ABSTRACT:- This paper intends to provide a brief review of the various techniques to evaluate the interface bond strength of Bituminous Overlays. Bitumen Overlays are typically placed over tack coated surfaces. However premature delamination failure and crescent shaped cracks appear on the pavement surface, reduce service life of overlays. These failures occur due to excessive shear stresses which are developed at the interface. MORTH (Ministry of Road Transportation and Highways) has given specifications about the amount of tack coat (bitumen emulsion) that has to be applied over the pavement surface above which it is overlaid. However, bond strength mobilized at the interface depends largely on the characteristics of residual binders (i.e., Bitumen Emulsion), binder content, existing texture of pavement surface, gradation of overlaid material, thickness of bituminous overlay. Other than the techniques to evaluate interfacial bond strength, the various parameters that affect the interfacial bond strength have also been discussed in this paper.

Keywords – Delamination, Interface Bond Strength, Residual Binders.