Semicircular bending test of asphalt mixture under freezethaw cycles
1. School of Civil Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; 2. Qinghai Highway Research Institute of Survey and Design, Xi′ning, Qinghai 810001, China
Abstract: At the temperature range from -20 to 20 ℃ under freezethaw cycles, the semicircular bending test (SCB test) was designed. Three kinds of asphalt mixture of AC16, AC20 and SMA16 were prepared with respective SBS content of 0,4%,5% and 6%. The effects of SBS content on bottom layer tensile strength and tensile strain were analyzed for 0,6,12 and 18 times of freezethaw cycles. The experimental results show that for the same freezethaw cycles, with the increasing of SBS content, the tensile strength and the tensile strain at the bottom layer are gradually increased with latter decreasing. When the SBS content is 5%, 3 kinds of asphalt mixture all show good bottom layer tensile strength and tensile strain. The bottom layer tensile strength and tensile strain of AC asphalt mixture are better than those of SMA asphalt mixture. In the seasonal freezing area, AC16 asphalt mixture with SBS content of 5% can better alleviate the cracking of road surface.