Effect of Asphalt Film Thickness on Engineering Performance of Asphalt Mixtures

Asphalt film thickness has a significant influence on performance of asphalt mixtures. Generally the recommended minimum asphalt film thickness ranges from 6 to 8 μ m,but it is concluded on insufficient research grounds. This paper studies the effect of asphalt film thickness on performance of asphalt mixtures in order to determine the optimum asphalt film thickness of different asphalt mixtures. The results show that the optimum asphalt film thickness is about 8 μ m for asphalt mixture with 3～6% air voids,the optimum asphalt film thickness is about 10 μ m for asphalt mixture with 4～10% air voids,and the optimum asphalt film thickness is about 12 μ m for asphalt mixture with above 15% air voids.