BITUMINOUS BASE AND SURFACE COURSES
The bituminous base courses included in the MoRTH Specifications for Road and Bridge works (5th revision 2013) and which are normally used in pavement construction are:
The bituminous surface courses include:
For more details, Clause 501 of MoRTH Specifications shall be referred.
1. PRIME COAT AND TACK COAT
1.1 Prime coat over granular base
Prime coat is the application of a single coat low viscosity bituminous material over a granular base or subbase to prevent entry of water into the subgrade. The main function of the prime coat in bituminous pavement is to protect the subgrade from moisture and weathering. The specifications and procedure for applying prime coat is giver under Clause 502 of MoRTH Specifications (5th revision).
1.2 Tack coat
A tack coat is a very light spray application of a bitumen emulsion to create a bond between the new bituminous layer and the existing surface.
Table: Rate of application of tack coat
Type of surface |
Rate of spray in kg/m2 |
Bituminous surface |
0.20-0.30 |
Primer granular surface |
0.25-0.30 |
Cement concrete pavement |
0.30-0.35 |
2. BITUMINOUS MACADAM (BM)
Constructing bituminous macadam base shall generally be done as per IRC: 27-1967. The specifications and construction procedure of bituminous macadam is given under Clause 504 of MoRTH Specifications (5th revision).
Table: Physical requirements for coarse aggregates for BM
Property |
Test |
Code |
Requirement |
Cleanliness |
Grain size analysis |
IS: 2386 (Part 1) |
Max 5% passing 75 micron sieve |
Particle shape |
Flakiness and elongation indices (Combined) |
IS: 2386 (Part 1) |
Max 35% |
Strength* |
Los Angeles Abrasion value |
IS: 2386 (Part 4) |
Max 40% |
Aggregate Impact value |
IS: 2386 (Part 5) |
Max 30% |
|
Durability |
Soundness – Sodium Sulphate (5 cycles) |
IS: 2386 (Part 5) |
Max 12% |
Soundness – Magnesium Sulphate (5 cycles) |
IS: 2386 (Part 5) |
Max 18% |
|
Porosity |
Water absorption |
IS: 2386 (Part 3) |
Max 2% |
Bitumen adhesion |
Coating and stripping of bitumen aggregate mixtures |
IS: 6241 |
Minimum 95% coating retained |
Water sensitivity |
Retained tensile strength** AASHTO 283 |
IS: 6241 |
Min 80% |
Table: Physical requirements for coarse aggregates for BM
Sl .No |
Test prescribed |
Code |
Minimum test frequency |
1 |
Vescosity of binder |
IS: 73, IS: 15462 |
One test for each supply. |
2 |
Ductility |
IS: 73, IS: 15462 |
One test for each supply. |
3 |
Penetration |
IS: 73, IS: 15462 |
One test for each supply. |
4 |
Softening point |
IS: 73, IS: 15462 |
One test for each supply. |
5 |
Grain size analysis |
IS: 2386 Part 1 |
Two tests per day. |
6 |
Flakiness & elongation |
IS: 2386 Part 1 |
One test per 350 m3 |
7 |
Los Angeles Abrasion |
IS: 2386 Part 4 |
One test per 200 m3 |
8 |
Aggregate Impact value |
IS: 2386 Part 4 |
One test per 200 m3 |
9 |
Water absorption |
IS: 2386 Part 3 |
One test for each source. |
10 |
Stripping |
IS: 6241 |
One test for each source. |
11 |
Soundness |
IS: 2386 Part 5 |
One test for each source. |
12 |
Plasticity index |
IS: 2720 Part 5 |
One test for each source. |
13 |
Temperature check |
- |
At regular intervals. |
14 |
Binder content |
ASTM D 2172 |
Two tests per day. |
15 |
Mix grading |
IS: 2386 Part 1 |
Two tests per day. |
16 |
Layer density |
- |
One test per 700 m3 area |
3. DENSE BITUMINOUS MACADAM (DBM)
The specifications for the design and construction of Dense Bituminous Macadam are giver under Clause 505 of MoRTH Specifications (5th revision 2013).
Table: Physical requirements for coarse aggregates for DBM
Property |
Test |
Code |
Specification |
Cleanliness |
Grain size analysis |
IS: 2386 (Part 1) |
Max 5% passing 75 micron sieve |
Particle shape |
Flakiness and Elongation Indices (Combined) |
IS: 2386 (Part 1) |
Max 35% |
Strength* |
Los Angeles Abrasion value |
IS: 2386 (Part 4) |
Max 35% |
Aggregate Impact value |
IS: 2386 (Part 4) |
Max 27% |
|
Durability |
Soundness – Sodium Sulphate (5 cycles) |
IS: 2386 (Part 5) |
Max 12% |
Soundness – Magnesium Sulphate (5 cycles) |
IS: 2386 (Part 5) |
Max 18% |
|
Porosity |
Water absorption |
IS: 2386 (Part 3) |
Max 2% |
Bitumen adhesion |
Coating and stripping of bitumen aggregate mixtures |
IS: 6241 |
Minimum 95% coating retained |
Water sensitivity |
Retained tensile strength** |
AASHTO 283 |
Min 80% |
*Any one of these shall need to be satisfied.
**Anti-stripping agent shall be added if the value falls below 80%.
Table 2300-12: Quality control test on DBM
Sl. No |
Test prescribed |
Code |
Minimum test frequency |
1 |
Viscosity of binder |
IS: 73, IS: 15462 |
One test for each supply. |
2 |
Ductility |
IS: 73, IS: 15462 |
One test for each supply. |
3 |
Penetration |
IS: 73, IS: 15462 |
One test for each supply. |
4 |
Softening point |
IS: 73, IS: 15462 |
One test for each supply. |
5 |
Grain size analysis |
IS: 2386 Part 1 |
Two tests per day. |
6 |
Flakiness & elongation |
IS: 2386 Part 1 |
One test per 350 m3 . |
7 |
Los Angeles abrasion |
IS: 2386 Part 4 |
One test per 350 m3 . |
8 |
Aggregate impact |
IS: 2386 Part 4 |
One test per 350 m3 . |
9 |
Water absorption |
IS: 2386 Part 3 |
One test for each source. |
10 |
Stripping |
IS: 6241 |
One test for each source. |
11 |
Soundness |
IS: 2386 Part 5 |
One test for each source. |
12 |
Sand equivalent |
IS: 2720 Part 37 |
One test for each source. |
13 |
Plasticity index |
IS: 2720 Part 5 |
One test for each source. |
14 |
Temperature check |
- |
At regular intervals. |
15 |
Binder content |
ASTM D 2172 |
Two tests per day. |
16 |
Aggregate mix grading |
IS: 2386 Part 1 |
Two tests per day. |
17 |
Marshall test |
AASHTO T 245 |
Three tests per 400 tonnes. |
18 |
Max sp. gravity of mix |
AASHTO T 209 |
Three tests per 400 tonnes. |
19 |
Volumetric analysis |
MS-2 |
Three tests per 400 tonnes. |
20 |
Moisture susceptibility |
AASHTO T 283 |
One test for each mix. |
21 |
Layer density |
- |
One test per 700 m2 area. |
4. SAND BITUMEN MIX
The sand bitumen mix can be used both as subbase and base.
The requirements for sand are prescribed in table 2300-13 (Ref: Table 500-14 of MoRTH Specifications).
Table 2300-13: Grading and physical requirements of sand for sand bitumen mix
Sieve size mm |
Cumulative percentage passing by weight of aggregate |
9.5 |
100 |
2.75 |
85-100 |
2.36 |
80-100 |
1.18 |
70-98 |
0.600 |
55-95 |
0.300 |
30-75 |
0.150 |
10-40 |
0.075 |
4-10 |
Plasticity index (PI) |
6 (Max) |
Sand equivalent (IS:2720 part 37) |
30 (Min) |
Los Angeles abrasion (IS: 2386 Part4) |
40 (Max) |
The mix requirements are prescribed in table 2300-14 (Ref: Table 500-15 of MoRTH Specifications).
Table 2300-14: Requirements for sand base course
Mix parameter |
Requirement |
Minimum stability (kN at 60°C) |
2.0 |
Minimum flow (mm) |
2 |
Compaction level (Blows) |
75 on each face |
Air voids in the mix (%) |
3-5 |
Voids in the mineral aggregate (VMA) % |
16 (Min) |
Percentage voids filled with bitumen (VFB) % |
65 - 75 |
The binder content of the mix shall be determined in the laboratory by Marshall method given in the Asphalt Institute Manual MS-2.
Table 2300-15: Control tests for sand bitumen base / subbase.
Sl. No |
Test prescribed |
Code |
Minimum test frequency |
1 |
Viscosity of binder |
IS: 73, IS: 15462 |
One test for each supply. |
2 |
Ductility |
IS: 73, IS: 15462 |
One test for each supply. |
3 |
Penetration |
IS: 73, IS: 15462 |
One test for each supply. |
4 |
Softening point |
IS: 73, IS: 15462 |
One test for each supply. |
5 |
Grain size analysis |
IS: 2386 Part 1 |
Two tests per day. |
6 |
Water absorption |
IS: 2386 Part 3 |
One test for each source. |
7 |
Sand equivalent |
IS: 2720 Part 37 |
One test for each source. |
8 |
Plasticity index |
IS: 2720 Part 5 |
One test for each source. |
9 |
Temperature check |
- |
At regular intervals. |
10 |
Binder content |
ASTM D 2172 |
Two tests per day. |
11 |
mix grading |
IS: 2386 Part 1 |
Two tests per day. |
12 |
Marshall test |
AASHTO T 245 |
Three tests per 400 tonnes. |
13 |
Max sp. gravity of mix |
AASHTO T 209 |
Three tests per 400 tonnes. |
14 |
Volumetric analysis |
MS-2 |
Three tests per 400 tonnes. |
15 |
Layer density |
- |
One test per 700 m2 area. |
QC tests on material and work for surface dressing shall be as indicated in table 2300-16 (Ref: Table 900-4 of MoRTH Specifications).
Sl. No |
Test prescribed |
Code |
Minimum test frequency |
1 |
Viscosity of binder |
IS: 73, IS: 15462 |
One test for each supply. |
2 |
Ductility |
IS: 73, IS: 15462 |
One test for each supply. |
3 |
Penetration |
IS: 73, IS: 15462 |
One test for each supply. |
4 |
Softening point |
IS: 73, IS: 15462 |
One test for each supply. |
5 |
Grain size analysis |
IS: 2386 Part 1 |
Two tests per day. |
6 |
Flakiness & elongation |
IS: 2386 Part 1 |
One test per 350 m3 . |
7 |
Los Angeles abrasion |
IS: 2386 Part 4 |
One test per 350 m3 . |
8 |
Aggregate impact |
IS: 2386 Part 4 |
One test per 350 m3 . |
9 |
Water absorption |
IS: 2386 Part 3 |
One test for each source. |
10 |
Stripping |
IS: 6241 |
One test for each source. |
11 |
Soundness |
IS: 2386 Part 5 |
One test for each source. |
12 |
Temperature check |
- |
At regular intervals. |
13 |
Binder content |
ASTM D 2172 |
Two tests per day. |
14 |
Moisture susceptibility |
AASHTO T 283 |
One test for each mix. |
The QC tests on material and work shall be as given in table 2300-19 (Ref: Table 900-4 of MoRTH Specifications).
Table: Quality Control tests for open / close graded premix surfacing
Sl. No |
Test prescribed |
Code |
Minimum test frequency |
1 |
Viscosity of binder |
IS: 73, IS: 15462 |
One test for each supply. |
2 |
Ductility |
IS: 73, IS: 15462 |
One test for each supply. |
3 |
Penetration |
IS: 73, IS: 15462 |
One test for each supply. |
4 |
Softening point |
IS: 73, IS: 15462 |
One test for each supply. |
5 |
Grain size analysis |
IS: 2386 Part 1 |
Two tests per day. |
6 |
Flakiness & elongation |
IS: 2386 Part 1 |
One test per 350 m3 . |
7 |
Los Angeles abrasion |
IS: 2386 Part 4 |
One test per 350 m3 . |
8 |
Aggregate impact |
IS: 2386 Part 4 |
One test per 350 m3 . |
9 |
Water absorption |
IS: 2386 Part 3 |
One test for each source. |
10 |
Stripping |
IS: 6241 |
One test for each source. |
11 |
Soundness |
IS: 2386 Part 5 |
One test for each source. |
12 |
Temperature check |
- |
At regular intervals. |
13 |
Binder content |
ASTM D 2172 |
Two tests per day. |
14 |
Moisture susceptibility |
AASHTO T 283 |
One test for each mix. |
5. CLOSE-GRADED PREMIX SURFACING/MIX SEAL SURFACING
The specifications and construction procedure for close-graded premix surfacing are given under Clause 508 of MoRTH Specifications. Close-graded premix surfacing/mix seal surfacing shall be either Type A or Type B and is laid to a thickness of 20 mm. Type A surfacing is recommended for areas where average annual rainfall is more than 1500 mm.
6. SEAL COAT
Clause 511 of MoRTH Specifications provides the details for the application of a seal coat for sealing the voids in the bituminous surface laid to the specified levels, grade and cross fall (Camber). The seal coat shall be either type A (Liquid seal coat) or type B (Premixed seal coat).
Table 2300-21: Physical requirements for stone chips for Type A seal coat.
Test |
Code |
Specification |
Grain size analysis |
IS: 2386 (Part 1) |
Max 5% passing 75 micron sieve |
Flakiness and Elongation Indices (Combined) |
IS: 2386 (Part 1) |
Max 35% |
Los Angeles Abrasion value |
IS: 2386 (Part 4) |
Max 35% |
Aggregate Impact value |
IS: 2386 (Part 4) |
Max 27% |
Soundness – Sodium Sulphate (5 cycles) |
IS: 2386 (Part 5) |
Max 12% |
Soundness – Magnesium Sulphate (5 cycles) |
IS: 2386 (Part 5) |
Max 18% |
Water absorption |
IS: 2386 (Part 3) |
Max 2% |
Coating and stripping of bitumen aggregate mixtures |
IS: 6241 |
Minimum 95% coating retained |
Retained tensile strength** |
AASHTO 283 |
Min 80% |
7. SLURRY SEAL
Slurry seal is a mixture of mineral aggregate, slow setting cationic bitumen emulsion, water, additives if required, proportioned, mixed and uniformly spread over a previously prepared surface. The detailed specification and construction procedure for slurry seal is given under Clause 512 of MoRTH Specifications. The three different types of slurry seal and their applications are given in table 2300-22 (Ref: Table 500-25 of MoRTH Specifications).
7.1 Filler
Ordinary Portland Cement (OPC) in the range of 0.5% to 2% by weight of total aggregates shall be incorporated as filler.
8. Mix Design
a) The mix design criteria for slurry seal mix is given in IRC: SP-81.
b) The requirements for the slurry seal mix is given in table 2300-26 (Ref: Table 500-29 of MoRTH Specifications).
Table 2300-26: Mix Design criteria for sluryy seal
Property |
Code |
Requirement |
Mix time |
IRC:SP-81, Appendix 1 |
180 sec (Min) |
Consistency |
IRC:SP-81, Appendix 3 |
3 cm (Max) |
Wet cohesion |
IRC:SP-81, Appendix 4 |
20 kgcm (Min) |
Wet stripping |
IRC:SP-81, Appendix 5 |
90% (Min) |
Wet track abrasion loss (1 hour soak) |
IRC:SP-81, Appendix 6 |
800 gm/m2 (Max) |
c) The design report shall indicate the proportion of aggregate, filler, water and residual bitumen content based on dry weight of aggregate, additives to be used.
a) The surface finish of construction shall meet the requirements of Clause 2202 (Clause 902 of MoRTH Specifications).
b) Control on the materials and paving shall be done as given in table 2300-28 (Ref: Table 900-4 of MoRTH Specifications).
Table 2300-28: Quality control tests
Test prescribed |
Code |
Minimum test frequency |
Quality of emulsion |
IS: 8887 |
One test per lot of 20 tonnes. |
Aggregate moisture |
IS: 2386 Part 3 |
Two tests at site per day. |
Water absorption |
IS: 2386 Part 3 |
One test for each source/site. |
Soundness |
IS: 2386 Part 5 |
One test for each source/site. |
Sand equivalent |
IS: 2720 Part 37 |
One test for each source/site. |
Binder content |
ASTM D 2172 |
Two tests per lane/km. |
Aggregate grading |
IS: 2386 Part 1 |
Two tests at site per day. |
Calibration of machine |
- |
Once per project. |
Quantity of slurry (By weight of aggregate) |
- |
Daily (Travel time of machine). |
9. MICRO-SURFACING
Micro-surfacing is provided for surface treatment of pavements in accordance with the procedure given in Clause 514 of MoRTH Specifications.
The micro-surfacing is applied to an existing pavement surface which is structurally sound but the surface showing signs of premature ageing, aggregate loss, cracking, higher degree of polishing. The types of micro-surfacing and rates of application are given in table 2300-29 (Ref: Table 500-31 of MoRTH Specification).
9.1 Material
9.1.1 Bitumen
The bitumen emulsion shall be a modified bitumen emulsion conforming to requirements specified in table 2300-30 (Ref: Table 500-32 of MoRTH Specifications).
Table 2300-30: Requirement for modified bitumen emulsion for micro-surfacing
Property |
Code |
Requirement |
Residue on 600 mic sieve (% by mass) |
IS: 8887 |
0.05 (Max) |
Saybolt Furol viscosity at 250C |
IS: 8887 |
20-100 sec |
Coagulation of emulsion at low temperature |
|
|
Storage stability after 24 hrs (168 hrs) |
IS: 8887 |
2 (4) % (Max) |
Particle charge |
IS: 8887 |
+ve |
a) Paving bitumen complying with IS: 73 shall be used for designing BC mix.
b) Coarse aggregates shall be crushed rock retained on 2.36 mm sieve. The source of aggregate shall be approved only after testing for stripping. The physical requirements for coarse aggregates specified in table 2300-33 (Ref: Table 500-16 of MoRTH Specifications) shall be achieved.
Table 2300-33: Physical requirements for coarse aggregate for BC
Property |
Test |
Code |
Specification |
Cleanliness (Dust) |
Grain size analysis |
IS: 2386 (Part 1) |
Max 5% passing 75 micron sieve |
Particle shape |
Flakiness and Elongation Indices (Combined) |
IS: 2386 (Part 1) |
Max 35% |
Strength |
Los Angeles Abrasion value Or Aggregate Impact value |
IS: 2386 (Part 4) |
Max 35% |
Durability |
Soundness – Sodium Sulphate |
IS: 2386 (Part 5) |
Max 12% |
Soundness – Magnesium Sulphate |
IS: 2386 (Part 5) |
Max 18% |
|
Polishing |
Polished stone value |
BS: 812-114 |
Min 55 |
Porosity |
Water absorption |
IS: 2386 (Part 3) |
Max 2% |
Bitumen adhesion |
Coating and stripping of bitumen aggregate mixtures |
IS: 6241 |
Minimum 95% coating retained |
Water sensitivity |
Retained tensile strength** |
AASHTO 283 |
Min 80% |
recommended to meet the requirement.
10. Quality control
a) The control of alignment, level and surface regularity shall be as given in Clause 2202 (Clause 902 of MoRTH Specifications).
b) The control tests and their minimum frequencies for BC work shall be as given in table 2300-37 (Ref: Table 900-4 of MoRTH Specifications).
Table 2300-37: Quality Control tests for bituminous concrete (BC)
Sl. No |
Test prescribed |
Code |
Minimum test frequency |
1 |
Viscosity of binder |
IS: 73, IS: 15462 |
One test for each supply. |
2 |
Ductility |
IS: 73, IS: 15462 |
One test for each supply. |
3 |
Penetration |
IS: 73, IS: 15462 |
One test for each supply. |
4 |
Softening point |
IS: 73, IS: 15462 |
One test for each supply. |
5 |
Grain size analysis |
IS: 2386 Part 1 |
Two tests per day. |
6 |
Flakiness & elongation |
IS: 2386 Part 1 |
One test per 350 m3 . |
7 |
Los Angeles abrasion |
IS: 2386 Part 4 |
One test per 350 m3 . |
8 |
Aggregate impact |
IS: 2386 Part 4 |
One test per 350 m3 . |
9 |
Water absorption |
IS: 2386 Part 3 |
One test for each source. |
10 |
Stripping |
IS: 6241 |
One test for each source. |
11 |
Soundness |
IS: 2386 Part 5 |
One test for each source. |
12 |
Sand equivalent |
IS: 2720 Part 37 |
One test for each source. |
13 |
Plasticity index |
IS: 2720 Part 5 |
One test for each source. |
14 |
Temperature check |
- |
At regular intervals. |
15 |
Binder content |
ASTM D 2172 |
Two tests per day. |
16 |
Mix grading |
IS: 2386 Part 1 |
Two tests per day. |
17 |
Marshall test |
AASHTO T 245 |
Three tests per 400 tonnes. |
18 |
Max sp. gravity of mix |
AASHTO T 209 |
Three tests per 400 tonnes. |
19 |
Volumetric analysis |
MS-2 |
Three tests per 400 tonnes. |
20 |
Moisture susceptibility |
AASHTO T 283 |
One test for each mix. |
21 |
Layer density |
- |
One test per 700 m2 area. |
Table 2300-38: Physical requirements of aggregates for SMA
Property |
Test |
Code |
Specification |
Cleanliness |
Grain size analysis |
IS: 2386 (Part 1) |
<2% passing 0.075 mm sieve |
Particle shape |
Flakiness and Elongation Indices (Combined) |
IS: 2386 (Part 1) |
<30% |
Strength |
Los Angeles Abrasion value |
IS: 2386 (Part 4) |
<25% |
Aggregate Impact value |
IS: 2386 (Part 4) |
<18% |
|
Polishing* |
Polished stone value |
BS: 812-114 |
<55% |
Durability |
Soundness |
Either sodium or magnesium ( 5 Cycles) |
|
Sodium Sulphate |
IS: 2386 (Part 5) |
<12% |
|
Magnesium Sulphate |
IS: 2386 (Part 5) |
<18% |
|
Water absorption |
Water absorption |
IS: 2386 (Part 3) |
<2% |
12.1. Mix requirements
Table: 2300-43: Quality Control tests for SMA
Sl. No |
Test prescribed |
Code |
Minimum test frequency |
1 |
Viscosity of binder |
IS: 73, IS: 15462 |
One test for each supply. |
2 |
Ductility |
IS: 73, IS: 15462 |
One test for each supply. |
3 |
Penetration |
IS: 73, IS: 15462 |
One test for each supply. |
4 |
Softening point |
IS: 73, IS: 15462 |
One test for each supply. |
5 |
Grain size analysis |
IS: 2386 Part 1 |
Two tests per day. |
6 |
Flakiness & elongation |
IS: 2386 Part 1 |
One test per 350 m3 . |
7 |
Los Angeles abrasion |
IS: 2386 Part 4 |
One test per 350 m3 . |
8 |
Aggregate impact |
IS: 2386 Part 4 |
One test per 350 m3 . |
9 |
Water absorption |
IS: 2386 Part 3 |
One test for each source. |
10 |
Stripping |
IS: 6241 |
One test for each source. |
11 |
Soundness |
IS: 2386 Part 5 |
One test for each source. |
12 |
Sand equivalent |
IS: 2720 Part 37 |
One test for each source. |
13 |
Plasticity index |
IS: 2720 Part 5 |
One test for each source. |
14 |
Temperature check |
- |
At regular intervals. |
15 |
Binder content |
ASTM D 2172 |
Two tests per day. |
16 |
Mix grading |
IS: 2386 Part 1 |
Two tests per day. |
17 |
Marshall test |
AASHTO T 245 |
Three tests per 400 tonnes. |
18 |
Max sp. gravity of mix |
AASHTO T 209 |
Three tests per 400 tonnes. |
19 |
Volumetric analysis |
MS-2 |
Three tests per 400 tonnes. |
20 |
Moisture susceptibility |
AASHTO T 283 |
One test for each mix. |
21 |
Layer density |
- |
One test per 700 m2 area. |
13. SEMI-DENSE BITUMINOUS CONCRETE
The specifications for SDBC are more or less similar to dense bituminous macadam (DBM). This item is not included in the 5th revision published in 2013. Hence for the detailed specifications and construction procedures of Semi-dense Bituminous Concrete (SDBC) wearing and profile corrective courses (PCC) Clause 508 of MoRTH Specifications for Road and Bridge works (4th revision 2001) shall be referred.
13.1 Materials
a) Paving bitumen complying with IS: 73 shall be used for designing SDBC mix.
b) Coarse aggregates shall be crushed rock retained on 2.36 mm sieve. The source of aggregate shall be approved only after testing for stripping. The physical requirements for coarse aggregates are specified in table 2300-44 (Ref: Table 500-14 of MoRTH Specifications - 4th revision).
Table: 2300-44: Physical requirements for coarse aggregate for SDBC
Property |
Test |
Code |
Specification |
Cleanliness (Dust) |
Grain size analysis |
IS: 2386 (Part 1) |
Max 5% passing 0.075 mm sieve |
Particle shape |
Combined flakiness and elongation indices |
IS: 2386 (Part 1) |
Max 30% |
Strength |
Los Angeles Abrasion value Or Aggregate Impact value |
IS: 2386 (Part 4) |
Max 30% Max 27% |
Durability |
Soundness – Sodium Sulphate |
IS: 2386 (Part 5) |
Max 12% |
Soundness – Magnesium Sulphate |
IS: 2386 (Part 5) |
Max 18% |
|
Polishing |
Polished stone value |
BS: 812-114 |
Min 55 |
Porosity |
Water absorption |
IS: 2386 (Part 3) |
Max 2% |
Stripping |
Coating and stripping of bitumen aggregate mix* |
IS: 6241 |
Retained Coating 95% Min
|
Water sensitivity |
Retained tensile strength** |
AASHTO 283 |
Min 80% |
The aggregate may satisfy one of the requirements.
If the minimum coating retained is ≥95%, the water sensitivity test need not be carried ou
If the minimum retained tensile strength falls below 80%, use of anti-stripping agent is recommended to meet the requirement.
Table: 2300-49: Control tests for SDBC
Sl. No |
Test prescribed |
Code |
Minimum test frequency |
1 |
Viscosity of binder |
IS: 73, IS: 15462 |
One test for each supply. |
2 |
Ductility |
IS: 73, IS: 15462 |
One test for each supply. |
3 |
Penetration |
IS: 73, IS: 15462 |
One test for each supply. |
4 |
Softening point |
IS: 73, IS: 15462 |
One test for each supply. |
5 |
Grain size analysis |
IS: 2386 Part 1 |
Two tests per day. |
6 |
Flakiness & elongation |
IS: 2386 Part 1 |
One test per 350 m3 . |
7 |
Los Angeles abrasion |
IS: 2386 Part 4 |
One test per 350 m3 . |
8 |
Aggregate impact |
IS: 2386 Part 4 |
One test per 350 m3 . |
9 |
Water absorption |
IS: 2386 Part 3 |
One test for each source. |
10 |
Stripping |
IS: 6241 |
One test for each source. |
11 |
Soundness |
IS: 2386 Part 5 |
One test for each source. |
12 |
Sand equivalent |
IS: 2720 Part 37 |
One test for each source. |
13 |
Plasticity index |
IS: 2720 Part 5 |
One test for each source. |
14 |
Temperature check |
- |
At regular intervals. |
15 |
Binder content |
ASTM D 2172 |
Two tests per day. |
16 |
Mix grading |
IS: 2386 Part 1 |
Two tests per day. |
17 |
Marshall test |
AASHTO T 245 |
Three tests per 400 tonnes. |
18 |
Max sp. gravity of mix |
AASHTO T 209 |
Three tests per 400 tonnes. |
19 |
Volumetric analysis |
MS-2 |
Three tests per 400 tonnes. |
20 |
Moisture susceptibility |
AASHTO T 283 |
One test for each mix. |
21 |
Layer density |
- |
One test per 700 m2 area. |
RELATED CODES :
1. MoRTH Specifications for Road and Bridge Works, 5th Edition 2013 -Published by IRC, New Delhi.
2. MoRTH Specifications for Road and Bridge Works, 4th Edition 2001 -Published by IRC, New Delhi.
3. MoRTH Manual for construction and supervision of bituminous works, Edition 2001 – Published by IRC, New Delhi.
4. IRC SP: 11 Quality Control for the Construction of Roads and Runways -Published by IRC, New Delhi.
5. MS-2 Marshall method of mix design for asphalt concrete and other hot mix types – Asphalt Institute Manual Series No. 2 (MS-2) - Published by Asphalt Institute (USA).
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