Quality Assurance Handbook for Rural Roads Volume-I - pmgsy

4. SECTION 500: BITUMINOUS CONSTRUCTION
4.1 Prime Coat
1. Material
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Quality Assurance Handbook for Rural Roads
Check that Slow Setting bituminous emulsion with required viscosity and quantity as per Table
502.1 has been used and that where bituminous cutback has been used, it is only in situations of
sub-zero temperatures or in emergency applications.
2. Application of Bituminous Primer
(i) Check if the surface to be primed has been properly prepared.
(ii) Check that only self-propelled or towed sprayer is used and that spraying with the use of a
perforated canister has not been resorted to.
(iii) Check if the rate of spray of primer has been checked by a tray test at least twice a day.
(iv) Check if the sprayed primer is cured for atleast 24 hours before opening to traffic.
4.2 Tack Coat
1. Material
(i) Check, if the type of binder used for tack coat is a bituminous emulsion of RS-1 grade and
not a straight-run bitumen.
(ii) Check, if a bituminous cutback is used, it is only in areas of sub-zero temperature or in
emergency applications.
(iii) Check that the rate of application of bituminous emulsion has been selected on the basis of
the type of receiving surface as per MORD Specifications.
2. Application of Binder
(i) Check, if the surface receiving the tack coat has been properly prepared.
(ii) Check that only self-propelled or towed sprayer is used and that spraying with the use of a
perforated canister has not been resorted to.
(iii) Check, if the rate of spray of binder has been checked by a tray test, atleast twice a day.
(iv) Check that the tack coat has been left to cure until all volatiles have evaporated and that no
traffic is allowed to ply on the tack coat.
4.3 Bituminous Wearing Course-Surface Dressing
1. Aggregate
(i) Check, if the size of aggregate in use is appropriate to the surface on which it is being laid
and the anticipated traffic on the road.
(ii) Check, visually, if the flaky aggregates do not exceed the permissible limit.