Characterization of Shear Resistance of Interlayer between Concrete Bridge Deck and Asphalt Concrete Overlay Utilizing Inclination Shear Test

Hot-mix asphalt (HMA), which can be employed as a wearing course on concrete bridge decks, provides a smooth surface for riding. However, some bridge deck asphalt surfaces experienced layer slippage, which is a result of failure of interlayer between HMA overlay and concrete deck due to the lack of layer bonding. In this study, the shear properties of the interlayer between concrete decks and HMA overlay were evaluated through inclination shear tests. Three types of interlayer materials were investigated, including asphalt emulsion, asphalt cement, and epoxy asphalt. The inclination shear test procedure was developed to determine the envelope of shear strength and energy consumption during the shear test. This test was used to evaluate the contribution of internal friction angle and cohesion to shear resistance. Results indicated that as the temperature increased, the contribution of cohesion to shear resistance decreased. The contribution of internal friction angle was associated with the applied normal stresses. The energy consumption of cohesion was sensitive to temperature. Epoxy asphalt interlayer exhibited better shear resistance performance than the other two types of material.