Characters of Interlayer in Thin Lift AC Overlay on Asphalt Pavement

The interlayer performance of thin overlay structure on asphalt pavement was studied through theoretical analysis and laboratory experiments. The BISAR3.0 program was used to analyze the responses of thin overlay structure under different loading, thickness, temperature or horizontal force coefficient, the results indicated that the horizontal force coefficient, load and temperature had much more obvious influence on the maximum interlamination shearing and tensile stress than that of the thickness. And the technological indexes of interlayer were put forward to choose the bonding materials. Then, the direct shear experiment and pullout experiment were tested on two overlay materials and three bonding layer materials. The varying rules of the interlamination shearing stresses with the dosages of the bonding layer materials were analyzed and the corresponding optimum dosages for the two overlay materials were obtained. Meanwhile, the bonding performance of SBS modified asphalt is superior to the 70-A asphalt, and the modified emulsified asphalt is slightly worse.