Material Quality Control and Supervision

Background

 Site Clearance
 Earth work
 Embankment Construction
 Earthwork in Cutting
 Sub grade Construction
 Sub base
 Base
 Surfacing
 Structural Works
 Site Clearance
 The road land should be cleared of all materials unsuitable for the work by cutting, trimming, removing
and disposing of all materials, such as trees, bushes, shrubs, stumps, roots, grass, weeds, top organic soil
not exceeding 150 mm in thickness and rubbish, etc. This should be carried out well in advance of
earthwork operations.

 The top soil removed during clearing and grubbing of site, if suitable for re-use shall be transported,
conserved and stacked for re-use.

 All trees, stumps, etc. falling within the excavation and embankment lines should be cut to such depth
below ground level that in no case these fall within 500 mm of the sub-grade. Beyond these limits, they
need to be cut down to 500 mm below ground level.

 Excavations below the ground level arising out of removal of trees, stumps, etc., should be filled in layers
with suitable material and compacted to the specified density given by the Engineer.

 Measurement of trees having girth more than 300 mm should be done as per sizes given in the Bill of
Quantities (BOQ)

 Ant-hills both above and below the ground shall be removed by excavating to a suitable depth as directed
by the Engineer. Cavities in the ground after removal of ant-hills shall be filled with appropriate material
and properly compacted to the specified density.

 Existing structures which are within the road land and designated for removal should be dismantled
carefully and the resulting materials so removed as not to cause any damage to the serviceable materials to
be salvaged, the parts of the structure to be retained and any other adjoining properties and utilities.

 Holes and depressions caused by dismantling operations or caused by rats etc. shall be backfilled with
approved material and compacted to the required density.
Site Clearance
 Earth work
Embankment Construction
 Obtain materials (soil) for embankment from approved sources. Preference should be given to materials
that are suitable and become available from nearby road excavation.
 Remove stagnant water, if any, from the foundation of the embankment

 The size of the coarse material in the mixture of earth used for embankment construction should ordinarily
fulfill ERA’s specification requirement

 The soil should be spread over the entire width of the embankment in layers not exceeding 150 mm
compacted thicknesses. The clods should be broken to less than 75 mm size. Each layer at moisture
content within (±) 2 % of the optimum moisture content should be thoroughly compacted by roller, to the
specified requirements as set forth in ERA Technical Specification and finished parallel to the final cross-
section of the embankment. (Compacted layer thickness can be increased up to 200 mm if heavy vibratory
rollers are used)

 Compaction of soil should be done at OMC with a tolerance limit of (±) 2 percent. If the moisture content
of soil is outside these limits, it shall be made good by adding water or drying by aeration and exposure to
sun till the moisture content is acceptable for compaction

 Each layer should be compacted to at least 97 percent of the Standard Proctor Density. The top 300 mm of
the embankment constituting the sub grade should be compacted to 100 percent Standard Proctor Density

 Approval of the Engineer should be obtained for each finished layer. Subsequent layers shall be placed
only after the finished layer has been tested and accepted by Engineer. (Such an approval would require
surface level and compaction control tests)
Earth work
Embankment Construction
 Obtain materials (soil) for embankment from approved sources. Preference should be given to materials that are
suitable and become available from nearby road excavation.
 Remove stagnant water, if any, from the foundation of the embankment

 The material used in embankment, sub-grade, shoulders, etc. shall be soil, moorum, gravel, a mixture of these or
other material approved by the Engineer. It shall be free from logs, stumps, roots, rubbish, etc.
 The following types of material shall be considered unsuitable:-

– Material from swamps, marshes and bogs

– Peat, log, stump and perishable materialMaterials susceptible to spontaneous combustion
– Clay having liquid limit exceeding 70 and plasticity index exceeding 45
– Material with salts resulting in leaching action e.g. sodic soils (pH > 8.5)
– Expansive clay with free swelling index exceeding 50 per cent
– Materials in a frozen condition
– Fill materials with a soluble sulphate content exceeding 1.9 gm of sulphate, (expressed as SO3) per liter, if
deposited within 500 mm or other distance described in the Contract, of concrete, cement bound materials
or other cementitious materials forming part of permanent works
– Material with a total sulphate content (expressed as SO3) exceeding 0.5 per cent by mass, if deposited
within 500 mm or other distance described in the Contract, of metallic items forming part of permanent
works

 The size of coarse material shall not ordinarily exceed 75 mm when placed in embankment and 50 mm when
placed in sub-grade

 Only the materials satisfying the density requirements given in the Technical Specification should be used for the
embankment.
 The embankment shall be compacted to satisfy the density requirements given in the Technical Specification
(ERA, Others...)
 Earth work
Embankment Construction

 Material quality Requirements for borrow material, Earth work for embankment and subgrade construction
 The material used in embankment, sub-grade, shoulders, etc. shall be soil, moorum, gravel, a mixture of these or other
material approved by the Engineer. It shall be free from logs, stumps, roots, rubbish, etc.

 Soil Classification Tests

– Sieve Analysis
– LL, PL, and PI

 Standard Proctor Compaction Test results to ascertain Dry-Density/Moisture Relationship

 Free swell Index Test

– Deleterious Content
– Organic matter content by los-on-ignition method

 Total soluble sulphate content where suspected on past experience. This can easily confirmed by quick test using
barium chloride

 CBR Test Soaked/unsoaked as per specification

 Granular Sub-base

 Gravel material to be used for sub-base shall be obtained from approved sources in borrow areas, cuts or existing
pavement layers. The complete sub-base shall contain no material having a maximum dimension exceeding two-thirds
of the completed layer thickness. Gravel Sub-base material shall, unless otherwise stated, conform to the following
requirements.
 Granular Sub-base
Grading Limits
 The sub-base material shall comply with one of the grading shown in the following Table as described in
the Contract. The material shall have a smooth continuous grading within the limits for grading A, B or C
given below.

Grading Modulus

The minimum Grading Modulus shall be 1.5 except where a material, having a lower Grading
Modulus but not less than 1.2, is approved for use by the Engineer.
 Granular Sub-base
Plasticity Index

 All sub-base materials shall have a maximum Plasticity Index of 6 or 12, as described in the Contract, and when
determined in accordance with AASHTO T-90. The plasticity product (PP = PI x percentage passing the 0.075mm
sieve) shall not be greater than 75.

California Bearing Ratio (CBR)

• The minimum soaked Californian Bearing Ratio (CBR) shall be 30% when determined in accordance with the
requirements of AASHTO T-193. The Californian Bearing Ratio (CBR) shall be determined at a density of 95% of the
maximum dry density when determined in accordance with the requirements of AASHTO T-180 method D.

Compaction Requirements

• The minimum in- situ dry density of sub-base material shall be as specified hereinafter for the layers in terms of a
percentage of modified AASHTO density.
(i) 95% or 97% as required for material not chemically stabilized.
(ii) 95% or 96 % as required for chemically stabilized material.

Los Angeles Abrasion

• The Los Angeles abrasion value shall not exceed 51% when determined in accordance with the requirements of
AASHTO T-96.
 Material Requirements for Crushed Stone Sub-base

 The aggregate used for crushed stone sub-base shall be derived from a parent rock that is hard, sound,
durable, and un weathered. It shall be obtained from sound rock from an approved quarry or clean sound
boulders. It shall contain no deleterious material such as decomposed rock, clay, shale, or mica. The
crushed aggregate shall comply with the following requirements:
Grading Limits
 The grading of the crushed stone sub-base shall comply with one of the gradings shown in Table 5105/1 as
described in the Contract, or as approved or directed by the Engineer. The grading shall follow a smooth
curve without any marked gaps or excessive quantities at a particular size, unless specified otherwise.
 Crushed Stone Sub-base
Grading Modulus

• The minimum Grading Modulus shall be 1.5 except where a material, having a lower Grading Modulus but
not less than 1.2, is approved for use by the Engineer.

Plasticity Index
 The Plasticity Index shall not exceed 6.
Compaction Requirements
• The minimum dry density to which the material shall be compacted shall be 95% unless specified otherwise, shown on
the drawings or ordered by the Engineer, of the maximum dry density as determined by AASHTO T 180. Field dry
densities shall be determined by the sand replacement method as specified in AASHTO T 191 or nuclear method as
specified in AASHTO T 238.
Los Angeles Abrasion

• The Los Angeles abrasion value shall not exceed 45% when determined in accordance with the requirements of
AASHTO T-96.

Particle shape; Flakiness Index

The flakiness index, determined by testing in accordance with BS812, Part 105 or ASTM D 3398, shall not exceed 35.
Road Base Material Types

 materials used for the construction of road base layers shall be one of the
following as described in the Contract:-

• Crushed Rock or Stone;

• Naturally occurring Granular Materials, Boulders,
Weathered Rock;
• Dense Bitumen Macadam.
Crushed Stone as Road Base Material

Grading Limits
 Crushed Stone as Road Base Material
Plasticity Index

 The fine fraction of a GB1 material shall be non-plastic or shall have a maximum Plasticity Index of 6
when determined in accordance with AASHTO T-90.

California Bearing Ratio (CBR)

• The in- situ dry density of the placed material should be a minimum of 98% of the maximum dry density
obtained in the ASTM Test Method D 1557 (Heavy Compaction). The compacted thickness of each
layer should not exceed 200 mm. Crushed stone base courses constructed with proper care with GB1
materials described above should have CBR values in excess of 100 per cent.

Aggregate Crushing Value (ACV)

• Requirements expressed in terms of the results of the Aggregate Crushing Value (ACV)(British Standard
812, Part 110) may be used: the ACV should preferably be less than 25 and in any case less than 29.
Other simpler tests e.g. the Aggregate Impact Test (British Standard 812, Part 112, 1990) may be used
in quality control testing provided a relationship between the results of the chosen test and the Ten
percent Fines Value (TFV) has been determined.
Crushed Stone as Road Base Material
Mechanical Strength Requirements (TFVT)
 To ensure that the materials are sufficiently durable, they should satisfy the criteria given in Table 5200/2.
These are a minimum Ten Per Cent Fines Value (TFV) (British Standard 812, Part 111) and limits on the
maximum loss in strength following a period of 24 hours of soaking in water. The likely moisture conditions
in the pavement are taken into account in broad terms based on annual rainfall.

Flakiness Index

The flakiness index shall not exceed 30% when determined in accordance with BS 812 Part 105-1990.
 Material Requirements for Naturally Occurring Granular
Materials, Boulders, weathered Rock for Road Base
 The aggregate used for crushed stone sub-base shall be derived from a parent rock that is hard, sound, durable, and
un weathered. It shall be obtained from sound rock from an approved quarry or clean sound boulders. It shall contain
no deleterious material such as decomposed rock, clay, shale, or mica. The crushed aggregate shall comply with the
following requirements:
 Graded Natural Gravel (GB2, GB3): A wide range of materials including lateritic, calcareous and quartzitic gravels,
river gravels, boulders and other transported gravels, or granular materials resulting from the weathering of rocks can
be used successfully as base course materials. The material shall be of such a nature that it can be readily
transported, spread and compacted without segregation.

Grading Limits
Material Requirements for Naturally Occurring Granular Materials,
Boulders, weathered Rock for Road Base

Plasticity Index
 The fine fraction of a GB1 material shall be non-plastic or shall have a maximum Plasticity Index of 6 when determined
in accordance with AASHTO T-90. If the PI approaches the upper limit of 6, it is desirable that the fines content be
restricted to the lower end of the range. To ensure this, a maximum PP of 60 is recommended or alternatively a
maximum Plasticity Modulus (PM) of 90 where: PM = PI x (percentage passing the 0.425 mm sieve) If difficulties are
encountered in meeting the plasticity criteria, consideration should be given to modifying the material by the addition of
a low percentage of hydrated lime or cement.

Californian Bearing Ratio (CBR)

• When used as a base course, the material should be compacted to a density equal to or greater than 98 per cent of the
maximum dry density achieved in the ASTM Test Method D 1557 (Heavy Compaction). When compacted to this density
in the laboratory, the material should have a minimum CBR of 80% after four days immersion in water (ASTM D 1883).
Material Requirements for Naturally Occurring Granular Materials,
Boulders, weathered Rock for Road Base
Aggregate Crushing Value (ACV)

Minimum soaked Ten percent Fines Value (TFV) Value (BS 812, Part 111) shall be 50 KN.

Abrasion

The Los Angeles Abrasion value, determined by testing in accordance with AASHTO T96 shall not exceed 45
at 500 revolutions unless otherwise specified in the Project Specifications.

Flakiness Index

The flakiness index shall not exceed 30% when determined in accordance with BS 812 Part 105-1990.

Crushed Ratio

The crushed ratio shall be a minimum of 60%.

Grading Modulus

The minimum Grading Modulus for material once placed and compacted on the road shall be:-

 For natural material. . . . . . . . . . . . . . . . . . ………. . 2.00

 For material to be chemically stabilized. . . . . . . . . . 1.75
 Material Requirements for Naturally Occurring Granular
Materials, Boulders, weathered Rock for Road Base

Aggregate Crushing Value (ACV)

Minimum soaked Ten percent Fines Value (TFV) Value (BS 812, Part 111) shall be 50 KN.

Abrasion

The Los Angeles Abrasion value, determined by testing in accordance with AASHTO T96 shall not
exceed 45 at 500 revolutions unless otherwise specified in the Project Specifications.

Flakiness Index

The flakiness index shall not exceed 30% when determined in accordance with BS 812 Part 105-
1990.

Crushed Ratio

The crushed ratio shall be a minimum of 60%.

Grading Modulus

The minimum Grading Modulus for material once placed and compacted on the road shall be:-

 For natural material. . . . . . . . . . . . . . . . . . ………. . 2.00

 For material to be chemically stabilized. . . . . . . . . . 1.75
Priming material

 The priming material shall be one of the following as specified or as directed by the Engineer: MC-30, MC-
70, or MC-250 cutback bitumen complying with AASHTO M 81 or M 82, as applicable;

 Invert bitumen emulsion complying with SABS 1260

Mineral Aggregate for Blinding

 The aggregate used for blinding the primed surface shall consist of crushed rock or river sand, with 100%
passing the 6.7 mm sieve and not more than 10% passing the 2.36 mm sieve. The aggregate shall be
clean, hard and free from excessive dust. It shall contain no clay, loam, or other deleterious matter.
Tack coat material

The material used for tack coats shall be one of the following as specified or as directed by the Engineer:-

 RC-70 cutback bitumen complying with AASHTO M 81 or M 82, as applicable;

 Bitumen emulsion complying with AASHTO M-140 or M-208

Water for the Production of Bitumen Emulsion (emulsified asphalt)

Water used for the production of bitumen emulsion (emulsified asphalt) shall comply with
the requirements of water quality type A.
Tack coat

WEATHER AND OTHER LIMITATIONS

No tack coat shall be applied under the following adverse conditions:

 during foggy or wet conditions;

 when rain is imminent;
 when wind is sufficiently strong to cause uneven spraying;
 when the surface of the layer is wet or damp;
 when the temperature of the surface of the layer immediately prior to
commencing
 the application of the tack coat is below 200 C;
 when the air temperature immediately prior to commencing the application of
the
 tack coat is below or, in the opinion of the Engineer, likely to fall below 100 C;
 after sunset.

The Engineer's decision on whether or not to apply the tack coat under specific
weather
conditions shall be final.
Tack coat
Conventional Bituminous Binders

Bituminous binders shall comply with the following specifications:

 Penetration-grade bitumens AASHTO M 20
 Cutback bitumens AASHTO M 82
 Anionic bitumen emulsions (emulsified asphalts) AASHTO M 140
 Cationic bitumen emulsions (emulsified asphalts) AASHTO M 208

Spray-grade bitumen emulsions shall be subject to the following viscosity

requirements:

 Anionic spray-grade emulsion (60 %): minimum 12 degrees Engler

at 20O C
 Cationic spray-grade emulsion (60, 65, 70 %): minimum 80 seconds
Saybolt Furol at 50O C
Cationic Modified Bitumen Emulsion
 Chippings for Surface Treatments
1. Grading:-Single Sized Crushed Aggregate Grades 1, 2 and 3
Sands for Surface Treatments
 Chippings for Surface Treatments

2. Hardness
The Los Angeles Abrasion value, determined by testing in accordance with AASHTO T96
shall not exceed 30 at 500 revolutions unless otherwise indicated in the project
specifications.
The 10% FACT value (dry) shall be at least 210 kN and the wet to dry ratio shall be at least
75%.
The polished stone value (PSV) shall be at least 50 unless otherwise indicated in the project
specifications.
3. Shape
The flakiness index, determined by testing in accordance with BS812, Part 105 or ASTM D
3398, shall not exceed the values in Table 6300A/10.

If so required for special purposes the average least

dimension (ALD) shall be as indicated in the project
specifications.
 Chippings for Surface Treatments

4. Soundness

The sodium sulfate soundness value, determined by testing in accordance with AASHTO T
104, shall not exceed 12.
 Aggregates for Slurry Seal

The aggregate for slurry seal shall be approved crusher sand obtained from a parent rock
having a Los Angeles Abrasion value not exceeding 40 or a mixture of crusher sand and
approved clean natural sand where the mixture contains not more than 25% of natural sand.
The aggregate shall be clean, tough, durable, angular in shape, and shall conform to the
following grading requirements:
Aggregates for Slurry Seal
Minimum Road Surface Temperatures for Spraying Binder
Moisture Content

No surface treatment shall be placed unless the moisture content of the upper 50 mm of
the
road base is less than 50% of the optimum moisture content of the road base as
determined by
the Engineer.

To prevent the trapping of water in the pavement structure, after prolonged or

intense rain no seal or reseal shall be placed on an existing partly cracked and/or highly
permeable surfacing for a period of at least 24 hours or such extended period as
determined
by the Engineer.

Curing Periods

Unless otherwise indicated in the project specification, the following curing periods shall
apply to the various treatments listed prior to applying a seal or reseal:
Texturing using fine slurry................................................6 weeks
Rapid setting slurry .........................................................12 weeks
Crack sealing .....................................................................2 weeks
Repair of distressed patches..............................................6 weeks
CUTTINGBACK OF BITUMEN

The cutting back of bitumen will only be allowed where authorised by the Engineer
and in
accordance with Engineer’s requirements. Only approved kerosene shall be used
for cutting
back. Addition of kerosene
Storage and spraying temperature for bituminous binders
Spaying temperature limits for bituminous binders
Surface Treatment Works---

Minimum testing frequencies

 Single Surface Treatment Works---

Average Least Dimension

Nominal Application Rates for Chippings and Conventional Binders

Double Surface Treatment Works---
Average Least Dimension

Nominal Rates of Application for the First Layer

Nominal Rates of Application for the Second Layer

 Double Surface Treatment Works---

Average Least Dimension

Nominal Rates of Application for the First Layer

Nominal Rates of Application for the Second Layer

 Structural Works---

Select Granular Backfill Gradation

Cement

Cement used for structures shall be either ordinary Portland or sulphate resisting cement
complying with the requirements of AASHTO M-85 or blended hydraulic cement complying
with the requirements of AASHTO M-240.

Maximum amount of deleterious substances

 Structural Works---
Grading of Fine Aggregate

Nominal Size and Grading of Coarse Aggregate

 Structural Works---
Grade of Concrete for Structures

Nominal Mixes
 Structural Works---
Grade of Concrete for Structures

Minimum Period Before Striking Formwork for Concrete for

Structures
 Structural Works---

Minimum Period Before Striking Formwork for Concrete for Structures

 Structural Works---

Minimum Period Before Striking Formwork for

Concrete for Structures