Technical Specifications
1.
STANDARD SPECIFICATIONS
The Standard Specifications forming part of this Contract shall be the “Standard Specifications for
Highway and Bridge Construction” issued by the Ministry of Public Works and Housing, Highway
Department and shall hereinafter be referred to as the Standard Specifications, 1991.
Reference to Section numbers in the special specifications refers to corresponding sections in the
standard specifications and the sub-sections, clauses, and items contained in these sections constitute
additions, modifications and revisions corresponding clauses in the Standard Specifications.
Volume II-1
Technical Specifications
PART TWO: EARTHWORKS
SECTION 2.03 - HIGHWAY EXCAVATION
SUB - SECTION 2.03.2 - CONSTRUCTION
Replace item No. (1.1) by:
All suitable soils, rock, boulders and other materials complying with table 2.1 and 2.2 shall be
excavated in such a manner that they can be utilized, if intended to be used as embankment fill or in
sub-grade or elsewhere as appropriate.
SUB-SECTION 2.03.3 - MEASUREMENT
Replace this Sub-Section by:
1.
All excavated material (to the top of subgrade) of whatever type (except for unauthorized
undercut below top of subgrade) shall be measured as “unclassified” which shall be deemed to
include all materials encountered of any nature, including silts, clays, sand, gravel and granular
materials, fractured, jointed and solid rock, unsuitable material, existing concrete slab, existing
pavements, existing curbstone, existing rip rap, existing gabions and existing concrete wall.
2.
Highway Excavation (including authorized benching, roadside ditches, channel, at up /down
stream of culverts if needed, excavation at wadis up to finished level indicated on drawings and
excavation for replacement of unsuitable material if directed) shall be measured by cu.m of
material excavated, hauled away and either wasted, stockpiled, or deposited on or in vicinity of
highway embankment areas, completed and accepted.
Measurements shall be of volumes computed from the cross sections shown on the Drawings
and the original ground elevations taken jointly by the Employer, and the Consultant and the
Contractor before clearing and grubbing operations.
3.
Cut-off ditch excavation shall be measured by linear meter of each type excavated and trimmed
to required line, grade and cross section, including depositing excavated material along the side
of the ditch if directed or hauling away and wasting, stockpiling or depositing on or in the
vicinity of highway embankment areas, completed and accepted.
4.
Excavation of Unstable Material (from areas outside the ROW) where indicated or directed
shall be measured as Unclassified Highway Excavation.
Measurements shall be of volumes computed from surveyed cross sections of original and final
ground elevations. When cross sectioning is impractical in the opinion of the Engineer,
approval may be given to measure volumes in the vehicles removing such excavated material,
adjusted to reflect in situ volumes.
5.
Rock blasting, backfilling of over breakage, the trimming and grading of cut slopes, ditches and
of other below-subgrade surfaces, drainage of excavation areas, cleaning cut sections from
surface rock boulders which is not stable to avoid their falls on the road, obliteration of disused
roadways, and other ancillary excavation works shall not be measured for direct payment, but
shall be considered as subsidiary works the costs of which will be deemed to be included in the
Contract prices of Pay Items.
Volume II-2
Technical Specifications
Pay Item
Unit of Measurement
(1) Unclassified Highway Excavation
Cubic Meter
SECTION 2.06 - EMBANKMENT CONSTRUCTION
SUB-SECTION 2.06.5 - MEASUREMENT
Delete Clause No. (2) and replace by:
2.
Embankment Construction shall be measured by cu.m of approved unclassified material placed,
spread, watered as necessary, compacted and finished, and accepted. Measurements shall be of
volumes computed from cross sections shown on the Drawings and the original ground
elevations, including the 600 mm layer of embankment (described in Clause 2.06.2)
immediately below the sub-grade layer and including embankment fill for authorized excavated
benches (described in clause 2.06.3), and for replacement of unsuitable material ( if any).
SECTION 2.07
SUBGRADE CONSTRUCTION AND TOPPING
2.07.2 MATERIALS
Add new clause 4
4.
Topping material shall be prepared for tests in accordance with AASHTO (T-146)- (wet
preparation)
SUB-SECTION 2.07.4 - MEASUREMENT
Amend Clause No. (2) of this sub-section to read as follows:
2.
Scarifying, removing of undesirable matter, watering, mixing, compacting and completion and
accepted of the top 20 cm of sub-grade level (bottom of topping layer) in areas of approved in
situ material, shall not be measured or paid for, and the payment of such work shall be deemed
to be included in the Unclassified Excavation.
Amend clause No. (3) of this subsection to read as follows:
3.
Sub excavation of unsuitable material below the top of subgrade layer shall be measured as
unclassified highway excavation as prescribed in section – 2.03. Highway embankment used
to replace the excavated material shall be measured as embankment construction as prescribed
in section – 2.06.
Delete the Pay Items and replace by:
Pay Item
Unit of Measurement
(1) Sub-grade Layers (Topping)
Cubic Meter (Cu.m)
Volume II-3
Technical Specifications
SECTION 2.09 - EXCAVATION AND STRUCTURAL BACKFILL
SUB-SECTION 2.09.4 - MEASUREMENT
-
Modify Clause No. (4) to read as follows:
4.
-
Structural Excavation shall be measured by cubic meter of material excavated for the
major structures other than those specified in Clause 3 above, hauled away and disposed
as directed, or stockpiled on or in the vicinity of the Works, and the excavated areas
backfilled, completed and accepted.
Amend Clause No. (6) to read as follows:
6.
Subexcavation of unsuitable material, hauled away and disposed of as directed, and
backfilling with approved material of the excavated areas shall be measured and paid for
as Unclassified structural Excavation, of whatever type.
Delete the Pay Items and add the following Pay Item:
Pay Item
Unit of Measurement
(1) Unclassified Structural Excavation (each type)
Volume II-4
Cubic Meter
Technical Specifications
PART THREE-SUB-BASE AND BASE COURSES
SECTION 3.01 - MATERIALS
SUB-SECTION 3.01.3 – GRANULAR MATERIAL FOR SUB-BASE
-
Add the following at the end of Clause No. 4:
The specified sand equivalent value corresponds to the value obtained in accordance with
AASHTO T. 176 (Dry method), for the material in dry condition.
-
Replace the first sentence in Clause 5 by:
The loss in weight of granular material shall not exceed 40 % after 500 revolutions when tested
in accordance with AASHTO T96 (Los Angeles Abrasion Test).
Abrasion after 100 Rev
The ratio of wear loss = ----------------------------- should not be more than 0.25.
Abrasion after 500 Rev
-
Add the following new Clause:
10.
11.
12.
Chert content (determined as percentage by weight insoluble in hydrochloric acid) for
sub-base material shall be within reasonable limits, which will not affect the formation of
intact cohesive surface, usually less than 5% and to the approval of the Engineer.
The amount of fraction of material passing No.200 mesh Sieve shall not exceed 67% of
the fraction passing the No. 40 Sieve.
For other specification requirement refer to attached tables in Part (9).
Delete table 3.1 : Gradation for Granular Material by class and replace by:
Table 3.1:
Gradation Granular Material
Sieve Designation (square openings)
63
50
37.5
25
12.5
4.75
2.00
0.425
0.075
0.075
Percent by Weight Passing (Class A)
mm (2-½ in)
mm (2 in)
mm (1- ½ in)
mm (1 in)
mm (½ in)
mm ( No. 4)
mm ( No. 10)
mm (No. 40)
mm (No. 200), (before compaction)
mm (No. 200), (after compaction)
100
80-100
70-95
55-90
45-75
30-60
22-48
10-30
5-12
Max 15%
SUB-SECTION 3.01.4 – AGGREGATE FOR BASE COURSES
-
-
Add the following to end of Clause 5:
The specified sand equivalent corresponds to the value obtained in accordance with AASHTO
T.176 (dry method), for the material in dry condition.
Replace the first sentence in Clause 6 by:
Volume II-5
Technical Specifications
The loss in weight of granular material shall not exceed 40 % after 500 revolutions when tested in
accordance with AASHTO T96 (Los Angeles Abrasion Test).
Abrasion after 100 Rev
The ratio of wear loss = ------------------------------ should not be more than 0.25.
Abrasion after 500 Rev
-
Add the following new Clause:
11.
12.
13.
14.
Of the particles which are retained on a 3/8 in (9.5 mm) sieve, at least 75 % shall have
two or more fractured faces.
Chert content (determined as percentage by weight insoluble in hydrochloric Acid) for
base course material shall be within reasonable limits which will not affect the formation
of intact cohesive surface, usually less than 5% and to the approval of the Engineer.
The amount of fraction of material passing No.200 mesh Sieve shall not exceed 67% of
the fraction passing the No. 40 Sieve.
For other specifications requirements refer to attached tables in Part (9).
Delete table 3.2 : Gradation Granular of Base Course Aggregate by Class and replace by:
Table 3.2:
Gradation Granular of Base Course Aggregate by Class
Sieve Designation (square openings)
50
37.5
25
19.0
12.5
9.5
4.75
2.00
0.425
0.075
0.075
mm (2 in)
mm (1- ½ in)
mm (1 in)
mm (3/4 in)
mm (½ in)
mm (3/8 in)
mm ( No. 4)
mm ( No. 10)
mm (No. 40)
mm (No. 200), (before compaction)
mm (No. 200), (after compaction)
Percent by Weight Passing
Class A
100
75-100
60-90
45-80
40-70
30-65
20-40
8-20
5-10
max 13 %
SECTION 3.03 – AGGREGATE FOR BASE COURSES
SUB-SECTION 3.03. 6 – CONSTRUCTION
Replace Items No. 4.2 and 4.4 by:
4.2
4.4
The elevations of the finished base course shall be checked by the Contractor in the presence of
the Engineer at intervals of 10.0 m and its intermediate points as directed.
When the finished surface is tested with a 3 m long straightedge, placed parallel to, or at right
to the centerline, the maximum deviation of the surface from the testing edge between any 2
contact points shall not exceed 10 mm.
Volume II-6
Technical Specifications
PART FOUR – BITUMINOUS CONSTRUCTION
SECTION 4.01 - MATERIALS
SUB-SECTION 4.01.3 – AGGREGATES FOR BITUMINOUS PAVING MIXES
-
Replace Clause 11 by:
11.
Combined coarse and fine aggregates for bituminous mixes, including mineral filler,
when tested in accordance with AASHTO T 27 and T 11, shall conform to the
gradations shown in Table 4.1:
Table 4.1:
Gradation of Aggregates for Bituminous Mixes
Sieves Designation
1"
¾"
½"
3
/ 8"
No. 4
No. 8
No. 20
No. 50
No. 80
No. 200
-
Heavy Traffic
Binder Course
100
70-100
53-90
40-80
30-56
23-38
13-27
5-17
4-14
2-8
Wearing Course
100
90-100
71-90
56-80
35-56
23-38
13-27
5-17
4-14
2-8
For other main specification requirements refer to attached tables in Part (9).
SECTION 4.03 - BITUMINOUS COURSES
SUB-SECTION 4.03.8 – DELIVERY, SPREADING AND FINISHING
-
Add the following new clause:
1.7
Rolling shall not continue after the temperature of the mix on the road has dropped
below 110° without the express approval of the Engineer and that no vibrating roller
shall, under any circumstance, be used below that temperature.
SECTION 4.05 - BITUMINOUS BINDER AND WEARING COURSE
SUB-SECTION 4.05.10 – SURFACE TOLERANCES
-
Amend Clause 2 to read as follows:
2.
-
The Tolerances on elevations of the final bituminous wearing and binder course surfaces
shall not be greater than 10 mm.
Amend Clause 3 to read as follows:
3.
When the finished wearing and binder course surface are tested with a 3m long
straightedge, placed parallel to, or right angles to the centerline, the maximum deviation
of the surface from the testing edge between any 2 contact points shall not exceed 3 mm
and 4 mm, respectively.
Volume II-7