Effects of design parameters and moisture conditions on interface bond strength between thin friction course (TFC) and underlying asphalt pavements

Abstract

As a new pavement surface treatment, thin friction course (TFC) is mixed with asphalt emulsion, SBR modifier, single particle size basalt aggregate, and cement. In this study, a test apparatus derived from the pure direct shear test was proposed to investigate the effects of design parameters and moisture conditions on the interface strength. Specifically, the design parameters include the tack coat application rates, the material compositions of TFC, and the texture depths of the underlying pavement. Finally, the analysis of variance (ANOVA) was conducted. According to the results, the increased application rate of tack coat and texture depth of underlying pavement could improve the interface bonding performance. The existence of moisture degraded the bond strength between TFC and the underlying pavement. The increased tack coat application rate could mitigate the detrimental effects of moisture conditions on the interface bond strength. In addition, the optimized material compositions of TFC can only strengthen the interface bond strength slightly. To sum up, the tack coat application rate shows the most significant effect on the interface bond strength, followed by the texture depths of the underlying pavement surface and moisture conditions. Furthermore, the interaction of texture depth and tack coat application rate also has a significant influence on interface bonding performance between TFC and the underlying pavement surface.