Specification Part 3 - Road & Bridge Works - Urban Administration ...

Increase in Softening Point, °C,
Maximum 7 6 5 IS:1205-1978
Reduction in Penetration at 25°C,
%, Maximum
35 35 35
Elastic Recovery of Half Thread in
Ductilometer at 15°C, %, Minimum 45 35 30
IS:1203-1978
ASTM
D5976-1996
* Relevant to snow bound cold climate areas
not less than three pairs of samples shall not exceed 5°C. Other pre-blended modified binders
shall be stored with appropriate circulation or agitation facility, according to the manufacturer’s
instructions.
521.6. Measurement for Payment
Modified binder supplied for the Contract shall be paid for in Tonnes.
TABLE 500-46.
REQUIREMENTS OK POLYMER MODIFIED BINDERS (TREATED WITH MODIFIED CRUMB
RUBBER)
Designation
Grade and Requirements
PMB 120 PMB 70 PMB40
Method of Test
Penetration at 25°C, 0.lmm, l00g, 5 sec. 50-70 50-60 40-60 IS:1203-1978
Softening Point. (R&B), °C,
Minimum
50 55 60 IS:1205-1978
Elastic Recovery of Half Thread in
Ductilometer at 15°C, %, Minimum 60 50 40
Test on Thin Film Oven Test Residue (IS:9382-1979)
ASTM
D5976-1996
Reduction in Penetration at 25°C,
% Maximum
60 60 60 IS:1203-197
Increase in Softening Point (R&B),
°C, Maximum
5 5 5 IS:1205-1978
Elastic Recovery of Residue of Half
ASTM
Thread in Ductilometer at 15°C, %,
25 20 15
D 5976-1996
Minimum
CRMB - Crumb Rubber Modified Bitumen
521.7 Rate
The contract rate for modified binder shall be as per contract agreement.
522. CRACK PREVENTION COURSES1
522.1. Scope
(i)This clause covers the provision of Stress Absorbing Membrane (SAM) and Stress
(ii)Absorbing Membrane Interlayer (SAMI) as measures to inhibit the propagation of cracks.
(iii)A SAM is an elastomeric bitumen rubber membrane, which is laid over a cracked road surface,
together with a covering of aggregate chips, in order to extend the life of the pavement before
major treatment is carried out.
(iv)SAM can be laid as a single coat or a double coat.
(v)A SAMI is a layer which is applied to a cracked pavement surface but which is followed (within
12 months) by the application of an overlay course.
(vi)A SAMI may be a material similar to that used for a SAM.
(vii)It may alternatively consist of a bitumen impregnated geotextile.