285
Hardness (IRHD/ Shore A) 60 - 75 70 – 75
Softness (BS 2571) - 42 C - 52 C
Specific gravity 1.1 (+5%) 1.3 + (5%)
5.8.3.2.2 Alternative Materials
Self-sealing hydrophilic rubber-based water-stops or Injection systems with perforated PVC

hoses and polyurethane foam may be proposed as alternatives to pre-moulded water-stops,
subject to a satisfactory documentation and prior approval from the Engineer in each case.
5.8.3.3 Workmanship
Water-stops shall be fixed in strict accordance with the manufacturer's recommendations. The
Contractor shall ensure that they are firmly fixed and secured in the form before casting, and
that they do not get dislocated during casting operations.
All intersections and junctions in water-stops shall be made with factory produced
T's, L's etc. shapes so that the only joints made on site will be straight butt joints between units
of identical cross section and material.
Site joints shall be in strict accordance with the manufacturer's recommendations and shall be
made with appropriate tools.
5.8.4 Sliding Pads and Slip Membranes

Sliding pads and slip membranes shall be installed with materials, dimensions and locations as
shown on the approved drawings.
Sliding pads shall be elastomer units of appropriate strength and flexibility where nothing else is
specified.
Slip membranes shall as a minimum be a two-layer separating membrane of pre formed bitumen
sheets not less than 1.5 mm thick, where nothing else is specified.
5.8.5 Embedded Items
5.8.5.1 Planning
All required sleeves, inserts, anchors, and embedded items required for adjoining work or for its
supports shall be positioned and detailed in accordance with an approved design, taking into
account the loads imposed through these items and the weakening which the items may cause
in the structure where they are placed.

Openings which are required for piping through concrete, etc, shall be formed, not cut.
Items made from aluminium shall not be embedded in concrete unless effectively coated to
prevent concrete-aluminium reactions.
Anchor bolts or other steel embedment’s shall not be used as the means for grounding electric
equipment and shall not be tied to grounding neutral conductors, or any part of a lightning
protection system.
5.8.5.2 Placing
Embedded items shall be positioned accurately and supported against displacement. Voids shall
be filled temporarily with an easily removable material to prevent the entry of concrete into the
voids.
Location, projection length, etc, shall be within the tolerances stated in the design. Templates
for placing shall be used wherever necessary for complying with the specified tolerances.
Projecting parts of embedded items shall be protected against damage, and shall have
permanent or temporary corrosion protection applied as stated in the approved design.
Where flanged pipes are cast-in, the casting shall be with a concrete identical to the surrounding
concrete, and it shall not be done until the fit with connecting pipework has been checked. The
casting joints between old and new concrete shall be prepared in accordance with Section 5.4.7.
5.8.6 Quality control for Movement Joints and Embedded Items

The Contractor shall as a minimum perform and keep records for the following quality control:
• Visual inspection of materials upon delivery.

• Visual inspection and detailed control measurements of all geometry (setting out, lines,
levels, dimensions) of all joints and embedded items when fixed, prior to casting.
o Repetition of inspection and control measurements after completion of casting.
o Visual inspection on geometry, surface quality, water-stops, etc, at all joints before
applying the sealer.
Test of the sealer's adhesion in joints, as directed by the Engineer. The extent of testing shall
include at least one destructive test in each work section (not exceeding one week’s work) in
order to document a satisfactory bond between sealer and concrete.
5.9 Structural Precast Concrete
5.9.1 General
Precast concrete means any concrete component which is not cast In its final position but
produced elsewhere for later erection in its final place. Precast concrete may be cast on site
under the direct control of the Contractor, or off site by a third party.
Precast concrete from offsite plants will be acceptable only from suppliers who have been
approved in writing by NEOM. Such approval shall specifically mention the project or projects
for which the supplier has been accepted: the approval may be withdrawn at any time in case of
non-conformity with the requirements. Precast concrete suppliers will be approved only if they
can document that they maintain and follow an adequate quality management system and have
a proven ability and capacity to produce concrete elements in accordance with these
specifications.
Components may be precast only if this is in accordance with an approved detailed design based
consistently on a recognized international standard such as BS EN 1992-1-1.

A prefabricated structure may have a distinctly different characteristics compared with an in-situ
structure, including less design redundancy and increased vulnerability to accidental loads; this
may in particular be the case during erection where the unfinished structure may depend on
temporary supports for its stability. Bearing details may also become more critical in a
prefabricated assembly than they would have been in an in-situ structure.
It is not permissible to change a design for an in-situ structure into a scheme for prefabrication
(or vice versa) unless a proper re-design is submitted and approved.
5.9.2 Design and Detailing, Submittals

Design and detailing of pre-cast structures shall as a minimum be in compliance with BS EN
1992-1-1. The following shall be adequately documented in the design wherever relevant:
• Design Basis and Stability Provisions

• Precast Concrete Construction
• Structural Connections between Precast Units
• Composite Concrete Construction
Particular attention shall be given to corrosion resistance of all protruding steel parts, especially
the parts which become load bearing in the completed structure.
Fully detailed calculations and working drawings of all elements and all erection details shall be
submitted for the Engineer's approval before production commences.
5.9.3 Production, Handling and Erection
All requirements stated elsewhere in this Specification, including requirements to cover layer
and curing shall apply also for prefabricated structures wherever relevant, unless they are
specifically modified by the requirements in this Chapter.
Each unit shall be given an adequate marking to show unambiguously the identity date of
casting, weight, location and orientation.
5.9.3.2 Tolerances
The permissible tolerances for prefabricated units and their connections shall be stated by the
designer on the relevant drawings. BS EN 1992-1-1 shall apply wherever relevant.
The tolerances may be of critical importance for the desired load transfer, strength and stability.
The contractor shall therefore check and document that they are complied with.
In case of dimensional non-compliance, the Contractor shall propose what action to take,
supported by the designer's comments if relevant, for approval by the Engineer.
5.9.3.3 Handling and Erection of Precast Concrete Units
Precast units shall be manufactured, handled and assembled by methods that are safe and yield
a completed structure which is satisfactory in relation to its stability, performance, durability, and
appearance.
The recommended actions in BS 5531 shall be followed where relevant; in addition the following
items shall be agreed based on either an approved design or the Contractor's proposal for the
approval of the Engineer:

a) Minimum wages for handling and transporting.
b) The position and design of lifting points.
c) The method of lifting.
d) The type of lifting equipment.
e) Methods of supporting and stacking, both whiles being stored and transported.
f) Method of assembly and erection.
g) The accuracy of assembly and erection.
h) Method of providing temporary support.
i) Method of providing final structural connections.
j) Composition of concrete and mortar used to fill the joints,
k) Method of protecting the units from damage at all times.
I) Safety plan for all handling and erection works.
The agreed precautions and procedures shall be incorporated in the relevant Method Statement.
5.9.3.4 Quality Control During Handling and Erection
The Contractor's check and records during handling and erection shall ensure that the planning
is being strictly followed; the quality control shall include but not be limited to ensuring that:
• each unit bears adequate identity, date, weight, location and orientation marks;
• each unit is placed in its intended final position within the applicable tolerances:
• temporary supports or connections to newly positioned units are provided as soon as practicable,
and completed before the lifting equipment is removed; final structural connections are completed
as soon as practicable;
• contact surfaces intended to be bonded with in-situ concrete have been properly prepared;
• reinforcement is accurately located, particularly in the ends of members;
• structural steel sections in ends of members and additional reinforcement needed for connection
are accurately located;
• joints are properly packed, with particular attention given to joints packed with concrete or mortar,
especially if these are horizontal load-bearing joints;
• all levelling devices, such as nuts and wedges, which have no loadbearing function in the finished
structure shall be slackened, released or removed as necessary;
• elements with signs of defects (damage, cracks, deviating geometry) shall be removed and
replaced.
5.9.4 Cover Layer - Thickness and Tolerances

The cover layer on reinforcement steel shall be:
• Exposure Class A: 65 mm on any steel;
• Exposure Class B: 65 mm on any steel in civil or plant works; 45 mm on any steel in office buildings,
housing, etc.
• Exposure Class C: 35 mm on main bars; 25 mm on links and stirrups.
The tolerances on the cover layer measured at any point shall be -3/+3 mm on the above
dimensions.

For prefabricated wall panels a concrete cover of 35 mm on main bars and 25mm on links and
stirrups can be implemented if the durability of the panels can be proved by the Contractor in
coastal areas.
5.9.5 Prefabricated wall panels

Prefabricated wall panels can be coloured by using pigments in the concrete mix. The colour
should be specified on the drawings and approved by the engineer.
Unless otherwise approved by the Engineer the exterior surface of the prefabricated wall panels
should be sand-blasted, so that coarse aggregate is exposed with roughness of not less than 3
mm depth.
If sand blasting is used for surface treatment, the concrete cover has to be chosen accordingly.
5.10 Prestressed Concrete
5.10.1 10.1 General
5.10.1.1 10.1.1 Definitions
Prestressed structures as specified in this chapter shall mean structures which

are either:
• pre-tensioned by tendons stressed in the form before pouring the concrete;

• post-tensioned by tendons stressed in ducts or sheeting after the concrete has hardened.
5.10.1.2 Limitations, Acceptance of Prestressed Concrete
5.10.1.2.1 General
The potential consequences of corrosion are considered more serious in prestressed tendons
than in normal reinforcement because it involves the possibility of a sudden loss of large tension
forces. For this reason, the use of prestressing shall be limited and subject to NEOM's approval
in each case, as specified below.
5.10.1.2.2 Pre-tensioning
Pre-tensioned structures shall not be permitted in Exposure Glass A and B, and they shall be
permitted in Class C only if it can be shown that they will not be exposed to ingress of moisture
and chlorides during their lifetime.
Pre-tensioning shall be permitted for precast structures only, and only if they are produced under
well controlled factory conditions. Pre-tensioned precast components will be acceptable only
from suppliers who have been approved in writing by NEOM. Such approval shall specifically
mention the project or projects for which the supplier has been accepted; the approval may be
withdrawn at any time in case of non-conformity with the requirements. Suppliers will be
approved only if they can document that they maintain and follow an adequate quality man
agreement system and have a proven ability and capacity to produce pre-tensioned concrete
elements in accordance with these specifications.
5.10.1.2.3 Post-tensioning
Post-tensioned structures are permitted if it is documented that the tendons will remain protected
against ingress of chlorides in their design lifetime, considering the actual exposure.

Post-tensioning may be performed in in-situ structures as well as precast components. Post-
tensioned precast components shall be subject to same conditions as stated in 5.10.1.2.2 for
pre-tensioned precast components.
External prestressing by use of post-tensioning tendons placed outside the concrete shall be
allowed only if a complete specification is included as part of an approved detailed design, and
satisfactory precautions are taken to ensure the safety and durability of the structure in its actual
exposure. Tendons for such purposes shall be greased and sheathed from the manufacturer.
5.10.2 Design and Detailing, Submittals

Design and detailing of prestressed structures shall as a minimum be in compliance with BS EN
1992-1-1. It shall be carried out by professional engineers with comprehensive experience in
such work.
Particular attention shall be given to the E-modulus, range of working temperature, shrinkage,
and creep in the actual concrete for which the prestressing is designed.
Fully detailed calculations, working drawings and work procedures shall be submitted for the
Engineer's approval before work commences on prestressed structures.
5.10.3 Specifications and Workmanship
5.10.3.1 General
All requirements in other Chapters of this Standard Specification shall apply to prestressed
concrete unless modified by this Chapter.
Specific requirements to materials including steel grades, steel properties, tensioning

procedures, etc, shall be stated on approved working drawings.
BS EN 1992-1-1, shall apply wherever relevant.
5.10.3.2 Prestressing Steel and Anchors

Prestressing steel and anchors shall be obtained from approved manufacturers with well
documented experience and references from production in accordance with recognized
international standards.
Work certificates for steel and performance documentation for anchors shall be submitted for
the Engineer's approval.
5.10.3.3 Ducts
Ducts must not be galvanized. They shall remain watertight with a close fit to anchors so that no
concrete can enter the duct during casting.
Samples with the manufacturer's documentation shall be submitted for the Engineer's approval.
5.10.3.4 Grout
Composition and properties of grout shall be documented through the manufacturer's

documentation and through pre-trials to check the following in accordance with BS EN 1992-1-
1:
• fluidity;

• bleeding and re-absorption;
• compressive strength (3 cubes at 28 days, all > 30 N/mm2);
• mixing ratios (w/c < 0.40);
• expansion (0 < 10%);
• acid soluble chloride content (< 0.1 %).
The fluidity shall be measured at 15 min intervals for a period equal to the planned time for
grouting operation.
Fluidity, bleeding, and re-absorption results shall be used as reference values when assessing
quality control results during construction.
It must be documented that the specified properties will be maintained at the actual temperature
at which the grouting will take place.
5.10.3.5 Tensioning and Grouting
Detailed step-by-step procedures shall be prepared by the Contractor for:
• stressing operations, stating equipment, tensioning loads, steps in tensioning, expected elongation
at each step, time and sequence for stressing the tendons. Tensioning shall be performed by crews
specialised in this work, directly supervised by a competent and experienced engineer; the controls
shall include calibration of stressing equipment immediately before and after each stressing
operation
• cleaning, draining, venting, injection equipment, and controls to ensure a complete filling of the
ducts and all associated cavities in anchors, etc; the controls shall include but not be limited to
testing fluidity, bleeding, reabsorption and strength for each grouting operation.
These procedures shall form part of the Contractor's Method Statement and shall be submitted
to the Engineer for approval before commencing the stressing works.
5.10.4 Quality Control

The contractor's quality control shall include but not be limited to checking, testing, and keeping
records of the following;
• work certificates shall be obtained for all prestressing steel and anchors; traceability shall be
ensured so that each tendon and each anchor in the finished structure can be related to the correct
certificate;
• visual inspection when receiving steel and anchors to ensure that marking, handling, storage and
surface condition is conforming to the specification; necessary additional testing shall be made by
the Contractor wherever the visual inspection in the opinion of the Engineer gives reason for
concern;
• pretesting of all grout to check that it conforms with the requirements and to establish reference
values for fluidity, and bleeding;
• check on correct positioning, fastening and watertight sealing of ducts, ten dons and anchors;
• records from tensioning stating equipment, force, and elongation of each tendon;

• all calibration results for stressing equipment;
• records from grouting of ducts, including mix recipe and test results for temperature, fluidity,
bleeding, re-absorption, expansion, and strength.
• The Contractor shall keep these records in a log with times and dates stated for each operation.
5.11 Sprayed Concrete
5.11.1 General
Spray concrete (unite, shotcrete) shall not be used for general construction. It may be applied
for special purposes where a conventional placing is not possible, but always subject to prior
approval by the Engineer.
All requirements in this Standard Specification shall apply to spray concrete unless modified by
this chapter; this includes requirements to constituent materials, concrete grades, w/c ratio,
cover layer, curing, and all testing and trials.
The following standards and guidelines shall apply where nothing else is stated in the
Specification;
ACI 506 R: Guide to Shotcrete.
ACI 506.2 R: Specification for Materials, Proportioning, and Application of Shotcrete.

Concrete Society: Code of Practice for Sprayed Concrete.
Sprayed concrete is a specialized process which shall be planned and performed only by
companies, engineers and operators with proven expertise in this field.
The works shall be thoroughly planned, and the Contractor shall submit a complete
documentation for his proposed plant, materials and operational procedures in a Method
Statement for the Engineer's approval before any work commences.
5.11.2 Constituent Materials

All requirements of Chapter 5.2 shall apply. Additional requirements to grading curves and
aggregate shapes shall be agreed as necessary to achieve a high-quality spray concrete.
5.11.3 Proportioning and Mixing

Spray concrete shall be by the dry method. Pre-packed mixes may be used if they are
conforming to the requirements in this Standard Specification.
All requirements of Chapter 5.3 shall apply, including requirements to design and pre-testing of
concrete mix. However, mixing of spray concrete shall be in an appropriate mixer which has
been proven to produce a spray concrete of the required quality.
The moisture content of the aggregates is important for keeping a consistent quality of the spray
concrete. The moisture content shall be kept as constant as possible and within the
recommended limits of 3 - 6% by weight of the aggregates.

5.11.4 Trial panel and workmanship
5.11.4.1 Crew
Spray concrete shall be applied only by certified nozzlemen with comprehensive practical
experience from such work. The contractor shall submit certificates and valid documentation for
the nozzleman, for the Engineer's approval.
A trial application shall be made by the same operators who perform the actual work, and no
work shall proceed until the crew has successfully performed the required trials.
5.11.4.2 Trial Panel
5.11.4.2.1 Size and Purpose of Panel
Before permission is given to proceed with spray concrete works, a trial panel shall be made
and found satisfactory in the opinion of the Engineer.
The trial panel shall simulate the actual position, substrate, form geometry, member thickness,
reinforcement lay-out, and access restraints as expected for the actual application. The panel
shall be not less than 2 m by 2 m; the thickness shall be not less than 0.15 m.
The procedures developed for the trial panel shall be adhered to during production, once the
panel has been inspected and approved for reference.
A new panel shall be made if the first panel fails, and so on until an acceptable standard has
been achieved.
5.11.4.2.2 Homogeneity, Density and Strength
Six cores of 100 mm diameter shall be taken from the trial panel and inspected for homogeneity;
photos and descriptions shall be made for the cores, and them visual appearance shall be used
as reference for later work. After the appearance has been recorded, the cores shall be tested
for density and compressive strength (BS EN 12390) as follows:
• 1 core after 3 days,
• 1 core after 7 days.
• 1 core after 14 days,
• 3 cores after 28 days.
The strength requirements are as specified in Chapter 5.3. They shall be considered fulfilled if
the "in-situ" compression strength of the core (corrected for age and any length/diameter
deviation) is at least 80% of the specified cylinder specimen strength or 65% of the specified
cube specimen strength.
The density results shall be used as reference values for the approved trial panel.
5.11.4.2.3 Chloride and Sulphate
Three of the six cores from the trial panel shall be used for testing the contents of acid soluble
chlorides and sulphates (BS EN 12390). The acceptance criteria are as stated in Chapter 5.3.

5.11.4.3 Permanent Works
5.11.4.3.1 Preparation
All requirements in Chapter 5.4, 5.6, 5.7, 5.8 are applicable. Where spray concrete is applied
against old concrete, this shall be considered as a construction joint. The old concrete shall be
cut back if damaged, roughened by grit blasting, and wetted before proceeding.
5.11.4.3.2 Placement Techniques
Spraying in windy or hot weather or on warm surfaces shall be avoided. Spraying shall take
place with the nozzle held at such angles and at distances from the sprayed surfaces as required
to ensure that no rebound is entrapped in the finished concrete, and that no voids or sand
pockets are built in, e.g. behind reinforcement bars. Rebound shall be removed from the work
area continuously during the spraying.
The sprayed surface shall preferably not be worked but shall be left with a finish as sprayed.
The sprayed surface shall be covered with tight-fitting plastic sheets as soon as possible and
until the proper curing can be implemented.

Quality control, sampling and testing during production shall be as specified for conventional
concrete. However, samples for strength testing shall be cores of 100 mm diameter instead of
150 mm cubes. The conversion of in-situ core strength to sample cube strength shall be as
stated in 5.11.4.2.2.
Deviations on in-situ strength of spray concrete shall not be more than + 20% from the average
strength within any set of cylinders.
The cores shall be inspected for homogeneity, using the test panel cores as reference. The
Contractor shall review his work procedure in case of inhomogeneities being observed, and he
shall perform such further testing as may be required by the Engineer in order to prove that the
completed parts of the works are made of a dense and homogeneous concrete.
5.12 Underwater Concreting
5.12.1 Use of Underwater Concreting

Underwater concreting means placing fresh concrete under water. It shall be used only for
unreinforced structures and only where specifically stated in a design approved by NEOM.
All requirements in this Standard Specification shall apply to underwater concrete wherever
applicable unless modified by requirements in this Chapter.
5.12.2 Method, Materials, Workmanship
5.12.2.1 General
Placing of underwater concrete shall be with the tremie method, which means that the concrete
is placed in hoppers, flows down through tremie pipes, and flows horizontally to fill the form after
leaving the tremie pipe. ACI 304 chapter 8 shall apply where nothing else is stated in this
Specification or in the approved design.
Placing shall always be within a form which shall be able to protect the fresh concrete against
any current, wave action, or running water. The form shall be a cofferdam or a similar robust,

tight and firmly anchored structure; it shall be high enough to provide the desired protection, and
shall not be removed or cut back until the concrete has hardened.
Where bond is required between previously placed steel or concrete and the fresh concrete,
such surfaces shall be thoroughly cleaned immediately prior to the casting. Cleaning shall be
accomplished by high-pressure water jetting or similar approved.
Airlifts or pumps shall be used if necessary, to remove mud, silt, or sand from placement areas,
and the area shall be inspected and approved immediately prior to the casting.
5.12.2.2 Casting Programme
The Contractor shall develop a comprehensive Method Statement for all underwater concrete in
accordance with the provisions of this specification. The Method Statement shall include
concrete materials, concrete mix proportions, tremie equipment, placement procedure, trials,
sampling, testing, and inspection.
No underwater placements shall be made until the Method Statement has been accepted by the
Engineer, and an agreed trial casting has been successfully performed with the relevant
equipment, materials, and procedures.
5.12.2.3 Equipment
Tremie pipes shall be spaced in a grid at a centre-centre distance not exceeding 5 m.
The tremie pipe shall be of heavy gauge (min. 6.5 mm wall thickness) steel pipe with a minimum
inside diameter of 250 mm. The pipe shall be marked with a scale in its full length to show
distance from the mouth of the tremie; the marking shall state distance in meters, with
subdivisions per 0.1 m. The tremie pipe shall be sufficiently heavy to eliminate uplift on an empty
pipe.
Joints between sections of tremie pipe shall be gasketed and bolted so as to remain watertight
during placement. The pipe shall have an end seal plate when placing commences.
A supply of extra end plates and gaskets shall be maintained to allow resealing of tremies, if
necessary.
A hopper or funnel of at least 0.5 m3 capacity shall be provided on top of the tremie pipe to
facilitate transfer of concrete to the tremie.
A power hoist (which is capable of steady vertical control) shall be provided to accommodate
vertical movements of the tremie. A stable platform shall be provided to support the tremie pipe,
hopper, and hoist.
A crane or other lifting device shall be available to completely withdraw the pipe as necessary
for the purpose of resealing or horizontal relocation.
5.12.2.4 Concrete
Concrete shall be grade A with admixtures to ensure a cohesive concrete and a slump not less
than 180 mm at any time during the placing. The slump is extremely important for a successful
placing.
5.12.2.5 Trial Casting
The extent of the trial casting shall be agreed with the size and importance of the structure in
mind. Trial castings shall always be monitored by divers and documented by video.

As a minimum, it shall be demonstrated by the trial casting that the concrete can be placed with
the selected equipment at the depth and with a flow distance as planned, without leakage or
wash-out. It shall also be demonstrated that the planned sounding method is reliable and gives
a true picture of the surface levels during placing.
5.12.2.6 Placing the Concrete
All placement shall be monitored by divers and documented by video. In addition, the placing
shall be controlled through an agreed depth-sounding program; monitoring by divers only,
without independent soundings, shall not be permitted.
The placement shall begin with the tremie pipe sealed with a watertight plate. "Rabbits" or "go-
devils" shall not be used to start the tremie. The sealed tremie pipe shall be lowered to the bottom
and filled with concrete. The tremie shall then be lifted 150 mm and the end-seal removed to
initiate concrete flow; the flow shall continue with the pipe in this position until the required
embedment is developed around the pipe.
The embedment shall be from 1 to 1.5 m into the concrete.
The embedment shall be maintained by controlled retraction throughout the placing operation.
The concrete placement rate shall be sufficient to produce a minimum vertical rise of concrete
of 0.2 m/hr, calculated by dividing the entire placement area by the concrete production rate.
All vertical movements (retraction) of the tremie pipe shall be carefully controlled to prevent loss
of seal. If loss of seal occurs, placement through that pipe shall be halted immediately. The
leaking pipe shall be removed, resealed or replaced, and the placing shall be restarted.
Placement of tremie concrete shall be a continuous operation until the entire placement is
completed. Interruptions of placement through one of the tremie pipes shall not exceed 30
minutes without removal of the pipe and restarting the procedure.
If circumstances force a suspension in placement greater than the time of initial set, then the
surface of the concrete shall be green-cut after the concrete has set. Placement shall not be
resumed until the concrete surface has been cleaned by water jetting.
Tremie pipes shall be relocated during the placement in accordance with the placement plan
and as indicated by soundings. A pipe shall not be moved horizontally while concrete is flowing
through it. To relocate a tremie pipe, it shall be empty, lifted out of the water, resealed, relocated,
and restarted.
At no time shall concrete be allowed to fall through water.
Airlifts or pumps shall be provided to remove laitance with accumulates during placement. Airlifts
and pumps shall be relocated as indicated by soundings and divers’ observations.
5.12.3.1 General
Underwater placing of concrete is an unusual and difficult operation. The Contractor must ensure
that all work is directly supervised by qualified and experienced personnel. An experienced
person must be available to interpret soundings and make necessary decisions concerning
relocation of placement pipes and airlifts and to observe overall placement procedures.

5.12.3.2 Minimum Required Checks and Records
The Contractor shall as a minimum check and record the following:
• preparation and cleaning of form and substrate before casting, checked by depth-soundings and
by divers with video;
• monitoring during placing for leaks and wash-outs, checked by divers with video;
• monitoring pipe embedment and surface levels during placing, checked by depth-soundings and
by divers with video;
• monitoring cast volume, checked against theoretical volume;
• concrete slump every 15 minutes during placing, measured at hopper over tremie pipe;
• concrete production control as specified elsewhere in this Standard Specification;
• after hardening, inspect surface for geometry, levels and casting defects; take cores to determine
casting quality and in-situ strength as per section 5.12.3.3;
• after removal of forms (where relevant), inspect formed faces for any casting defects;
• after dewatering, inspect for any leaks.
5.12.3.3 Assessment of Strength

At least four cores 150 mm by 300 mm from each day's casting or each 400 m 3 (whichever is the
smallest volume) shall be taken and inspected for homogeneity; photos and descriptions shall be made
for each cores.
After the appearance has been recorded, the cores shall be tested for density and compressive
strength (BS EN 12390). The strength requirements are as specified in Chapter 5.3. They shall
be considered fulfilled if the "in-situ" compression strength of the core (corrected for age and any
length/diameter deviation) is at least 80% of the specified cylinder specimen strength or 65% of
the specified cube specimen strength.
5.12.3.4 Corrective Actions
If the underwater concrete is found inhomogeneous and/ or leaking, and if this is detrimental to
the intended function of the concrete, then the Contractor shall propose appropriate corrective
actions for the approval of the Engineer.
If the underwater concrete is found to have less in-situ strength than expected, and this may
have an influence on the structural integrity, then the Contractor shall either submit the
designer’s acceptance of the actual strength, or he shall propose appropriate corrective actions
for the acceptance of the designer and the approval of the Engineer.

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5 Concrete and Reinforcement

'NEOM" NEOM Company (NEOM).

"The Contractor" The party defined in the contract documents.

"BS" British Standard

"ASTM" American Society for Testing and Materials

"ACI" American Concrete Institute

"Particular Amendments to the Standard Specification":

"Acceptance" and "Approval":

5.1.2 Minimum requirements and additional requirements

5.1.3 Applicable Standards

BS 14188-1 Hot-applied joint sealant system for concrete pavements: Methods of

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BS 6093 Design of joints and jointing in building construction. Guide

BS 6213 Selection of construction sealants. Guide

BS 8666 Scheduling, dimensioning, bending and cutting of steel reinforcement

BS EN 196 Methods of testing cement

BS EN 480 Admixtures for concrete, mortar and grout - Test methods

BS EN 933 Tests for geometrical properties of aggregates

BS EN 1097 Tests for mechanical and physical properties of aggregates

BS EN 12620 Aggregates for concrete

BS EN 1367 Tests for thermal and weathering properties of aggregates

BS EN 1744 Tests for chemical properties of aggregates

BS EN 1992-3 Eurocode 2. Design of concrete structures - Liquid retaining and

BS EN 12350 Testing fresh concrete

BS EN 12390 Testing hardened concrete

BS EN ISO 11600 Building construction - Jointing products - Classification and

ASTM C33/C33M Standard specification for concrete aggregates

ASTM C150/C150M Standard specification for Portland Cement

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ASTM A775 Standard specification for epoxy-coated reinforcing steel bars

ACI 301 SI Specifications for Concrete Construction

ACI 305R Guide to Hot weather concreting

ACI 506R Guide to shotcrete

ACI 506.2 Specification for shotcrete

5.1.4 Exposure Classes

5.1.4.1 Class A, Aggressive, with Chlorides and Sulphates

5.1.4.2 Class B, Aggressive, With Risk of Chlorides, but no Sulphates

Any area subject to water spillage or washing

Tanks and other structures containing product water.

5.1.4.3 Class C, Moderate, With no Risk of Chlorides or Sulphates

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5.1.5 As-Built Documentation and Maintenance Manual

5.1.6 Quality Assurance and Quality Control

5.1.6.2 Quality Assurance System and Organization

5.1.6.3 Quality Plans

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The Quality Plan shall include:

• the scope of work which they cover;

5.1.6.4 Control Plans

• definition of control sections;

5.1.6.5 Independent Testing Contractor and Laboratory Facilities

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5.1.6.7 Engineer's Approvals or Acceptance

5.2 Concrete Constituent Materials

5.2.2.1.1 Reinforced Concrete

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5.2.2.1.2 Un-reinforced Concrete

5.2.2.1.4 Quality Control