China Harbour Engineering Co.L.L.C.

QUALITY CONTROL PROCEDURE

FOR
CONCRETE BLOCK WORK

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TABLE OF CONTENTS

1.0 PURPOSE
2.0 SCOPE
3.0 REFERENCES
4.0 DEFINITIONS
5.0 RESPONSIBILITIES
6.0 PROCEDURE
6.1 Preliminary Checks
6.2 Quality Control Checks
6.3 Site Preparation and Setting-out Block Work
6.4 Cement Mortar Mixing and Control
6.5 Block Work Installation
6.6 Block Work Accessories & Reinforcement
6.6.1 Anchors / Wall Ties

6.6.2 Horizontal Reinforcing

6.7 Control Joints

6.8 Sampling and Testing
6.8.1 Testing of Concrete Blocks

6.8.2 Testing of Mortar

7.0 ATTACHMENTS

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1.0 PURPOSE

The purpose of this procedure is to ensure the quality control is achieved during the concrete block
work wall construction and to ensure the documentation is produced to record fundamental checks
at each stages of block work operation in compliance with the specifications and drawing
requirements. And to ensure that the block work materials, accessories, mock ups, samples and tests
are complies in accordance with the specifications.

2.0 SCOPE

The scope of work described in this method statement is applicable for the concrete block work at
exterior and interior walls, patricians, fire rated walls i.e. service shafts, stair cases, storage rooms,
electrical and transformer rooms for the “Construction Of New Administration Building for Borouge at
Ruwais. The procedure covers the quality control inspection of setting-out of block work walls, mock
ups, materials, accessories, samples, tests and related items to verify the specified requirements are
met in accordance with the specifications and drawings.

3.0 REFERENCES

 MS-5986-008 Rev.01
 ITP-5986-008 Rev.01
 RA-5986-008 Rev.01
 FM-5986-008 Rev.01
 Specification: Section 04220 Division 4, Volume 4, Part A of Civil and Architectural Works.

4.0 DEFINITIONS

MS : Method Statement
ITP : Inspection and Testing Plan
RA : Risk Assessment
HSE : Health Safety & Environment
FM : Check Sheet Form
QC : Quality Control
QCP : Quality Control Procedure
ITR : Inspection and Testing Request for Approval
ITL : Independent Testing Laboratory
CMU : Concrete Masonry Units

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5.0 RESPONSIBILITIES

The Project Manager shall review and approve the methodology for the execution of the works, and
ensure that the works are implemented in an efficient manner. The Project Manager is generally
responsible for the overall project execution, quality and safety.

The Construction Manager is responsible for the implementation of approved method statement and
relevant procedures. He will ensure that all involved site personnel are aware of the method
statement, relevant procedure s and shop drawings are followed on the site. He will be responsible for
the monitoring of the work progress on daily basis to ensure activities are accomplished as per the construction
program.

The Project / Site Engineer shall ensure that the works are carried out according to design, approved shop
drawings and procedures. He will be responsible to coordinate, check and follow up the masonry block works
and ensure that proper sequence of activities is followed in order to achieve target completion. He will ensure
that safe work practices are followed for all works under his care. Coordinates with the MEP discipline and
ensure all services are in place and all necessary inspections have been carried out.

The MEP coordinator / Engineer will coordinate with the Construction Manager / or Project Engineer in
advance of all MEP installation works interfacing in line with block work progress and work schedules. He will
coordinate with MEP subcontractor and ensure that all MEP services/openings identified and located in block
walls are completed. He will submit separate ITR to the Company Engineer for MEP services/installation where
shown in the approved shop drawings. A copy to be forwarded to the QA/QC Engineer for all submitted ITRs
and copy of approvals.

The QA/QC Engineer shall ensure that the works are carried out in accordance to the requirement of quality
control. He shall ensure that all ITP requirements are met. The QA/QC Engineer shall ensure that all necessary
ITR and Checklist for inspection and testing are processed and put forward to the Company Engineer for
notification. He shall ensure that materials being used are approved of the Company. He will ensure that all
arrangements and equipment for the sampling, curing, storing and transportation of cubes are properly
planned and organized. The QA/QC Engineer has the responsibility to review and submit all concrete test
results to the Company representative and to ensure that all related documentation is prepared, distributed,
signed-off and filed.

The Surveyor shall be responsible in setting-out, line and levels for concrete block work for walls/partitions and
other dimensional requirements in accordance with approved shop drawings.

The HSE Officer shall monitor and implement all HSE related issues. He shall ensure that all necessary
requirements regarding health, safety and environment concerns are met and adhered to. The HSE Officer shall
ensure that all permits and authorization are on hand prior to starting any site operation.

The Foreman/Supervisor will be responsible to carry out the work in safe manner and to supervise the work
force together with the proper execution and monitoring of works, and all appropriate checks will be carried
out during progressive and completion stage of block work.
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The Independent Testing Laboratory (ITL) shall be responsible for sampling, testing and reporting the test
results as per the project specifications.

6.0 PROCEDURE

6.1 Preliminary Checks

Prior to start of the concrete block work, ensure that this document together with the following
documents are submitted and approved by the company.
 Shop Drawings
 MS, QCP, ITP, Safety risk assessment and Check sheets and relevant concrete block work materials,
accessories and samples are submitted and approved by the Company.
 Acceptance of materials by the Company upon delivery at site (material inspection)
 Testing of concrete block work materials are complied as per the specifications and accepted by
the Company.
 Manufacturer’s certificates attesting that materials supplied are as per referenced standards.

6.2 Quality Control Checks

Carry-out quality control checks at all stages of masonry block work construction involved
for the following activities.
 Preliminary Checks (section 6.1)
 Site preparation and setting-out of block work (section 6.3)
 Cement mortar mixing and control (section 6.4)
 Block work installation (section 6.5)
 Block Work Accessories & Reinforcement (section 6.6)
 Control Joints (section 6.7)
 Sampling and Testing (section 6.8)

6.3 Site Preparation and Setting –out of Block Work

 Check and ensure that the area of concrete surface is clean to receive block work and
wetted before laying mortar base course.
 Check the setting-out of block work layout marked as per the approved shop drawings at
each area/room.

6.4 Cement Mortar Mixing and Control

Mixing of cement mortar that is to be used in block work walls shall be controlled by the site
supervisor/ Foreman the following.

 Check and ensure the cement and sand mortar will be dry mixed uniformly as per the
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specified mix ratio (1:3) of 1 part cement and 3 parts sand. Add enough water and mix
thoroughly and uniformly to make mortar tightly ball in a man’s hand and slightly ooze
through fingers as the hand is closed.
 Ensure mortar mix shall be used within half an hour of mixing. Hardened mortar shall not
be used in the work and shall be disposed of from the site. Do not re-temper mortar.
 Check ingredients for mortar shall be measured and controlled in proper clean gauge
boxes and mixing shall be carried out by means of a mechanical batching mixer.
 Mortar Mix Proportion:
 Cement 1 bag / 50kg (volume – 0.035cum)
 Washed sand 0.105 cum
 Water (Fresh/Potable) 23.00 liters
Size of the gauge box shall be 320mm x 320mm x 340mm (3nos. boxes in full will be 0.105 m3)

6.5 Block Work Installation

 Check where the block work is required to stand on the ground slab, ground beams or
foundations, install one layer of damp proof course in the lowest block work course consisting of
tropical quality bituminized fiber felt complying with type B of BS 73 and weighing not less than
3.3 kg/sq.m.
 The damp proof course will be well lapped at corner and joints and bedded in cement mortar
and pointed on both sides.
 Check the intended locations of concrete blocks to be used shall be of solid and / or hollow
blocks of specified sizes as per the approved shop drawings and in accordance with specifications.
Where fire rated walls are called for, construct with solid concrete blocks to provide required
rating. Solid concrete blocks shall be laid at all jambs of concrete block work.
 Check the first course of block work should be laid as per the set-out on cement mortar bed of
thickness about 10 to 30mm to ensure horizontal level accuracy.
 When setting-out of block with one course is ready, an ITR will be submitted in advance of the
scheduled inspection by the Company Engineer for approval.
 Check all blocks shall be well soaked before being used and tops of walls left off shall be wetted
before work is restarted.
 Check randomly the subsequent block work course to be laid on 10 to 12 mm thick bed mortar
and ensure all joints shall be uniform. Line Pegs shall be removed as the work progresses,
resulting holes filled and tooled before mortar has set.
 Check cut units to accommodate wall dimensions, steel framing, fixtures, recesses and other
work and ensure cutting of masonry units shall be carried out by power driven masonry saw.

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 Check and ensure that block work units shall be set out with a storey rod so that coursing lines
up at steel shelf angle, sills, heads of windows and doors with full courses. Pointing of block walls
shall be carried out as work proceeds, fair faced work shall be flush pointed internally with
cement mortar.
 Check and ensure block walls to be carried up evenly, course by course, ensuring that all
horizontal joints are properly level and vertical joints are lined as the work proceeds. Not more
than 1.2 m height of block walls shall be raised during a day. Not more than 1.0 m height of block
walls shall be raised above any adjacent un-built course, and no area of walling higher than 600
mm. above any course which is not fully set. Angle and reveal shall be kept true, square and
plumb.
 Check and ensure block work to be constructed with a sprit level so that the course will proceed
at an even level. Check and ensure block walls that are constructed as true plumb and level and
tested with a 3000 mm straight edge placed anywhere on the wall in any direction shall be true
to place within 3mm and plumb within 6 mm as per the specifications. Each horizontal joint shall
be level and at same height in all walls around the room and true to the lines and dimensions
indicated on the shop drawings.
 Check the block work to be laid up in running stretcher bond with vertical joints in successive
course centering on midpoint of the unit below. Intersecting concrete block walls shall be tied
together in masonry bond.
 Check and ensure masonry wall openings are correct that are left to fix hollow metal frames into
masonry work at correct elevations. Frames to be set and maintained square, plumb and true.
Frames which are to be set on finished floors are to be anchored both jambs with bolts and
expansion shield.
 Ensure to fill interior of hollow metal frames with cement/sand mortar grouting as per the
specifications.
 Check and ensure that block wall is extended, unless shown otherwise, to within 20 mm of
underside of structure. Fill the 20 mm gap with mineral wool or fibrous glass board insulation
under 25% compression as per the approved materials, so placed that space is left each side of
the finished wall to accept joint sealant. At fire rated enclosure ensure gap at top is filled to meet
wall fire rating.
 Check and ensure where block work more than 5m in height, shall construct with reinforced
concrete stiffening frame work comprising of 200 x 200 mm verticals at 4.0 m centre and 200 x
300 mm horizontal at mid height or at every 3.0 m in case wall height is bigger than 5.0 m. When
the distance between the structural columns is more than 6.0 m, and the height of the panel is
more than 4.0 m, construct non structural columns (200 x 200) not exceeding 6.0 m on centres
as stiffeners.
 Ensure that MEP works/services and other trades are coordinated to determine the location and

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size of openings to be left in the block walls for HVAC ducting, Plumbing, electrical pipes, panels,
boxes, etc.
 Ensure chasing of completed walls or formation of holes shall be carried out only when approved
by the Company.
 Check any damaged / broken blocks are to be collected and disposed off from the site.

6.6 Block Work Accessories & Reinforcement

6.6.1 Anchors / Wall Ties

 Check and ensure where block work abutting against concrete surfaces, approved type of
stainless steel wall ties shall be fixed in the concrete at second course and every third bed course
thereafter, full height of wall.

 Check and ensure Top of the block work walls up to 45 mm thick shall be secured to cast in place
concrete slabs above with strap anchor securely fixed to the slab and securely embedded in to
mortar joints of the wall. Space anchors not more than 600 mm apart.

6.6.2 Horizontal Reinforcing

 Check and ensure galvanized reinforcement steel mesh is placed in block walls and patricians in
horizontal as follows
 Mesh to be set in mortar bed joints and lapped at least 300 mm at all splices and at
corners and intersections.
 Mesh to terminate at each side of expansion and control joints.
 Mesh to be placed continuous and set in the second bed course at 200 mm height from
slab and every second bed course at 400 mm height, to full height of wall partition.
 Bed joint of the top course of block wall shall be placed with mesh in all cases.
 Mesh to be placed in the second and third bed joints 200 mm apart immediately above
lintels and below sills of openings and shall extend at least 900 mm beyond the jambs.

6.7 Control Joints

Check and ensure that vertical control joint in block work walls at maximum 6.0m .o.c. and /or
where directed by the Company. Joints shall be constructed full height of the walls or partitions.
Joints shall be constructed full height of the walls as patricians. Joints shall be formed by using
one half and full blocks to form a continuous straight vertical joint and placing continuous tarred
or waxed paper asphalt emulsion on the end half-cells of the blocks. The resulting centre key
cavity is to be completely filled with mortar each course is placed. Vertical joint between the

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block ends shall be raked out to a depth of 12mm full height on both sides of the wall and left
ready to receive caulking with approved joint sealant as per the specification section 07920.
6.8 Sampling and Testing
6.8.1 Testing of Concrete Blocks

 Carry-out compressive strength test in accordance with BS 6073 for concrete blocks and submit
test results for Company’s review and approval.

 The tests shall comply the following properties of blocks.

 The compressive strength of the individual blocks at twenty eight days shall an average
compressive strength of 12.5 N/mm2 with minimum individual strength of less than 10
N/mm2 for load bearing blocks and an average strength more than 7.5 N/mm2 with a
minimum individual strength of not less than 7 N/mm2 for non-load bearing blocks.

 The average transverse strength of 5 blocks shall not be less than 0.65 N/mm2.

 Water absorption shall be 15% or less of dry weight.

 Shrinkage, when measured in accordance with BS 6073 shall not exceed 0.05%.

 Minimum 75% solid blocks shall be used for fire rated walls.

Concrete Block for Fire-rated Construction: Blocks shall comply with BS 6073, Part 1 & 2 and BS En
772-2 shall have minimum compressive strength of 12.5 N/mm2 and at least 75% solid.
Hourdi Blocks: Blocks shall have a minimum compressive strength of 7.0 N/mm2 and maximum 60%
solid.

6.8.2 Testing Mortar

Upon arrival of the materials at site, carry out compressive strength test in accordance with BS 4551
for mortar and submit test result for Company’s review and approval.
 The test shall comply the following properties for mortar
 Prepare a sample consisting of six (6) specimens of 75mm / or 100mm cubes for
every storey of the building.
 Samples shall be tested for compressive strength at 7 days – 3 nos. & 28 days – 3
nos.
 The average compressive strength shall not be less than 3.0 N/mm2 at 7 days, and
shall have minimum strength of 4.0 N/mm2 at 28 days.
 Two copies of all test reports shall be submitted to the Company within 3 days after specified

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period of testing.

7.0 ATTACHMENTS

 ITP...................
 checklist...........

--------------------------------------------------END----------------------------------------------

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CHECK SHEET FOR : CONCRETE BLOCK WORK Form No. : FM-5986-012

SUBCONTRACTOR CONTRACTOR Rev. No. :
Page :
SECTION OF WORK: CIVIL LOCATION:
LEVEL: GROUND LEVEL TO ROOF SLAB
Checked by DATE
STAGE ITEM
HGC CHEC DG DC
Concrete blocks & samples approved
Mortar mix approved
1. PRELIMINARY Block work accessories approved
CHECKS Latest drawing revision used
Method statement, QCP, ITP approved
Check manufacturer’s test certificate for cement, sand
and Masonry Blocks
Set-out (position) and profile with one course of block
2.SETTING-OUT work installed
Line, level, Alignment, Plumb, dimensions are correct
Gauging and mixing of mortar as per the mortar mix
proportions.
Damp proof course installed where required
Check type and size of blocks are at intended locations
of use.
Bed mortar joints are uniform, horizontally leveled,
vertical joints are lined.
Check tolerances for 3.0 m length on the wall
should be within 3mm and plumb within 6mm.
Masonry openings are correct for hollow metal
3.EXECUTION frames, doors & windows, square, plumb, straight
Door and window lintels correct- level and size
Check wall ties, Anchors, Horizontal reinforcing
mesh installed correct- type and spacing
Control joints- size and type correct
Pointing of bed joints
Check walls- Plumb, line, alignment correct
Chasing of block walls or formation of holes
Ensure MEP works/ services completed
FOR S/C QA/QC FOR CONTRACTOR QA/QC FOR DG-DC REP
Name: Name: Name:

Sign: Date: Sign: Date: Sign: Date:

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