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Technical Specifications
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TABLE OF CONTENTS
SCOPE OF WORKS ............................................................................................................................. 12
A 101. Introduction .............................................................................................................................. 13
A 102. Limits of Site ............................................................................................................................ 13
A 103. Kilometre Referencing System ................................................................................................ 13
A 104. Scope of Works ....................................................................................................................... 13
SECTION 4B: DESIGN SPECIFICATION ........................................................................................... 14
B 101. Introduction .............................................................................................................................. 15
PART 1: GENERAL DESIGN OBLIGATIONS .................................................................................... 16
B 102. Design Responsibility .............................................................................................................. 16
B 103. Contractor´s Documents.......................................................................................................... 16
B 104. Technical Standards and Regulations ..................................................................................... 17
PART 2: SURVEYS AND INVESTIGATIONS ..................................................................................... 18
B 105. Topographical Surveys ............................................................................................................ 18
B 106. Axle Load Survey .................................................................................................................... 23
B 107. Bridge Foundation Ground Investigation ................................................................................. 23
PART 3: DESIGN ................................................................................................................................. 25
B 108. Highway Design ....................................................................................................................... 25
B 109. Pavement Road Design............................................................. Error! Bookmark not defined.
B 110. Drainage Design ...................................................................................................................... 27
B 111. Design of Protection Works ..................................................................................................... 28
B 112. Bridge Design .......................................................................................................................... 31
B 113. Retaining Wall Design ............................................................................................................. 33
B 114. Road Furniture Design ............................................................................................................ 33
B 115. Road Marking Design .............................................................................................................. 34
SECTION 4C : CONSTRUCTION SPECIFICATION .......................................................................... 36
SECTION C 100: PRELIMINARIES ..................................................................................................... 37
PART 1 .................................................................................................................................................. 39
Health and Safety ................................................................................................................................. 39
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Protection of the Environment: General ............................................................................................... 40
Protection of the Environment: Particular Requirements ..................................................................... 41
Programme Error! Bookmark not defined.
Methods of Construction: Method Statements ..................................................................................... 43
Setting Out 44
Quality Control and Quality Assurance ................................................................................................ 44
Approval of Suppliers ........................................................................................................................... 44
Materials: Alternative Standards .......................................................................................................... 45
Temporary Works ................................................................................................................................. 45
Traffic Safety and Control ..................................................................................................................... 45
Temporary Road Diversions ................................................................................................................. 46
Existing Services and Service Diversions ............................................................................................ 46
Restriction on Working Hours ............................................................................................................... 47
Landmines and Unexploded Ordinance ............................................................................................... 47
Graves and Burial Sites ........................................................................................................................ 47
Local Liaison and Consultation ............................................................................................................ 47
‘As Built’ Drawings ................................................................................................................................ 48
PART 2: FACILITIES AND SERVICES FOR THE ENGINEER AND EMPLOYER ............................. 49
Facilities and Services to be Provided ................................................... Error! Bookmark not defined.
Project/ Site Offices ................................................................................ Error! Bookmark not defined.
Office Accommodation ........................................................................... Error! Bookmark not defined.
Office Equipment .................................................................................... Error! Bookmark not defined.
Office Consumables ............................................................................... Error! Bookmark not defined.
Survey Equipment ................................................................................................................................ 50
Site Cabins Error! Bookmark not defined.
Residential Accommodation ................................................................... Error! Bookmark not defined.
Overnight Site Accommodation .............................................................. Error! Bookmark not defined.
Newly Purchased Vehicles ................................................................................................................... 50
Radio Communication Facilities ............................................................. Error! Bookmark not defined.
Insurance and Ownership....................................................................... Error! Bookmark not defined.
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Maintenance and Security .................................................................................................................... 52
Office Consumables and Telephone Charges ....................................... Error! Bookmark not defined.
Progress Photographs ............................................................................ Error! Bookmark not defined.
Works Signboards .................................................................................. Error! Bookmark not defined.
Measurement and Payment ................................................................... Error! Bookmark not defined.
SECTION C 200: QUALITY CONTROL ............................................................................................... 53
Scope of Section .................................................................................................................................. 53
Quality Control Plan .............................................................................................................................. 54
General Requirements in Respect of Testing ...................................................................................... 54
PART 1: LABORATORY / FIELD TESTS AND PROCEDURES ......................................................... 55
SOILS, GRAVELS AND AGGREGATES ............................................................................................. 55
Sampling and Preparation of Samples ................................................................................................. 55
Standard Methods of Testing ............................................................................................................... 55
Cement or Lime Treated Materials ....................................................................................................... 56
Stone, Aggregates, Sand and Filler ..................................................................................................... 56
Average Least Dimension .................................................................................................................... 57
The Quantab Test ................................................................................................................................. 58
PORTLAND CEMENTS AND CONCRETES ....................................................................................... 59
Portland Cement ................................................................................................................................... 59
Concrete 59
BITUMINOUS MATERIALS .................................................................................................................. 59
Bituminous Binders ............................................................................................................................... 59
Cut-back Bitumen ................................................................................................................................. 61
AASHTO T201 ...................................................................................................................................... 61
Bituminous Mixes ................................................................................................................................. 61
Loss of Stability: Alternative Test ......................................................................................................... 62
REINFORCEMENT STEEL................................................................................................................... 62
Reinforcing Steel .................................................................................................................................. 62
Prestressing Steel ................................................................................................................................ 62
PART 2: CONSTRUCTION CONTROL TESTING AND QUALITY ASSURANCE ............................. 63
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Construction Control ............................................................................................................................. 63
Frequency of Testing ............................................................................................................................ 63
Earthworks 63
Pavement Materials .............................................................................................................................. 63
Concrete Works 65
Quality Control of Concrete Production ................................................................................................ 66
Records of Concrete Placing ................................................................................................................ 69
Testing Requirements (Reinforcement) ............................................................................................... 70
Abbreviations 71
SECTION C 300: SETTING OUT AND TOLERANCES ....................................................................... 72
PART 1: PAVEMENT CONSTRUCTION ............................................................................................. 73
Horizontal Alignment ............................................................................................................................ 73
Thickness of Pavement Layers ............................................................................................................ 73
Surface Layers 73
Surface Regularity ................................................................................................................................ 73
Rectification 73
PART 2: CONCRETE STRUCTURES .................................................................................................. 75
Concrete Structures .............................................................................................................................. 75
SECTION C 400: SITE CLEARANCE .................................................................................................. 76
Site Clearance 77
Demolition of Bridges and Culverts ...................................................................................................... 78
Replacement of Bearings by Jacking ................................................................................................... 80
Removal of Road Furniture .................................................................................................................. 80
Removal of Culvert End Structures ...................................................................................................... 80
Removal of Abandoned Military Tanks, Military Vehicles and other Vehicles ..................................... 80
Measurement and Payment ................................................................................................................. 81
SECTION C 500: EARTHWORKS ....................................................................................................... 82
Scope of Section .................................................................................................................................. 83
Classification of Materials ..................................................................................................................... 83
Excavation of Topsoil ........................................................................................................................... 84
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Preparation Prior to Deposition of Fill ................................................................................................... 84
Construction of Embankments ............................................................................................................. 85
Capping Layer 85
Widening of Existing Embankments ..................................................................................................... 85
Compaction of Earthworks ................................................................................................................... 86
Sub-formation 86
Geotextile Membrane ........................................................................................................................... 86
Structural Excavation ............................................................................................................................ 86
Structural Backfill .................................................................................................................................. 87
Benching 87
Preparation of Formation ...................................................................................................................... 87
Trimming of Embankment Slopes ........................................................................................................ 88
Trimming of Existing Cut Slopes .......................................................................................................... 88
Resoiling 88
Watercourses and Side Drains ............................................................................................................. 88
Scarification of Existing Pavement ....................................................................................................... 88
Reinstatement of Batter Slopes ............................................................................................................ 89
Measurement and Payment ................................................................................................................. 89
SECTION C 600: CULVERTS, DRAINAGE AND PROTECTION WORKS ........................................ 90
Scope of Section .................................................................................................................................. 91
General 91
Classification of Excavated Materials ................................................................................................... 91
Excavation for Culverts and Drainage Structures ................................................................................ 91
Structural Elements Cast Against Excavated Surfaces ....................................................................... 92
Backfilling for Culverts and Drainage Structures .................................................................................. 92
Bedding and Laying of Culverts ........................................................................................................... 92
Jointing 92
Waterproofing 92
Inlet and Outlet Structures .................................................................................................................... 93
Guiding Dams and Scour Checks ........................................................................................................ 93
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River Training and New Watercourses ................................................................................................. 93
Riprap 93
Grouted Stone Pitching ........................................................................................................................ 94
Carriageway Drainage Outlets ............................................................................................................. 94
Measurement and Payment ................................................................................................................. 95
SECTION C 700: GRANULAR PAVEMENT MATERIALS .................................................................. 96
(SUB-BASE, SHOULDERS AND CRUSHED STONE BASE) ............................................................ 96
Material Requirements ......................................................................................................................... 97
Field Trials 97
Subbase 98
Cement Stabilized Subbase ................................................................................................................. 98
Crushed Stone Base ............................................................................................................................ 98
Shoulders 100
Deposition and Compaction ............................................................................................................... 101
Measurement and Payment ............................................................................................................... 101
SECTION C 800: BITUMINOUS PAVEMENT WORKS ..................................................................... 102
Scope of Section ................................................................................................................................ 103
PART A: MATERIALS FOR ASPHALTIC CONCRETES .................................................................. 104
Bitumen 104
Aggregates for Asphaltic Concrete ..................................................................................................... 104
Adhesion Agents ................................................................................................................................ 105
PART B: ASPHALTIC CONCRETE MIX DESIGN ............................................................................. 106
Mix Design Procedure ........................................................................................................................ 106
Refusal Density Design ...................................................................................................................... 107
Grading Requirements ....................................................................................................................... 107
Physical Properties ............................................................................................................................. 108
Full Scale Production Trials ................................................................................................................ 108
Field Trials 108
PART C: ASPHALTIC CONCRETE PRODUCTION .......................................................................... 110
Storage of Bitumen ............................................................................................................................. 110
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Mixing 110
Preparation of Surfaces ...................................................................................................................... 111
Transportation and Deposition ........................................................................................................... 111
Field Density Requirements ............................................................................................................... 112
Joints 112
PART D: OTHER BITUMINOUS MATERIALS .................................................................................. 113
Double Layer Surface Dressing ......................................................................................................... 113
Cut-back Bitumen ............................................................................................................................... 118
Bitumen Emulsion ............................................................................................................................... 118
Prime Coat 118
Tack Coat 120
Application of Prime Coat and Tack Coat .......................................................................................... 120
PART E: PAVEMENT REPAIRS ....................................................................................................... 121
Patching 121
Crack Sealing 122
Regulating 123
Measurement and Payment ............................................................................................................... 123
SECTION C 900: CONCRETE WORKS ............................................................................................. 124
Scope of Section ................................................................................................................................ 125
Definitions 125
AASHTO Standards ........................................................................................................................... 125
PART A: MATERIALS FOR CONCRETE .......................................................................................... 126
Cement 126
Fine Aggregate 126
Coarse Aggregate .............................................................................................................................. 127
Water 128
Admixtures 128
Pozzolanic and Fly Ash admixtures ................................................................................................... 128
Reinforcement 129
PART B: DESIGN OF CONCRETE MIXES ........................................................................................ 130
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Classes of Concrete ........................................................................................................................... 130
Design of Concrete Mixes .................................................................................................................. 130
PART C: MANUFACTURE AND PLACING ....................................................................................... 133
Mixing 133
Transportation of Concrete ................................................................................................................. 133
Placing of Concrete ............................................................................................................................ 133
Protection of Concrete from the Environment .................................................................................... 134
Compaction of Concrete ..................................................................................................................... 135
Curing of Concrete ............................................................................................................................. 135
Construction Joints ............................................................................................................................. 136
Finishes on Unformed Surfaces ......................................................................................................... 137
Finishes on Formed Surfaces............................................................................................................. 137
PART D: FORMWORK and FALSEWORK ....................................................................................... 139
General Obligations ............................................................................................................................ 139
Falsework 139
Formwork 139
Removal of Formwork ........................................................................................................................ 140
PART E: REINFORCEMENT .............................................................................................................. 141
Bar Bending Schedules ...................................................................................................................... 141
Fixing 141
Splicing 141
Substitution by Bars of Different Sizes ............................................................................................... 142
Cover 142
PART F: PILING ................................................................................................................................. 143
General 143
Pile Tests 143
PART G: MISCELLANEOUS.............................................................................................................. 145
Mortar and Grout ................................................................................................................................ 145
Grouting of Pockets and Holes ........................................................................................................... 145
Underpinning of Baseplates ............................................................................................................... 145
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Precast Concrete ................................................................................................................................ 146
Placing Concrete under Water ........................................................................................................... 146
Sulphate Resisting Concrete .............................................................................................................. 146
Interruptions to Placing ....................................................................................................................... 147
Remedial Work to Defective Concrete ............................................................................................... 147
Waterproofing Buried Concrete Surfaces ........................................................................................... 147
Waterstops 148
Measurement and Payment ............................................................................................................... 148
SECTION C 1000: PRESTRESSED PRE-TENSIONED CONCRETE ............................................... 149
General 150
Submission of Working Drawings ....................................................................................................... 150
Prestressing Wire and Strand ............................................................................................................ 150
Testing 151
Prestressing Operations ..................................................................................................................... 151
SECTION C 1100: CONCRETE REPAIRS ........................................................................................ 153
General 154
Scope of Repair Works ....................................................................................................................... 154
Surface Cleaning ................................................................................................................................ 154
Removal of Existing Concrete ............................................................................................................ 155
Reinforcement 155
Replacement Concrete ....................................................................................................................... 156
Repair Concrete to Beam Soffits ........................................................................................................ 156
Polymer Modified Mortar .................................................................................................................... 157
Impregnation 157
Epoxy Mortar 158
Replacing Handrails ........................................................................................................................... 159
Footpath Repairs ................................................................................................................................ 160
SECTION C 1200: MISCELLANEOUS BRIDGE WORKS ................................................................ 162
Bridge Bearings: General ................................................................................................................... 163
Elastomeric Bearings .......................................................................................................................... 163
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Hot Poured Elastic Type Expansion Joints ........................................................................................ 164
Strip Type Expansion Joints ............................................................................................................... 165
Filler-Type Expansion Joints .............................................................................................................. 165
Bridge Deck Waterproofing ................................................................................................................ 166
Paint for Structural Steelwork ............................................................................................................. 166
Galvanised Coatings .......................................................................................................................... 166
SECTION C 1300: ROAD FURNITURE ............................................................................................. 167
General 168
Retroreflective Material for Permanent Road Signs ........................................................................... 168
Permanent Road Signs ...................................................................................................................... 169
Guardrail 169
Kerb and Drainage Offlets .................................................................................................................. 170
Measurement and Payment ............................................................................................................... 172
General 172
Equipment 172
Application of Road Markings ............................................................................................................. 173
Retroreflective Studs .......................................................................................................................... 173
Tolerances for Thermoplastic Road Markings.................................................................................... 174
Measurement and Payment ............................................................................................................... 174
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Section A: SCOPE OF WORKS
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A 101. Introduction
This section of the Technical Specifications defines the scope of the Works to be designed
and constructed under the Contract. The details contained in this section shall be read in
conjunction with Drawings included in this section.
Specifications for the design of the Works are contained in the following Section 4B.
Specifications for the construction of the Works are contained in the following Section 4C.
A 102. Limits of Site
The roads that comprise the Site of the Permanent Works to be designed and
constructed are NASAJI GULBAHAR TO SANJAN ( Koh Band district,
Kpisa province) 7+530 KM Road
A 103. Kilometre Referencing System
The kilometer referencing system described above is based on preliminary surveys. All
kilometer reference points and road lengths given in Bidding Document are not to be
considered as precise and they may be amended by the Contractor after completing the
detailed topographical survey that forms part of the design works.
A 104. Scope of Works
The scope of works to be designed and constructed under the Contract shall include the
following:
(i) NASAJI GULBAHAR TO SANJAN ( Koh Band district, Kpisa
province) 7+530 KM Road
which shall include:
(a) Preliminaries;
(b) Earthworks
(c) Culverts and Drainage Works;
(d) Pavement Works and
(e) Road furniture and markings
A 105 Mobilization at site is for the cost of establishing security, plant, equipment, facilities and
personnel upon the site. Provision and installation of two (2) sub-project sign boards as directed by the
Engineer.
A106 Demobilization from site shall be compensation in full for the costs of removing plant,
equipment, facilities, personnel, and restoration of site.
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Section B: DESIGN SPECIFICATION
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B 101. Introduction
The Design Specification defines the Contractor’s general design obligations, and other
specific requirements related to surveys, investigations and design.
Part 1 of the Design Specification details the Contractor’s general design obligations.
Part 2 of the Design Specification details specific requirements in respect of surveys and
investigations that are to be carried out by the Contractor.
Part 3 of the Design Specification details design criteria and specific requirements in respect
of design that is to be carried out by the Contractor.
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PART 1: GENERAL DESIGN OBLIGATIONS
B 102. Design Responsibility
The Contractor shall carry out and be responsible for the design of the Works which shall be
carried out in accordance with the Design Specification and all other requirements of this
Contract.
On completion of the design, the Contractor shall provide a certificate to the Engineer
confirming that it has exercised due care in the preparation of the design.
The surveys and investigations to be carried out by the Contractor as detailed in Part 2 of the
Design specification are deemed to be part of the design of the Works.
Design shall be carried out by qualified designers who are professional engineers. For each
part of the Works, the prior consent of the Engineer shall be obtained to the designer and
design Subcontractor, if they are not named as such in the Contract. Nothing contained in the
Contract shall create any contractual relationship or professional obligations between any
designer, and design Subcontractor, and the Employer.
The Contractor holds itself, its designers and design Subcontractors as having the experience
and capability necessary for the design. The Contractor undertakes that the designers shall be
available to attend discussions with the Engineer at all reasonable times during the period of
the Contract.
B 103. Contractor’s Documents
The Construction Documents shall comprise of all design (including survey and investigation)
drawings, calculations, models, reports, and other manuals and information of a similar nature
that the Contractor shall prepare and submit to the Engineer as part of its design obligations.
The Contractor shall prepare the Construction Documents in sufficient detail to demonstrate
that it has complied with the requirements of the Contract, to satisfy all regulatory approvals,
to provide sufficient instruction to execute the Works. The Engineer shall have the right to
review and inspect the preparation of the Construction Documents, wherever they are being
prepared.
Each of the Construction Documents shall, when considered ready fore use, be submitted to
the Engineer for pre-construction review and for the Engineer’s consent. Each submission of
a Construction Document made by the Contractor in an agreed format and shall be
accompanied by notice that the Contractor considers the Construction Document ready for a
pre-construction review and for use. The Engineer shall have a review period of 28 days,
calculated from the date on which the Engineer receives a Construction Document to carry
out the pre-construction review and grant its consent. If the Engineer, within this review
period, notifies the Contractor that such Construction Document is incomplete or fails (to the
extent stated) to comply with the Technical Specifications, it shall be rectified, resubmitted
and reviewed in accordance with this Clause at the Contractor’s cost.
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For each part of the Works, and except to the extent that the prior consent of the Engineer
shall have been obtained:
(i) Construction shall not commence prior to the expiry of the review periods for the
Construction Documents which are relevant to the design and construction such part;
(ii) Construction shall be in accordance with such Construction Document; and
(iii) If its is necessary, the contractor could modify any design or document which has
previously been submitted for such pre-construction review, the Contractor shall
immediately notify the Engineer, and shall subsequently submit revised Documents to
the Engineer for pre-construction review and consent. Once the contractor’s
documents are approved it is not intended that they should be modified for the
convenience of the contractor. Modifications will be considered if: deemed necessary
by the engineer; if required by changed conditions or conditions not contemplated by
the initial contractor design; if required by updated codes and/or standards; or if the
original design proves to have significant constructability problems
If the Engineer instructs that further Construction Documents are necessary for carrying out
the Works, the Contractor shall upon receiving the Engineer’s instructions prepare such
Construction Documents.
If errors, omissions, ambiguities, inconsistencies and other defects are found in the
Construction Documents, they and the Works shall be rectified by the Contractor at its cost.
B 104. Technical Standards and Regulations
The design and the Construction Documents shall comply with the Country’s national
specifications, technical standards, building, construction and environmental regulations and
the standards quoted in the Technical Specifications. References in the Contract to such
specifications or standards shall be understood to be references to the edition applicable on
the Contract Commencement Date. If substantially changed or new applicable national
specifications, technical standards or regulations come into force after the Contract
Commencement Date, The Contractor shall submit proposals for compliance to the Engineer.
In the event that the Engineer determines such proposals to be a variation, the Engineer shall
then initiate a Variation in accordance with Clauses 13 of the Conditions of Contract.
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PART 2: SURVEYS AND INVESTIGATIONS
B 105. Topographical Surveys
General
The Contractor shall carry out the following topographical surveys:
(i) Topographical survey and level survey along all the alignments that have been
projected between the project sites and shall be plotted out on 1 to 2,000 scale
drawings;
(ii) Cross section survey of the road section
(iii) Topographical survey of the site of the new bridges, which shall be plotted out on 1 to
200 scale drawing(s).
Existing Survey Control Data
Translations of bench mark record sheets have been obtained from the Department of
Cartography and Geodesy in the areas adjacent to the Contract roads.
No recent inspection has been made to ascertain whether or not all the bench marks are still in
existence, and no check has been made on the national datum levels quoted on the bench
mark record sheets.
The Department of Cartography and Geodesy have no primary trigonometric points close to
the Works and the Contractor shall adopt a local grid system.
Primary Survey Control
Prior to the commencement of the topographic and level surveys, primary control monuments
shall be established along the full length of the section at nominal 5 km spacing. A primary
control survey shall then be carried out to determine X and Y co-ordinates of the primary
control monuments by traversing or by a GPS survey. The elevations of the primary control
monuments shall also be determined with reference to the existing National Datum and they
shall be tied into the existing National Datum benchmarks.
The primary control monuments shall be as follows:
(i) Monument centre shall be a stainless steel pin of 12 mm diameter.
(ii) Body of monument shall be concrete with 20Mpa strength, constructed to the
following dimensions: .
- Monument top surface: 40cm x 40cm
- Monument bottom: 50cm x 50cm
- Monument height: 50cm
- Monument base: 60cm x 60cm x 10cm
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Monuments shall be established at ground level in stable ground conditions in location where
they shall not be disturbed by the construction works and they shall be maintained throughout
the Contract Period. Sufficient space shall be provided around each monument to enable
survey instruments to be erected and operated.
Each monument shall be marked with its reference number, date of construction, elevation
and co-ordinates. A Survey Monument Description Sheet for each primary control
monuments shall be prepared to the format of the form shown in Appendix B2 and these
sheets shall form part of the Contractor’s Construction Documents.
The traverse survey connecting the primary control monuments shall be carried out using
theodolites, electronic distance meters (EDMs) or total station instruments. The elevation of
each monument shall also be recorded with reference to the Afghanistan National Datum.
Requirements for the traverse survey shall be as follows:
(i) horizontal angle measurement
(a) Horizontal angles shall be observed by 2 rounds of angle on 2 different zero
settings;
(b) a total station or theodolite instrument capable of reading horizontal and
vertical angles to at least 10 seconds shall be used;.
(ii) Distance measurement
an Electronic Distance Meter (EDM) shall be used for distance measuring, which shall
be accurate to at least 10mm + 5ppm x D;
Note: 5ppm: 5cm per 17.427.44km, D: measured distance)
(iii) accuracy of primary traverse
Linear miss-closure of the primary traverse shall be better than 1/10,000.
Requirements for a GPS (Global Positioning System) survey shall be as follows:
(i) GPS observation and measurement
(a) More than three GPS instruments shall be used which shall be capable of
reading to a horizontal and vertical accuracy of at least +5 ppm x distance
between primary control monuments (e.g. 5cm per 10km);
(b) Elevation mask shall be 15 degrees;
(c) Observations shall be made simultaneously at 3 points;
(d) Signals from more than 3 satellites shall be received at each point
simultaneously;
(e) Observations shall be made for more than 1 hour;
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(f) Maximum measured distance between observation points shall be 10 km;
(ii) Expected accuracy of GPS traverse
Mis-closure of GPS traverse shall be not more than 5ppm x measured distance.
Secondary Survey Control
The Contractor shall establish the secondary control points to provide a suitable basis for the
topographical and level survey of the roads and bridge site. The secondary control survey
shall then be carried out to determine X and Y co-ordinates of secondary control points by
traversing. The elevations of the secondary control points shall also be determined with
reference to the existing National Datum and they shall be tied into the existing National
Datum benchmarks via primary control monuments.
The secondary control points shall be spaced at maximum intervals of 500m and located so
that a minimum of two adjacent points are inter-visible. The secondary control points shall be
located to fully enclose the required area of topographic survey for the roads (scale: 1/2000),
and shall be at a sufficient distance from the proposed works so as not to be disturbed during
the construction. The location of points shall also be suitable for use in setting out.
The secondary control points shall be established at ground level in stable ground conditions
with the requirement that they remain stable during construction. Each point (monument)
shall be as follows:
(i) Control point centre shall be a stainless steel pin of 12mm diameter;
(ii) Body of control point shall be concrete with 20Mpa strength, constructed to the
following dimensions:
- point top surface: 20cm x 20cm
- point bottom: 30cm x 30cm
- point height: 40cm
Each secondary control point shall be marked with its reference number and date of
construction. A Survey Monument Description Sheet for each secondary control point shall
be prepared to the format of the form shown in Appendix B2 and these sheets shall form part
of the Contractor’s Construction Documents.
The requirements for horizontal angle measurement and distance measurement in the
secondary control point traverse survey shall be the same as those specified above for primary
control survey.
Linear miss-closure of secondary traverse shall be less than 1/8,000.
Leveling
Leveling shall be started from an existing National Datum benchmark, a primary control
monument or a secondary control point and closed to another of these benchmarks,
monuments or points.
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Requirements for the leveling survey shall be as follows:
(i) An automatic level or digital level shall be used;
(ii) miss-closure of leveling between existing National Datum benchmarks and primary
control monuments shall not exceed + 30 mm √D, where D is distance in kilometers
between existing National Datum benchmarks or Primary Control Monuments.
Topographical Survey of Roads (1 / 2,000)
A plan topographic survey shall be conducted to locate man-made features such as roads,
buildings, etc to prepare plans to a scale of 1 to 2000. and natural features such as creek,
canals, etc along the road section using the plan co-ordinates and heights of the primary
control monuments and secondary control points,. The minimum required features and details
to be surveyed are listed in Appendix B3. All features shall have elevations based on the
National Datum benchmarks.
The extent of the 1/2000 plan map survey shall be at least 30m either side of the existing road
highway centerline, and this survey corridor shall be extended as required to ensure that the
full extent of the existing road construction is covered.
Where features cannot be surveyed to the required accuracy without extensive clearing or due
to other obstructions, the Contractor will seek the instruction of the Engineer.
The line or point to be surveyed on a feature shall be at the features intersection with the
ground-surface unless otherwise instructed by the Engineer.
Any feature, which is in a state of change during the survey, will be annotated to this effect,
with the proposed boundary changes marked, if known.
The ground surface shall be surveyed to truly indicate any change in feature, vertical
alignment or horizontal alignment.
Appropriate references such as road section name, section limits (km-marks), north and east
co-ordinates, benchmarks and other important data shall be shown in the topographic plans
and profiles.
The requirements for the survey shall be as follows:
(i) an automatic-level, total station, EDM, theodolite, and surveying tape shall be used;
(ii) traversing points for the topographic survey shall be set up by closed traverse from the
control points;
(iii) the height of traversing points shall be obtained by closed leveling from control
points;
(iv) spot height point shall be measured and distributed uniformly 2 cm x 2 cm for the
1/2,000 scale mapping area;
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(v) accuracy of closed traverse:
linear mis-closure of closed traverse between control points shall be better than
1/5,000;
(vi) accuracy of closed leveling:
mis-closure of closed leveling between control points and traversing points shall be
within + 30 mm √K;
(vii) accuracy of radiation traverse and cross section survey:
positioning error and height error of spot height point shall be within + 5 cm from
traversing points;
(viii) minor control points established for the mapping survey shall not be permanently
marked.
(ii) Accuracy of cross section leveling:
(a) height error between beginning point, end point, curve point, and cross section
points on structures shall be within + 2 cm and the ground surface points shall be
within + 5 cm;
(b) distance error between beginning point, end point, or curve point and cross section
points shall be within + 5 cm.
Topographical Survey of Bridge Site
A survey of the site of the new bridges shall be carried out to prepare plans to a scale of 1 to
200. This survey shall cover the dry river bed for a minimum distance of 250 metres from the
bridge location, on the upstream side and 200 metres on the downstream side. All other
requirements for the survey shall be as specified above for the 1 to 2,000 scale topographical
survey of the roads.
Survey Drawings
The requirements for all survey plans shall be as follows:
(i) all survey drawings shall be prepared on A1 size drawing sheets;
(ii) names and annotations shall be aligned parallel to the gridlines except for names
relating to linear features which shall be aligned parallel with those features;
(iii) all final drawings shall be provided with a standard border of 50mm for the left
margin and 25mm for the remaining margins. Each drawing will be labelled with the
date of generation, and version number.
(iv) the overlap of adjacent drawings shall give a minimum overlap of 75mm of detail
common to each drawing and match lines shall be included on each drawing;
23
(v) the co-ordinates and heights of all primary control monuments, secondary control
points and the existing National Datum benchmarks within the survey limits shall be
shown on the drawings;
(vi) copies of the survey drawings shall be form part of the Contractor’s Construction
Documents.
The survey drawings shall be used as the base for the As-Built Drawings that the Contractor is
required to prepare.
B 106. Axle Load Survey
The survey shall be carried out for a minimum period of 12 hours on 4 consecutive days and
the wheel loads on each axle of a representative sample of the following vehicle
classifications in each direction shall be determined:
Buses: 2 axle and 3 axle;
Rigid Trucks: 2 axle and 3 axle;
Articulated trucks : 4 axle, 5 axle, 6 axle and more than 6 axle.
The electronic wheel measuring device shall be calibrated and checked using a standard load
weight at the start and finish of the survey.
The Contractor shall be responsible for all traffic management and temporary signing in order
that delays to traffic are minimised and vehicles to be weighed do not impede the safe passage
of other vehicles.
Equivalent standard axle (ESA) values shall be calculated for each vehicle weighed and
average ESA values for each of the vehicle classifications on each road shall be determined.
The detailed method of carrying out the axle load survey as well as the analysis and
presentation of the survey results and the method of calculating ESA values is to be in
accordance with the recommendations given in the Transport Research Laboratory Overseas
Road Note 31 “ A guide to the structural design of bitumen surfaced roads in tropical and sub-
tropical countries” fourth edition 1993 and the Transport and Road Research Laboratory Road
Note 40 “ Guide to the measurement of axle loads in developing countries using a portable
weighbridge” 1978.
B 107. Bridge Foundation Ground Investigation
The Contractor shall carry out a ground investigation at the sites of the new bridges to be
constructed to provide data for the design of the bridge foundations.
A minimum of 1 borehole shall be drilled at the location of each abutment and pier, to a depth
of at least 25 metres (in normal material). If rock is encountered, the drilling can be
terminated after penetrating the rock for a minimum depth of 3 metres.
In-situ standard penetration tests shall be carried out in each borehole.
24
The Bridge foundation ground investigation shall be carried out according to the AASHTO
Manual on Subsurface Investigations, 1988.
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PART 3: DESIGN
B 108. Highway Design
Highway Cross Section
The general highway cross section that shall be adopted is as follows:
Carriageway width to be 42meters.
Minimum carriageway cross fall of 2.0%
Foot path width to be 3 meters
Minimum shoulder slope of 4%
Horizontal Alignment
The designed horizontal alignment shall be a smooth flowing alignment that matches the
existing road alignment as closely as possible. This alignment is to be computed from survey
data collected during the topographical survey. Horizontal curves shall be designed to
comply with the geometric standards given in the AASHTO publication “A policy on
Geometric Design of Highways and Streets”, 4th edition (The Green Book) 2001, for a design
speed of 80 km/h for flat terrain, 60 km/h for rolling terrain, and 40 km/h for mountainous
terrain. In urban areas, the design speed may be reduced as required to enable the designed
alignment to follow the existing alignment.
Horizontal Alignment of the designed road are included :section 6 drawing
Vertical Alignment
Wherever possible, vertical curves shall be designed to comply with the geometric standards
given in the AASHTO publication “A policy on Geometric Design of Highways and Streets”,
4th edition (The Green Book) 2001, for a design of 80 km/h for flat terrain, 60 km/h for
rolling terrain, and 40 km/h for mountainous terrain. In the next page is shown the Table B01
with the main geometric design Standards Parameter that have to be adopted in the
construction of this road project.
Super elevation shall be designed to comply with the geometric standards given in the
AASHTO publication “A policy on Geometric Design of Highways and Streets”, 4th edition
(The Green Book) 2001, for a design speed of 80 km/h for flat terrain, 60 km/h for rolling
terrain, and 40 km/h for mountainous terrain
Vertical Alignments of the designed road are included: section 6 -drawing
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Table B01
Main Geometric Design Standards Parameter
Lay-byes
The Contractor shall design and construct new lay-byes on both sides of the road at intervals
of approximately 20+000 kilometers. The locations of the lay-byes shall be selected so as to
best meet the following requirements:
(i) lay-byes should be provided in pairs on each side of the carriageway, but they must
not be directly opposite each other. The lay-byes should be staggered by a minimum
distance of 50 meters so that the lay-bye on the driving side of the carriageway (right
hand side) is reached before the lay-bye on the opposite side (left hand side);
(ii) lay-byes should be located close to major junctions, wherever possible;
(iii) in open country, lay-bye locations should be selected to minimize earthworks.
The lay-byes are to have the following dimensions: (please review the dimension of a lay-bye.
It may be too big.)
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lay bye pavement to be 20000 meters long and 6 meters wide with 10 meter long entry
and exit taper sections;
Shoulder width to be 2 meters.
(i) The designed horizontal alignment shall be a smooth flowing alignment that matches
the existing road alignment as closely as possible. This alignment is to be computed
from survey data collected during the topographical survey. Horizontal curves shall
be designed to comply with the geometric standards given in the AASHTO
publication “A policy on Geometric Design of Highways and Streets”, 4th edition
(The Green Book) 2001, for a design speed of 100 kilometers per hour. In urban
areas, the design speed may be reduced as required to enable the designed alignment
to follow the existing alignment.
(ii) The designed vertical alignment shall be a smooth flowing alignment that runs parallel to the
existing vertical profile as closely as possible and provides for the construction of the designed
pavement layer thicknesses above the surface that results after existing asphalt layers have
been scarified and re-compacted or removed. Any regulation of this surface to meet the
designed vertical profile shall be carried out using the sub base material. The vertical profile
shall be designed to minimise the need for regulation with additional sub base material. In any
case, the maximum gradient for exceptional situation will be 18 %
Wherever possible, vertical curves shall be designed to comply with the geometric standards
given in the AASHTO publication “A policy on Geometric Design of Highways and Streets”,
4th edition (The Green Book) 2001, for a design speed of 80 km/h for flat terrain, 60 km/h for
rolling terrain, and 40 km/h for mountainous terrain
(iii) Super elevation shall be designed to comply with the geometric standards given in the
AASHTO publication “A policy on Geometric Design of Highways and Streets”, 4th edition
(The Green Book) 2001, for a design speed of 80 km/h for flat terrain, 60 km/h for rolling
terrain, and 40 km/h for mountainous terrain
The Contractor shall lease and coordinate with the contractors for the Rehabilitation of the
nearby Road projects to ensure that the horizontal and vertical alignments at the end point are
identical to those of the adjacent Contract.
B 109. Drainage Design
Inlet and Outlet Control at Culverts
Guiding ditches and guiding dams shall be provided wherever necessary to give an
unimpeded flow of water run off into and out of culverts.
The locations of guiding ditches shall be selected by site inspection and by reference to the 1
to 2,000 scale topographical survey plans.
Guiding ditches are to have a 3 meter wide invert and side slopes of 1.5 horizontal to 1
vertical.
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Guiding dams are to have a 3 meter wide crest and side slopes of 2.5 horizontal to 1 vertical.
The guiding dams are to be constructed to the same requirements as embankments (re. Clause
C 505).
Rehabilitation of Side Drainage in Cut Sections
Effective side drainage shall be provided in all cut sections to ensure no surface water run off
ponds against the carriageway and that all surface water run off is led away from the cut
section into culverts or towards ground that slopes away from the road.
This rehabilitation of side drainage shall involve:
(i) Removal of screen material and boulders from the foot of cut slopes;
(ii) Provision of retaining walls formed by gabion boxes at the foot of cut slopes at
locations where there is a likely hood of future falls of screen material;
(iii) Re-establishing unlined side drains adjacent to existing cut slopes.
The locations of these works shall be selected by site inspection and by reference to the 1 to
2,000 scale topographical survey plans.
B 110. Design of Protection Works
Protection works for embankment slopes, culvert inlets and outlets, river training works,
guiding dams and around bridge abutments and piers shall be provided where scour has
occurred or where there is a risk of future scour taking place.
Protection works shall be constructed using gabions, grouted stone pitching or rip rap in
accordance with the following requirements:
(i) Gabions
Gabion mattresses and boxes shall have galvanized steel wire mesh and shall be laid
on a geotextile filter membrane, which is suitable for the underlying soil. The
physical and dimensional properties of the stone filling shall conform to gabion
manufacturer’s recommendations.
(ii) Grouted Stone Pitching
Grouted stone pitching shall conform to the construction requirements contained in
clause C 615.
(iii) Rip rap
Rip rap protection shall conform to the construction requirements contained in clause
C 614 and shall be designed in accordance with the following procedure:
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(a) Rip rap for sloping surfaces
Size and weight of stones for pitching:
The size of the stone required on sloping surface to withstand erosive action of
flow is to be calculated by following equation:
d = Kv^2
Where d is the equivalent diameter of stone in meters,
V is the mean design velocity in meter/second,
And K is a constant and is to be taken as 0.0282 for face slope of 2:1 and
0.0216 for a face slope of 3:1.
The weight of the stone can be worked out by assuming a spherical shape stone
with a specific gravity of 2.65. However the minimum diameter of a stone
shall be 300mm. and the weight shall not be less than 40 kg.
Thickness of pitching:
The thickness of pitching is to be worked out by the following formula:
T= 0.06Q^1/3
Where T is the thickness of pitching and Q is the design discharge in
m^3/second.
Filter design
Filter provided below the boulders pitching shall consist of sound gravel,
stone, over burnt brick ballast and coarse sand. Geotextiles can also be used as
filter material.
(b) Rip rap for launching aprons or cut off blankets
The design of launching apron or cut off blanket shall be carried out based on
following considerations:
Size and weight of stone:
The size of stone required for launching apron is to be calculated based on
following formula-
V = 4.893x (d) ^1/2
Where V is the mean design velocity in meter/second and d is the equivalent
diameter of stone in meters.
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The weight of the stone can be worked out by assuming spherical shape of
stones having a specific gravity of 2.65. However the minimum diameter of
stone shall be 300mm. and the weight shall not be less than 40 kg.
Depth of scour
The maximum depth of scour for surfaces of the protection works is to be
determined as follows:
Up-stream curved surfaces 2.5 dsm
Straight surfaces upstream and downstream 1.5 dsm
Where dsm is the mean depth of scour
Width of launching apron:
A width of launching apron of 1.5 dmax is to be provided where dmax. Is the
maximum anticipated scour below the bed level in metres.
Thickness of launching apron:
The thickness of pitching is to be worked out by the following formula:
T= 0.06Q^1/3
Where T is the thickness of pitching and Q is the design discharge in
m^3/second.
The thickness of launching apron at inner end is to be kept as 1.50T and outer
end as 2.25T.
Slope of launching apron:
The slope of the launching apron is to be considered as 2 Horizontal and 1
Vertical for loose boulders and 1.50 Horizontal, 1 Vertical for gabions.
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B 111. Bridge Design
Structural Arrangement Requirements for New Bridges
The Contractor shall design the new bridges which intersect with the new projected road.
(i) Span Arrangement
(ii) Superstructure
(iii) Substructure
(iv) Bearings and Expansion Joints
Bearings shall be Pot c um PTFE type that meet the requirements of section 18 of the
AASHTO Standard Specifications for Highway Bridges, 17th Edition, 2002.
Expansion joints shall be strip seal type that meets the requirements of section 19 of
the AASHTO Standard Specifications for Highway Bridges, 17th Edition, 2002.
(v) Foundations
The foundations will be calculated once studied the geologic conditioners of the land
next to the bridge
(vi) `Miscellaneous
The surfacing for the bridge deck shall consist of:
(i) 6 mm thick layer of mastic asphalt laid on a bituminous prime coat over the
concrete deck. The mastic asphalt is to contain 75% lime stone dust filler and
25% of 30/40 penetration grade bitumen and it shall be laid at a temperature of
1900 C.
(ii) Two layers, each 25 mm thick, of asphalt wearing course.
Drainage spouts with gratings at the top surface shall be provided on the bridge to
ensure proper drainage of surface water.
An approach slab 3.50m long and 300mm thick resting on the bracket taken out from
the dirt wall shall be provided on both sides of the bridge, resting on a 150mm thick
leveling course. The gap between the approach slab and dirt wall shall be filled with a
bituminous joint filler sealing compound.
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Design Loading Requirements for New Bridges
The contractor shall design the bridges to sustain the most critical combination of the various
loads, forces and stresses that can coexist as given in the Standard Specifications for Highway
Bridges, 17th Edition, 2002. The allowable stresses and the permissible increase in stresses
for various load combinations shall be adopted as given in the relevant clauses of the
AASHTO Standard Specification for Highway Bridges.
Design loadings that shall be considered for bridge are as follows:
(i) Carriageway Live Load
The bridge shall be designed for a carriageway live load of HS20-44.
(ii) Longitudinal Force
The bridge shall be designed for the effect of a longitudinal force of 5% of the live
load in all lanes carrying traffic headed in the same direction. The centre of gravity of
the longitudinal force shall be assumed to be located 6 feet above the deck slab and it
shall be transmitted to the sub-structure through the super-structure.
(iii) Impact
The amount of impact shall be expressed as a fraction of live load stress and it shall be
calculated by the following formula:
I = 50/(L+125)
Where, I = impact fraction maximum 30 percent
L = length in feet of the portion of the span that is loaded to produce the
maximum stress in the member.
(iv) Footpath Live Load
The footpath live load shall be considered as 85 lb. / sq ft.
(v) Krebs Loading
Krebs shall be designed to resist a lateral force of 500 pounds per linear foot of curb,
applied at the top of curb.
(vi) Wind Forces
The effect of wind shall be considered as 50 pounds per square foot. This force shall
be applied at a point 6 feet above the deck level.
(vii) Buoyancy Effects
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The following buoyancy effects shall be considered, wherever applicable, for the
design of various components of the bridges:
For foundations 100 %
For substructure below water level 15 %
(viii) Seismic Forces
The bridge falls in a seismic zone and it shall be designed to safely sustain the seismic
forces.
Requirements for Design of Bridge Rehabilitation Works The structural arrangements requirements for the bridge deck surfacing, bridge deck drainage
and bridge deck approach slabs in the bridge rehabilitation works shall be as given above for
the new bridges.
The Contractor shall design the bridge rehabilitation works so that they can safely sustain the
most critical combination of the various loads, forces and stresses that can coexist as given in
the Standard Specifications for Highway Bridges, 17th Edition, 2002. The allowable stresses
and the permissible increase in stresses for various load combinations shall be adopted as
given in the relevant clauses of the AASHTO Standard Specification for Highway Bridges.
The design loadings given above for the new bridges shall be considered, where appropriate.
B 112. Retaining Wall Design
Retaining walls shall be designed to comply with the following requirements:
(i) a factor of safety of 1.5 shall be provided against sliding;
(ii) a factor of safety of 2.0 shall be provided against overturning;
(iii) a factor of safety of 2.0 shall be provided for foundation bearing capacity.
The retaining walls to be provided at the foot of the reinstated sections of embankment slope
can be designed as either:
- gravity retaining walls to be constructed in mass concrete, grouted masonry or
gabion boxes;
or
- Cantilever retaining walls to be constructed in reinforced concrete.
B 113. Road Furniture Design
Road national and standards Signs
34
The Contractor shall provide advance direction road signs, route confirmatory road signs,
warning road signs and regulatory road signs and all road signs necessary for safe and
effective traffic operations. The road signs shall be in accordance with national standards.
Road sign posts and foundations shall be designed to withstand forces generated by a
minimum wind velocity of 50 meters per second.
Sign plate and text height dimensions for all road signs shall be suitable for a traffic speed of
100 kilometers per hour.
Text shall be provided in Dari and English languages.
Guardrail
The Contractor shall provide guardrail at the following general locations:
(i) on the outside of horizontal curves with radii generally less than 500 meters;
(ii) where the embankment height exceeds 4 meters.
(iii) before and after bridge parapets where it is necessary to provide a transition barrier.
(iv) where the road is in a mountainside cut with a steep and high drop-pff
B 114. Road Marking Design
The Contractor shall provide the following road markings on all roads, in accordance with
national standards:
(i) centre line marking for normal conditions
3 meter long white line (100mm wide) with 6 meter long gap;
(ii) warning centre line marking at approaches to junctions, at horizontal curves with radii
less than 600 meters and other locations where potential hazards exist
6 meter white line (100 mm wide) with 3 meter long gap
(iii) no overtaking centre line marking where the overtaking sight distance of 375 meters is
not provided (sight distance to be based on eye height and object height of 1.10
meters)
(a) Overtaking sight distance not provided on one lane
Continuous 100 mm wide white line on the side where the overtaking sight
distance is not provided and warning line provided on the other side (gap of
100 mm between the two lines)
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(b) overtaking sight distance not provided on both lanes
single continuous 100 mm wide line;
(iv) carriageway edge line
continuous white 150 mm wide line on both carriageway edges;
(v) carriageway edge line at lay byes
0.6 meter long, white line (150 mm wide) with 0.3 meter long gap;
(vi) give way line at junctions
double 0.6 meter long white line (200 mm wide) with 0.3 meter long gap across mouth
junction – (lines to be 300 mm apart);
(vii) stop line at junctions
double continuous white line 200 mm wide – (lines to be 300 mm apart).
36
Section C : CONSTRUCTION SPECIFICATION
37
SECTION C 100: PRELIMINARIES
38
Introduction
Part 1
Part 1 of this Section details specific requirements in respect of the following general
obligations of the Contract:
Health and Safety;
Protection of the Environment;
Programmed and Method Statements;
Setting out of the Works;
Quality Control;
Materials supply;
Standards;
Temporary Works;
Traffic Safety Temporary diversions and Control;
Protection of Existing Services;
Landmines and unexploded ordinance;
Graves and burial sites;
Local Liaison and Consultation.
Compliance with the requirements of Part 1of this Section shall not relieve the Contractor of
its obligations in respect of these matters either under Contract or at law.
Part 2
Part 2 of this Section details specific requirements in respect of facilities and services to be provided by the Contractor for the Engineer/Employer.
39
PART 1
Health and Safety
In accordance with Clauses 4.8, 4.22 and 6.7 of the Conditions of Contract:
The Contractor shall take all measures necessary to safeguard the health, safety and welfare of
all persons entitled to be on the Site and shall ensure that the Works are carried out in a safe
manner. The Contractor shall take all reasonable precautions to protect members of the
public and road users from any activity under its control.
The Contractor shall provide and maintain barriers, fencing and lighting around its working areas when and where necessary for the safety and security of the public and road traffic.
The Contractor shall provide adequate lighting wherever any work is to be carried out at night.
The Contractor shall maintain the Site in safe, tidy and sanitary condition. The Contractor
shall provide latrines at areas of the Site where work is in progress and ensure that they are
regularly cleaned and maintained in a hygienic state. The Contractor shall be responsible for
disposing of all rubbish and waste occurring on the Site from whatever source.
The Contractor shall provide, and enforce the utilization of appropriate safety equipment for
all workmen and staff employed directly or indirectly by the Contractor. Such safety
equipment shall include, as appropriate, safety helmets, eye protectors, hearing protectors, and
safety harnesses. The Contractor shall provide, where appropriate, rescue equipment and fire
safety equipment.
First-aid equipment shall be provided at all work locations.
The Contractor shall appoint one member of its staff to act full-time as Safety Officer, and it
shall notify the Engineer of such appointment. The Safety Officer shall be experienced in all
matters relating to health and safety on construction sites and shall be familiar with all
relevant safety regulations and legislation. The Safety Officer shall be authorized to receive
instructions from the Engineer on matters relating to the health and safety.
The Contractor shall maintain such records and make such reports concerning safety, health
and welfare of persons and damage to property as the Engineer may from time to time
prescribe, and as required by law.
In the event that the Contractor temporarily closes down site operations seasonally or for any
other reason, he shall ensure that the Works are left in a safe condition. He shall appoint one
member of its staff to be responsible for the Works during such shutdown period and shall
supply to the Engineer and other relevant authorities the name and contact telephone number
of the responsible person.
The Contractor shall ensure that clauses equivalent to the above in relation to health and
safety are included in all sub-contracts.
The Contractor shall conduct Information, Education and Consultation campaigns, addressed
to all the site staff and workmen employed directly or indirectly by the Contractor, concerning
the risks, dangers and impact, and appropriate avoidance behavior with respect to sexually
transmitted diseases in general and HIV/AIDS in particular.
40
Protection of the Environment: General
The Contractor shall take all reasonable measures to avoid nuisance or disturbance arising
from the construction of the Works. The Contractor shall comply with the requirements
pertaining to construction that is contained in:
(i) the Asian Development Bank publication “Environmental Guidelines for Selected
Infrastructure Development Projects”;
(ii) the Asian Development Bank’s Environment Policy.
Environmental Protection Plan
The Contractor shall prepare an Environmental Protection Plan detailing how the Contractor’s
works shall comply with the relevant environmental laws and the particular requirements of
the Contract.
This Plan shall be submitted to the Engineer, the Employer and relevant Local Authorities at
the same time as its submission of the Programmed prepared in accordance with Clause 8.3
of the Conditions of Contract.
This Plan shall detail the Contractor’s proposed measures in respect of:
fuel storage and distribution;
control of water borne pollution (waste water and rain ‘run-off’);
prevention of pollution of rivers and water courses where these are adjacent to the
works (for example at bridge sites);
control of dust;
removal of rubbish;
sanitation for its work force;
control and reduction of noise;
operation of borrow areas, quarries and tips.
The Plan, and the Contractor’s proposed working methods, shall, so far as they relate to
environmental matters, be subject to the approval of the Employer, any relevant
Environmental Agency and the Engineer.
Environment Protection Manager
The Contractor shall appoint an Environment Protection Manager to be responsible for environmental matters and whose duties shall include supervising the Works to ensure compliance with its Environmental Monitoring Plan.
The Environmental Protection Manager shall liaise directly with the Engineer and Employer
(or Employer’s Environmental Agency) on matters relating to the environment and shall have
power to effect changes in the Contractor’s working practice which affect the environment.
41
Protection of the Environment: Particular Requirements
The Contractor shall comply with the following particular requirements in respect of the
environment.
Fuel and Chemical Storage
All fuel and chemical storage shall be sited on impervious bases within a bund, and shall be secured by fencing. The storage area shall be located away from any watercourse or wetlands. Filling and refueling shall be strictly controlled. All valves and trigger guns shall be locked when not in use.
The contents of any tank or drum shall be clearly marked.
Water Quality
The Contractor shall prevent any interference with, or pollution of, the supply or abstraction
of water, arising from the construction of the works.
The Contractor shall protect all watercourses and waterways adjacent to the works from
pollution, silting, flooding or erosion.
The Contractor shall not discharge or deposit any matter arising from the Works into any
watercourse.
Air Quality: Dust Prevention
The Contractor shall employ effective measures to control dust.
Water shall be sprayed during the delivery and handling of materials when dust is likely to be
created.
Stockpiles of materials shall be sited in sheltered areas or protected by hoarding and /or tarpaulins and away from residential or other sensitive areas. Where appropriate, stockpiled materials shall be sprayed with water to prevent dust pollution.
Vehicles used for transporting potentially dust producing material shall have properly fitting
side and tail boards and the materials shall be covered with a clean tarpaulin.
Works shall not be carried out in windy conditions when this would cause nuisance.
Air Quality: Exhaust Emissions
Construction vehicles and machinery shall be kept in good working order and engines turned
off when not in use.
Measures shall be taken to limit particulate exhaust emissions from construction vehicles, and equipment.
The location of generators and other permanent equipment shall be governed by considerations of exhaust emission, taking into account predominant wind direction.
42
Noise
The Contractor shall take all necessary measures to ensure that the operation of all mechanical
equipment and construction processes on and off the Site shall not cause any unnecessary or
excessive noise.
Generators and other standing equipment near residential areas (including site offices and camps) shall be silenced.
When operating close to residential, medical facilities, or other similar locations, the
Contractor’s hours of working shall be limited to 8 a.m. to 6 pm.
Borrow Areas, Spoil Tips and Quarries
Borrow pits and quarries shall be operated to minimize the impact on the environment, taking
into account requirements in respect of drainage and erosion.
Borrow areas and quarries shall be reinstated to smooth contours, shall be re-soiled and re-
vegetated with matching ground cover.
Spoil arising from the works shall be disposed of to the requirements of the local planning
agency.
Programmed
The Programmed to be furnished in accordance with Clause 8.3 of the Conditions of Contract
shall be fully resourced and developed from proprietary computer software.
The Programme shall be presented in the following formats:
a project bar chart (Gantt Chart) for the Whole of the Works;
a time-chain age chart for earthworks and pavement construction;
resource histograms for major items of equipment;
resource histograms for lab our;
a cumulative cash flow forecast.
The Programme shall include for the surveys, investigations and design that the Contractor is
required to carry out. The Programme shall also show the dates when various Construction
Documents are to be submitted to the Engineer for approval and the Engineer’s review
periods as detailed in clause B 102.
The Programme shall be updated monthly and actual progress charted against the base programme. The monthly updates shall be submitted to the Engineer not later than 7 days after the end of each month and in any event not later than the submission of the Contractor’s Monthly Statement.
The Contractor shall license the Engineer for the use of the software.
43
Methods of Construction: Method Statements General Method Statement
At the time of submission of its Clause 8.3 Programme, the Contractor shall submit a Method Statement detailing its general planning arrangements for the principal work operations, including:
Site establishment;
quarries and borrow areas;
earthworks operations;
aggregate extraction;
screening and crushing operations;
road pavement operations;
new bridge works;
structural repair works.
This general Method Statement shall include details of intended equipment and labour together with general planning and production arrangements in relation to the Works as a whole. Detailed Method Statements
Prior to any particular works operation, the Contractor shall submit a Detailed Method
Statement indicating:
the lab our and equipment resource to be used;
work procedures;
supervision (by named individual);
quality control;
survey methods;
Temporary Works (if any);
particular measures in respect of environmental protection;
Particular measures in respect of health and safety.
Where Temporary Works involve detailed structural calculations, these shall be submitted
separately.
No work shall be carried out by the Contractor prior to his submitting notice to the Engineer. Such notice shall give full details of the operation concerned and be sufficiently in advance of the commencement of the operation to enable the Engineer to make such arrangements, as he deems necessary for inspection and checking.
44
Setting Out
The Contractor shall be responsible for establishing and maintaining temporary survey control
points such as to allow the proper setting out of the Works. The Contractor shall furnish all
such relevant setting out control information to the Engineer to allow independent checking.
Quality Control and Quality Assurance
Pursuant to its obligations under Clause 4.9 of the Conditions of Contract, the Contractor
shall be responsible for implementing quality control and quality assurance procedures.
The Contractor shall prepare and implement a Quality Control Plan, compliance with which
will demonstrate that the various requirements of the Construction Specification in respect of
quality of materials and workmanship are being complied with.
This Plan shall be submitted to the Engineer at the same time as its submission of the
Programme prepared in accordance with Clause 8.3 of the Conditions of Contract. The Plan
shall be subject to the approval of the Engineer.
The Contractor shall establish and operate a Site Laboratory in order to carry out the acceptance and control testing detailed in Section C 200 of the Technical Specifications and its Quality Control Plan.
Notwithstanding the Contractor’s obligation in regard to quality control of its works, the
Engineer retains the right to undertake independent quality control tests. To this end, the
Contractor shall make the facilities in its Site Laboratory available to the Engineer. The
Contractor shall provide, at no charge to the Employer, all assistance, labour, and transport to
enable the Engineer to carry out such independent sampling, field and laboratory tests in the
Contractor’s laboratory.
The tests and testing regime detailed in Section C 200 of the Construction Specification and
any alternative or supplementary testing arranged by the Contractor as part of its Quality
Control Plan shall be deemed to be clearly intended and provided for in the Contract, and
their costs shall be borne by the Contractor.
Should the Contractor default in its obligation to implement quality control in accordance
with the above provisions, the Engineer shall make alternative arrangements for the testing of
the Works, the cost of which shall be contra-charged to the Contractor.
Approval of Suppliers
Before placing any order for supplied materials and/or manufactured articles for incorporation
in the Works, the Contractor shall submit to the Engineer the names of the firms from whom
he proposes to obtain such materials and/or manufactured articles together with a description,
their origin, the manufacturer's specification, and any other relevant details.
The Contractor shall provide the Engineer with samples of such materials and manufactured
articles and, where appropriate, shall provide manufacturer's certificates of recent tests carried
out. In particular, manufacturer’s certificates shall be provided for supplies of:
bitumen;
45
cement;
reinforcement;
bearings;
Pre-cast products.
The Contractor shall provide further test certificates during the course of the Works to demonstrate continuing compliance with the Construction Specification.
Materials: Alternative Standards
Unless otherwise specified, all materials incorporated in the Works shall comply with
“Standard Specifications for Transportation Materials and Methods of Sampling and Testing,
Part 1 Specifications, Seventeenth Edition, 1995” or the latest edition, as adopted by the
American Association of State Highway and Transportation Officials (AASHTO).
Should the Contractor wish to depart from the Standards stated in the Construction
Specification, or to furnish material under equal but alternative standards or specifications, a
statement of the exact nature of the departures fully supported by copies of the alternative
standards / specifications shall be included in the Construction Documents.
Any further testing which the Engineer may consider necessary in order to grant approval shall be at the Contractor’s expense.
Temporary Works
The Contractor shall include in the Construction Documents, full details of its proposed
arrangements in respect of Temporary Works.
Such details shall include drawings, calculations, setting-out details and all other information as the Engineer may reasonably require enabling him to review and give consent to the proposals.
Consent by the Engineer to the Contractor’s proposals shall not relieve the Contractor of its
responsibilities and liabilities under the Contract.
Traffic Safety and Control
The Contractor shall construct the Works without disruption to existing traffic. Accordingly,
the Contractor shall take whatever measures are necessary to maintain traffic flow.
Road closures shall not be permitted. Where the contractor’s working methods prevent the
use of the existing carriageway, diversion roads shall be constructed.
In association with the local Traffic Authorities, the Contractor shall produce a Traffic
Management Plan indicating how traffic is to be managed for the duration of the Works.
This Plan shall be submitted to the Engineer, the Employer and relevant Local Authorities at
the same time as its submission of the Programme prepared in accordance with Clause 8.3 of
the Conditions of Contract.
This Plan shall be subject to the approval of the relevant Traffic Authorities as well as the
Engineer and Employer.
46
For each working area, the Contractor shall provide further a Local Traffic Management Plan.
These Plans shall indicate the actual traffic control measures to be effected at each location.
The Contractor shall appoint a Traffic Control Supervisor who shall be responsible for co-ordinating traffic safety and control between the Engineer and the local Traffic Authorities.
All traffic diversions and traffic management works shall be provided with adequate traffic
warning signs and other traffic flow indicators, which shall be provided and maintained on a
24 hour, 7 day a week basis during the period of construction of the relevant Works.
Temporary Road Diversions
Temporary Diversions shall comply with the following requirements:
at grade construction but with a maximum gradient of 10%;
150 mm thick gravel surfacing to be provided that is to be construction in accordance
with the requirements of Section C 507 of the Construction Specification;
minimum carriageway width of 7m to be provided;
culverts and side drainage to be provided as necessary.
The layout of diversions shall be subject to the approval of the Engineer and shall be included
in the Detailed Traffic Management Plans.
Temporary road diversions shall be maintained throughout their use and original ground
reinstated on completion of the diverted works. The maintenance shall include regular
grading, watering and compaction to provide a smooth, corrugation free running surface that
is free from soft spots.
Existing Services and Service Diversions
‘Services’ includes water, gas and oil pipelines and electricity and telecommunications cables.
The Contractor shall include in its rates and prices for locating and taking measures for the support and protection of pipes, cables and other apparatus during the progress of the Works and for making arrangements with the appropriate authority / owner.
The Contractor shall indemnify the Employer against any claims arising from damage to
existing services.
Where the Contract requires a service diversion, the Contractor shall be responsible for liaising with the owner / operator (or its contractor) and for all matters in connection therewith. In this context ‘diversion’ means any relocation or alteration in position.
The Contractor shall keep Engineer informed of all arrangements he makes with the owners
or suppliers and its proposals shall be subject to the approval of the Engineer and the owner /
operator of the respective service.
The contractor shall have sole and complete responsibility for scheduling and for the timely
implementation of relocations and diversions. No claims will be entertained on the basis that
the contractor’s work was delayed, disrupted or otherwise interfered with by the actions of
those doing the relocations or delays or by their delays in doing such work
47
Restriction on Working Hours Further to Condition of Contract Clause 6.5, ‘night working’ is deemed to be between 20:00 and 07:00 and the ‘locally recognized days of rest’ are Thursday from 12:00 and all day on Friday Should the Contractor’s Programme involve working during ‘night’ or ‘rest days’ or Public Holidays and should this incur the Employer in additional supervision costs, the provisions of Clause 6.5 in respect of the Employer’s right to recover such costs shall apply without the requirement for notice to the Contractor in addition supervision costs, the Employer shall be entitled to recover from the contractor such costs without the requirement of a prior notice to the contractor
Landmines and Unexploded Ordinance
Requirements in respect of surveying and clearing landmines and unexploded ordnance are
given in Sub-Clause 4.25 Part B- Particular Conditions of Contract.
Graves and Burial Sites
There are a number of graves and burial sites located in the road shoulders, on the
embankment slopes and in other areas occupied by the Works. The Contractor shall ensure
that all graves and burial sites are not disturbed or damaged by any site clearance or
construction operation. Suitable temporary warning signs and demarcation measures are to be
provided by the Contractor during the period when site clearance and construction operations
are in progress in the vicinity of the graves and burial sites.
The Contractor shall agree with the Engineer any local modifications to the Permanent Works
that are required in order to ensure that the graves and burial sites remain undisturbed.
Local Liaison and Consultation
The Contractor shall liaise and consult fully with local authorities and local people during the
construction of the Works. Matters covered by this local liaison shall include safety, social
and cultural issues, assistance with recruitment of staff and lab our, design matters relevant to
local residents and landowners, land required for Permanent Works beyond the existing
embankment toe, land required for Temporary Works, local access during the construction of
the Works, traffic safety and control, environmental matters and security. This local liaison
and consultation shall be carried out through correspondence, formal meetings with
authorities, public meetings, and meetings with individuals, the local press and the local radio
and television services.
The Contractor shall prepare a Local Liaison and Consultation Plan detailing the procedures
to be adopted for local liaison and consultation, as well as the extent and coverage of the
liaison and consultation. This Plan shall be submitted to the Engineer, the Employer and
relevant local authorities at the time of submission of the Programme prepared in accordance
with Clause 8.3 of the Conditions of Contract. The Plan shall be subject to the approval of
the Engineer.
The Contractor shall appoint a Local Liaison Officer to be responsible for all local liaison and
consultation. Contact details for the Local Liaison Officer shall be included in the Local
Liaison and Consultation provided to the Engineer, the Employer and local authorities.
48
‘As Built’ Drawings
The Contractor shall submit a full set of draft ‘As-Built’ drawings in hard copy for the
Engineer’s consent. A full set of final ‘As-Built’ drawings shall then be submitted by the
Contractor that incorporate any revisions required by the Engineer, within one month of any
Taking-Over Certificate. The Contractor shall submit one paper copy of the final ‘As-Built’
drawings together with a copy of each drawing in an agreed electronic format.
49
PART 2: FACILITIES AND SERVICES FOR THE ENGINEER AND EMPLOYER
50
Survey Equipment
The Contractor shall provide the following survey equipment.
Schedule of Survey Equipment No.
Engineer's Precise Level (+/- 2mm per km) complete with tripod and staff 2
Total station: Nikon 5 second or equal, including 'Half traverse' set, prisms and on
board data logger. 1
Steel or Fibroin tape: 100m 3
Fibroin tape: 50m 5
Newly Purchased Vehicles The Contractor shall supply vehicles in accordance with the following schedule and specification:
Schedule of Vehicles
Vehicle Type A (car)
Vehicle Type B (de luxe 4x4 sports utility vehicle)
Vehicle Type C (standard 4x4 jeep type)
Vehicle Type D (standard 4x4 hatchback)
Vehicle Type E (mini-bus)
Vehicle Type F (4 x 4 pick up)
The newly purchased vehicles shall be comprehensively insured for any authorized driver.
The vehicles shall be licensed and taxed for use within Afghanistan.
A driver shall be provided for each vehicle. The drivers shall be available during all working
hours and otherwise as required by the Engineer.
Vehicles shall be washed, cleaned and fuelled on a daily basis.
The Contractor shall be responsible for the care of vehicles during any shut down periods.
The vehicles shall be fully serviced and made ready for the use of the Engineer’s staff prior to
the resumption of the construction of the Works immediately following any shut down period.
The vehicles shall revert to the Employer at the date of issuing the Taking over Certificate for
the Whole of the Works, or at such other date instructed by the Engineer.
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Vehicle Specification
Vehicle Type: Type A
(Car)
Type B
(de luxe
4x4)
Type C
4x4 jeep
Type D
4x4 h/back
Type E
(mini-bus)
Type F
(pickup)
Basic Specification
4x4 (4 wheel drive) No Yes Yes Yes No Yes
Left hand drive Yes Yes Yes Yes Yes Yes
Length (minimum) : meters 4.2 4.8 4.6 4.05 4.44 4.2
Seating capacity 4 5 5 4 7 3
Ground clearance (minimum) 0.18 0.28 0.22 0.22 0.22 0.22
Cargo capacity (minimum) Kg 500 1000 950 300 1150 1000
Engine / Transmission
Engine : petrol / diesel Petrol Either Either Either Either Either
Engine capacity (minimum) : cc 1800 3000 2445 1600 2445 1800
Horse power (minimum) : HP 20 150 75 72 75 90
Transmission (4 or 5 speed) 5 speed 5 speed 4 speed 4 speed 4 speed 4 speed
High/low transfer gear No Yes Yes Yes Yes Yes
Fuel tank (minimum) : litres 60 90 80 40 80 65
Mechanical / Equipment
Power assisted steering Yes Yes No No No No
Independent front suspension
Yes Yes Yes Yes Yes Yes
Independent rear suspension Yes Yes No No No No
Brakes : front Disc Disc Disc Disc Disc Disc
Brakes : rear Disc Disc Drum Drum Drum Drum
ABS system No Yes No No No No
Odometer / tachometer No Yes No No No No
Internal
Air conditioner Yes Yes No No No No
Tinted laminated windscreen Yes Yes No No No No
Clock Yes Yes No No No No
Lockable glove box Yes Yes Yes Yes Yes Yes
External
Rear view side mirrors Fold-away Fold-away Yes Yes Yes Yes
Mudguards front and rear Yes Yes Yes Yes Yes Yes
Safety Equipment
Driver and passenger airbags Yes Yes No No No No
Front and rear seat belts Yes Yes Yes Yes Yes Yes
Head restraints All All Front Front Front Front
First aid kit Yes Yes Yes Yes Yes Yes
Fire extinguisher Yes Yes Yes Yes Yes Yes
Security locking Yes Yes No No No No
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Vehicle Type: Type A
(Car)
Type B
(de luxe
4x4)
Type C
4x4 jeep
Type D
4x4 h/back
Type E
(mini-bus)
Type F
(pickup)
Miscellaneous
Spare tyre, jack and tools Yes Yes Yes Yes Yes Yes
Front and rear tow hitch Yes Yes Yes Yes Yes Yes
Tool kit Yes Yes Yes Yes Yes Yes
Shovel and steel cable tow-rope Yes Yes Yes Yes Yes Yes
Snow chains Yes Yes Yes Yes Yes Yes
º
Maintenance and Security The Contractor shall service and maintain all facilities provided for the Engineer throughout the duration of the Works, until such time as the facilities are taken over or returned.
Maintenance shall include:
1. cleaning, and repair of buildings and fixtures;
2. servicing of equipment and furniture;
3. the uninterrupted supply of water, electricity and gas (where provided);
4. telephone rental charges including internet access;
5. the maintenance, of driveways, access roads, hard standings, footways, fences,
security lighting, and areas of landscaping including the removal and disposal of
vegetation and debris;
6. refuse collection and disposal;
7. sewage disposal facilities;
8. the provision of toilet and kitchen consumables including cleaning materials;
9. the provision of all survey consumables including field books, road markers, etc;
10. cleaning, repair and replacement of protective clothing;
11. Cleaning, servicing and repair of vehicles including the provision of fuel, oil,
lubricants, and other consumables and replacement parts.
At the principal Site Office the Contractor shall provide a full time chainman / utility person
for general attendance duties for the Engineer.
The Contractor shall provide 24 hour security to the Engineer’s Site Offices and Residential
Accommodation including during any shutdown periods.
If the Works are not completed within the stipulated period or within the granted extension
time of completion, maintenance of all facilities provided for the Engineer shall be carried out
by the Contractor at his own cost beyond the stipulated/extended time of completion.
53
SECTION C 200: QUALITY CONTROL
Scope of Section
54
This Section details testing regimes and standards for the quality control of workmanship and
materials.
The Contractor shall carry out the tests detailed in this section in accordance with its Quality
Control Plan.
Quality Control Plan The Contractor shall prepare a Quality Control Plan which shall detail quality control procedures such as to demonstrate that the requirements of Clause 4.9 of the Conditions of Contract in respect of quality are met. The Quality Control Plan shall provide a formal framework for the approval of the Works by the Engineer.
In particular the Quality Control Plan shall include:
quality control procedures in respect of the selection and control of materials,
distinguishing between approval testing and compliance testing;
quality control procedures in respect of construction operations, identifying
procedures for production control and procedures for survey control;
procedures for the Contractor and Engineer to ‘sign off’ approved construction works.
In preparing the Quality Control Plan the Contractor shall take into consideration the requirements and obligations of the Engineer in respect of checking and inspection of the Works.
The Contractor shall appoint a Quality Control Manager who shall be responsible for ensuring
that the quality control procedures set out in the Quality Control Plan are adhered to. The
Quality Control Manager shall have independent control of all quality control activities.
General Requirements in Respect of Testing
The Contractor shall carry out sampling procedures and testing of materials incorporated in
the Works in accordance with AASHTO Part 2, Sampling and Testing.
Sieves
ASTM E-11 sieves shall be used for all tests. The sieve series in mm and μm are as follows:
Coarse 100, 90, 75, 63, 53, 50, 45, 37.5, 31.5, 26.5, 25.0, 22.4, 19.0, 16.0, 13.2, 12.5, 11.2, 9.5,
8.0, 6.7, 6.3, 5.6, 4.75, 4.00 mm;
Fine 3.35, 2.80, 2.36, 2.00, 1.70, 1.40, 1.18, 1.00 mm, 850, 710, 600, 500, 425, 355, 300, 250,
212, 180, 150, 125, 106, 90, 75, 63, 53, 45, 38 μm.
55
PART 1: LABORATORY / FIELD TESTS AND PROCEDURES SOILS, GRAVELS AND AGGREGATES
Sampling and Preparation of Samples
Sampling of soils and gravels and their sample preparation shall be carried out as specified in:
AASHTO T87 - Dry Preparation of Disturbed Soil and Soil Aggregate Samples for Test;
AASHTO T146 - Wet Preparation of Disturbed Soil Samples for Test.
Standard Methods of Testing
Tests on soils and gravels shall be performed in accordance with the Test Procedures given in
Table 2-1.
Wherever in the text of these Construction Specification, the term "x% of the MDD
(AASHTO T99 or T180)" is used it shall mean that a standard of compaction shall be
achieved such that the dry density of the compacted material is x% of the maximum dry
density determined from the AASHTO T99 or T180 compaction test.
TABLE 2-1: Test Procedures Applicable to Disturbed Samples of Soils and Gravels
Description Test Procedure
Particle Size Analysis of Soils AASHTO T88
Determining the Liquid Limits of Soils AASHTO T89
Determining the Plastic Limit and Plasticity Index of Soils AASHTO T90
The Moisture-Density Relations of Soils Using a 2.5 kg Rammer and a
305 mm Drop AASHTO T99
Specific Gravity of Soils AASHTO T100
Plastic Fines in Graded Aggregates and Soils by Use of the Sand
Equivalent Test AASHTO T176
The Moisture-Density Relations of Soils Using a 4.55 kg Rammer and a
457 mm Drop AASHTO T180
Density of Soil and Soil – Aggregate In-Place by the Sand-Cone Method AASHTO T191
The California Bearing Ratio AASHTO T193
Density of Soil and Soil-Aggregate In-Place by Nuclear Methods AASHTO T238
Moisture Content of Soil and Soil-Aggregate In-Place by Nuclear
Methods AASHTO T239
Laboratory Determination of Moisture Contents of Soils AASHTO T265
Density - Moisture Content Relationship, Vibrating Hammer BS 1377 Test 14
Field Moisture Content Determination AASHTO T217
Samples for the AASHTO T99 and T180 compaction tests shall be taken from the Works
before compaction of the layer concerned begins unless, in the opinion of the Engineer, the
compactive effort proposed by the Contractor is such that the material characteristics would
be altered by the process of compaction, in which case the samples for the tests shall be taken
after all compaction is complete.
56
Compaction tests on materials, which are susceptible to crushing during compaction, shall
require a separate new sample to be prepared for the determination of each point on the
moisture/density curve.
The field density and moisture content of material placed in the Works shall be determined by the Sand Cone Method (AASHTO T191) and the oven and calcium carbide gas pressure moisture tester (AASHTO 217). The Contractor may also employ nuclear methods in accordance with AASHTO T238 and T239.
The standard method of test for density of soil in place by the sand cone method, AASHTO
T191 shall be used for initial calibration of the nuclear density testing equipment and for
check/comparison tests.
For crushed aggregates and granular soils, the laboratory compaction test using vibratory
hammer, BS 1377 - Test 14, may be employed as an alternative to AASHTO T 180.
Cement or Lime Treated Materials Samples shall be prepared in accordance with BS1924. For preparing samples containing particles larger than 20mm for compaction and CBR tests, the fraction coarser than 20mm shall be rejected and replaced by an equal weight of 5mm to 20mm size material.
The tests shall be performed in accordance with the standard methods given in Table 2-10.
It is further specified that:
(a) for compaction tests when cement is used, compaction shall start within one hour
and be complete within two hours after the start of mixing operations;
(b) for determination of the Unconfined Compression Strength (UCS), the specimens
shall be statically compacted to a predetermined density;
(c) for determination of the CBR, the specimens shall be dynamically compacted with a
4.5kg rammer, the number of blows being governed by the relative compaction
chosen. If it is required to soak the specimen, the mould shall be immersed in water
to allow free access of water to the top and bottom of the specimen. During soaking
the water level in the mould and the soaking tank shall be maintained approximately
25mm above the top of the specimen.
Stone, Aggregates, Sand and Filler
Sampling shall be carried out and the samples shall be prepared in accordance with AASHTO
T2 - Sampling of Aggregates.
Tests on stone, aggregate, sand and filler shall be performed in accordance with the Standard
Methods of Test given in Table 2-2.
Table 2 - 2 Test Procedures Applicable to Stone, Aggregates, Sands and Fillers
57
Description Test Procedure
Unit Weight and Voids in Aggregate ASTM C 29
Potential Reactivity of Aggregates (Chemical Method), ASTM C 289
by Washing AASHTO T11
Organic Impurities in Fine Aggregate AASHTO T21
Sieve Analysis of Fine and Coarse Aggregates AASHTO T27
Specific Gravity and Absorption of Fine Aggregate AASHTO T84
Specific Gravity and Absorption of Coarse Aggregate AASHTO T85
Resistance to Degradation of Small-Size Coarse Aggregate by
Abrasion and Impact in the Los Angeles Machine AASHTO T96
Soundness of Aggregates by Use of Sodium Sulphate or
Freeze/Thaw AASHTO 104-99
Flakiness Index BS 812
Elongation Index BS 812
Chloride Content of Fine Aggregates BS 812
Field Moisture Content Determination “Speedy “Apparatus (AASHTO T 217)
Polished Stone Value BS 812
Average Least Dimension Where required in the Contract, the Average Least Dimension (ALD) of an aggregate shall be determined as follows:
A representative sample of such a size as to give at least 200 aggregate particles of each
fraction to be tested shall be divided out by means of a riffle. The sample shall be passed
through a sieve with an aperture size of half the nominal size of the aggregate to be tested and
the particles passing the sieve shall be discarded. The nominal size of aggregate is defined as
the smallest sieve through which at least 85% of the aggregate will pass.
The smallest dimension of each particle retained on the sieve accurate to 0.1 mm shall be
measured by means of calipers with platens of at least 5 mm diameter (or square). The
measurement and the number of particles tested shall be recorded. The Average Least
Dimension is then calculated as the sum of the smallest dimension of the particles divided by
the number of particles measured.
58
The Quantab Test
The Quantab Test is a field test for determining the chloride content of aggregates.
Apparatus required:
Plastic buckets,
Spring balance capable of reading to 5 kg with an accuracy of ± 10 g,
Plastic drinking cups or similar containers,
Whatman No. 90 filter papers 125 mm diameter,
Quantab chloride titrators Type 1175.
Method:
Weight out 2 kg of the aggregate under test into a bucket.
Add 2 kg of clean chloride free water.
Stir once every minute for 15 minutes.
Take a container of the solution from the bucket and place into it, point downwards a filter
paper folded into a cone.
Insert into the clear liquid within the filter paper a Quantab titrator strip and leave until the yellow bar at the top of the strip has turned completely blue.
Read off from the scale on the strip the level reached at which the strip has turned white (to
first decimal point).
Consult the calibration chart supplied with the test strips and read the percentage NaC1
corresponding to the test strip reading.
Calculation:
If the % NaC1 is X, the amount of C1 ion by weight of aggregate is given by:
C1 ion = 0.61X %
Note: It is important to ensure that the control number on the chart corresponds with the
control number on the bottle of test strips in use.
59
PORTLAND CEMENTS AND CONCRETES
Portland Cement
Portland cement shall be sampled in accordance with AASHTO T127, Sampling Hydraulic
Cement.
Tests on Portland cement or Granulated Blast Furnace Slag for compliance with the above
standard maybe performed by an independent testing laboratory.
Testing in the Site laboratory shall be in accordance with the Standard Methods of Test given
in Table 2-3.
Table 2 - 3 Test Procedures Applicable to Portland Cement
Description: Test Procedure
Compressive Strength of Hydraulic Cement Mortars and Slag
Activity Tests AASHTO T106
Mechanical Mixing of Hydraulic Cement Pastes and Mortars of
Plastic Consistency AASHTO T162
Concrete
Sampling and testing of concrete shall be performed in accordance with the methods given in
Table 2-4. Water to be used in concrete shall be tested in accordance with AASHTO T26.
Table 2 - 4 Test Procedures Applicable to Concrete
Description: Test Procedure
Potential Alkali Reactivity of Cement Aggregate Combinations ASTM C 227
Slump of Hydraulic Cement Concrete AASHTO T119
Weight Per Cubic Foot (or Cubic Meter), Yield, and Air Content
(Gravimetric) of Concrete AASHTO T121
Air Content of Hydraulic Cement Mortar AASHTO T137
Sampling Freshly Mixed Concrete AASHTO T141
Air-Entraining Admixtures for Concrete AASHTO T157
Bleeding of Concrete AASHTO T158
Resistance of Concrete to Rapid Freezing and Thawing AASHTO T161
Evaluation by Freezing and Thawing of Air-Entraining Additions
to Portland Cement AASHTO T188
Air Content of Freshly mixed Concrete By the Volumetric
Method AASHTO T196
Methods of Sampling Fresh Concrete BS 1881 Part 1
Methods of Testing Fresh Concrete BS 1881 Part 2
Methods of Making and Curing Test Specimens BS 1881 Part 3
Methods of Testing Concrete for Strength BS 1881 Part 4
BITUMINOUS MATERIALS
Bituminous Binders
60
Sampling of bitumen and cut-back bitumen shall be carried out in accordance with AASHTO T40, Sampling Bituminous Materials.
Bitumen
The Contractor shall provide the Engineer with manufacturer’s certificates for each delivery of bitumen. Testing of bitumen shall be performed in accordance with the methods given in Table 2-5 below.
Table 2 -5 Test Procedures Applicable to Bitumen
Description: Test Procedures
Solubility of Bituminous Materials AASHTO T44
Flash and Fire Points by Cleveland Open Cup AASHTO T48
Penetration of Bituminous Materials AASHTO T49
Softening Point of Bitumen (Ring-and-Ball
Apparatus) AASHTO T53
Water in Petroleum Products and Bituminous
Materials by Distillation AASHTO T55
Effect of Heat and Air on Asphalt Materials (Thin Film
Oven Test) AASHTO T 179 / AASHTO T 240
Kinematics Viscosity of Asphalts (Bitumen) AASHTO T201
Specific Gravity of Semi-Solid Bituminous Materials AASHTO T228
Determination of the Breaking Point of Solid or Semi-
Solid Bitumen (FRAAS method) DIN 51011 or IP 80
61
Cut-back Bitumen Testing of cut-back bitumen shall be performed in accordance with the methods given in Table 2 –6.
Table 2- 6: Test Procedures Applicable to Cut-Back Bitumen
Description: Test Procedure
Residue of Specified Penetration ASTM D 243
Solubility of Bituminous Materials AASHTO T44
Flash and Fire Points by Cleveland Open Cup AASHTO T48
Penetration of Bituminous Materials AASHTO T49
Ductility of Bituminous Materials AASHTO T51
Water in Petroleum Products and Bituminous Materials by
Distillation AASHTO T55
Distillation of Cut-Back Asphaltic (Bituminous) Products AASHTO T78
Flash Point by Tag Open-Cup Apparatus For Use With Materials
Having a Flash Less than 93.3o C AASHTO T79
Spot Test of Asphaltic Materials AASHTO T102
Effect of Heat and Air on Asphalt Materials (Thin Film Oven Test) AASHTO T 179
Kinematics Viscosity of Asphalts (Bitumens) AASHTO T201
Specific Gravity of Semi-Solid Bituminous Materials AASHTO T228
Determination of the Breaking Point of Solid or Semi-Solid
Bitumen’s (FRAAS method) DIN 51011
Bituminous Mixes
Sampling of bituminous mixtures shall be carried out in accordance with AASHTO T 168,
Sampling Bituminous Paving Mixtures.
Testing of bituminous mixes shall be performed in accordance with the methods given in
Table 2-7.
Table 2-7: Test Procedures Applicable to Bituminous Mixes
Description Test Procedure
Mechanical Analysis of Extracted Aggregate AASHTO T30
Quantitative Extraction of Bitumen from Bituminous Paving Mixtures AASHTO T164
Bulk Specific Gravity of Compacted Bituminous Mixtures Using
Saturated Surface-Dry Specimens AASHTO T166
Sampling Bituminous Paving Mixtures AASHTO T168
Maximum Specific Gravity of Bituminous Paving Mixtures AASHTO T209
Degree of Pavement Compaction of Bituminous-Aggregate Mixtures AASHTO T230
Resistance to Plastic Flow of Bituminous Mixtures Using Marshall
Apparatus AASHTO T245
Percent Air Voids in Compacted Dense and Open Bituminous Paving
Mixtures AASHTO T269
62
Loss of Stability: Alternative Test
As an alternative to ASTM 1075, the Contractor may measure the loss of stability on
immersion in water by measuring the loss of Marshall Stability.
In this case the test procedure shall be modified as follows:
ASTM 1075 7.1.1 Group 1 - Immerse the test specimen in water for 30 – 40 minutes at 60
degrees Celsius +/- 1 degree. Follow the Marshall procedure to
measure the Marshall Stability;
ASTM 1075 7.1.2 Group 2 - Immerse the test specimen in water for 22 – 24 hours at 60
degrees Celsius +/- 1 degree. Follow the Marshall procedure to
measure the Marshall Stability.
REINFORCEMENT STEEL
Reinforcing Steel
Steel for the reinforcement of concrete shall comply with either the AASHTO Standard
Specifications or the British Standards set out in Table 2 - 8.
The Contractor shall supply certified mill test reports for all reinforcement.
Reinforcing steel shall be tested at an independent testing laboratory acceptable to the Engineer for compliance with and in accordance with the applicable specification.
1.1.a.i.1.1 Table 2 - 8 Specifications Applicable To Reinforcing Steel
Description Specification Number
Deformed and Plain Billet-Steel for Concrete Reinforcement
(Metric) AASHTO M 31M
Steel Welded Wire Fabric, Deformed, for Concrete
Reinforcement AASHTO M 221M
Steel Wire, Deformed, for Concrete Reinforcement AASHTO M 225 M
Carbon Steel Bars for the Reinforcement of Concrete BS 4449
Steel Fabric for the Reinforcement of concrete BS 4483
Prestressing Steel
High tensile steel wire strand for the prestressing of concrete shall comply with AASHTO M
203M, Steel Strand, Uncoated Seven-Wire for Priestesses Concrete.
High tensile alloy steel bars for the prestressing of concrete shall comply with AASHTO M
275, Uncoated High-Strength Steel Bar for Prestressing Concrete.
Prestressing steel shall be tested at an independent testing laboratory.
63
PART 2: CONSTRUCTION CONTROL TESTING AND QUALITY ASSURANCE
Construction Control As part of its Quality Control Plan the Contractor shall institute a Quality Assurance (QA) scheme that shall allow for the systematic control of the works. The QA scheme shall allow for ‘signing off’ by the Contractor’s and Engineer’s delegated representatives of each work area.
The QA scheme shall allow for the systematic submission by the Contractor and the consent
of the Engineer of:
all materials to be incorporated in the Works;
earthworks layers (by section);
backfill to culverts and other structures;
pavement layers (by section);
all foundations (prior to blinding concrete);
all placement of in-situ structural concrete.
The scheme shall reference all relevant testing and works shall not be submitted to the Engineer for consent until all relevant tests have been satisfactorily concluded.
Frequency of Testing The frequency of testing shall be in accordance with the guidelines set out below. In case of obtaining variable results or results which are only marginally acceptable, the Engineer will instruct the Contractor to increase the frequency of testing and the contractor shall comply
Earthworks Original Ground
The AASHTO T99 maximum Dry Density and Optimum Moisture Content for existing ground under new embankments shall be determined for each new material encountered and at a frequency of at least once per 1,000 m
2 or once per 100 m along the alignment whichever is the more frequent.
Embankment Construction
The physical properties defined in Section C 500 of the Construction Specification for
earthworks shall be determined at source for each new material encountered and at least once
per 10,000 m3 of earthwork excavated for use as suitable fill or structural backfill.
The field dry density in the permanent works for general earthworks shall be determined at
least once per 1,000 m3 of each layer of compacted material placed.
The field dry density in the permanent works for earthworks within 300mm of subgrade shall
be determined at least once per 750 m2 of each layer of compacted material placed.
The field dry density in the permanent works for structural backfill shall be determined at least once per 100 m
3 of compacted material.
Pavement Materials Granular Materials in Shoulders and Sub base
The physical properties for materials in shoulders and sub base respectively shall be determined at source for each new material encountered.
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The field dry density in the permanent works shall be determined at least once per 750m2 of
each layer of compacted material.
Crushed Stone Base
Granular sub base material shall consist of crushed rock or stone and shall be clean and free
from dirt, organic matter and other deleterious substances, and shall be of such nature that it
can be compacted readily under watering and rolling to form a firm, stable sub base to the
specified standards.
a) The sub base material shall have a smooth gradation curve.
b) The material shall have a CBR value of at least 30% determined according to
AASHTO T-193, soaked for 4 days and the maximum swell shall be 0.5%. The CBR
value shall be obtained at a density corresponding to ninety five (95) percent of the
maximum dry density, determined according to AASHTO T- 180 Method-D.
c) 50% or more of particles retained on the 4.75mm sieve shall have at least one crushed
face
d) The fraction passing the 0.075mm (no. 200) sieve shall not be greater than two thirds
of the fraction passing the 0.425mm sieve and shall have a Liquid Limit of not greater
than 35. The sub base material shall have a Plasticity Index of 6 or less and a Linear
Shrinkage of 3 or less.
The physical properties shall be determined after crushing, screening, and washing for each
new source of material and at least once per 1000 m3
of material processed.
The field dry density in the permanent works shall be determined at least once per 750 m2 of
each layer of compacted material.
Bituminous Mixes: Aggregates
The physical properties of aggregates shall be determined after crushing, screening, and washing for each new source of material and at least once per 1000 cu m of material processed.
In addition, the grading of aggregates shall be determined at least once per day during mixing.
Mineral Filler
The grading and bulk density in toluene shall be determined once per 100 tones of filler used, or when the source of filler is changed.
Bitumen
Bitumen shall be tested for each new delivery for Penetration and Softening Point, before and after Rolling Thin-film Oven tests. All other tests shall be carried out for each 2500 tones of bitumen delivered.
Bituminous Mixture (from the mixing plant)
The following properties of the bituminous mixture, as appropriate to the type of mix specified, shall be determined every 4 hours from samples taken from the mixing plant, or from the asphalt pavers:
bitumen content,
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grading,
Marshall stability,
flow,
absorbed water,
voids,
voids at refusal density.
Bituminous Mixture (on cores from the compacted layer)
The following properties of the bituminous mixture shall be determined at least once for every
500 m2 of mix laid from single core samples cut through the compacted layer:
density,
voids in mix.
A minimum of 2 cores shall be cut for any single working day.
The positioning of the cores shall be to a systematic method approved by the Engineer.
Double Layer Surface Dressing
The physical properties of the aggregate chippings shall be determined after crushing,
screening, and washing for each new source of material and at least once per 1000 cu m of
material processed. In addition, the grading of the aggregate chippings shall be determined at
least once per 250 cu m of aggregate chippings used.
Application rates of bituminous binder shall be determined for every 1,000 sq m of a surface
dressing layer and at least once per day by the following two methods:
(i) By measuring the increased weight of a timber board placed on the road surface
during spraying of bituminous binder;
(ii) By recording the tank volume (or weight) before and after each days spraying
operations and comparing this with the total area sprayed.
Application rates of aggregate chippings shall be determined for every 1,000 sq m of a surface
dressing layer and at least once per day by measuring the increased weight of a steel tray
placed on the road surface during spraying of bituminous binder.
Concrete Works Cement
All cement to be used in the Works shall be tested by the Contractor in an independent
laboratory acceptable to the Engineer. The Contractor shall supply a copy of each test
certificate or test result to the Engineer.
The frequency of testing shall be one set of tests for every 200 tones of cement delivered to Site.
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The Contractor shall keep full records of all data relevant to the manufacture, delivery, testing
and use of all cement used in the Works and shall provide the Engineer with copies thereof. Aggregates: Acceptance Testing
Before casting any concrete, the Contractor shall deliver to the Engineer sample loads of all aggregates that it proposes to use in the Works. Representative samples of each proposed source of aggregate shall be prepared by the Contractor in accordance with AASHTO T2, of minimum mass 50 kg for fine aggregate and 100 kg for coarse aggregate, and forwarded to the Engineer together with such further samples as the Engineer may require. Each sample shall be clearly labelled to show its origin and shall be accompanied by all the information called for in AASHTO T2.
Tests to determine compliance of the aggregates with the requirements of Section C 900 of
the Construction Specification shall be carried out by the Contractor.
Aggregates: Compliance Testing
The Contractor shall carry out routine testing of aggregates for compliance with the
Construction Specification and Project Quality Control Plan.
The tests set out below shall be performed on aggregates from each separate source on the
basis of one set of tests for each day on which aggregates are delivered to Site provided that
no set of tests shall represent more than 250 tonnes of fine aggregates nor more than 500
tonnes of coarse aggregate, and provided also that the aggregates are of uniform quality. If
the aggregate from any source is variable, the frequency of testing shall be increased as
instructed by the Engineer.
(a) Grading AASHTO T27;
(b) Flakiness index BS 812;
(c) Plastic fines AASHTO T176;
(d) Moisture content “Speedy” Apparatus;
(e) Check on organic impurities AASHTO T21.
In addition to the above routine tests, the Contractor shall carry out the following tests at the intervals stated:
(a) moisture content; as frequently as may be required in order to control the water
content of the concrete as required by the Construction Specification;
(b) chloride content: as frequently as may be required to ensure that the proportion of
chlorides in the aggregates does not exceed the limit stated in Section C 900 of the
Construction Specification.
The Contractor shall take account of the fact that when the chloride content is variable it may be necessary to test every load in order to prevent excessive amounts of chloride contaminating the concrete. For this purpose the Contractor may elect to use a rapid field test such as the Quanta test. In the event of disagreement regarding the results of such rapid field tests, the chloride content of the aggregate shall be determined in the laboratory as described in BS 812 (the Volhard test).
Quality Control of Concrete Production Sampling
For each consistence and class of concrete in production at each plant, samples of concrete for
use in the Works shall be taken at the point of mixing or of deposition as required by the
Project Quality Control Plan or as instructed by the Engineer, all in accordance with the
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sampling procedures described in BS 1881 and with the further requirements set out in these
Construction Specification.
Six 150 mm size cubes shall be made from each sample and shall be cured and tested all in
accordance with BS 1881 Part 3, three at seven days and three at 28 days.
Each sample shall be taken from one batch selected at random and at intervals such that each sample represents not more than 50 m
3 of concrete.
Until compliance with the Construction Specification has been established the frequency of
sampling shall be such that each sample represents not more than 20 m3 of concrete or as
otherwise instructed by the Engineer.
The Contractor shall arrange for the Engineer to be present during the sampling of the concrete and the manufacture, storing and curing of the test cubes. Unfitness test cubes shall be deemed unacceptable for quality control purposes.
Consistence
The slump or compacting factor of the concrete shall be determined for all batches at the
frequency instructed by the Engineer.
The slump of the concrete in any batch shall not differ from the value established by the Site
trial mixes by more than 20 mm or one third of the value, whichever is the greater.
The variation in value of the compacting factor, if used in place of a slump value, shall be
within the following limits:
(a) for a value of 0.9 or more ±0.03;
(b) for a value of between 0.8 and 0.9 ±0.04;
(c) for a value of 0.8 or less ±0.05.
Water/Cement Ratio
The water/cement ratio shall not vary by more than five per cent from the value established during Site trial mixes.
Air Content
The air content of air-entrained concrete in any batch shall be within 1.5 percentage points of the values specified in Table 9 - 5 in Section C 900 of the Construction Specification and the averaged value of four consecutive measurements shall be within 1.0 percentage points of the specified value, expressed as a percentage of the volume of freshly mixed concrete. Testing shall be in accordance with AASHTO T196.
Flakiness Index
If the Flakiness Index of the coarse aggregate should vary by more than five units from the average value of the aggregate used in the approved mix and if the workability of the mixes should be adversely affected by such variation, a new set of Site trial mixes and corresponding tests shall be carried out.
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Crushing Concrete Cubes
The compressive strength of test cubes shall be determined in accordance with BS 1881 Part
4.
The results of all cube tests shall be shown on an approved form that shall include, but not be limited to, the following information:
(a) the cube reference number,
(b) the cube size and weight,
(c) the date the cube was made,
(d) the grade of concrete from which the cube was made,
(e) the location in the structure at which the concrete sample was taken,
(f) the slump of the concrete,
(g) the date on which the cube was tested,
(h) the total load at failure, and,
(i) the stress in MPa at failure.
Two copies of each test certificate, containing all the information mentioned above, shall be forwarded to the Engineer for his retention and a third copy retained in the Site laboratory.
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Valid Cube Results
A result is defined as the average 28 day compressive strength from testing a set of three cubes from one batch of concrete. The testing of a set of three cubes shall be deemed valid only if the range in compressive strength of the three cubes tested is less than 15% of their average compressive strength.
Until such time as sufficient valid test results are available to apply the method of control described in Section C 900 of the Construction Specification, the compressive strength of the concrete at 28 days shall be such that no single result is less than the characteristic strength minus 3 MPa and the average value of any three consecutive results shall be greater than the characteristic strength plus 2 Map.
If the average of any three consecutive results is less than the characteristic strength plus 2
Map but at least equal to the characteristic strength, the concrete shall be considered
acceptable but the Contractor shall adjust the mix design and the standard of control.
The 7-day cube result may be used as an early strength indicator, at the discretion of the
Engineer.
Acceptance Criteria for Characteristic Strength Concrete
When valid cube results are available for at least 30 consecutive batches of any class of concrete of the same consistence mixed in any one plant, the mean compressive strength shall be greater or equal to the characteristic strength plus 1.7 times their standard deviation and each individual cube tested shall be greater than 85 per cent of the characteristic strength.
Non-Compliant Test Results
If any one test cube result in a group of three consecutive results is less than 85 per cent of the
characteristic strength but the average of the group of three results of which it is part satisfies
the strength requirements of Section C 900 of the Construction Specification, then only the
batch from which the failed cube was taken shall be deemed not to comply with the
Construction Specification.
If more than one test cube result in a group of three consecutive results is less than 85 per cent of the characteristic strength or if the average strength of the group of three results fails to satisfy the specified strength requirements then all the batches between those represented by the first and last cubes in the group of three results shall be deemed not to comply with the Construction Specification, and the Contractor shall immediately adjust the mix design, subject to the approval of the Engineer, to restore compliance with the Construction Specification. After adjustment of the mix design the Contractor shall again comply with the requirements of Section C 900 of the Construction Specification.
If the mean compressive strength of three test cores is more than 85 % of the characteristic
strength and no single test core has a compressive strength of less than 75 % of the
characteristic strength, the Engineer may, at his discretion, consider leaving the defective
concrete in place.
Records of Concrete Placing
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Records, in a form agreed by the Engineer, shall be kept by the Contractor of the details of every pour of concrete placed in the Works. These records shall include, but not be limited to:
(a) Class of concrete,
(b) Slump,
(c) Location of pour,
(d) Date of pour,
(e) Ambient temperature and concrete temperature at time of placing,
(f) Moisture contents of aggregates,
(g) Details of mixes,
(h) Batch numbers,
(i) cement batch number,
(j) Ambient temperatures during curing,
(k) Results of all tests undertaken,
(l) Location of test cube sample points, and,
(m) Details of any cores taken.
The Contractor shall supply to the Engineer four copies of these records each week covering
work carried out during the preceding week. In addition he shall supply to the Engineer
monthly histograms of all 28 day cube strengths together with cumulative and monthly
standard deviations and any other information that the Engineer may require concerning the
concrete placed in the Works.
Testing Requirements (Reinforcement)
The Contractor shall obtain reinforcement from an approved manufacturer and shall submit
manufacturer’s test certificates to the Engineer.
The Contractor shall test all reinforcement intended for use in the Works for compliance with
the applicable AASHTO Standard in a laboratory acceptable to the Engineer, and supply two
copies of each test certificate to the Engineer. The frequency of testing shall be as set out in
the appropriate AASHTO Standard.
In addition to the testing requirements described above, the Contractor shall be required to
carry out such additional tests as may be instructed by the Engineer.
The Contractor shall promptly remove from Site any reinforcement that does not comply with
the Construction Specification.
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Abbreviations
The following abbreviations are used in this Section.
AASHTO American Association of State highway and Transportation Officials
ACV Aggregate Crushing Value
ASTM American Society of Testing and Materials
AIV Aggregate Impact Value
ALD Average Least Dimension
BA Bitumen Affinity
BS British Standard
CBR California Bearing Ratio
DIN Deutche Industrie Norm
FI Flakiness Index
IP Institute of Petroleum
LAA Los Angeles Abrasion Value
LL Liquid Limit
LS Linear Shrinkage
MC Moisture Content
MDD Maximum Dry Density
OMC Optimum Moisture Content
OPC Ordinary Portland Cement
PI Plasticity Index
PL Plastic Limit
PM Plasticity Modulus
SE Sand Equivalent
QA Quality Assurance
SG Specific Gravity
SSS Sodium Soleplate Soundness Test, loss on 5 cycles
STV Standard Tar Viscosity
UC Uniformity Coefficient
UCS Unconfined Compressive Strength
VIM Voids in Mix
VMA Voids in Mineral Aggregates
w/c Water / cement (ratio)
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SECTION C 300: SETTING OUT AND TOLERANCES
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PART 1: PAVEMENT CONSTRUCTION
Horizontal Alignement The centerline co-ordinates of the pavement surface as constructed and offsets there from shall be correct within a tolerance of ± 10 mm.
Thickness of Pavement Layers
The average thickness of any pavement layer measured at five points in any length of 100 m
shall not be less than 100% nor more than 120% of the thickness specified. In addition the
thickness of any pavement layer measured at any point shall be not less than 95% nor more
than 125% of the thickness specified.
Surface Layers
The level measured at any point on the surface of a finished pavement layer or formation level
shall not deviate from the corresponding level calculated from the Construction Documents
by more than the tolerances shown in Table 3-1. For verification of compliance with Table 3-1, measurements of surface levels shall be taken at points to be selected by the Engineer at 10 m centers longitudinally and at 1.5 m centers transversely to the road centerline. At junctions the requisite grid point spacing to verify compliance shall be determined by the Engineer.
Description of the pavement projected - Section 6 Drawing
Surface Regularity The surface regularity of a finished pavement layer or formation level shall be tested at points decided by the Engineer with a rigid steel straight-edge, 3 m long, placed parallel or perpendicular to the centerline of the road. The maximum allowable deviation of the surface below the straight-edge shall be as given in Table 3 - 1. In addition the longitudinal slope or transverse cross fall shall not deviate from that shown in the Construction Documents by more than the tolerances shown in Table 3 – 1.
Rectification Areas failing to comply with Clauses 301 to 304 shall be rectified; the minimum such area to be rectified shall be 3 m wide and 30 m long.
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Table 3 – 1 Surface Tolerances for Formation Level and Pavement Layers
Layer Max. deviation from
surface level
Max. depth below
3 m straight-edge
Max. deviation
from slope or
crossfall
Wearing course ± 6 mm 6 mm ± 0.25%
Asphalt concrete base
course ± 6 mm 6 mm ± 0.25%
Unbound Road Bases +10 mm
- 15 mm 10 mm ± 0.25%
Sub base and shoulders +10 mm to -30 mm 15 mm ± 0.50%
Formation level +10 to -30 mm 20 mm ± 0.50%
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PART 2: CONCRETE STRUCTURES
Concrete Structures Concrete elements shall be constructed within the tolerances set out in Tables 3-2 and 3-3 in relation to substructure and superstructure respectively.
Table 3 - 2: Tolerances for Concrete Elements for Substructure
Category Tolerance
Variation from specified cross-sectional dimensions + 10 mm, -5 mm
Displacement from specified position in plan 10 mm
Variation from specified level of top surfaces ± 10 mm
Variation from specified level of bearing areas ± 5 mm
Variation from plumb over full height 10 mm
Table 3 - 3 Tolerances for Concrete Elements for Superstructure
Category Tolerance
Variation from specified thickness of slabs, box girder slabs and T-
girder flanges + 10 mm, -5 mm
Variation from specified web thickness + 10 mm, -5 mm
Variation from specified overall depth or width ± 5 mm
Variation from specified overall length and length between bearings ± 10 mm
Allowable deviation of the surface below 3 m straight-edge or
template 5 mm
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SECTION C 400: SITE CLEARANCE
77
a-Site Clearance
Site clearance is defined as the clearing, grubbing, breaking out, removal, and disposal of all
vegetation, underground obstructions, structures, and debris.
Site clearance shall be carried out only as instructed by the Engineer or as described in the Contract.
Trees or other features immediately adjacent to the road reserve shall be protected.
Voids arising from the removal of underground obstructions shall be backfilled with suitable
material compacted to 95% MDD (AASHTO T99) up to the existing ground level.
B-DESCRIPTION
This Specification section address excavating, ripping, loading, hauling and
spreading in waste areas, of soil material designated by the Engineer as
“Unsuitable” from 3+200 up to 7+200 located un suitable material should remove
30cm from both site wide 25 m and transport in a safe area with advice site
engineer
UNSUITABLE MATERIAL
(a) Material shall be classified as “Unsuitable” in the following cases:
When the material resulting from the excavation made for the construction of the road or structure is declared in writing by the Engineer to be unsuitable for use in the embankment or other work. Such materials will generally include highly organic clays and silts, peat, soil containing large amounts of roots, grass and other vegetable matter, domestic or industrial waste.
When the material resulting from the excavation made for the construction of the road is surplus to the amount required for the construction of the embankment, provided, however, it is not material rendered surplus by reason of the Contractor having opened borrow pits solely for his own convenience as provided under Specification section 03300.
(b) The material proposed for wasting shall not be wasted until approved or directed in writing by the Engineer.
(c) Materials that are soft or unsuitable merely because they are too wet or dry are not to be classified as unsuitable unless otherwise directed by the Engineer.
WORK REQUIREMENTS
(a) Unsuitable material shall be excavated below sub-grade level in cut and below
embankment foundation level to the depth shown on the Drawings or directed by
the Engineer. Where unsuitable material is excavated below the normal sub-grade
level or below embankment foundation or for benching under embankments, the
excavation shall be back filled with material and in a manner in conformance with
the requirements of Specification section 03400 “Embankment Construction”.
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(b) Unsuitable material shall be removed and disposed of in waste areas provided by
the Contractor in such manner as to present a neat appearance and not to obstruct
drainage to any highway nor to cause injury to highway works or property. If it
becomes necessary for the Contractor to locate or relocate any waste areas, the
Engineer prior to spreading any waste shall approve them.
(c) The relevant provisions of Specification section 01700 “Environmental
Management” shall be adhered to for the hauling and disposal of unsuitable
materials.
(d) Waste areas shall be left in a smooth, neat and drainable condition, as required by
the Engineer, and all waste material shall be placed in such manner that adjacent
property will not be damaged or endangered. Soil slopes shall not be steeper than
2:1, unless otherwise noted on the drawings or as directed by the Engineer.
MEASUREMENT AND PAYMENT
MEASUREMENT
The quantity of Unsuitable Material to be paid for shall be the number of cubic meters
of material acceptably excavated in accordance with Specification requirements and
approved by the Engineer, based on field measurements. The material shall be
measured in the original position in the natural ground after Site Clearing.
Demolition of Bridges and Culverts
The Contractor shall not demolish any bridge or culvert until the Traffic Control measures
prepared in accordance with Section C 100 have been put into operation.
Demolition of bridges and culverts shall include the removal of the superstructure and
complete substructure down to existing ground level or watercourse bed level.
Over excavation shall be reinstated with Class 10/20 concrete or compacted selected granular
fill.
Materials arising from bridge and culvert demolition shall be disposed of in a manner
approved by the Engineer.
Partial demolition shall include the removal of deck components including pre cast concrete
deck beams, concrete footways and up stands, bridge bearings, pedestrian handrails, vehicular
guard-rails, expansion joints, road pavement and other sundry items.
Partial demolition shall be carried out in manner that avoids damage to the remaining parts of
the structure.
The Contractor shall make well the existing ground and banks of watercourses following
demolition works.
Where indicated in the Drawings or the Construction Documents or elsewhere in the Contract,
materials to be retained by the Employer are to be carefully dismantled and set aside for re-
use, or transported to a store designated by the Employer.
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Replacement of Bearings by Jacking Where required in the Contract, the Contractor shall raise bridge decks by jacking to allow replacement of bearings. The jacking shall be carried out from temporary supports which shall be designed by the Contractor to support all relevant loads from and maintain stability of the existing bridge deck. The temporary supports shall remain in place until the replacement bearings have been installed and the bridge deck lowered onto the bearings. The bridge deck shall be jacked in a manner approved by the Engineer. The sequence of jacking operations shall be such as to maintain the integrity of the existing bridge deck. All jacks shall be suitable for their intended purpose and shall have a load capacity adequate to support all relevant loads from the bridge deck. The jacks shall contain a suitable locking mechanism.
Removal of Road Furniture
Where required in the Contract road furniture including traffic signs, vehicular safety barriers,
posts and foundations and the like shall be removed. The resulting voids shall be backfilled
with selected suitable material and compacted.
All debris shall be disposed of. Road furniture shall be retained for re-use when so required or
delivered to a store designated by the Employer, or otherwise disposed of.
The Contractor shall install such temporary replacement signs and barriers that may be required to ensure the safety of the public until such time as permanent replacement road furniture is installed.
Removal of Culvert End Structures
Demolition of an end structure shall include the removal of the structure down to the levels
shown in the Construction Documents or, if not shown, to a depth 200 mm below existing
ground level or watercourse bed level or new invert level, whichever is the lower.
Over excavation shall be filled with grade 10/20 concrete or compacted selected granular fill.
Removal of Abandoned Military Tanks, Military Vehicles and other Vehicles
All abandoned military tanks, military vehicles and other vehicles located within 10 meters of
the edge of the existing carriageway shall be moved to a location at least 25 meters clear of
the Permanent Works, which does not obstruct any vehicular or pedestrian access or surface
water drainage path and does not lie on any cultivated land.
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Measurement and Payment The units that have been used in this contract associated to the Bill 2 ( Site Clearance ), are
the following
Note : Section 4, The Bill of Quantities described all the measurement method that have to be
taken in order to assign the Payment for every Item in this project
Nº of Item Description Unit
401 General site clearance Ha
402Removal of abandoned military tanks, military vehicles and other
vehicles
No
403 Demolition of existing buildings, structures or other elements cu m
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SECTION C 500: EARTHWORKS
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Scope of Section
This Section covers earthworks for new embankment construction. This includes:
excavation of cuttings, including the removal and stockpiling of topsoil,
excavation of side drains and benches,
ground compaction and preparation of the sub grade,
placing and compaction of material for fill in embankments,
excavation and rock fill to swamps,
top soiling and grassing,
Excavation and backfilling at highway structures such as bridges, culverts and walls.
The Section also contains clauses in respect of earthworks for rehabilitation works to existing
carriageways. This includes:
milling / scarifying existing pavement;
preparation of sub grade;
the reinstatement of revetments and batter slopes at existing bridges, including
reinstatement of protection works.
Classification of Materials
Earthworks materials shall be classified as follows.
1. “Topsoil” shall mean the top layer of soil which can support vegetation.
2. “Hard material” shall mean material which cannot be ripped by a track type crawler tractor
rated 250 kW flywheel power or over, or an operating weight of not less than 30 tonnes, using
a single type rock ripper.
The use of explosives will, of itself, not be a sufficient reason for classification of
material as “hard”.
Individual boulders greater than 0.3 cu meters in volume shall be classified as hard
material.
3. “Soft” excavation shall mean all excavation other than that in “hard material”.
4. “Unsuitable material” shall be material not acceptable for embankment construction
and shall include:
material with an organic content greater than 2% when tested accordance with
AASHTO 267,
material from swamps, peat, logs, stumps or perishable material and topsoil,
material with a swell of more than 2.5%,
material containing clays with a Liquid Limit exceeding 45% or Plasticity Index
exceeding 20%, unless otherwise permitted by the Engineer,
materials susceptible to spontaneous combustion,
frozen material which may otherwise be suitable when unfrozen,
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material with a CBR of less than 4 % measured after a 4-day soak on a laboratory
mix compacted to a dry density of 95 % MDD (AASHTO T180).
5. “Suitable material” shall be material acceptable for embankment construction and is
defined as material other than that classified as unsuitable. Suitable material will
comprise “soft suitable” and “hard suitable”. “Hard suitable” material shall comprise
excavated hard material broken down or otherwise treated to comply with the
Construction Specification for use in embankment construction.
6. “Non frost susceptible material” shall be suitable material with the following
additional properties:
maximum particle size of 63mm;
CBR greater than 6% measured after a 4-day soak on a laboratory mix compacted
to 95% MDD (AASHTO T180);
Plasticity Index of less than 9%;
Liquid Limit of less than 25 %;
Passing 75 μm sieve: less than 10%.
7. “Rock fill” shall mean hard material to the requirements of Clause C 507 placed in
designated areas of the Works.
Excavation of Topsoil
Topsoil shall be excavated prior to other earthworks operations.
Where instructed by the Engineer the Contractor shall, prior to removal of topsoil, excavate
trial holes to a depth sufficient to enable the Engineer to measure the depth of topsoil.
The Contractor shall regularly water topsoil heaps as required to promote the re-establishment
of covering vegetation and prevent loss of topsoil by wind erosion.
Topsoil shall remain the property of the Employer and shall not be run to spoil without approval.
Preparation Prior to Deposition of Fill
Prior to the deposition of fill, existing ground shall be leveled off and compacted to 90%
MDD (AASHTO T180).
Whenever the existing ground is, in the opinion of the Engineer, unsuitable for receiving fill,
the Contractor shall excavate to the depth instructed by the Engineer, remove the unsuitable
material and replace it with suitable material.
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Construction of Embankments Suitable materials shall be placed in layers and compacted. The maximum depth of layer for the proposed compaction equipment shall be determined from field trials in accordance with Section C 200 of the Construction Specification.
In the absence of field trials, soft suitable material in embankments shall be deposited in
layers not less than 150 mm, or exceeding 200 mm.
Each layer shall extend over the full width of the embankment.
Hard suitable material used for fill shall have a maximum dimension of 350 mm and shall be well graded. The material shall be deposited in horizontal layers not exceeding 400 mm loose depth and shall extend over the full width of the embankment. The material shall be spread and leveled by a crawler tractor weighing not less than 15 tones. After compaction each layer shall, if voids remain, be blinded with smaller rock fragments and granular material so as to fill as many of the voids as possible. The top of the layer shall be blinded with a fine graded material to seal the surface.
During the construction of embankments the Contractor shall control and direct construction
traffic uniformly over the full width
When constructing embankments up to drainage structures and bridges, the Contractor shall
raise the embankment equally on each side of such structure.
Capping Layer
In those zones which are describe in the Volume V drawings, a capping layer will be designed
as a coronation layer over the rest of the embankment
The measurement of imported suitable fill for capping layer shall be the volumes of the
compacted fill, less the volumes of:
(a) the suitable material excavated from within the Site measured in this Section;
(b) Other stated types of imported fill.
The measurement of other stated types of fill shall be to the outlines shown on the Drawings
or ordered by the Engineer. This type of fill is obtained in the cut zones
A CBR superior to 10 is required for this material.
Imported rock fill shall only be separately measured where rock fill as such is specifically
shown on the Drawings or ordered by the Engineer.
Widening of Existing Embankments
Widening of existing embankments shall be carried out using suitable material placed in
layers and compacted. Each layer shall be benched into the existing embankment in
accordance with Clause C 512. The width and maximum depth of each layer shall be suitable
for the compaction plant used and shall be determined from field trails in accordance with
Section C 200 of the Construction Specification.
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Compaction of Earthworks Soft Material
Each layer of material shall be compacted to a minimum of 95 % MDD (AASHTO T180).
The moisture content of the material shall be brought into the range –2% to +1% of OMC. (AASHTO T180). The Contractor shall provide all water necessary for compaction. The water to be used shall be clean, fresh, and free from all impurities and deleterious substances. Hard Material
Each layer of hard material used, as fill in embankments shall be systematically compacted by
at least 6 passes of a towed vibrating roller weighting not less than 3 tones per meter.
During compaction the surface of the layer shall be watered as necessary to facilitate the
filling of the voids with blinding material.
Sub-formation
Sub-formation is defined as the 0.5 m immediately below the earthworks outline indicated in
the Construction Documents, other than below pavement scarified in accordance with Clause
C 519.
The sub-formation shall be constructed in ‘non frost susceptible material’.
The sub-formation shall be compacted to 98% MDD (AASHTO T188).
In cuttings, where this level of compaction cannot be achieved on the existing soil, it shall be
removed and replaced as necessary.
Geotextile Membrane Where rock fill is placed onto geotextile membrane, the fabric shall be blinded with a cushioning layer.
Where the geotextile membrane is placed around the rock fill the final layer of rock fill shall be blinded with gravel so as to present a smooth surface to receive the geotextile membrane.
Geotextile membrane shall extend at least one meter beyond the toe of the fill.
Structural Excavation
Structural excavation shall mean excavation for the repair or construction of bridges and
culverts.
Structural excavations shall be excavated to the underside of the foundation or to the
underside of blinding layer (if shown). The bottom of the excavation shall be trimmed to
level with all loose and soft material being removed. Voids in hard material below the bottom
of base level shall be filled with Class 10/20 concrete
87
Where in the opinion of the Engineer the material in the bottom of the excavation is for any reason unsuitable, the additional material may be removed, as directed by the Engineer, down to a firm base. The resulting voids shall be filled with Class 10/20 concrete or otherwise as directed.
Structural excavations shall be kept dry at all times.
Structural Backfill The Contractor shall submit to the Engineer his proposals for the compaction of backfill adjacent to structures prior to commencing such work.
Where shown on the Drawings or Construction Documents, structural backfill shall be with
selected granular fill complying with the grading requirements of Table 5-1.
Table 5 -1 Selected Granular Fill
Sieve Size Percent Passing
37.5 mm 100 %
19 mm 70 – 100 %
9.5 mm 45 - 65 %
4.75 mm 30 - 50 %
2.36 mm 15 - 40 %
425 μm 5 - 25 %
75 μm < 5%
Selected granular fill shall also comply with the following:
material passing the 425µm sieve shall have a plasticity index of less than 6;
the water soluble sulphate content shall be less than 2 g of sulphate per litre.
Benching
Where the existing slope is greater than 10%, or elsewhere, where shown on the Construction
Documents, the Contractor shall excavate benches in natural ground or to existing
embankment side slopes. The initial bench at the toe of the fill shall be cut to sufficient
dimensions to permit the operation of placing and compaction equipment. Each subsequent
bench shall be cut as the fill is compacted and built up. The material that is excavated to form
benches shall either be taken to spoil or, if suitable in accordance with this section of the
Construction Specification, the material shall be reused as fill. The maximum bench height
shall be 500 mm or as shown on the Construction Documents.
Preparation of Formation
“Formation” is defined as the top surface of the earthworks outline as shown in Drawings or
Construction Documents overlain by pavement or shoulder construction.
88
Prior to the laying of pavement materials and / or shoulder material any protection layer shall
be removed and any soft or damaged areas shall be rectified. The surface of the formation
shall be trimmed and cleaned free from mud, slurry and loose material.
Trimming of Embankment Slopes
The side slopes of embankments shall be trimmed to uniform batters as shown on the
Construction Documents. Any loose, improperly compacted or oversize material shall be
trimmed back and removed from embankment faces.
Any rock or boulder appearing in the face of an embankment shall be trimmed back to within
the tolerance specified. If any exposed rock or boulder should be unstable, it shall be
completely removed and the resulting void filled with suitable material compacted to the
approval of the Engineer.
Trimming of Existing Cut Slopes
Existing cut slopes shall be trimmed to remove unstable or loose material, where indicated in
the Scope of Works.
Resoiling
Topsoil arising from the Works shall be reused as topsoil to new embankment side slopes or
elsewhere shown on the Drawings or Construction Documents. After placing and spreading,
topsoil shall be renovated and lightly compacted. The Contractor shall water topsoil areas
during summer months to promote plant growth.
Watercourses and Side Drains
Where shown in the Construction Specification, Drawings, or Construction Documents,
existing drains and watercourses shall be cleaned and re-graded. The original channels shall
be cleared of all vegetable growth and obstructions prior to earthworks. Where soft spots
occur below finished invert level the unsuitable material shall be removed and replaced with
suitable fill.
The final invert and slopes shall be trimmed to provide a uniform cross section and
longitudinal profile.
Scarification of Existing Pavement In this clause “Pavement” means bituminous bound surfacing materials only.
“Scarification” means the breaking down of the pavement in place by mechanical means to
dis-aggregate the bound material to particles no larger than 50mm.
The existing pavement shall be saw cut at the limits of scarifying to provide a sound
construction joint with subsequent paving materials.
89
The resulting surface shall be bladed smooth, graded and compacted such that the surface is
tight and free from movement. The surface shall be to the tolerance requirements of formation
level.
The Contractor shall be required to demonstrate the efficacy of its proposed method of
scarification at a field trial. This unit is not defined in the budget , so it could be used
specially in urban areas
Reinstatement of Batter Slopes
Batter slopes shall be reinstated where shown in the Scope of Works and Construction
Documents.
Areas of subsidence and slippage shall be excavated and backfilled in accordance with the
requirements for earthworks as set out in this section of the Construction Specification. The
area reinstated shall be finished to match the profile of the existing slope.
Measurement and Payment The units that have been used in this contract associated to the Bill 3 ( Earthworks ), are the
following
Note : Section 4, The Bill of Quantities described all the measurement method that have to be
taken in order to assign the Payment for every Item in this project
Nº of Item Description Unit
Excavation of Materials
In cross sections, according to drawings cu m
In improvement of profile section cu m
502 Deposition of suitable fill for capping layer ( origin cut zones) cu m
503 Deposition of imported suitable fill for capping layer cu m
504 Deposition and compaction of fill adjacent to structures cu m
505 Re-shaping sand dunes cu m
Disposal of Materials
In cross sections, according to drawings cu m
In improvement of profile section cu m
Deposition of Suitable Fill in Embankments
In cross sections, according to drawings cu m
In improvement of profile section cu m
508 Provisional gravel path sq m
506
507
501
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SECTION C 600: CULVERTS, DRAINAGE AND PROTECTION WORKS
91
Scope of Section
This section covers:
culverts and drainage structures generally;
installation and repair of concrete culverts;
culvert inlet and outlet works;
carriageway drainage offlets, chutes and the like;
ditching;
drainage protection works.
Concrete works forming part of drainage structures shall be in accordance with Section C 900 of the Construction Specification.
General
All concrete for culverts and drainage structures shall be made with sulphate resisting cement.
The works are described in the Contract generally as precast elements. Cast in place concrete
to an equivalent standard shall be acceptable, subject to the consent of the Engineer. In the
case of highly visible items such as kerb, any proposal to use cast in place methods will be
subject to a trial to demonstrate that an acceptable and aesthetically pleasing visual
appearance is achieved
Cast in place concrete works in drainage structures shall be class B 30/20 unless described
otherwise. Cast in place concrete shall comply with the requirements of Section C 900 of the
Construction Specification. All RCP that is not certified to meet the pertinent AASHTO
designation, or similar, will be covered with a nominal mix concrete at least form the mid-
point up and for 300 mm over the top
Classification of Excavated Materials Earthworks materials shall be classified in accordance with Section C 500 of the Construction Specification.
Excavation for Culverts and Drainage Structures
The Contractor shall make provision for dealing with and maintaining water flows and for
maintaining excavations free from water.
The final excavated surface on which culverts or structures are to be constructed shall be
compacted to a dry density of at least 95% MDD (AASHTO T99) to a depth of 150 mm
below the foundation..
Where ground conditions are such that a satisfactory foundation cannot be achieved, the
Contractor shall remove the unsuitable material to the depth and width instructed by the
Engineer.
Where, in the opinion of the Engineer, the surface of the excavation has become soft or
unsuitable due to the Contractor’s method of working, the Contractor shall at his own cost
remove and replace the unsuitable material with approved granular material or non-structural
concrete as instructed by the Engineer.
92
In hard material, excavations shall allow for a minimum of 50mm Class 10/20 concrete to the
underside of foundation.
Structural Elements Cast Against Excavated Surfaces
Where the Construction Documents show structural elements cast against an excavated
surface, the Contractor shall carry out the excavation neatly to the specified slope and shape.
Over-excavation shall be backfilled with concrete Class 10/20.
Backfilling for Culverts and Drainage Structures
Backfill to culverts and drainage structures shall be with selected granular fill to the
requirements of Table 5-1 (Section C 500).
Backfill shall be compacted to a minimum dry density of 95% MDD (AASHTO T180).
Moisture content shall be adjusted to –2% to +1.5% of OMC (AASHTO T180).
Above ground level the Contractor shall use the same material as that being used for the
adjacent embankment.
Bedding and Laying of Culverts
Pipe bedding material shall be well graded granular material with a maximum stone size of 20
mm and a maximum of 10% by weight passing the 75mm sieve.
Pipe bedding shall be compacted to 95% MDD (AASHTO T180).
Voids shall be formed under the sockets to allow pipe jointing. When the pipe joint has been
completed, the void shall be rammed with pipe bedding material.
Jointing
Culvert joints shall be filled with oakum filler or similar, taped for 25cm each side of the joint
and covered with one layer of bit mastic paint or similar.
Waterproofing
A protective bituminous coating shall be applied to the outside surfaces of the culvert barrel
and other concrete faces in contact with soil.
93
The protective coating shall be one of:
one coat of proprietary bit mastic paint;
one coat of mastic asphalt or similar propriety product;
one coat of brush applied bitumen;
two coats of cut-back bitumen or bitumen emulsion.
Inlet and Outlet Structures
Inlet and outlet structures shall include headwalls, wing walls and apron slabs.
In-situ concrete for drainage structures shall be Class 20/20. The surface finish shall be Class
U1 for unformed surfaces and Class F1 for formed surfaces.
Guiding Dams and Scour Checks
The construction of embankments for guiding dams shall conform to provisions of Section C
500 of the Construction Specification.
Guiding dams shall be formed in selected/suitable fill material compacted to a minimum dry
density of 95% MDD (AASHTO T99).
Concrete for scour checks shall be Class 20/20 complying with the requirements of Section C
900 of the Construction Specification.
River Training and New Watercourses
Excavation for river training shall include site clearance, trimming of slopes, grading of beds
and disposal of the excavated material.
Where watercourses are required to be diverted, the original channels shall be cleared of all
vegetative growth and soft deposits and backfilled and compacted with approved materials.
Riprap
Stone for riprap shall consist of well shaped, hard, dense and durable rock. The minimum weight and dimensions of individual stone pieces shall be as shown in the Construction Documents.
The stones shall be laid with close joints from the bottom of the slope of embankment, or existing ground upward, the larger of the stones being laid at the bottom. The surface shall be hand packed, carefully bedded and tightly wedged with suitable spells to form an even, densely packed surface.
94
Grouted Stone Pitching
Stone for pitching shall be hard and durable and shall exclude mudstones and the like. Stone shall be free from weathering, cracks, and other deleterious imperfections. Stone pitching shall be roughly dressed square. The least dimension of any stone shall not be less than 200 mm, and the weight not less than 10kg. No rounded cobbles or boulders shall be used.
The area to be pitched shall be prepared by excavating, shaping and trimming to
accommodate the stonework and bedding. The area shall be compacted by plate compactor or
equivalent.
Grouted stone pitching shall be placed on a selected granular fill bedding as shown on the Construction Documents.
A trench shall be excavated along the toe of any slope to be pitched or along the unprotected edge of the pitching in the beds of watercourses. Commencing at the bottom of the trench stones shall be laid and firmly bedded into the slope and against adjoining stones. The stones shall be set on edge with their largest dimension at right angles to the slope. The stones shall be securely rammed into the surface to be protected. The stones shall be fitted closely together so as to leave only a minimum of interstices which shall be filled with suitably shaped and tightly wedged spalls. The top of the pitching shall be finished flush with the adjacent material.
Before grout is applied the surfaces of the stones shall be thoroughly cleaned and free from
adhering dirt and clay. Grout, composed of one part cement to three parts sand, shall be
rammed into the wetted interstices between the stones so as to ensure all voids are completely
filled. The grout shall be smoothed off flush with the pitched face and the stones shall be
thoroughly brushed such that their top surfaces are exposed. The grouted stone pitching shall
be cured with wet sacking or other approved method for a period of not less than seven days
after grouting.
Carriageway Drainage Outlets
Carriageway drainage outlets comprise:
drainage outlet channels;
embankments chutes;
toe of slope energy dissipaters.
In-situ concrete shall be Class 15/20.
Bedding shall be well graded granular material to the requirements of Clause C 607. 1.1.a.i.1.1.1.1.1
95
Measurement and Payment The units that have been used in this contract associated to the Bill 4 (Culvert and drainage
works), are the following
Note : Section 4, The Bill of Quantities described all the measurement method that have to be
taken in order to assign the Payment for every Item in this project
Nº of Item Description Unit
Box Culverts
601A Concrete box culverts 1x1 lin m
601B Concrete box culverts 1.5x1 lin m
601C Concrete box culverts 2x2 lin m
601D Concrete box culverts 4x2 lin m
601E Concrete box culverts 6x4 lin m
601F Concrete box culverts 2x(4x2) lin m
601G Concrete box culverts 2x(6x4) lin m
End Structures
602A End structures units to concrete box culverts 1x1 No
602B End structures units to concrete box culverts 1.5x1 No
602C End structures units to concrete box culverts 2x2 No
602D End structures units to concrete box culverts 4x2 No
602E End structures units to concrete box culverts 6x4 No
602F End structures units to concrete box culverts 2x(4x2) No
602G End structures units to concrete box culverts 2x(6x4) No
603 In-situ concrete for repairs to pipes, headwalls, wingwalls and aprons cu m
604 Concrete lined channel ln m
605 Riprap protection works cu m
606 Gabions cu m
607 De-silting of culverts No
96
SECTION C 700: GRANULAR PAVEMENT MATERIALS (SUB-BASE, SHOULDERS AND CRUSHED STONE BASE)
97
Material Requirements
Materials for sub-base and shoulders may be from naturally occurring sands and gravels, or
from crushed rock, crushed slag, or crushed concrete.
Materials for crushed stone base shall be crushed rock, crushed slag, or crushed concrete.
Materials shall be free from deleterious components including organic matter, friable or
weathered materials, clay minerals, plate-like or scaly particles, soft stones, potentially
expansive minerals, chemically unsound materials and soluble salts.
Field Trials
Full-scale laying and compaction trials shall be carried out by the Contractor on all pavement
materials.
The trials shall be carried out in the presence of the Engineer.
Each trial area shall be at least 100 meters long and of the full construction width. Material
shall be placed and compacted to achieve the depth specified. The trial area may form part of
the Works provided that it fully complies with the Construction Specification.
The Contractor shall compact each type of material over the range of comp active efforts
proposed for each pavement layer.
The following data shall be recorded for each level of comp active effort, as appropriate:
1) the composition and grading of the material before the Site trial,
2) the composition and grading of the material after compaction,
3) the moisture content at the time of compaction and the optimum moisture content for
the specified compaction,
4) the type, size, tire pressures, frequency of vibration and the number of passes of the
compaction equipment,
5) the maximum dry density or target density as appropriate measured on a sample before
and at intervals throughout the Site trial,
6) the density achieved,
7) the compacted thickness of the layer.
Where the results of the site trial indicate that the proposed equipment and methods place material in accordance with the Construction Specification, the proposed methods may be incorporated into a formal Method Statement for the consent of the Engineer.
98
Subbase Material shall be processed to give a product with a smooth grading curve within the specified envelope and with the engineering properties specified below.
Table 7 - 1 Gradation Requirements for Subbase Material
Sieve Size Percentage passing
(by mass)
63.0 mm 100%
37.5 mm 85 - 100%
9.5 mm 40 - 70%
4.75 mm 25 - 45%
425 μm 6 - 20%
75 μm 2 – 8%
Sub base shall comply with the following:
Liquid limit: maximum 25%;
Plasticity Index: maximum 6%;
Plasticity Modulus: maximum 60;
CBR at 98% MDD (AASHTO T180) and after a 4-day soak: minimum 30.
Cement Stabilized Sub base
Cement stabilized sub base shall comprise sub base material to Clause C 703 with the
addition of 6% cement (or other percentage stated in the Contract).
Mixing shall be by batching. The period from mixing to deposition and compaction shall not
exceed 3 hours. Moisture shall be added as necessary to achieve 98% MDD (AASHTO
T188).
The Contractor shall demonstrate the efficacy of his mixing and deposition methods by a
Field Trial.
This unit is not defined in the project, but if the contractor considered it necessary , this unit
could be used.
Crushed Stone Base The grading of crushed stone base after placing and compaction shall be a smooth curve within and approximately parallel to the envelope shown in Table 7 - 2.
99
Table 7 - 2 Gradation Requirements for Graded Crushed Stone Base Material
Sieve Size Percentage passing
(by mass)
50.0 mm 100%
37.5 mm 90 - 100%
25.0 mm 80 - 95%
19.0 mm 60 - 80%
9.5 mm 40 - 60%
4.75 mm 25 - 40%
2.00 mm 15 - 30%
425 μm 7 - 19%
75 μm 2 - 8%
Non-plastic angular sand from an approved secondary source may be combined with crushed
materials if the amount of fine aggregate produced during crushing is insufficient.
Crushed stone base shall comply with the following:
Plasticity Index: NIL;
Los Angeles Abrasion Value (AASHTO T96): maximum 30;
Flakiness Index (BS 812): maximum 35.
Crushed stone base material shall be free from any potentially deleterious material such as
significantly weathered igneous rock. In case the material contains any significant fraction
(more than 2%) of mica, the contractor shall be required to demonstrate to the satisfaction of
the Engineer that the methods selected to verify proper compaction are truly representative of
the condition actually obtained in the field.”
After the third bullet point add a fourth stating: “Not less than 90% by weight of the total
particles retained on the 4.75mm sieve shall have at least two crushed faces
100
Shoulders Preparation of Shoulder
In all cases there shall be a requirement to construct a ‘formation’ at the earthworks outline in
the shoulder area.
Depending on site conditions this may involve:
trimming of the existing shoulder to the earthworks outline; or
formation on widened embankment; or
a combination of both.
In the case of widened embankments, the embankment shall be formed to the earthworks
outline and formation prepared at that outline prior to commencing shoulder fills.
In the case of trimming, the existing shoulder shall be cut back to the earthworks outline and
formation prepared at that outline prior to commencing shoulder fills.
Shoulder Fill
Shoulder Fill shall be formed in sub-base material complying with Clause C 702.
Shoulder fill may be placed contiguously with sub base under carriageway.
Granular Shoulder Material
The upper 100mm of shoulder shall be constructed with Granular Shoulder Material.
Granular Shoulder Material shall comply with the grading requirements of Table 7-3 and the
following engineering criteria.
Table 7.3: Gradation Requirements for Granular Shoulder Material
Sieve Size Percentage Passing*
(by mass)
25 mm 100%
9.5 mm 80 – 100%
4.75 mm 60 – 85%
2.36 mm 45 – 70%
425 μm 25 – 45%
75 μm 10 – 25%
*Not less than 10% of the material shall be retained between each pair of successive sieves,
excepting the 20mm and 10mm.
Granular Shoulder Material shall have:
a minimum CBR of 30 at 95% MDD (AASHTO T180) and 4 days soak;
a maximum Liquid Limit of 25;
101
a Plasticity Index of between 4 and 9.
Deposition and Compaction The moisture content during compaction shall be maintained between 1% above and 2% below the Optimum Moisture Content (AASHTO T180).
Granular pavement materials up to 200 mm compacted thicknesses may be spread and
compacted in one layer. Granular pavement materials of compacted thickness greater than
200 mm shall be laid in two or more layers and the minimum compacted thickness of any
such layer shall be 110 mm. for granular sub base and 80 mm. for crushed stone base.
Shoulder fill, and sub base shall be compacted to a minimum of 97 % MDD (AASHTO
T180). Crushed stone base and Granular Shoulder Material shall be compacted to a minimum
of 98 % MDD (AASHTO T180).
On completion of compaction, the surface shall be well closed and free from movement under
compaction plant and from compaction planes, laminations, ridges, cracks, loose or
segregated material, potholes, ruts or other defects.
Pavement operations shall be conducted in such a manner that the works are well drained.
Measurement and Payment The units that have been used in this contract associated to the Bill 5 ( Pavement Works ), are
the following
Note : Section 4 The Bill of Quantities are described all the measurement method that have to
be taken in order to assign the Payment for every Item in this project
Nº of Item Description Unit
Granular Pavament MaterialsCrushed Stone Base ( Macadam )
Base cu m
Hard shoulders and verge cu m
702 Gravel Subbase cu m
703 Imported suitable fill for subgrade cu m
Bituminous Pavement Works
801 Prime coat sq m
802 Tack coat sq m
803 Asphaltic concrete base course cu m
804 Asphaltic concrete wearing course cu m
805 Bitumen for asphaltic concrete tonne
806 DBST (Double Bituminous Surface Treatment) on hard Shoulders sq m
807 Sidewalk sq m
701
102
SECTION C 800: BITUMINOUS PAVEMENT WORKS
103
Scope of Section
This Section covers bituminous works generally.
Part A covers material requirements for asphalted concretes.
Part B covers design requirements for asphalted concretes.
Part C covers asphalted concrete production and laying
Part D covers other bituminous products.
Part E covers repairs to existing bituminous pavements.
104
PART A: MATERIALS FOR ASPHALTIC CONCRETES
Bitumen Bitumen for asphalted concrete shall be Penetration Grade 60/70. Please review this and recommend proper type of bitumen.) Complying with Table 8-1.
Table 8 – 1 Bitumen for Asphaltic Concrete (please revise accordingly)
Unit
Penetration at 25˚C (100 g, 5 s) 60/70 0.1 mm
Softening point (Ring-and-Ball) Min 48 - Max 57 ˚C
Flash point (Cleveland open cup) > 220 ˚C
Frays breaking point < -8 ˚C
Viscosity at 135˚C > 250 centistokes
Solubility in tricolour-ethylene 99 % min
Water content 0,2 Max
1.1.a.i.1.2 Tests on Residue from thin-film oven test
Loss on heating after thin film oven test < 0.5%
Change of Softening Point temperature < 5 ˚C
Loss of penetration at 25˚C (100 g, 5 s) < 50% (% of original)
Bitumen shall be homogeneous, free from water, and shall not foam when heated to 175 ˚C.
Bitumen from different suppliers or sources shall not be combined.
Aggregates for Asphalted Concrete Coarse Aggregate
At least three different sizes of aggregate, plus mineral filler if required, will be mixed in the
asphalt concrete mix plant Coarse aggregate (material retained on a 6.3 mm sieve) shall
consist of crushed angular stone free from, muscovite in excess of 1% by weight” and in the
second paragraph substitute “90%” instead of clay, silt, organic and other deleterious matter.
The minimum size of the stone to be crushed shall be at least 4 times the nominal size of the
aggregate. At least 90% by weight of the total fraction of the blended aggregates in the mix
which are retained on the 4.75mm sieve shall have two or more faces split by the crushing.
The aggregate shall comply with the following requirements:
Los Angeles Abrasion max. 25;
Sodium Sulphate Soundness max. 12;
Water Absorption max 2%;
Flakiness Index max. 25.
Fine Aggregate
105
Fine aggregate (material passing a 6.3 mm sieve) shall consist of crushed stone screenings
produced from stone having a Los Angeles Abrasion value of not more than 30.
Fine aggregates shall be free from, clay, silt, organic and other deleterious matter and shall be
non-plastic.
The Sand Equivalent of the fine aggregate shall not be less than 40.
Subject to the approval of the Engineer, and following production and field trials, the total
aggregates in the mix may contain 5% to 15% by weight of natural sand.
Mineral Filler
Mineral filler shall consist of finely ground particles of limestone, hydrated lime, ordinary
Portland cement or other non-plastic mineral matter approved by the Engineer. It shall be
thoroughly dry and free from lumps. At least 75% by weight of the mineral filler shall pass
the 75 micron sieve and 100% shall pass the 425 micron sieve.
Mineral filler shall have a bulk density in toluene measured in accordance with BS 812 of
between 0.5 g/ml and 0.9 g/ml.
Adhesion Agents The Contractor may, subject to the approval of the Engineer, use adhesion agents.
106
PART B: ASPHALTIC CONCRETE MIX DESIGN
Mix Design Procedure
The Contractor shall be responsible for asphalted concrete mix design shall be conducted
using the actual aggregates produced in at least three different sizes plus mineral filler, if
required for production paving
The mix designs shall be carried out in accordance with the Marshall Test Procedure detailed
in the Asphalt Institute’s Manual No. 2 (MS-2) (6th
edition; 1996), ‘Mix Design Methods for
Asphalt Concrete’, using 75 blows on each face, (referred to hereinafter as the ‘standard
Marshall Design’).
The standard Marshall Design shall be augmented by the ‘Refusal Density Design’ described
in Clause C 806.
The design will establish a Job Mix Formula for each mix required for the Contract.
The Job Mix Formula shall be determined using the following procedure:
laboratory testing in accordance with the Marshall Test Procedure;
full scale production trials using the Contractor’s production equipment over the range
of binder contents used in the laboratory design procedure;
field trials to determine the adequacy of the Contractor’s compaction equipment.
On completion of the above process, the Contractor shall submit a Job Mix Formula to the Engineer.
A Job Mix Formula shall be defined by:
(a) a single percentage of aggregate passing each required sieve size,
(b) a single percentage of bitumen to be added to the aggregate,
(c) a temperature range within which the mixture is to be mixed,
(d) a recommended temperature range for compaction of the mixture.
(e) proportions of the different aggregate sizes and mineral filler, if required, to be
mixed in the plant
The Engineer shall give consent to the use of the proposed Job Mix Formula or shall reject the
proposal with reasons for its rejection.
The Contractor shall use only the approved standard mix formula for the production of each
bituminous mixture. No modifications to a standard mix or changes in the nature or source of
the constituent materials shall be made without a written submission by the Contractor to the
Engineer and his subsequent consent.
If a standard mix formula proves unsatisfactory, a new standard mix formula together with
supporting test data shall be submitted by the Contractor for review and approval by the
Engineer prior to production.
107
Refusal Density Design
Additional test samples, in sets of three, shall be prepared at three binder contents:
(a) that corresponding to 5% Voids in Mix (VIM);
(b) 0.5% above (a);
(c) 0.5% below (a).
These sample sets shall then be compacted to ‘refusal’. ‘Refusal’ is defined as 300 blows on
each face of a Marshall specimen at the temperature defined in MS-2.
A graph of VIM at the refusal density shall be plotted against binder content.
The binder content that corresponds to VIM of 3 per cent, shall be determined. This value
shall be obtained by interpolation and not by extrapolation. Further samples shall be made
and tested in order to comply with this condition.
The Job Mix binder content shall be based on consideration of the various Marshall Design
parameters and the value at 3% VIM at ‘refusal’. If a VIM of 3% at refusal can not be
attained using the proposed grading, the mix shall be re-designed with an alternative grading.
Grading Requirements
The grading of the mixture of coarse and fine aggregate shall be within and approximately
parallel to the grading envelopes given in Table 8-2. The grading of the mix shall not pass
through the “Restricted Zone Boundary” as defined in “Super pave Mix Design1 ”.
Table 8-2: Grading Requirements of Aggregate for Asphalted Concrete
Sieve Size
Mm
Percentage by Mass Passing
Base Course Wearing Course
25 mm 100 % -
19 mm 84 – 95 % 100 %
12.5 mm 60 – 77 % 75 – 88 %
9.5 mm 50 – 68 % 62 – 79 %
4.75 mm 32 – 53 % 39 – 60 %
2 mm 20 – 41 % 26 – 47 %
9 – 21 % 10 – 25 %
5 – 10 % 5 – 12 %
It will be permitted to deviate from the above envelopes in order to comply with the
requirements of Clause C 806.
1 Published by the Asphalt Institute (SP-20, 1996).
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Physical Properties
Asphalted concrete shall comply with Table 8-3.
Table 8-3: Physical Properties for Asphalted Concrete
Base Course Wearing Course
Marshall Stability 75 blows (N) Min 8000 Min 7000
Flow Value (mm) 3 – 5 3 – 5
Voids in total mix (VIM)(%) 3 – 5 3 – 5
Voids in mix at refusal density (%) 2 - 3 2- 3
Voids in Mineral Aggregate (VMA)
(%) 13 - 15 14 – 16
% voids filled with bitumen (VFB) 65 - 78 65 – 78
Water sensitivity (ASTM 1075) Loss
of stability on immersion in water
Min. 75% retained
strength
Min. 75% retained
strength
Where the asphalt mix does not meet the requirements in Table 8-3 above for the Water
Sensitivity Test (ASTM 1075), the Contractor shall propose the use of a suitable adhesion
agent such as Portland cement, hydrated lime or other proprietary agent for the Engineer’s
approval. The beneficial properties of the proposed agent when incorporated in the mix and
the percentage of agent to be added to the mix shall be demonstrated by further test results.
Full Scale Production Trials
Following completion of the laboratory Marshall Design Procedure, augmented by the
Refusal Design, the Contractor shall undertake full scale production trials.
These trials shall involve a repetition of the Marshall Design Procedure and the Refusal
Density Procedure using material produced from the Contractor’s proposed asphalt mixing
plant.
The purpose of the production trials is to validate the laboratory mix design for the actual
production process.
Field Trials The Contractor shall carry out full-scale laying and compaction trials on all proposed asphalt mixes. The trials shall be carried out, under supervision of the Engineer and at a location approved by the Engineer. Each trial area shall be at least 50m long, and to the full construction width and depth for the material.
The Contractor shall compact each section of the trial area over the range of compactive effort it proposes. The following data shall be recorded for each level of compactive effort:
(a) the composition and grading of the material including the bitumen content,
(b) the temperature of the bitumen and aggregate immediately prior to entering the mixer, and
the temperature of the mix on discharge from the mixer, on commencement of laying, on
commencement of compaction and on completion of compaction,
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(c) the type, size, mass, width of roll, number of wheels, wheel-load, tyre pressures,
frequency of vibration and the number of passes of the compaction equipment, as
appropriate for each roller type,
(d) the density and voids achieved,
(e) the compacted thickness of the layer
(f) pavement riding quality,
(g) Pavement level tolerances.
Site trials shall determine the minimum number, type and condition of rollers required to
compact the mixture to the specified density and pavement tolerances.
The Contractor shall, in the presence of the Engineer, carry out tests on at least eight cores
from each trial section.
The field trial shall be considered successful if:
the results of the tests on the cores satisfy the requirements for Field Density
Requirements of Clause C 815; and
the surface after compaction complies with the requirements of Clause C 817, and
the pavement tolerance complies with the requirements of Section C 300 of the
Construction Specification.
On completion of a successful field trial the Contractor shall submit, for the Engineer’s
consent, a proposed Job Mix Formula and a proposed surfacing Method Statement..
The Engineer shall give consent to the Formula and Method Statement, or reject both or
either, giving reasons for their rejection.
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PART C: ASPHALTIC CONCRETE PRODUCTION
Storage of Bitumen
The maximum continuous storage temperature for bitumen over a 24 hour period shall not
exceed 125oC.
Bitumen tanks shall be capable of maintaining their contents at the specified temperature
within a tolerance of ±5oC, and shall be equipped with thermostatic control to prevent the
temperature rising above 170oC.
Bitumen tanks shall have fixed thermometers able to be read from outside the tanks.
Mixing The Contractor shall mix bituminous materials in a mixing plant complying with AASHTO M156. The mixing plant may be either the batch-mix type or the continuous-mix type and shall be capable of regulating the composition of the mixture to within the tolerances detailed in Table 8-4. In case the contractor elects to use a continuous mix-type plant, the contractor shall propose for the Engineer’s approval, and then implement when approved, a rigorous program of sampling and testing the gradation of the various sizes of aggregate produced by taking samples directly off the crusher/screening plant discharge belts as well as from the various stockpiles for each size of aggregate
Bins shall be covered to prevent ingress of moisture. Mixing plants shall be fitted with
adequate filters to prevent dust pollution.
Bitumen and aggregate shall be mixed within the range 140˚C to 170˚C. Bitumen shall not be
heated above 180 ˚C.
Acceptability criteria for mix composition are detailed in Table 8-4.
Table 8-4 Acceptability Criteria for Asphalted Concrete Mixes
Tolerance relative to Job Mix Formula
Bitumen Content ± 0.2% by total weight of total mix
Passing 10 mm sieve and larger sieves ± 6% by total weight of dry aggregate including
mineral filler
Passing sieves between 10 mm and 1 mm sieves ± 4% by total weight of dry aggregate including
mineral filler
Passing sieves between 1 mm and 75 m sieves ± 3% by total weight of dry aggregate including
mineral filler
Passing 75 m sieve ± 2% by total weight of dry aggregate including
mineral filler
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Preparation of Surfaces
Immediately before placing asphalted concrete, the Contractor shall clean the existing surface
of all loose material and foreign matter and make good any defects.
All crushed stone base course shall be prime coated prior to the laying of binder course. Primed surfaces shall be cured.
All binder courses shall be tack coated prior to laying wearing course.
Transportation and Deposition Ambient Weather Conditions
Asphalted concrete shall be placed only when either of Case 1 or Case 2 conditions shown
below are met.
Ambient air
temperature
Road surface
temperature Wind velocity
Case 1 > 5 deg C > 10 deg C < 14m/sec
Case 2 > 0 deg C > 0 deg C < 5 m/sec
Notwithstanding these provisions, the Contractor shall not carry out asphaltic concrete work
in otherwise adverse weather conditions.
Transportation and Deposition
Base course shall be placed using guide wires and joint matching ski and electronic sensors.
Subject to achieving the specified grades on the base course surface, the wearing course shall
be placed by setting the pavers to run constant depth and manual operation to avoid an
undulating surface.
The width of the paving and the fleet of hauling equipment shall be such that a constant and
reasonable rate of forward movement of the pavers can be maintained, non-stop throughout
each daily shift given the output of the mixing plant
Asphalted concrete shall be kept free of contamination during transportation. Each load shall be covered. Transportation vehicles shall be cleaned after each trip. Tipper bodies shall be lightly oiled to prevent adhesion.
Asphalted concretes shall be placed only by purpose built self-propelled asphalt paver
equipped with automatic controls.
Compaction shall be carried out in accordance with the procedures determined from the Field
Trials. The minimum temperature of asphalt concrete at the commencement of compaction
shall be 125oC and the minimum temperature at completion of compaction shall be 80
oC.
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The final surface shall be uniformly textured free from segregation, tearing, tracking or other
surface irregularities and within the tolerances specified in Section C 300 of the Construction
Specification.
Compaction equipment shall not be parked on asphaltic concrete surfaces which are less than
48 hours old.
Field Density Requirements
Field densities of asphaltic concrete shall be verified by taking cores in accordance with
Section C 200 of the Construction Specification.
Cores shall be cut through the full thickness of the layer.
The average field density shall be determined daily from core densities.
The daily average field density shall be not less than 98 % of the average density of Marshall
specimens compacted from that day’s mix (the ‘Field Marshall Density’).
Not more than 1 in any 10 consecutive core densities shall be less than 97% of the Field
Marshall Density and not more than 1 in any 10 consecutive core densities shall be more than
102% of the Field Marshall Density.
Areas of asphaltic concrete where the standard of compaction specified above has not been
achieved shall be identified and further cores taken and tested.
Where the Field Density Requirements are not met the material shall be replaced.
Joints
Transverse joints shall be cut in a straight line across the previous face to expose the full
depth of the course. The vertical face so formed shall be heated with a propane joint heater
and painted lightly with hot bitumen.
The above treatment shall be required at longitudinal joints where these are exposed for more
than 24 hours. Otherwise, cold longitudinal joints should be avoided either by full-width
paving if the mixing plant has sufficient capacity to sustain fast enough forward motion by a
full-width paver to achieve good rideability, or by operating two pavers in tandem with a
slight stagger and properly hand-raking the joint to obtain a well-filled and barely visible
joint.
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PART D: OTHER BITUMINOUS MATERIALS
Double Layer Surface Dressing
General
Double layer surface dressing shall consist of an initial application of bituminous binder to the
road surface followed immediately by a layer of uniformly graded aggregate chippings. A
second application of bituminous binder is again applied which is followed immediately by a
second layer of uniformly graded chippings.
Bituminous Binder
The bituminous binder shall be Penetration Grade 80 / 100 (please amend as according to C
802.) complying with Table 8-6.
Table 8 – 6 Bituminous Binder for Double Layer Surface Dressing
Unit
Penetration at 25˚C (100 g, 5 s) 80 / 100 0.1 mm
Softening point (Ring-and-Ball) > 47 ˚C
Flash point (Cleveland open cup) > 220 ˚C
Frass breaking point < -20 ˚C
Viscosity at 135˚C > 250 centistokes
Solubility in trichloro-ethylene 99 % min
Water content Nil
1.1.a.i.1.3 Tests on Residue from thin-film oven test
Loss on heating after thin film oven test < 0.5%
Change of Softening Point temperature < 5 ˚C
Loss of penetration at 25˚C (100 g, 5 s) < 50% (% of original)
Bituminous binder shall be homogeneous, free from water, and shall not foam when heated to
175 ˚C.
Bituminous binders from different suppliers or sources shall not be combined.
Other grades of cut back bituminous binder may be used with the agreement of the Engineer,
subject to satisfactory field trials.
The penetration grade bitumen can be cut back with kerosene to suit road surface
temperatures at the time of spraying as detailed in Table 8-7.
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(ii) Table 8-7 Kerosene Volume for Cut Back Bitumen
Range of Road Surface
Temperatures oC
Maximum Addition of Kerosene
by Volume %
Range (approximately) of
corresponding ambient air
temperatures oC
16 – 24 7 10 – 16
24 – 32 5 16 – 21
32 – 40 3 21 – 26
40 – 48 1 26 – 31
The bituminous binder shall be heated in boilers or bulk storage containers equipped with
adequate pumps and accurate thermometers. No bitumen shall be heated in a boiler when the
thermometer is broken or inaccurate.
The minimum pumping temperatures, range of spraying temperatures and the maximum
heating temperatures of cut backs and penetration grade bitumen are given below in Table 8-
8.
Table 8-8 Pumping, Spraying and Maximum Heating Temperatures of Penetration
Grade and Cut Back Bitumen
Binder
Temperature o C
Minimum Pumping Spraying
Maximum Heating Slot Jets Atomising Jets
Penetration Grade
80 / 100 115 160 – 170 170 - 180 180
Cut Back MC 800 60 100 – 115 120 - 135 135
Cut Back MC 3000 80 125 – 135 135 - 150 150
Aggregate Chippings
Aggregate chippings shall consist of crushed angular stone free from, clay, silt, organic and
other deleterious matter.
Deleterious matter includes materials with potentially deleterious properties such as
muscovite in excess of 1%”. The minimum size of the stone to be crushed shall be at least 4
times the both nominal sizes of chippings of the aggregate. At least 90% by weight of the
coarse aggregate shall have two or more faces split by the crushing.
The aggregate chippings shall comply with the following requirements:
Los Angeles Abrasion max. 25;
Sodium Sulphate Soundness max. 12;
Water Absorption max 2%;
Flakiness Index max. 20.
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The polished stone value of aggregate chippings when determined in accordance with BS 812
shall not be less than 55 unless otherwise approved by the Engineer.
The grading of aggregate chippings shall be within the grading envelopes shown in Table 8-9
below.
Table 8-9 Grading Requirements for Aggregate Chippings
Sieve Size
(mm)
Percentage by Mass Passing
First Layer Second Layer
19 mm - -
13.2 mm 100 % -
9.5 mm 85 – 100 % 100 %
6.3 mm 0 – 25 % 80 – 100 %
4.75 mm 0 – 7 % 0 – 30 %
2.36 mm - 0 – 4 %
0.5 mm 0 – 0.5 % 0 – 0.5 %
Rates of Application of Bituminous Binder and Aggregate Chippings
The approximate rates of application of bituminous binder and aggregate chippings shall be as
given below:
(i) application of first layer of bituminous binder 1.0 liter / square metre
(ii) application of first layer of aggregate chippings 1.5 cubic meter / 100
square metres
(iii) application of second application of bituminous binder 1.0 liter / square metre
(iv) application of second layer of aggregate chippings 1.0 cubic metre / 100 square
metres
The rates of application of bituminous binder and aggregate chippings shall be fixed during
site trials so as to achieve:
(i) adequate coverage and adhesion of chippings without bleeding for the bituminous
binder
(ii) tight uniform packing of aggregate chippings without excessive traffic whip off.
Construction
(i) Weather Limitations
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The temperature at the road surface shall not be less than 10o C when bituminous
binder is sprayed.
No bituminous binder shall be applied during rain, fog or during a strong wind.
The existing road surface shall be dry prior to applying bituminous binder.
(ii) Preparation of Surface
Immediately before applying bituminous binder, the existing road surface shall be
cleaned of all loose material and foreign matter with mechanical brooms or
compressed air. The debris shall be deposited well clear of the surface to be covered.
Any defect in the surface shall be made good as instructed by the Engineer and no
bituminous binder shall be applied until the surface has been approved by the
Engineer.
Kerb, channels guardrails bridge parapets and any other structures that may be soiled
by the bituminous binders during spraying shall be covered with suitable plastic
sheeting during spraying operations.
(iii) Bitumen Distributors
All bituminous binder shall be applied with a truck mounted bitumen distributor that is
capable of spraying the binder uniformly over the width of the spray bar. The
distributor tank shall have a minimum capacity of 4,000 litres and shall be fitted with a
device for indicating the quantity in the tank at any time. It shall be fitted with heaters
capable of maintaining temperatures up to 200 o C and an accurate thermometer. The
circulation system shall be capable of pumping around the tank and around the spray
bar without actually spraying. Spray bars shall be available for spraying in widths
varying from 1 metre to 4 metres and shall be adjusted transversally so that the
operator can follow the required edge independently. The spray nozzles shall be
arranged to give a uniform spray and the shut off shall be quick acting with an anti-
drip device. The pressure in the spray bar shall be sufficient to give a good uniform
distribution and spaying of the binder.
Distributors shall be checked and calibrated during the site trials, before starting work
and when required by the Engineer.
No bituminous binder is to be applied with a hand spray lance.
(iv) Mechanical Aggregate Chipping Spreaders
Mechanical chipping spreaders shall be capable of spreading the chippings uniformly
over variable widths from 0.5 to 4.0 metres, at the rates fixed in the site trials.
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Chipping spreaders shall be checked and calibrated during the site trials, before
starting any work and when required by the Engineer.
Hand application of aggregate chippings shall not be permitted.
(v) Application of Surface Dressing
The spraying width shall normally be one lane so that construction traffic may run on
the other lane.
Immediately after the bituminous binder has been sprayed, clean dry aggregate
chippings shall be uniformly applied at the rate fixed in the site trials by the use of as
many mechanical aggregate chipping spreaders as necessary to match the rate of
spraying. The elapsed time between spraying of bituminous binder and spreading of
aggregate chippings shall in no case exceed one minute.
Chipping spreaders shall be operated in such a manner that the bituminous binder shall
be covered with aggregate chippings before the wheels of the chipping spreader or
truck pass over the binder.
Should it become apparent that the supply of aggregate chippings is about to fail, the
bituminous binder spraying shall be immediately stopped and shall not resume until an
adequate supply is assured.
(v) Compaction
The main compaction shall be carried out with self propelled pneumatic tyred rollers
or rubber covered steel drum rollers. Pneumatic tyred rollers shall have smooth tyres
and their pressure shall be more than 0.4 Mpa.
Compaction shall commence immediately after the aggregate chippings have been
spread and in no case later than two minutes after application of the bituminous
binder. Compaction shall continue until all chippings are firmly embedded into the
binder. The number of passes of each roller shall be fixed in the site trials, but usually
at least 6 passes shall be made.
Steel wheeled rollers shall not be used for surface dressing.
The number and output of rollers shall be sufficient to ensure that compaction does not
lag behind the spraying and chipping application operations.
Compaction shall be carried out in such a manner as to ensure that no crushing of the
aggregate chippings takes place.
Additional compaction on a previously completed section shall be given later by a
pneumatic tyred roller if required by the Engineer.
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(vi) Traffic Control and Finishing
Each layer of the surface dressing shall not be opened to traffic until the bituminous
binder has set sufficiently to retain the aggregate chippings. The Contractor shall erect
temporary restriction signs, barriers, removable bumps or other speed control devices
as agreed with the Engineer to prevent vehicles traveling too fast over the newly laid
surface dressing to ensure that excessive aggregate chippings do not become
dislodged.
After traffic has been permitted to run on a surface dressing layer for a period of at
least two days, and when required by the Engineer, all loose aggregate chippings shall
be swept and taken way. Windrows of loose aggregate chippings shall not be
permitted to acc umulate at the sides of the road.
(vii) Tolerances
The final average overall width of the surface dressing measured at six equidistant
points over a length of 100 metres shall be at least equal to the required width. At no
point shall the distance between the centre line of the road and the edge of the
surfacing be less than 20 mm of that required.
The rates of application of bituminous binder along and across each lane shall not vary
by more than plus or minus 10% of the rates fixed in the site trials and for each length
of lane sprayed in a single pass, the average rate of binder application shall not be less
than the fixed rate.
The average rate of application of aggregate chippings along and across the lane width
for each single pass of the spreader shall not vary by more than plus or minus 10% of
the rate fixed in the site trials.
Cut-back Bitumen
Rapid curing cut-back bitumen shall comply with all the requirements of AASHTO Standard
Specification M 81, Cut-Back Asphalt (Rapid-Curing Type).
Medium-curing cut-back bitumen shall comply with all the requirements of AASHTO
Standard Specification M 82, Cut-Back Asphalt (Medium-Curing Type).
Bitumen Emulsion
Bitumen emulsions shall comply with all the requirements of the following AASHTO
Standard Specifications:
M 140: Emulsified Asphalt,
M 208, Cationic Emulsified Asphalt, and
R 5, Standard Recommended Practice for Selection and Use of Emulsified Asphalts.
Prime Coat
119
Prime coat shall be MC 30 cutback bitumen.
The rate of application shall be determined from field trials and shall be such as to satisfy the
following requirements:
the depth of penetration shall be between 3mm and 10mm after 24 hours;
the minimum rate of application shall be 0.8 litres / sq metre.
Material treated with prime coat shall not be trafficked for 24 hours after application.
120
Tack Coat
Tack coat shall be either:
(a) a dilute bitumen emulsion, applied at sufficient time before laying the bituminous
layer to allow the emulsion to break and the water to run off or evaporate, spread to
give not less than 0.2 litres / sq metre residual bitumen.
Application of Prime Coat and Tack Coat
The Contractor shall thoroughly clean surfaces by compressed air or other approved means to
remove all loose material. Defects shall be made good.
Depending on site conditions, prior to the application of prime coat, surfaces of crushed stone road base may be lightly and evenly sprayed with water.
Prime and tack coats shall be sprayed from a constant pressure, or other approved, distributor.
Hand spraying shall be permitted only in small areas or to make good defective areas.
During spraying all kerb, road furniture, culvert headwalls and the like shall be protected.
MC30 cut back shall not be heated above 65˚C and shall be sprayed at a temperature between
40˚C and 60˚C depending on the type of equipment and ambient temperatures.
Tack coated base course shall be covered by surface course within 12 hours of application.
121
PART E: PAVEMENT REPAIRS
Patching
This work consists of repairs to an existing bituminous surface showing local discontinuous
damage in the form of pot-holes, ravelling, transverse and longitudinal cracking, crocodile
cracking, loss of edge support, local deformation or layer de-lamination. The main objetive
of this project is to construct a new road, so all the pavement will be designed despite this
unit will be able to be used when deteriorations of the pavement take place during the
construction of the same one
Classification
Patching work shall be classified into the following categories:
Type 1 Patching
Removal of damaged bituminous surfacing for a depth of up to 75 mm below the surface and
reconstruction in bituminous materials.
Type 2 Patching
Removal of the damaged bituminous surfacing and base layers for a depth of up to 250 mm
below the surface, and their replacement with corresponding layers of crushed stone base and
asphaltic concrete base and wearing courses.
Type 3 Patching
Removal of the damaged bituminous surfacing, base and subbase layers for a depth of up to
600 mm below the surface, and their replacement with corresponding layers of subbase,
crushed stone base, and asphaltic concrete base and wearing courses.
Prior to pavement works the exposed formation shall be re-compacted and prepared in
accordance with the Construction Specification for earthworks sub-formation and formation.
(iii) Work procedures
Areas of pavement requiring different the types of patching shall be identified and demarcated
by the Contractor in traffic-resistant paint.
Patching activities shall be carried out according to a programme and in accordance with
safety procedures agreed in advance on a weekly basis with the Engineer. Patching at any
particular time shall not occupy more than one traffic lane, if no diversion road is provided.
The marked pavement areas shall be excavated in accordance with their size and the type of
patching instructed. The excavated areas shall be regular in shape, having perpendicular sides
and vertical edges. Consecutive layers shall be stepped back by 150 mm on all sides. The
bottom of any excavated area shall have the same cross-fall as that of the finished surface.
The excavated area shall be cleaned out by air jetting.
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Reinstatement shall be as applicable for each pavement layer and material type. Before
placing asphalt the base and the sides of the excavation shall be treated with prime coat.
Crack Sealing
(iv) Classification
Sealing shall be classified as:
1. Sealing cracks up to 10 mm wide;
2. Patching cracks greater than 10 mm wide.
(v) Sealing cracks up to 10 mm wide
Crack sealing activities shall be carried out in accordance with safety procedures agreed in
advance on a weekly basis with the Engineer. Crack sealing at any particular time shall not
occupy more than one traffic lane, if no diversion road is provided.
The Contractor shall, in sections generally of about 1 km in length, identify and demarcate the
extent of cracks in the existing bituminous pavement. Individual cracks shall be denoted by
prominent marks (20 mm x 50 mm) across the crack ends, and at 5 m intervals where the
crack is longer than 10 m, in traffic-resistant paint.
The Contractor shall submit fully marked sections to the Engineer for his approval prior to
commencing crack sealing operations.
Prior to sealing, the Contractor shall ensure that cracks are clean of all dirt, dust, vegetation,
other loose materials by using wire brushes, mechanical brooms and high-pressure pneumatic
jetting. The cracks shall be dried by blowing with hot oil free compressed air.
After cracks have been thoroughly cleaned and dried they shall be sealed with a medium
curing cut-back bitumen MC 250 or MC 800 heated to a temperature of 80 - 100 degrees
Celsius. A spray lance blowing hot oil free compressed air may be used to introduce bitumen
into the crack. Fine sand and cement dust may be mixed with the cutback bitumen, to the
extent that the flow of bitumen into the crack remains unimpeded.
When cracks are fully sealed, a blinding layer of coarse sand shall be applied before the
bitumen cools.
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(vi) Patching cracks greater than 10 mm wide
The Contractor shall identify, demarcate the extent of and denote cracks greater than 10 mm
wide in the existing bituminous pavement as indicated above.
The existing asphalt pavement material shall be removed to a minimum width of 200 mm
along the line of the crack using powered pavement cutting or cold milling equipment.
The resulting void shall be dried by blowing with hot oil free compressed air.
The trimmed and cleaned void shall be painted at the bottom and sides using hot cut-back
bitumen MC 250 or MC 800. The void shall then be patched with asphaltic concrete wearing
course material.
Regulating
The Contractor shall identify and visibly delineate on the existing pavement surface all areas
to be regulated.
Regulating shall be in asphaltic concrete wearing course material.
Measurement and Payment The units that have been used in this contract associated to the Bill ( Preliminaries ), are the
following
Note : In the Section 4, The Bill of Quantities are described all the measurement method that
have to be taken in order to assign the Payment for every used Item in this project
Nº of Item Description Unit
901 Cast-in-place concrete cu m
902 Bridges sq m
903 Replacement concrete cu m
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SECTION C 900: CONCRETE WORKS
125
Scope of Section
This section covers:
material requirements for concrete mixes,
design of concrete mixes,
mixing, transport, placing, compaction and curing of concrete,
reinforcement,
falsework and formwork.
Part A covers material requirements.
Part B covers design requirements.
Part C covers concrete production and placing.
Part D covers falsework and formwork.
Part E covers reinforcing steel.
Part F covers piling.
Part G covers miscellaneous matters.
Definitions
In this Section, concrete means any cement bound concrete which is used in reinforced, pre-
stressed or non-reinforced concrete construction.
Structural concrete shall generally be load bearing and shall be described by its Class
reference detailed in Clause C 905.
Non-structural (or blinding) concrete means cement bound concrete Class 10/20.
AASHTO Standards
The Construction Specification in relation to Portland cement concretes refer generally to
AASHTO standards and relate primarily to concrete cast in place.
Structural elements pre-cast off site shall comply with standards set out in the Construction
Documents.
Structural elements pre-cast on site shall comply either with the Construction Specification in
relation to cast in place concrete or, in the alternative, standards set out in the Construction
Documents.
Concrete cast in place shall comply with the requirements of this Section C 900.
The Contractor shall detail in its Construction Documents, Quality Control Plan and its
Method Statements the Standards to which pre-cast elements are being constructed.
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PART A: MATERIALS FOR CONCRETE
Cement
Cement shall be either:
Ordinary Portland Cement (OPC) complying with AASHTO M85 Type 1A, or
Sulphate Resisting Cement (SRC) complying with AASHTO M85 Type 1A, or
as required in the Contract.
Granulated blast furnace slag for use with OPC shall comply with AASHTO M 302.
Cement shall be free flowing and free of lumps. It shall be supplied in the manufacturer's
sealed bags or in bulk from a certified supplier.
All cement for any one structure shall be from the same source.
Fine Aggregate
Fine aggregate shall be clean hard and durable and shall be natural sand, crushed gravel sand
or crushed rock sand complying with AASHTO M6. All the material shall pass through the
9.5 mm sieve and the grading shall be within and approximately parallel to the grading
envelopes in Table 9 - 1. In order to achieve an acceptable grading, it may be necessary to
blend materials from more than one source.
The fine aggregate shall not contain iron pyrites, iron oxides, ” add “mica (less than 1%
muscovite and 6% total mica), shale, laminar, soft or porous materials or organic matter.
Table 9 -1 Grading Requirements for Fine Aggregate
Sieve Size Percent passing by mass
Non-structural concrete
Percent passing by mass
Structural concrete
9.5 mm 100 % 100 %
4.75 mm 95 - 100 % 95 - 100 %
1.18 mm 45 - 80 % 45 - 80 %
300 μm 10 - 30 % 5 – 30 %
150 μm 2 – 10 % 0 – 10 %
The amount of fine aggregate retained between any pair of successive sieves shall not exceed
45 %.
Other properties of fine aggregate shall be:
the fineness modulus shall be between 2.3 and 3.1,
the content passing the 75 mm sieve shall not exceed 3 per cent for natural or crushed
gravel sand,
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the chloride content when tested with a Quantab chloride titrator shall not exceed 0.01
per cent by weight for prestressed concrete or 0.03 for other classes of concrete,
the soundness of aggregates by the use of sodium sulphate shall be less than 12%,
the aggregate shall be non-reactive when tested in accordance with ASTM C 289 for
alkali silica reaction.
Coarse Aggregate
Coarse aggregate shall be clean hard and durable crushed rock, crushed gravel or natural
gravel complying with the requirements of AASHTO M 80. The material shall not contain
any iron pyrites, iron oxides, flaky or laminated material, coal or other soft or porous material,
or organic matter.
The shape of the coarse aggregate shall be angular, rounded or irregular with a flakiness index
of less than 30%.
The maximum nominal size of coarse aggregate shall be 20 mm for prestressed and structural
concrete and 40 mm for non-structural concrete.
Grading of nominal sized coarse aggregate shall be within and approximately parallel to the
grading envelopes in Table 9 - 2.
Table 9 -2 Grading Requirements for Coarse Aggregate for Portland Cement Concrete
Sieve Size
Percentage passing by mass
Nominal Size
Nominal Size
Nominal Size
10 mm 20 mm 40 mm
50 mm - - 100 %
37.5 mm - - 95 - 100 %
25.0 mm - 100 % 65 - 85 %
19.0 mm - 90 - 100 % 35 - 70 %
12.5 mm 100 % 55 - 80 % 25 - 50 %
9.5 mm 85 - 100 % 20 - 55 % 10 - 30 %
4.75 mm 10 - 30 % 0 - 10 % 0 - 5 %
2.36 mm 0 -10 % 0 - 5%
1.18 mm 0 - 5%
For 20mm and 40mm nominal size aggregates, the amount of coarse aggregate retained
between any pair of successive sieves shall not exceed 45 %.
Other properties of course aggregate shall be:
the proportion of clay, silt and other impurities passing a 75 mm sieve shall be not
more than one per cent by weight;
the chloride content shall not exceed 0.05 per cent by weight when tested with a
Quantab chloride titrator;
the soundness of aggregates by the use of sodium sulphate shall be less than 12%;
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the aggregate shall be non-reactive when tested in accordance with ASTM C 289 for
alkali silica reaction;
the aggregate shall have a water absorption of less than 2.5 per cent when tested in
accordance with AASHTO T85;
the aggregate shall have a Los Angeles Abrasion (LAA) in accordance with AASHTO
T96 of less than 35%.
Water
Water for mixing or curing concrete shall be clean and free from harmful matter and shall
have a pH value between 6 and 8. Water shall be tested in accordance with AASHTO T26.
Water with the following properties shall not be used for mixing or curing concrete:
1) saline or brackish water,
2) containing more than 500 mg/l chloride ion,
3) containing more than 1000 mg/l sulphate ion,
4) containing more than 1000 mg/l alkali carbonates and bicarbonates,
5) containing more than 2000 mg/l total dissolved solids,
6) contaminated with oil, sugar, organic matter or other deleterious material.
Admixtures
Air-entraining agents shall be used to increase the durability of concrete subject to frost action
unless otherwise directed by the Engineer.
The Contractor shall submit to the Engineer full details of any admixture, including air entraining agents, he proposes to use.
Chemical admixtures used in concrete shall comply with the requirements of AASHTO
M194. Air-entraining admixtures shall comply with AASHTO M154. The Contractor shall
have all proposed air-entraining admixtures tested at a laboratory acceptable to the Engineer.
The effects of a proposed air entraining agent shall be tested by the Contractor in trial mixes
produced in the plant which he proposes to use for the Permanent Works.
Workability agents shall not have any adverse effect on the properties of the concrete.
The chloride ion content of any admixture shall not exceed 2 per cent by weight of the
admixture nor 0.03 per cent by weight of the cement in the mix.
Calcium chloride or admixtures containing calcium chloride shall not be used. Admixtures
shall not be mixed together.
Pozzolanic and Fly Ash admixtures
The use of pozzolanic admixtures, whether as a separate material or incorporated in the
cement before delivery to Site, may be permitted with the provision that the proportion of
pozzolanic material used shall not exceed 50 percent by weight of the cement in the mix,
except in the case of ground iron blast furnace slag, in which case the proportion shall be
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subject to the agreement of the Engineer. When ground iron blast furnace slag is blended
with cement the mixture shall comply with AASHTO M240. Fly ash shall have a carbon content not exceeding seven percent by weight. The maximum sulphate content expressed as SO3 shall be 2.0 percent by weight. The fineness shall be in accordance with that Specified in Table 2 of AASHTO M295. Fly ash shall only be used in conjunction with cement complying with ASTM C150 and the total sulphate content of the mix from all sources, expressed as SO3 shall not exceed four percent of the weight of cement.
Reinforcement
All reinforcing bars shall be high yield stress deformed.
Reinforcement shall comply with either of the following British Standards or AASHTO
Specifications:
BS 4449 Carbon Steel Bars for the Reinforcement of Concrete;
BS 4482 Cold Reduced Steel Wire for the Reinforcement of Concrete;
BS 4483 Steel Fabric for the Reinforcement of Concrete;
AASHTO M 31 M Deformed and Plain Billet-Steel Bars [Metric];
AASHTO M 221 M Steel Welded Wire Fabric, Deformed for Concrete Reinforcement;
AASHTO M 225 M Steel wire, Deformed for Concrete Reinforcement.
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PART B: DESIGN OF CONCRETE MIXES
Classes of Concrete
The classes of concrete shall be those designated in Table 9-3 below.
Table 9 - 3 Concrete Classes and Strengths
Concrete Class
Characteristic
Cube Strength at
28 days
Maximum
Nominal Size of
Aggregate
Maximum
water/cement
ratio
Target Mean
Strength
at 28 days
MPa Mm B MPa
10/20
(non structural) 10 20 0.45 None
20/20 20 20 0.45 28.5
25/20 25 20 0.42 33.5
30/20 30 20 0.43 38.5
30/10 30 10 0.43 38.5
40/20 40 20 0.40 48.5
40/10 40 10 0.40 48.5
Design of Concrete Mixes
The Contractor shall design mixes for all structural concrete. Design Parameters
The design parameters are:
the aggregate portion shall be well graded from the nominal maximum size of stone
down to the 150 m size;
the cement content shall be such as to achieve the target strengths called for in Table 9
– 3;
the minimum cement content shall be as shown in Table 9-4;
workability shall be consistent with ease of placing and proper compaction;
air-entraining agents shall be added to the Concrete in sufficient quantity to produce
the air contents set out in Table 9 – 5;
the water/cement ratio shall be the minimum consistent with adequate workability but
in any case not greater than that shown in Table 9 – 3;
the length change of hardened concrete determined in accordance with AASHTO
T160 shall not be greater than 0.05 per cent;
the total chloride content, expressed as chloride ion, arising from all constituents in a
mix including cement, water and admixtures shall not exceed the following limits,
expressed as a percentage of the weight of cement in the mix:
(a) for prestressed concrete, steam cured concrete or concrete containing sulphate
resisting cement: 0.05 per cent by weight,
(b) for any other reinforced concrete: 0.3 per cent in 95 per cent of all test results
provided no result is more than 0.5 per cent;
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The total sulphate content, expressed as SO3, of all the ingredients in a mix including
cement, water and admixtures shall not exceed 2.0% by weight of the aggregate or
4.0% of the weight of cement in the mix, whichever is the lesser.
Table 9 - 4 Minimum Cement Content for Durability and Low Permeability
Type of structure Minimum Cement Content (in kg/m3
of compacted concrete)
Thin sections, bridge decks, reinforced piles 435
Moderate sections, retaining walls, beams,
piers 420
Table 9 - 5 Air Content for Frost Resistance
Nominal maximum size of aggregate Entrained air content
40 mm 5.5 %
20 mm 6.0 %
10 mm 7.5 %
Proposed Mix Design
Before commencing placement of concrete in the Permanent Works, the Contractor shall
supply the Engineer with concrete mix designs for each proposed class of concrete together
with relevant test results.
The proposed concrete mix designs shall include:
(a) the cement type,
(b) the cement content in kg/m3,
(c) the sizes and grading of aggregates,
(d) the weights, in the saturated surface-dry condition, of aggregates in kg/m3,
(e) the water content in kg/m3, which shall be taken to mean the mixing water, the water
in any admixtures and any water in the aggregates in excess of the saturated surface-
dry condition,
(f) the design slump, measured in accordance with AASHTO T119,
(g) the manufacturer of the air-entraining agent and the required dose per cu m,
(h) the limits for air content,
(i) the manufacturers of any plasticisers, dispersing agents or other proposed admixtures
and their required doses per m3.
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Site Trial Mixes
As part of the design process, the Contractor shall prepare Site trial mixes.
For each Site trial mix of concrete the Contractor shall prepare three separate batches of
concrete using the mixing plant proposed for the execution of the Works. The volumes of
each batch shall be the capacity of the concrete mixer proposed for full production.
Samples shall be taken from each batch and the following tests carried out:
(a) the slump of the concrete shall be determined in accordance with AASHTO T119,
(b) from each batch six test cubes shall be cast, cured and tested in accordance with BS
1881,
(c) three cubes from each batch shall be tested for compressive strength at seven days and
the remaining three at twenty eight days,
(d) the density of all the cubes shall be determined before the strength tests are carried
out,
(e) the length change of hardened concrete shall be determined in accordance with
AASHTO T160 shall not be greater than 0.05 per cent.
The compacting factor apparatus may be used in place of a slump cone. In this case the
correlation between slump and compacting factor shall be established during preparation of
the trail mixes.
The average strength of the nine cubes tested at 28 days shall be not less than the applicable target mean strength shown in Table 9 - 3 and no single cube shall have a strength of less than 3 MPa lower than the applicable characteristic strength shown in Table 9 - 3.
Method Statement: Consent of Engineer
Following completion of successful site trials, the Contractor shall formally submit Method
Statements to the Engineer detailing the mix design(s) and the proposed working methods.
The Method Statement shall indicate procedures for adjusting added water to compensate for
the variability of aggregate moisture.
The Engineer shall give consent to the Method Statement and mix design(s) and or shall give
reasons for their rejection.
Structural Concrete shall not be used in the works without the formal consent of the Engineer
to the mix design. Structural Concrete which does not conform to a mix design shall not be
used in the Works.
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PART C: MANUFACTURE AND PLACING
Mixing
Concrete shall not be mixed by hand.
Cement and aggregates shall be batched by weight. Water may be measured by weight or
volume. Liquid admixtures shall be dispensed by an electrically controlled flowmeter.
The weights of cement, water, admixtures and of each size of aggregate as indicated by the
mechanisms employed shall be within the tolerance shown in Table 9 - 6.
Table 9 - 6 Allowable Tolerances in the Proportioning of Concrete Mixes
Allowable tolerance in
proportioning: Percentage by weight
Mass of cement 0 % to +4 %
Mass of fine aggregate -2 % to +2 %
Mass of coarse aggregate -2 % to +2 %
Admixtures -2 % to +3 %
Water -1 % to +1 %
All concrete batching equipment shall be calibrated prior to use.
The water to be added to the mix shall be adjusted to allow for the amount of free water
contained in the coarse and fine aggregates.
Transportation of Concrete
Concrete shall be transported in purpose built vehicles. During transportation the concrete
shall be protected from any adverse effects of sun, rain and wind.
The time elapsing between mixing and placing a batch of concrete shall, not exceed 60 minutes, provided that this period may be exceeded by the use of retarding agents, subject to the consent of the Engineer.
Concrete shall not be incorporated in the Works after the onset of initial set has occurred.
Placing of Concrete
The Contractor shall prepare a Method Statement for all concrete placement detailing:
equipment and methods to be used for placing,
preliminary treatment of surfaces,
compaction methods.
The following constraints on placing shall apply:
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the maximum height of free fall shall be restricted to 1.5m;
the formation of feather edges shall be avoided;
concrete shall be placed continuously between construction or expansion joints;
the delivery rate, placing sequence and methods shall be such that formation of cold
joints is precluded;
the dimensions and sequence of pours shall be such that cracking of the concrete due
to thermal or shrinkage is eliminated;
concrete shall be protected from the environment (Clause C 915 refers);
compaction shall be in accordance with Clause C 916.
The Contractor shall ensure that shuttering joiners and steel fixers are in attendance during all
concreting operations. They shall be responsible for ensuring that the formwork is maintained
in accordance with the Construction Specification, temporary construction joints are inserted
as necessary, and steel reinforcement and fittings are maintained in place as placing proceeds.
Protection of Concrete from the Environment General
The Contractor shall take all necessary precautions to protect concrete from damage due to climatic or other environmental conditions during placing and curing.
The temperature of the concrete immediately before placing shall be between 10˚C and 32˚C.
The maximum temperature of concrete for placement in bridge decks shall be 27˚C. Hot Weather Working
When ambient temperatures are above 32˚C, formwork, steel reinforcement, and other
surfaces that will come into contact with the fresh concrete shall be cooled by means of water
sprays or other approved methods.
All fresh concrete surfaces shall be protected from evaporation or be continuously wet-cured
with a fine mist spray. Cold Weather Working
If concrete is to be placed when, sub-zero ambient temperatures are likely the Contractor shall
make provision for heating water and aggregates.
Concrete shall not be placed without heating and protection from freezing if either:
(a) the ambient air temperature is falling and has fallen below 7˚C;
(b) the ambient air temperature is rising and is below 3˚C.
When the ambient air temperature is below 5˚C, the temperature of the concrete at the time of
placement in sections less than 300 mm thick shall be not less than 15˚C.
Irrespective of air temperature, aggregates shall be free of ice, frost and frozen lumps when
batched and concrete shall not be placed against any material whose temperature is 0 ˚C or
less.
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Aggregates may be heated to a temperature of between 20˚C and 65˚C and water shall be
heated to a temperature of between 55˚C and 65˚C. The temperature of the mixed concrete
shall be between 15˚C and 32˚C when placed in the formwork.
The newly placed concrete shall be protected against freezing for 8 full days after the
completion of the pour. Limitation of Temperature Differentials
The development of temperature differentials in placed concrete shall be inhibited by one or
other the following means, depending on ambient conditions and the exposure of the placed
concrete:
limiting concrete temperatures at placing;
the insulation of exposed concrete surfaces;
the use of insulated formwork left in place;
shielding exposed surfaces from the wind;
avoiding the use of ponding or sprayed water when such use would cause rapid
cooling of the surface.
The above requirements shall be taken into account in determining appropriate curing
methods.
Compaction of Concrete
Concrete shall be fully compacted throughout the full extent of the placed material. Concrete
shall be thoroughly worked against the formwork and around any reinforcement and other
embedded items, without displacing them.
Concrete shall generally be compacted with the assistance of mechanical poker (immersion)
vibrators. The Contractor may, use supplementary beam vibrators for the compaction of slabs
and bridge decks.
Non structural concrete may be compacted manually by the use of screeding boards or other
means, subject to satisfactory site trials and subject to the consent of the Engineer.
Curing of Concrete
All newly placed concrete shall be cured so as to prevent loss of water. Curing can be by one
of the following methods:
retaining formwork in position;
liquid membrane curing compound;
accelerated curing by steam treatment.
Curing methods shall be included in the Contractor’s Method Statement for concreting.
In addition, the Contractor shall provide sunshades and/or windshields to prevent excessive
drying of the concrete surface. If the surface of the concrete begins to dry before the selected
cure method can be applied, the surface of the concrete shall be kept moist by a fog spray.
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Curing shall be continued for as long as may be necessary to prevent loss of moisture and
shrinkage, and in any case, for not less than the periods stated in Table 9-8.
Table 9 - 8 Minimum Curing Periods
Cement type
Average ambient
temperature greater
than 15oC
Average ambient
temperature 5oC to
15oC
Average ambient
temperature less than
5oC
Portland Cement with
less than 10% added
pozzolans
7 days 10 days 14 days
Portland Cement with
more than 10% added
pozzolans
10 days 15 days 20 days
The curing method shall comply with the requirements in respect of limiting temperature
differentials described in Clause C 915.
Construction Joints
Construction joints shall be so arranged as to reduce to a minimum the effects of shrinkage in
the concrete after placing, and shall be placed in the most advantageous positions with regard
to stresses in the structures and the desirability of staggering joints.
The intersections of horizontal or near horizontal joints and exposed faces of concrete shall
appear as straight lines produced by use of a guide strip fixed to the formwork.
Surface aggregates shall be exposed either by brushing with a stiff bristled brush or by scabbling and / or sand blasting as necessary.
Fresh concrete cast against the exposed aggregate surface. Where directed, a mortar grout
shall be applied immediately prior to placing fresh concrete.
No concrete shall be placed in position or against a construction joint until the joint has been
inspected and approved by the Engineer.
Where a joint is to be formed to prevent bonding between contiguous structural elements, the Contractor shall place two intermediate layers of approved waterproof building paper at the location specified.
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Finishes on Unformed Surfaces All concrete shall be levelled to the tolerance stated in Table 9-9, as appropriate, to produce a uniform plain or ridged surface, surplus concrete being struck off by a straight edge immediately after compaction.
Where a floated finish is indicated in the Construction Documents, concrete shall be floated
with a wooden or cork surfaced hand or power float such as to produce a uniform surface free
from screed marks and to the appropriate tolerance of Table 9-9.
Where a power float finish is indicated in the Construction Documents, the surface shall be
floated as above, but to the tolerances stated in Table 9-9. When the moisture film has
disappeared and the concrete has hardened sufficiently to prevent laitance from being worked
to the surface, it shall be power floated to produce a dense, smooth uniform surface free from
trowel marks.
Table 9 - 9 Allowable Tolerances of Unformed Concrete Surfaces
Class of finish
Maximum gap between the
surface and a 3 m straight edge
or correctly shaped template
placed on the surface.
Maximum difference in level or
position from the correct level or
position
Unspecified 10 mm + 10 mm or - 10 mm
Floated finish 5 mm + 10 mm or - 10 mm
Power float finish 5 mm + 5 mm or - 5 mm
Finishes on Formed Surfaces
This finish shall be a smooth even concrete surface free of honeycombing, fins, projections,
bulges, offsets, streaks, surface discoloration or other surface imperfections.
Cavities or holes shall be filled carefully and to their full depth, with a cement-sand grout of the same quality and mix as that used in the surrounding concrete but with the fraction remaining on the 2.36 mm sieve discarded. Patched areas shall be rubbed flush with the surrounding surface after the cement grout has hardened.
Honeycombed concrete shall be removed and replaced in accordance with Clause C 937.
Where the overall finish is not of a uniform standard, the concrete shall be given a ‘rubbed’
finish as described below.
1. After grout for pointing has set the entire surface shall be thoroughly brushed with
clean water. The surface shall be rubbed with a power operated stone to bring the
surface to a paste. Rubbing shall be continued sufficiently to remove all formwork
marks, projections and other surface irregularities to produce a smooth dense surface
free from blemishes or other imperfections.
2. Material which has been ground to a paste during rubbing shall be spread uniformly
over the entire surface and allowed to take a set. The final finish shall be obtained
through a second rubbing with a fine carborundum stone that shall continue until the
entire surface is of a smooth even texture and a uniform colour.
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3. After the final rubbing has been completed and the surface has dried it shall be rubbed
with burlap to remove loose powder. The final surface shall be free from unsound
patches, paste, powder and objectionable marks. Under no circ umstances shall a
cement wash or plaster be applied.
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PART D: FORMWORK and FALSEWORK
General Obligations
The Contractor shall include in the Construction Documents design calculations and working
drawings showing details of the proposed formwork and falsework.
The structural design of formwork shall conform to ACI Standard, “Recommended Practice for Concrete Formwork,” (ACI 347) or some other internationally recognised standard acceptable to the Engineer.
The design calculations shall be undertaken and certified by a qualified structural engineer.
The calculations shall take into consideration the sequence and rate of concrete placing and
the equipment proposed for placing, compacting and finishing the concrete.
Falsework The design assumptions as to foundation support shall be stated in the design submission. The design submissions shall be verified by appropriate ground investigation and soils testing.
The Contractor shall make necessary allowances for dead load deflection and any other
deformations caused by the placing of concrete.
For cast-in-place concrete structures, the calculated deflection of falsework flexural members
shall not exceed 1/240 of their span.
Formwork
Formwork shall be of an approved construction surfaced with wood, steel or other approved
sheet material. The inner surfaces of the forms shall produce a smooth surface of uniform
texture and colour.
Where a plywood surface is shown in the Construction Documents or otherwise required by the Contract, formwork shall be faced with plywood complying with BS 1088 Plywood for Marine Craft or equivalent.
Joints in formwork for exposed faces shall be evenly spaced horizontally and vertically and
shall be continuous or form a regular pattern. The same type of formwork surfacing material
shall be used throughout each element of a structure.
All formwork surfaces that are to make contact with the concrete shall be thoroughly cleaned
and treated with an approved chemical or wax emulsion release agent before the reinforcing
steel is placed. Neat mineral oils and water soluble emulsions shall not be used. The
Contractor shall construct trial panels to demonstrate the suitability of any release agents
proposed.
Metal ties or anchorages within the forms shall be so constructed as to permit their removal to
a depth of at least 60 mm from the face without injury to the concrete. The cavities shall be
filled with cement mortar and the surface left sound in accordance with Section C 900 of the
Construction Specification.
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Supports for formwork may be bolted to previously placed concrete. If metal ties through the concrete should be used in conjunction with bolts, the metal left in place shall not be closer than 60 mm from the face of the concrete.
The internal and external angles on concrete surfaces shall be formed to a chamfer utilising 20
mm x 20 mm hardwood timber fillets of new material. New 25 mm square hardwood timber
shall be incorporated in the formwork to form a clean, level horizontal joint on exposed
concrete surfaces at the top of each lift unless otherwise agreed with the Engineer.
Removal of Formwork The minimum periods which shall elapse between completion of placing concrete and the removal of formwork and falsework are given in Table 9 – 10.
Table 9 - 10 Minimum Period Before Striking Formwork
Average ambient temperature
Formwork type Minimum period before striking
> 25 oC 20 oC 15 oC 10 oC 5 oC <0 oC
Vertical formwork to columns,
walls and large beams 9 hours 10 hours 12 hours 15 hours 20 hours 30 hours
Soffit formwork to slabs 3 days 3 days 4 days 5 days 7 days 10 days
Soffit formwork to beams and
props to slabs 7 days 8 days 10 days 13 days 17 days 25 days
Props to beams 10 days 12 days 14 days 18 days 24 days 36 days
Alternatively, formwork and falsework may be removed when the concrete has attained the
strength set out in Table 9 - 11, provided that the attained strength is determined from test
cubes cured under the same conditions as the concrete to which they refer.
Table 9 - 11 Minimum Concrete Cube Crushing Strengths to be Attained Before Striking Formwork
Type of formwork / falsework
Percentage of characteristic 28 day
compressive cube strength to be
attained before striking formwork
Vertical formwork to columns, walls and large beams 30 %
Soffit formwork to slabs 35 %
Soffit formwork to beams and props to slabs 40 %
Props to beams 50 %
As soon as formwork has been removed, bolt holes in concrete faces that are not required for subsequent operations shall be completely filled with mortar and made good in accordance with Clause C 920.
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PART E: REINFORCEMENT
Bar Bending Schedules The Contractor shall include bar bending schedules in the Construction Documents. Bar bending schedules shall include the following information:
bar location and placing details;
reference mark;
grade of steel;
size designation;
number of bars;
length of bars;
shape code of bars.
Fixing Reinforcing steel shall be supported in its proper position by use of mortar blocks, wire bar supports, supplementary bars or other approved devices.
All intersecting bars shall be tied together with annealed galvanised iron wire of not less than
1.25 mm diameter with the ends of the tying wire turned back into the main body of the
concrete.
Mortar blocks shall have a compressive strength of not less than that of the concrete in which
they are to be embedded. The face of blocks in contact with forms for exposed surfaces shall
not exceed 50 mm by 50 mm in size and shall have a colour and texture that will match the
concrete surface. Mortar blocks shall have an embedded annealed galvanised iron wire of
diameter 1.25 mm for securing the block to the reinforcement. An alternative type of spacer
block may be used subject to the approval of the Engineer.
Splicing
All reinforcement shall be fabricated in the full length indicated on the plans unless otherwise
permitted. Except where shown in the Construction Documents, splicing of bars shall be
subject to the approval of the Engineer. Splices shall be staggered as far as possible.
Lapped splices shall be of the lengths shown in the Construction Documents. If not
dimensioned in the Construction Documents, the length of lapped splices shall be in
accordance with Division I, Clause 8.32 of AASHTO Standard Specifications for Highway
Bridges.
Welding shall conform to the Structural Welding Code, Reinforcing Steel, AWS D1.4 of the
American Welding Society and applicable special provisions.
Mechanical couplings shall develop both in tension and compression at least 125% of the specific yield strength of the bar, two field splices out of each 100, or portion thereof, placed in the work, shall be selected by the Engineer, removed by the Contractor and tested to 125% of the specified yield strength.
Sheets of welded mesh reinforcement shall be spliced by a lap of one and a half times the
spacing of the mesh with all ends and edges securely tied.
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Substitution by Bars of Different Sizes Substitution of the reinforcement indicated in the Construction Documents with reinforcement of different sizes or yield strengths will be permitted at the discretion of the Engineer. The product of the area and yield strength of the substituted bars shall be not less than that of the bars indicated in the Construction Documents.
Cover Where not indicated on the Construction Documents, the minimum cover to reinforcement in in-situ reinforced concrete shall be 60mm in piles, pile caps and foundations constructed with sulphate resisting cement and 50mm elsewhere.
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PART F: PILING
General
Piling shall comply with the applicable recommendations of BS 8004.
Concrete, reinforcement and any pre-casting operations shall comply with the relevant clauses
of this Section C 900.
Piles shall be installed within the following maximum permitted tolerances:
Position: 75mm in either direction at cut-off level;
Verticality: 1 in 75 deviations from the vertical;
Rake: 1 in 25 deviations from the specified rake.
The Contractor shall include in the Construction Documents a programmed of its proposed
sequence and timing for casting or driving piles.
A piling record shall be kept by the Contractor, and a signed copy of the record of the work
done each day shall be given to the Engineer on a daily basis while piling is in progress. On
completion of piling the Contractor shall deliver to the Engineer a schedule recording the final
toe levels of all piles.
Pile Tests Test piles shall be working piles selected by the Engineer for load testing. Piles shall be tested by the Constant Rate of Penetration Method. Working piles shall not be used as reaction piles without the approval of the Engineer.
Load measuring devices shall be calibrated before and after each series of tests, whenever adjustments or replacements are made to the devices or at the intervals recommended by the manufacturer of the equipment. Pressure gauges and hydraulic jacks shall be calibrated together. Certificates of calibration shall be supplied to the Engineer for acceptance. The calibration shall be carried out at a testing house acceptable to the Engineer.
The Constant Rate of Penetration Method
The rate of loading shall be such that a constant rate of movement is maintained throughout
the test.
The rate of movement of the pile shall be agreed with the Engineer before the start of the test.
Each increment of test load shall be measured within an accuracy of 2%, and movements shall
be measured within an accuracy of 0.25mm.
Readings of load, movement and time shall be made simultaneously at regular intervals and
agreed with the Engineer.
Loading shall be continued until one of the following results is obtained:
(i) the test load is reached,
(ii) a constant or reducing load has been recorded for an interval of movement of
10mm,
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(iii) a total movement of the pile base equal to 10% of the base diameter has been
reached;
The load shall then be reduced in 5 approximately equal stages to zero load, and movement at
each load stage including zero load shall be recorded.
The Contractor shall, within 24 hours of the completion of the test, submit to the Engineer a complete record of each pile test including the maximum load reached and a graph of load against movement.
The Contractor shall, within seven days of the completion of the test, submit to the Engineer a
comprehensive pile testing report. The form of the report shall be as agreed with the Engineer.
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PART G: MISCELLANEOUS
Mortar and Grout
Surfaces to receive mortar or grout shall be cleaned of all loose or foreign material that would
inhibit bonding with the mortar. They shall then be flushed with water and allowed to dry to
a surface dry condition immediately prior to placing the mortar or grout.
Mortar shall be composed of fine aggregate complying with Section C 900 of the
Construction Specification and Portland cement Type IA complying with AASHTO M85.
The mix proportions shall be as stated in the Construction Documents or elsewhere in the
Construction Specification or if not stated shall be one part of cement to two parts of fine
aggregate by weight.
The water content of the mortar shall be as low as possible consistent with the use for which it
is required but in any case the water/cement ratio shall not be more than 0.5.
Mortar which is specified as "dry pack" shall be mixed with sufficient water for the mix to
become cohesive but not plastic when squeezed in the hand. Dry pack mortar shall be
rammed into the cavity it is required to fill, using a hand rammer with sufficient force to
ensure full compaction.
Grouting of Pockets and Holes Pockets and holding-down bolt holes shall be thoroughly cleaned out using compressed air and water jets. Holes drilled by diamond bit shall be roughened. Pockets and holes shall be filled with grout consisting of cement and clean fresh water mixed in proportion of two parts by weight of cement to one part by weight of water. The pouring of liquid grout shall cease as soon as each hole is filled and any excess grout on the surface of the concrete foundation shall be completely removed and the surface dried off before the next operation proceeds.
Underpinning of Base plates The space between the top surface of foundation concrete and the underside of base plates shall be filled with a special mortar made up of materials in the proportions of one part Portland cement to one part fine aggregate. An additive to counteract shrinkage, acceptable to the Engineer and in accordance with ASTM C845, shall be added in the proportions recommended by the manufacturer. The special mortar shall have the minimum water-cement ratio compatible with sufficient workability to enable maximum compaction to be achieved.
The special mortar shall be well rammed in horizontally below the base plate from one edge only until it is extruded from the other three sides. The mortar which has extruded shall then be rammed back to ensure complete support without voids.
146
Precast Concrete
Precast units manufactured on Site shall comply with the relevant clauses of this Section C
900.
Structural units shall be marked with a reference number and date of casting.
Pre-tensioned precast units shall comply with the further requirements of Section C 1100 of
the Construction Specification.
Placing Concrete under Water
Concrete shall be deposited either through funnel-shaped tremmies which shall have
discharging bottom fitted with a trapdoor or by concrete pumps fitted with a device at the end
of the discharge tube to prevent the ingress of water whilst the tube fills with concrete.
During pumping, once the delivery of concrete has started, the end of the discharge tube shall
be kept full of concrete and below the surface of the deposited concrete until placement is
completed.
The cement content of concrete that is to be placed under water shall be 10 per cent more than the standard mix for the corresponding grade and workability to compensate for loss due to washing.
Concrete shall be placed in one continuous operation and the surface of the concrete during
placement shall be kept as near to horizontal as practicable. Still water shall be maintained at
the discharge point of pumps and tremmies.
To ensure thorough bonding, each successive layer of concrete shall be placed before the
initial set of the preceding layer has taken place.
Sulphate Resisting Concrete
Where shown on the Drawings or the Construction Documents, concrete shall be made with
Sulphate Resisting Cement.
The water content of the mix shall be carefully controlled and regulated so as to produce concrete of minimum permeability. The concrete shall be thoroughly compacted to maximum density. The depth of cover from the face of the concrete to the reinforcing steel shall be not less than 60 mm.
Formwork shall be left in place for a minimum of 7 days after casting to protect newly formed
concrete surfaces from attack.
Except for the repair of any surface cavities and the plugging of form tie holes, the original
formed surface of the concrete shall be left undisturbed.
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Interruptions to Placing
If concrete placing is interrupted for any reason, the Contractor shall immediately take the
necessary action to form a construction joint.
Any concrete already placed shall be thoroughly compacted. All work on the concrete shall be completed while it is still plastic and it shall not thereafter be disturbed until it has hardened enough to resist damage.
Before concreting is resumed after such an interruption the Contractor shall cut out and
remove all damaged or un-compacted concrete, feather edges or any other undesirable
features and shall leave a clean, sound surface prepared in accordance with Section C 900 of
the Construction Specification against which fresh concrete may be placed.
If it should become possible to resume concrete placing without contravening the Construction Specification and with the Engineer's consent, new concrete shall be thoroughly worked into the existing concrete and compacted so as to eliminate any cold joints.
Remedial Work to Defective Concrete Defective surfaces shall not be made good by plastering.
Areas of honeycombing that the Engineer agrees may be repaired shall be cut back to sound
concrete or to 75 mm which ever is the greater distance. In the case of reinforced concrete the
area shall be cut back to at least 25 mm clear distance behind the reinforcement or to 75 mm,
whichever is the greater distance. The cavity shall have sides at right angles to the face of the
concrete. After cleaning out with water and compressed air the cavity shall be coated with an
approved epoxy resin and then be filled immediately with concrete of the same class as the
main body but with aggregate larger than 10 mm nominal size removed. A form shall be used
against the cavity, provided with a lip to enable concrete to be placed. The form shall be
filled to a point above the top edge of the cavity.
After seven days the lip of concrete shall be broken off and the surface ground smooth.
Surface irregularities which are outside the limits of tolerance set out in Section C 900 of the
Construction Specification shall be ground down to achieve transition slopes of less than 1 in
50 between adjacent surfaces in the manner and to the extent instructed by the Engineer.
Waterproofing Buried Concrete Surfaces All buried concrete surfaces, whether for new structures or in the repair and rehabilitation of existing structures, shall be protected by means of medium curing cut back bitumen, grades MC 30 or MC 70. A compatible primer shall be used having a viscosity which allows the primer to penetrate the concrete without forming a skin.
The concrete surfaces shall be thoroughly cleaned and primed to ensure complete coating and
penetration of the concrete. Two coats of cut back bitumen shall then be applied at a rate of
spread per coat of 0.6 litres / square metre. The first coat shall be allowed to dry before the
second coat is applied.
148
Waterstops All references to waterstops include groutstops.
Waterstops shall be made of material resistant to chlorides, sulphates, or other deleterious
substances which may be present in the environment of the Works. Rubber waterstops may
be of natural or synthetic rubber and shall have an elongation at breaking stress of at least 500
per cent at 25 ˚C and shall allow a joint movement of at least 50 mm.
Poly vinyl chloride (PVC) waterstops shall be extruded from an unfilled plasticised PVC
polymer or copolymer which does not contain any reclaimed or scrap PVC. PVC waterstops
shall have an elongation at breaking stress of at least 225 per cent at 25oC and shall allow a
joint movement of at least 10 mm.
Low modulus waterstops shall be of rubber or PVC as described above but shall have an
elongation of at least 200 per cent at 25oC under a tensile stress of 6 N/mm
2 and shall allow a
joint movement of at least 50 mm.
Measurement and Payment The units that have been used in this contract associated to the Bill 6 ( Structural Works ), are
the following
Note : In the Section 4, The Bill of Quantities are described all the measurement method that
have to be taken in order to assign the Payment for every used Item in this project
Nº of Item Description Unit
901 Cast-in-place concrete cu m
902 Bridges sq m
903 Replacement concrete cu m
149
SECTION C 1000: PRESTRESSED PRE-TENSIONED CONCRETE
150
General
The work shall consist of the fabrication and installation of precast pretensioned concrete
beams.
Notwithstanding the provisions of this Section, factory produced pretensioned precast
structural elements shall be acceptable for the Works, provided they comply with standards
set out in the Construction Documents.
All concrete work, including the production of precast units, shall comply with the appropriate requirements of Section C 900 of the Construction Specification.
Submission of Working Drawings
Prestressed pretensioned beams shall be constructed to the dimensions shown in the
Construction Documents subject to minor adjustments to individual beams as may be
necessary to conform with the lengths of the beams in the existing structure which are being
replaced.
The Contractor shall include in the Construction Documents detailled working drawings, with supporting calculations, showing the methods and materials the Contractor proposes to use. Such details shall include:
(a) the method and sequence of prestressing,
(b) specifications for the prestressing steel,
(c) working stresses,
(d) transfer stresses,
(e) arrangement of wires and strands in the precast units,
(f) allowances for prestressing losses,
(g) the arrangements for debonding of wires and strands,
(h) the arrangement of reinforcement,
(i) reinforcement bending schedules,
(j) details of any embedded or cast in items, and
(k) such other details pertaining to the prestressing operations.
Prestressing Wire and Strand
Prestressing wire shall be uncoated stress relieved wire conforming to the requirements of
AASHTO M204.
Prestressing strand shall be uncoated stress relieved seven wire strand conforming to the
requirements of AASHTO M203.
151
Testing
Sampling and testing shall be in accordance with AASHTO M203 or M204 as appropriate.
Each package of prestressing wire or strand shall be accompanied by a manufacturer’s
certificate of compliance, a mill certificate, and a test report. The mill certificate and test
report shall include:
(a) the cross-sectional area,
(b) yield strength,
(c) ultimate strength,
(d) elongation at rupture,
(e) modulus of elasticity, and,
(f) the stress strain curve for intended use.
All values certified shall be based on test values and nominal sectional areas of the materials
being certified.
Should the Engineer so require, the Contractor shall test samples of prestressed wire or strand
at a laboratory approved by the Engineer. Such testing shall be at the expense of the
Contractor. The selection of samples shall be made at the manufacturer’s plant by the
Engineer.
A test sample shall comprise a 2.0 m length of prestressing wire or strand. Three representative samples shall be supplied for each 20 tonne lot, or portion thereof, of material used in the Works.
Prestressing Operations Prior to prestressing the Contractor shall submit the work for inspection and approval by the Engineer. All prestressing wire or strand shall be tensioned by means of hydraulic jacks so that the force in the prestressing wire or strand is not less than that shown in the Construction Documents.
Tensioning shall not be carried out at a temperature below 0˚C without the approval of the
Engineer.
No welds shall be made on the forms or on the steel in the member after the prestressing steel
has been installed.
The tension in the wires or strands shall be maintained by some positive means during the
period between tensioning and transfer.
Where the Construction Documents show requirements for debonding the ends of specified
wires or strands debonding shall be accomplished by the use of polythene tubes or wrapping
the wires or strands subject to the approval of the Engineer.
Following concreting, no prestressing wire or strand shall be cut until the concrete in the member has attained a compressive strength at transfer of not less than that shown in the Construction Documents. The cutting and releasing of prestressing wire shall be performed in such an order that lateral eccentricity of prestressed will be a minimum. All prestressing wires and strands shall be cut off flush with the end of the member. The exposed ends of the prestressing wires and strands and a 25 mm strip of concrete shall be cleaned and painted. Cleaning shall be by wire brush or abrasive
152
blast cleaning. The surfaces which are not to be covered by concrete or mortar shall be painted with an approved zinc rich paint which shall be thoroughly mixed prior to application and worked into any voids in the prestressing strands.
153
SECTION C 1100: CONCRETE REPAIRS
154
General
This Section covers repair works to existing structures, including:
surface cleaning,
mortar repairs,
epoxy repairs,
concrete repairs,
repairs to existing furniture.
Scope of Repair Works
Repair works shall generally comprise one or other of the following treatments:
repair of superficial damage by cement mortar;
repair of deep damage by concrete;
protective waterproof treatment with a polymer based resin mortar;
repair by use of epoxy based concretes;
pressure injection of cracks with an epoxy resin.
The use of ordinary Portland or sulphate resisting cement shall be governed by the location of
the repair.
Where particular repair treatments are detailed in the Drawings or the Construction
Documents, these shall prevail over the requirements of this Section.
Surface Cleaning
Before cleaning work all surface attachments (signs, notices, electrical fittings etc.) shall be
removed from the areas to be repaired. The method of removal shall be such as to avoid
unnecessary damage.
The cleaning operation shall remove all dirt or other contaminants, previous coatings, laitance, paint, algae, moss, lichens, plant growth and shall comprise one or other of the following:
(1) grit blasting (wet, dry or vacuum blasting); and or
(2) high pressure water jetting, steam cleaning employing wax free detergents or
biocides together with power scrubbing as required.
Cleaning shall be undertaken without damaging underlying sound concrete.
Trial areas shall be carried out before the main cleaning operation commences.
155
Removal of Existing Concrete Existing concrete shall be removed to the extent necessary to reach sound concrete. The extent and depth of concrete removed at any time shall be approved by the Engineer as the work proceeds and shall be recorded by the Contractor.
The limits of each repair area shall be cut as a series of straight lines at right angles to the
surface to a depth of approximately 10 mm (5 mm for repairs using epoxy mortar) using a
disc cutter or similar. The disc cut surfaces shall be roughened prior to reinstatement.
Where reinforcing bars are exposed by concrete removal, the concrete shall be removed for a
minimum of 20 mm behind the bars or until sound concrete is reached, whichever is the
greater.
Additional concrete removal shall be carried out along actively corroding exposed bars until a
continuous length of 50 mm of bar free from active corrosion is exposed. The limit of active
corrosion shall be assessed on a visual basis. The edges of any additional areas removed shall
be cut square as specified above.
Where redundant fixings, including lifting hooks, formwork ties and the like, are present on a
concrete surface, the concrete shall be removed to a minimum depth of 25 mm around the
fixing. The fixing shall then be cut or ground back such that a minimum cover of 25 mm is
achieved to the fixing from the concrete surface. The area of concrete broken out shall then
be reinstated with repair mortar in accordance with this Section of the Construction
Specification.
Before concrete removal begins the Contractor shall install temporary propping at locations
directed by the Engineer. Temporary propping shall remain in place until the member has
been fully repaired and the repair mortar has gained the required strength.
Reinforcement
Rust scale corrosion products and other deposits shall be removed from reinforcement
exposed within the area of repair by grit blasting.
Abrasives shall be new, clean and dry and of a grade suitable for the preparation of steel to the
standard indicated above. Exhausted abrasive shall be bagged up and removed from site after
a single use.
The exposed reinforcement shall be thoroughly washed down with clean water as part of the
preparation operations.
Subject to the approval of the Engineer, the existing reinforcement shall be moved or
supplemented or replaced by new bars in accordance with Section C 900 of the Construction
Specification welded or spliced to existing bars. Bars to be removed shall be cut by disc
cutter.
Replacement bars shall be cleaned if required by the Engineer to the British Standard specified above. Where bars are lapped a minimum lap of forty times the bar diameter shall be provided.
156
Replacement Concrete
Concrete used in repair work shall comply with the requirements of Section C 900 of the
Construction Specification, supplemented by the additional provisions of this Section.
The mix required for any particular repair shall be as directed by the Engineer. In general, repair concrete shall be from one or other of the following:
Class 50/10 Bridge decks, piers and columns;
Class 40/10 Foundations: depths up to 50mm;
Class 40/20 Foundations: elsewhere.
Concrete in foundations or otherwise in contact with soil shall be made using Sulphate
Resisting Cement.
Non-reactive aggregates shall be used in beam and crosshead repairs; the maximum sodium
oxide content shall be 3.0 kg in any cubic meter of concrete.
Repair concrete shall not be placed without the prior inspection of he works and the consent of the Engineer.
Repair Concrete to Beam So fits
Where shown in the Construction Specification, the Drawings or the Construction
Documents, beam so fits shall be repaired by concrete ‘capping’.
For this repair work the Contractor shall be required to demonstrate the efficacy of its working methods by the means of a full scale field trial.
The following methodology involving a ‘Flow Test’ and a ‘Flow Trough Test’ shall be
acceptable.
Flow Test
The flow characteristics of the concrete shall be assessed at an ambient temperature of
between 50C and 20
0C in the flow trough shown in Figure 1.
The temperature of the materials and mixer shall be as close as possible to those expected
during the Contract.
The funnel shall be fitted with a rubber bung and charged with 6 liters of concrete. On the
release of the bung the concrete shall flow along the trough and the length of the flow shall be
measured. The minimum length of flow along the trough for each test shall be 450 mm
without signs of segregation or bleeding.
157
Flow Trough Test
The flow characteristics for repairs to so fits shall be assessed by pouring the concrete mix
having the same water: cement ratio as in Clause C 1107 into the model shown in Figure 2.
The pre-cast concrete slab shall be wetted for 2 hours before the test but the surface shall be
free of surplus water at the time of test. The concrete shall be poured from one side of the
model until the level of the concrete has reached at least 10 mm above the underside of the
top plate. The material shall be placed in the model in one pour.
After 24 hours the top plate shall be removed and the exposed surface shall be lightly brushed
with a stiff bristle brush to remove any surface cement skin which may be covering voids.
The exposed surface of the concrete shall be examined for air pockets, cracks, and other
defects.
The trial shall be deemed successful if the concrete thus formed is homogeneous and free from voids.
Polymer Modified Mortar
Where described in the Contract, polymer modified cementations mortar shall be used for
repairs.
The total chloride ion content shall not exceed 0.3 per cent of the mass of cement. Calcium
chloride or admixtures containing chloride salts shall not be used.
The content of equivalent sodium oxide in the mortar shall be restricted or non reactive
aggregates shall be used as specified in Clause C 1108 of this Section.
Batching and placing shall be in accordance with the manufacturer’s recommendations.
Impregnation Impregnation may be used in conjunction with concrete repairs in accordance with this Section of the Construction Specification.
Undiluted monomeric alkyl alkoxy silane (isobutyl) shall be used.
After 14 days curing of the concrete the material shall be applied evenly in two applications
each at a rate of 300 ml / m2 with a minimum interval of 2 hours.
Alternatively the first application may be made after 7 days curing of the concrete followed
by the final application not less than 7 days later.
Concrete surfaces shall be clean and free from dust and loose matter before treatment. Light
grit blasting may be used if necessary. Areas to be treated shall be surface dry and if
necessary protected from the weather before application.
158
Material shall not be applied in the following conditions:
(a) when the air temperature in the shade is greater than 350 C;
(b) when the air temperature in the shade is less than 50C;
(c) when it is raining unless suitable precautions have been taken which have been
approved by the Engineer.
Application shall be made by wet spray without misting at a nozzle pressure not greater than
0.2 N / mm2.
Epoxy Mortar
The epoxy resins for use in the mortar shall be obtained from an approved manufacturer and
shall be prepared in conformity with the manufacturer's recommendations.
The minimum requirements are:
Pot Life : 90 minutes at 25 degrees Celsius;
60 minutes at 30 degrees Celsius;
45 minutes at 35 degrees Celsius;
Bond Strength: 12 MPa;
Tensile Strength: 16 MPa.
Surface Preparation
Surface upon which epoxy is to be placed shall be free of rust, grease, oil, paint, asphalt, loose material, unsound concrete, dust or any other deleterious material. Contaminants, such as oil, grease, tar, asphalt, paint, wax curing compounds or surface impregnants like linseed oil or silicons, laitance and weak or loose concrete shall be removed.
Epoxy bonding agents shall not be applied in the rain, or in standing water. The surface must
be dry.
Two general methods of surface preparation shall be followed:
(a) mechanical, including grinding, grit blasting, water blasting and scarification; (b) chemical that includes acid etching with 15 percent by weight of hydrochloric solution,
followed by repeated flushing with high-pressure stream of water. Application
Epoxy primer coat shall be applied with the help of stiff nylon bristle brushes or hard rubber rollers or spray gun depending upon the nature of surface and extent of work area.
Before the primer coat is fully cured, epoxy mortar shall be applied by means off trowels and
floats. The interval between the application of primer coat and epoxy mortar shall be
approximately 15/30 minutes depending upon the ambient temperature. Seal coat shall be
applied after 24 hours curing, after mild roughening of the surface of the mortar.
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Coverage
The coverage of resin mix will depend in the system of resin used. However, as a general
guideline the coverage area shall be as under:
(a) primer coat: 1 kg of resin-hardener mix covers an area of 3-6 square metres per
cost depending on the finish of the concrete;
(b) epoxy mortar: one square metre of surface required approximately 20-24 kg of
epoxy when laid to a thickness of 10mm;
(c) seal coat: 4 to 6 square metres per kg of mix depending on the temperature of
application.
Replacing Handrails
Where shown in the Contractor´s Documents or as directed by the Engineer, existing
handrails shall be removed and replaced.
Where the existing railing post base concrete is sound, the new posts can be fitted directly to
the post footing. Where the existing railing post base is not sound, it shall be broken out to
expose the parapet / edge beam reinforcement to which dowel bars will be welded. The
existing concrete will be made good as directed either by epoxy mortar or by concrete.
The works are to be undertaken in accordance with the following general requirements.
(a) The existing handrails will be removed by cutting at the bottom of their railing posts.
(b) The steel base part of the existing handrails attached to the T-beam will be checked
for stability, corrosion and other defects.
(c) If, in the Engineer’s opinion, the existing steel base is unsatisfactory it will be
removed in accordance with sub-clause (e).
(d) If the Engineer accepts the steel base as suitable for further use four dowel bars shall
be welded on to it.
(e) A 500mm x 500mm x 40 mm deep void will be removed by hand (pneumatic
hammers shall not be used) in the concrete surface of the girder.
(f) The void shall be thoroughly cleaned by high-pressure water.
(g) The dowel bars to be placed on the inside of the railing posts shall be welded on to
the transverse reinforcement bar of the underlying beam. The hole will be filled
with epoxy concrete or OPC concrete as directed.
(h) No further work shall be carried out until the concrete infill has reached 70% of its
28-day-strength.
(i) The steel pipe railing posts will be placed over the dowel bars.
(j) The steel railing posts will be tightly filled in by M30 concrete.
(k) Hand railing will then proceed as for new construction.
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Footpath Repairs
Footpaths shall be reinstated with a 50mm nominal Class 30/20 plain concrete screed coat.
The existing footpath will be scabbled, and prior to the application of the concrete screed given a cement mortar bonding coat.
The footpath will be given a float finish.
Figure 1 - Flow Trough and Funnel
300
5
42 Int.
Bung onDrawWire
230
80 3 rad
Section A - A
FunnelDetails
230
80
3 rad.
1000
90°
90°
Rivetedend plate
Trough
A
A
Length of f
low
measured
at m
axim
um
83
238
1515
3 rad.
hole
10
Funnel Support
This edge to beflush with end
of trough 100
NOTES:
1. Trough and funnel to be made of galvanised steel (14 gauge).
2. Trough to be horizontal while concrete being poured.
3. All dimensions in mm.
161
Figure 2 - Model Flow Test for Horizontal Surfaces
7575
50
10
150 crs. 19
19
750 x 750Pre-cast concrete slab
with rough surface
Plywoodcontaining
walls600 x 600
top glass plate(6 mm float)
Top of Concretein Test
R6 Steel bars at 150 crs.each way mesh placedat mid-depth
Taped Joint
NOTES:-
1. Concrete to be mixed and poured using Contractor’s proposed site
apparatus and poured until it reaches underside of top plate and has
risen up containing walls to depth of at least 10 mm.
2. All dimensions in mm.
3. Wooden, 20 x 20 spacers at corners required to support glass.
162
SECTION C 1200: MISCELLANEOUS BRIDGE WORKS
163
Bridge Bearings: General Bearings shall comply with the requirements of AASHTO M251 and shall be designed in accordance with AASHTO Standard Specifications for Highway Bridges. Bearings shall be manufactured and installed in accordance with the details shown in the Construction Documents and as described in the Construction Specification. They shall adequately provide for the thermal expansion and contraction, rotation, tilting, creep and shrinkage of the structural elements that they support.
Bearing surfaces of bearings shall be kept free from contamination and after the deck has been
completed, each bearing and the area around it shall be left clean.
All bearings shall be indelibly marked with their appropriate type and identification numbers
that shall be visible after installation and shall be supplied complete with anchors, anchor
bolts, nuts, washers, bolts, seals and the like as required.
0Should the Contractor wish to use an alternative system to that shown in the Construction
Specification or Drawings it shall include in the Construction Documents full details and
technical specifications of the alternative system and shall satisfy the Engineer with regard to
the suitability of the alternative system. The Contractor shall obtain the written approval of
the Engineer for any alternative or amended type of bearing or bearing system.
Bearings shall not be dispatched to the Site until they have been tested in accordance with the
Construction Specification and the certified results of such tests approved by the Engineer.
Bearings and their components shall be stored clear of the ground in a storage shed until
required for installation. Particular care shall be taken to prevent damage to the sliding
surfaces of bearing components. Protective wrapping around bearings shall not be removed
until immediately prior to the installation of the bearings.
Elastomeric Bearings
Bearings shall be manufactured to the design dimensions and the Construction Specification
within the tolerances set out in Section 6 of AASHTO M251.
The Contractor shall submit manufacturer‘s test certificates for all raw materials.
Sampling, testing and acceptance criteria for bearings shall be made on a lot basis. The
physical properties of the cured elastomeric compound shall be determined by using samples
taken from production bearings. Testing of the physical properties of the elastomer may
require the destruction of one or more bearings.
The manufacturer shall select random sample bearings for testing from completed lots of bearings. The manufacturer shall carry out the required testing and determine compliance with the Construction Specification before submitting the lots for quality assurance inspection, testing, and acceptance consideration by the Engineer. The results of the manufacturer’s tests shall be furnished to the Engineer.
Testing shall be carried out by the manufacturer in accordance with the requirements of
Section 8 of AASHTO M251. A minimum of two bearings per lot shall be tested for cold
temperature shear in accordance with Section 9.1 of AASHTO M251.
164
If any bearings tested fail to satisfy any of these requirements the entire lot shall be rejected.
Bearings that sustain no discernible damage under testing may be incorporated in the
Permanent Works.
The Engineer shall have the right to obtain one sample bearing of each type from the Site for
testing to confirm compliance with the Construction Specification. A minimum of 28 days
shall be allowed for inspection, sampling, and quality assurance testing of production bearings
and component materials.
Where indicated in the Contract bearings shall be installed under the supervision of the
manufacturer’s representative. Bearing installation and seating shall be carried out in
accordance with the manufacturer’s instructions. The method adopted shall be subject to the
prior approval of the Engineer.
The bedding material beneath bearings shall be either a Portland cement based non-shrink
mortar with an air-entraining agent in accordance with Section C 900 of the Construction
Specification or an approved epoxy based grout. Proprietary grout mixes shall be mixed,
placed and cured strictly in accordance with their manufacturer’s instructions. The Contractor
shall conduct Site trials, to the satisfaction of the Engineer, to determine a preferred bedding
material, before any bridge bearings are seated.
Working loads shall only be transferred on to bearings when the bedding material has
developed sufficient strength as determined from cube crushing tests.
Hot Poured Elastic Type Expansion Joints Materials
Hot poured elastic type expansion joints shall comply with the following requirements:
(a) joints shall comprise a hot poured bituminous plug constructed in place using
approved proprietary expansion joint components,
(b) a strip extending down to the concrete surface and past the waterproof membrane shall
be saw cut through the finished asphalt concrete surfacing,
(c) the expansion gap between adjacent bridge elements shall be caulked with a foam
caulking,
(d) the base of the expansion joint shall be closed with a hot dip galvanised steel base
plate held in position by locating pins driven through the base plate into the caulking,
(e) the plug shall be constructed from a single size aggregate and hot poured elastomer
modified bituminous binder,
(f) the plug shall develop a strong bond with both the exposed horizontal concrete
surfaces and the vertical cut faces of asphalt surfacing,
(g) the dimensions of the joint shall be sufficient to accommodate longitudinal
movements of 50 mm as determined in accordance with the manufacturer’s
specifications,
(h) joints shall have a high load carrying capacity, be tolerant to ambient temperatures
ranging between -300C and +45
0C, completely waterproof and flexible in all
directions,
165
(i) joints shall be capable of accommodating movements in longitudinal, rotational, and
transverse directions.
The binder shall be a blend of bitumen, polymers, fillers, and surface active agents formulated to combine fluidity at application temperature with low temperature flexibility and resistance to flow at higher ambient temperatures.
The aggregate to be incorporated in expansion joints shall be 20 mm single-sized aggregate in
accordance with BS 63 from either the Basalt, Gritstone, Gabbro, or Granite groups listed in
BS 812. Aggregate shall be cleaned, sized, and bagged under factory conditions for dispatch
to site.
The finished asphalt surfacing layers shall be saw cut and the surfacing and the waterproofing
fully removed to expose the underlying concrete surfaces. The recess shall be thoroughly
cleaned and free from any dirt or debris. The surfaces of the recess shall be prepared with a
hot compressed air lance, the expansion joint caulked, and the base plate installed and fixed
all in accordance with the manufacturer’s recommendations.
The recess shall be primed with hot binder. A layer of heated stone of maximum thickness 40 mm shall be placed in the joint and flooded with hot binder. The joint shall be built up in successive layers until it is within 25 mm of the surface. The final layer shall be constructed from premix made from the same materials and finished flush with the asphalt concrete wearing course.
Strip Type Expansion Joints
Strip type expansion joints shall be in accordance with section 19 of the AASHTO Standard
Specifications for Highway Bridges (2002) and shall be constructed from the following
materials:
(a) profiled copper strip of minimum thickness 2 mm;
(b) tarred hemp yarn 40mm or 40 mm thick compressible bitumen-impregnated fibre;
(c) joint sealer comprising coarse sand and 6% bitumen or other approved joint sealing
compound.
Filler-Type Expansion Joints
This type of joint shall be constructed from the following materials:
(a) preformed joint filler to stated thicknesses; and,
(b) an approved joint sealing compound.
Preformed joint fillers shall conform to one of the following specifications either AASHTO
M213, Preformed Expansion Joint Fillers for Concrete Paving and Structural Construction, or
AASHTO M33, Preformed Expansion Joint Filler for Concrete.
Compressible bitumen-impregnated fibreboard or other approve expansion joint filler shall be
cut to shape from full size sheets of material.
166
Surfaces of joint gaps shall be thoroughly cleaned to remove all loose materials, dirt and
debris, then washed or jetted out. No joint shall be sealed without inspection and prior
approval by the Engineer.
Preformed expansion joint filler shall only be positioned immediately prior to the placing of
the contiguous material. If opposite surfaces of the same joint are to be placed at different
times, joint filler shall not be positioned until the material forming the second face is about to
be placed.
Sealants and joint primers shall be applied in accordance with their manufacturer’s recommendations. The joint sealant shall be of a type which is resilient to pedestrian traffic and which will perform satisfactorily in the environmental conditions prevailing in Afghanistan.
Bridge Deck Waterproofing
Where a proprietary bridge deck waterproofing system is shown in the Drawings or
Construction Documents, it shall be installed in accordance with the manufacturer’s
instructions.
Where no deck waterproofing system is shown in the Drawings or Construction Documents, bridge decks shall be waterproofed by a prefabricated cold applied sheet membrane. The membrane shall comprise a self-adhesive heavy-duty polypropylene mesh reinforced rubber bitumen compound membrane protected with a silicon release paper. The minimum overall thickness of the membrane shall be 1.5 mm. The membrane shall be supplied in rolls generally 1 m wide and 20 m in length. The membrane shall be capable of accepting a cold asphalt protective layer and hot rolled asphalt concrete surfacing.
The Contractor shall ensure that concrete surfaces to receive the waterproofing membrane are clean, dry, and free from laitance, loose aggregate, and other deleterious materials. Abrupt surface irregularities greater than 3 mm shall be ground down or filled with a high strength mortar. The concrete surface shall be primed in accordance with the manufacturer’s instructions prior to applying the waterproof membrane.
A cold asphalt protective layer complying with Section C 800 of the Construction
Specification shall be laid over the waterproof membrane.
Paint for Structural Steelwork Paint systems for steel structures shall comply with Division II, Construction - Section 14 Painting Metal Structures, of AASHTO Standard Specifications for Highway Bridges. The paint system shall comprise one of two alternatives:
two coats of organic zinc primer, vinyl wash undercoat, and two coats of vinyl finish
in accordance with Section 14.2 of the above referenced standard. The colour of the
last finish coat shall be as directed by the Engineer;
two coats of inorganic zinc primer, vinyl wash undercoat, and one coat of alkyd finish.
Galvanised Coatings
Galvanised coatings on ferrous materials shall comply with AASHTO M 232, Zinc Coating
(Hot-Dip) on Iron and Steel Hardware and AASHTO M 111, Zinc (Hot-Dip Galvanised)
Coatings on Iron and Steel Products as appropriate.
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SECTION C 1300: ROAD FURNITURE
168
General All road furniture shall comply with appropriate Afghanistan standards.
Retro reflective Material for Permanent Road Signs
The retro reflective material shall comply with AASHTO M 268, Retro reflective Sheeting for
Traffic Control as amended below.
The retro reflective material, when applied to the sign plate, shall give the appearance of a
continuous reflecting surface under any angle of observation. It shall consist of a smooth exterior
film with spherical lenses embedded beneath the surface, and shall have a protected, precoated
adhesive backing which shall be tack-free, heat-activated for mechanical vacuum-heat application.
The combination of various elements shall result in a non-exposed lens type optical reflecting
system. The retro reflective material shall be applied in accordance with the instructions from the
manufacturer of the retro reflective material used.
The retro reflective surface of the sign shall be weather resistant and shall show no appreciable
cracking, blistering, crazing or dimensional changes after 2 years unprotected outdoor exposure at
45˚ upwards inclination to the vertical facing west.
When retro reflective surface are laminated to the base materials, the adhesion shall be such that the
retro reflective material shall resist peeling, scuffing and marring during normal handling or
shocking off when jabbed with a spatula at 20˚C. It shall withstand 8 hours of soaking in water at
25˚C without any noticeable edge lifting or curling. The adhesive shall have no staining effect on
the retro reflective material. The adhesive shall permit the retro reflective material to adhere
securely 48 hours after application at temperatures between -40˚C and + 93˚C.
When bent around a 20 mm diameter mandrel at a temperature of 20˚C, the retro reflective material
applied to an aluminum panel of 0.5 mm thickness shall show no evidence of cracking around the
outside of the bend.
When a 25 mm diameter steel ball is dropped from 2 meters height onto the retro reflective face of
the sign specimen at the ambient temperature of 20˚C.
The retro reflective material around the impact point shall show no evidence of cracking or peeling
off.
After immersion of a specimen of retro reflective sign material for 10 minutes in methyl alcohol,
kerosene or turpentine, or for 1 minute in toluene or xylol, the retro reflective material shall show
no evidence of dissolving, puckering or blistering. The retro reflective material shall be capable of
withstanding washing with a mixture of water and mild detergent, turpentine and methanol.
The retro reflective surface shall be such as to be readily refurbished by cleaning and recoating in
accordance with the manufacturer's recommendations.
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Permanent Road Signs
The Contractor shall obtain road signs only from a manufacturer / supplier approved by the
Engineer.
The Contractor shall include the following information in the Construction Documents:
(a) name of the firm from which it proposes to obtain the signs together with place of
manufacture or fabrication;
(b) a description of the items to be supplied;
(c) manufacturer's specification together with a description of quality, grade, weight and
strength;
(d) Manufacturer's test certificates, or recent test results carried out on similar items by an
authority or laboratory recognized by the Engineer;
(e) A sample sign, post and fittings that shall be stored on site;
(f) Manufacturer’s instructions on the operation and maintenance of the signs.
Unless directed otherwise posts, frames, fittings and the backs of signs shall be painted with a finish
coat of grey. Bolts and nuts shall be spot welded after erection to prevent theft, and grey epoxy
paint shall be applied to all areas so treated.
Finished sign plates (with sign face attached) shall be clearly and durably marked on the back, with
the following information in English and Dari:
(a) the number of the Standard Specification to which they have been manufactured;
(b) the name, trade mark or other means of identification of the manufacturer or supplier;
(c) the classification of any retroreflective material used in the manufacture of the sign face;
(d) the month and year of assembly.
The Contractor shall excavate in any material for the foundation of the road signs, provide and place concrete Class 20/20, embedded all round and under the posts and backfill the remaining excavation all as shown in the Construction Documents. Foundations for signs of areas over 5 sq metres shall not be covered up until they have been approved by the Engineer.
Guardrail
Beams for guardrails shall be Class A with a Type 1 finish in accordance with AASHTO M180.
The beams shall be mounted on 150 x 75 x 5 mm steel posts with spacers provided between the
beam and post.
All exposed ends of guardrails shall be flared away from the traffic and fitted with terminal
sections. Connection pieces shall be provided where guard rail connects to bridge parapets. and
otherwise an AASHTO and rail manufacturer approved cable anchor assembly and concrete block
anchor will be provided at each run end
Guardrails shall be erected so that the over laps point in the same direction as the flow of the traffic.
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Posts for guard-rails off bridges shall either be driven or placed in pre-excavated holes as approved by the Engineer. Backfilling of postholes shall be with Class 10/20 concrete.
Guard-rail posts on bridges shall not be erected until the concrete in which the holding down bolts
have been cast has reached its 28 day strength.
Guard-rail shall be correct within a tolerance of ± 20 mm in line and level.
Kerb and Drainage Offlets Materials
Edge kerb include barrier kerb, mountable and semi-mountable kerb shall be constructed in Class
20/20 pre-cast concrete.
Chutes shall be manufactured in Class 20/20 pre-cast concrete, and the units shall fit neatly into each other.
Channels shall be constructed from Class 20/14 concrete and reinforced with high yield steel mesh
reinforcement in both faces.
Cold-poured joint sealant shall be a two-part polysulphide sealing compound conforming to the
requirements of BS 4254.
The material on which concrete kerb and channels are to be bedded shall consist of crushed stone
sand or other approved porous material with a maximum particle size of 13 mm.
Where concrete bedding material is shown in the Construction Documents, it shall be Class 10/20.
Construction
Trenches for kerb and channels shall be excavated to the required depth and all unsuitable material
shall be removed and replaced with a layer of selected bedding material at least 75 mm thick. The
bedding shall be compacted and accurately shaped to the required grade. No concrete shall be
placed on uncompacted or disturbed material.
Excavations for chutes shall be neatly trimmed. All loose material shall be compacted and where overbreak occurs in hard material it shall be backfilled with non-structural concrete.
Pre-cast concrete kerbing shall be laid and bedded in Class 15/20 concrete with close joints of 3:1
sand:cement mortar at the ends. The joints may not exceed 10 mm in thickness and must be neatly
pointed with a pointing trowel. Guidelines and straight-edges shall be used to ensure that the
exposed faces of kerb and edgings are set true to line and elevation. Kerbing around curves shall be
laid along the full curve length before the joints are made, unless otherwise allowed by the
Engineer.
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Concrete channels shall be cast in alternate sections. The lengths of sections shall be uniform
throughout and shall be equal to 2 m for every 100 mm average thickness or depth of concrete
measured perpendicular to the bed, except where shorter sections are necessary for closures or
where otherwise shown in the Construction Documents. The exposed surfaces of the concrete shall
be finished in accordance with Section C 900 of the Construction Specification. The concrete shall
be cured in accordance with the requirements of Section C 900 of the Construction Specification.
Abutting joints shall be painted with mastic asphalt coating before intermediate sections are cast.
Guidelines and straight-edges shall be used to ensure that the exposed are formed to line and
elevation.
When curing is complete the joints shall be sealed with an application of joint sealant as specified.
Concrete Chutes in cascades on side slopes shall be laid from the bottom upwards so that each
consecutive unit fits into the previous one, with the bottom unit resting against the outlet structure.
A transition section shall be constructed at the inlet to lead the water into the chute as shown in the
Construction Documents.
Concrete-Lined Open Drains shall be constructed from Class 20/20 concrete. The surface of the excavation against which the lining is to be placed shall be covered by polythene sheet 0.15 mm thick and all joints in the sheeting shall overlap by at least 150 mm. The concrete lining shall be cast in alternate panels and cold joints shall be painted as specified before adjoining slabs are cast.
Transition sections for chutes shall be constructed in situ in Class 20/20 concrete to the dimensions
indicated in the Construction Documents or as otherwise agreed with the Engineer. They shall be
built to the same standards as described for the edge kerbing.
Where kerb and channels are laid after construction of the base, the spaces between the concrete and
adjoining base shall be filled with compacted pre-mixed bituminous material and the cost shall be
included in the rates for the items.
Tolerances
The maximum horizontal deviation of kerb and drainage channels shall be 25 mm or 1:500 when
taken over any section more than 10 m in length.
The invert level of channels and drains and the top of kerbing shall nowhere deviate more than 10 mm from the required level and nowhere shall channels or drains have any adverse grade.
When tested with a 3 m straight-edge, no surface irregularities shall exceed 10mm.
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Measurement and Payment The units that have been used in this contract associated to the Bill 7 ( Road Furniture and markings
), are the following
Note : In the Section 4, The Bill of Quantities are described all the measurement method that have
to be taken in order to assign the Payment for every used Item in this project
SECTION C 1400: ROAD TRAFFIC MARKINGS
General
Road marking paint shall be specially manufactured for that purpose and comply with AASHTO M
248, Ready-Mixed White and Yellow Traffic Paints.
Thermoplastic material for road marking shall comply with AASHTO M249, White and Yellow Reflective Thermoplastic Striping Material (Solid Form). Road markings shall be reflectorised with glass beads that comply with AASHTO M247, Glass Beads Used in Traffic Paint.
The Contractor shall submit, for each consignment of thermoplastic material delivered to Site, a
Manufacturer’s certificate to show that the materials comply with the Construction
Specification.Paint will be cheaper and thermo will last longer
Equipment
Line marking and the surface application of glass beads shall be carried out only by mechanical
means.
Equipment shall be capable of mechanically extruding hot thermoplastic material to produce a line
thickness of between 4 and 6 mm. The Contractor shall conduct Site trials to demonstrate the
satisfactory performance of his equipment to the Engineer.
Nº of Item Description Unit
Road Furniture
1001 Edge marker posts No
1002 Kilometre posts No
1003-01 Road signs less than 1 sq m
Traffic signs No
Other signs (villages, directions,..) No
1003-02 Information road signs of 2 sq m No
1004 Guard-rail ( safety fence) lin m
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Letters, figures and symbols shall be marked on the road by means of stencils.
Application of Road Markings
Traffic markings shall be applied to bituminous surfaces only after sufficient time has elapsed to
allow for the evaporation of volatile substances from the bitumen.
Before road marking commences, the road surface shall be clean and dry and completely free from
soil, dust, grease, petroleum products or other deleterious material.
Thermoplastic material shall be applied mechanically in a single layer. Rates of application of thermoplastic materials shall be checked and adjusted if necessary on a daily basis.
The Contractor shall apply retro reflective beads to road markings by means of a spraying device,
forming an integral part of the road marking machine, immediately after the application of the road
marking material and in one continuous operation. Machines that apply beads by means of gravity
only shall not be used.
The rate of application of glass beads to thermoplastic material shall be 0.35 kg/m2 or such other
rate as may be instructed by the Engineer.
Retroreflective Studs
Retro reflective road studs shall not be placed over longitudinal or transverse pavement joints.
Dowel holes shall be drilled in accordance with the manufacturer’s instructions. The dowel hole
and the adjacent portion of the pavement surface to which the marker is to be bonded by adhesive
shall be thoroughly cleaned by blasting.
The adhesive shall be placed uniformly inside the dowel hole and on the adjacent pavement surface, or alternatively, directly to the dowel and on the underside of the marker in a quantity to ensure complete coverage of the contact area with no voids present and with a slight excess after the marker has been pressed into place. The marker shall be placed in position and uniform pressure applied until firm contact is established. Excess adhesive around the marker shall be immediately removed. Soft rags moistened with an approved solvent complying with the manufacturer’s recommendations may be used, if necessary, to remove adhesive from exposed faces of pavement markers. Only approved solvents may be used for this purpose.
Mixing and use of adhesive shall be in strict accordance with the manufacturer’s instructions to ensure that materials are used within the permissible limits. Any adhesive which becomes too viscous shall not be used.
Retro reflective markers shall be placed so that the reflective face of the marker faces the oncoming
traffic.
Retro reflective road studs shall be within ± 20 mm of the required longitudinal position and within
± 5 mm of the required lateral position.
174
Tolerances for Thermoplastic Road Markings
The width of lines and other markings shall not deviate from the specified width by more than 5%.
The position of letters, figures, symbols or lines shall not deviate from that shown in the Drawings
or Construction Documents by more than 20 mm in any direction.
The alignment of any edge of a line parallel to the road centreline shall not deviate from that shown
in the Drawings or Construction Documents by more than 10 mm in 15 m.
The length of segments of any broken line parallel to the road centreline shall not deviate from that
shown in the Drawings or Construction Documents by more than 150 mm.
Both broken and unbroken lines on horizontal curves shall not be marked as chords but shall follow
the correct arc, not deviating from it by more than 20 mm.
Measurement and Payment The units that have been used in this contract associated to the Bill : Road Furniture and markings
are the following
Nº of Item Description Unit
Road Markings
Thermoplastic Road Lane Markings
1101-01 Continous white line 100mm ln m
1101-02 Intermittent line 100mm (3:1) ln D47m
1102 Road marking symbols sq m
