In progress ................

Road Materials and section information

1) Embankment

Embankment

2) Granular Subbase (GSB)

GSB Layer

3) Granular Base (Grading I & II or WMM)

WMM befor compaction	WMM after compaction	WMM + Primer +DBM

4) Prime coat:- IRC:15

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Of emulsion such as RS1 , SS1 etc, shall penetrate into Granular Base upto 10 mm.

5) DBM/MPM/BM/BUSG

DBM laid	Fresh DBM layer

 

BM work using stringline and paver finishing	Tack Coat

 

Equivalency factor for various layers need to be calculated.

6) BC / Carpet + seal coat / Mastic /SMA / Micro surfacing

Fresh BC Mix	BC mix After 1 year traffic movement

 

Mastic Asphalt	Microsurfacing	SMA

 

 

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Q) After how much time sealcoat must be done??
Ans:- The seal coat shall be applied immediately after laying the premix carpet and rolled.
No traffic shall be allowed on the road until the seal coat has been laid.
Binder for premix carpet :-
1) Paving bitumen --> IS:73
2) Modified bitumen --> IRC:SP:53

Fine aggregates for Carpet should have sand equivalent value as min 60, as per test method in IS:2720 (Part 37)

Binder for tack coat --> Rapid setting cationic bitumen emulsion--> IS:8887

In snow bound areas where emulsion or Paving bitumen is not feasible,  cut back bitumen conforming to IS:217 or IS:454 can be useful.