Pavement Performance Of Warm Mix Open Graded Friction Course Mixtures With Asphalt Rubber

With the continuous improvement of China’s growing economic strength and people’s living standards, the requirements of road operation have shifted from convenient and unobstructed road to safe, beautiful, comfortable and eco-friendly road. Currently, roads are mainly built with dense and impermeable materials, which pose some prominent challenges to road safety and ecological environment. In view of this, it is essential to applya new energy-saving pavement material in pavement project.The paper takes the open graded friction course (OGFC) mixture as study subject, adopts rubber asphalt, Evotherm-DAT and the warm mix agent which is independently developed by myself, and carries out a study on the performance of warm-mixed rubber asphalt OGFC mixture.Firstly, the Marshall volume design which is based on the hot-mix OGFC mixture ratio design is adopted to determine the mix proportion of warm-mix OGFC mixture. Giving consideration to the characteristics of warm mix agents used in this study, Marshall stability and void content are set as volumetric parameters, in order to determine the blend and compaction temperatures of warm-mixed rubber asphalt OGFC mixture. The results indicate that blend and compaction temperatures of warm-mixed rubber asphalt OGFC mixture are about 10～15℃ lower than those of hot-mixed rubber asphalt OGFC mixture.Besides, wheel tracking test, cantabro test, leakage test and Marshall stability test are adopted to test the functional performance of warm-mixed rubber asphalt OGFC mixture ratio design. The results indicate that all the tested indicators of warm-mixed rubber asphalt OGFC mixture can meet the technical requirements of existing norms, and its performance has no obvious difference from that of hot-mixed rubber asphalt OGFC mixture.In addition, BBR test method is adopted to systematically analyze the low-temperature creep properties of warm-mixed rubber asphalt, and trabecular bending test is adopted to study the low-temperature anti-cracking performance of warm-mixed rubber asphalt OGFC mixture. The results indicate that the adoption of warm mix agent greatly improves the low-temperature properties of rubber asphalt, and warm-mixed rubber asphalt OGFC mixture has a better advantage than hot-mixed rubber asphalt OGFC mixture.Moreover, pressure vessel aging test, BBR test and freezing and thawing test are combined to analyze the durability of warm-mixed rubber asphalt and warm-mixed rubber asphalt OGFC mixture. The results indicate that the adoption of warm mix agent improves the anti-aging property of rubber asphalt, and the adoption of DAT warm mix agent can improve the freeze-thaw resistance of rubber asphalt OGFC mixture.Finally, the costs of raw materials of warm-mixed rubber asphalt OGFC mixture and expenses in constructionand maintenance phasesare taken into account, and the economic effect of warm-mixed rubber asphalt OGFC mixture is analyzed.