Effects of Tack Coat Type and Surface Characteristics on Interface Bond Strength

The objective of this study is to investigate the effects of tack coat material type, application rate, surface type, and surface characteristics on the interface bond strength. In this study, the Portable Bond Strength Tester (PBST) was adopted to measure the bond strength. A suitable sample preparation procedure was then defined. Test Results demonstrated that increasing the application rate increased interface bond strength up to a maximum, then decreased gradually. Optimum application rate varied from 0.6 similar to 0.8 L/m(2), depending on the tack coat and the interface types. The tack coat type was shown to play a key role in the interface bonding. Consistency was observed in the ranking of the bonding strength of all asphalt types on different surfaces, which is sequenced as follows: epoxy asphalt>hot asphalt>asphalt emulsion>cutback. Among the aforementioned asphalt, the bonding performance of epoxy asphalt and asphalt emulsions are most sensitive to the presence of dust.