Behavior Evolution on Performance of UV-Irradiation Aged Asphalt Mixtures Under Reduced-Scale Accelerated Trafficking

In order to investigate the actual behavior evolution of asphalt pavement after the Ultra Violet irradiation (UV-irradiation) aging, reduced-scale accelerated pavement tests were conducted on two separate asphalt mixtures with a stone matrix asphalt (SMA-13) structure, respectively, crumb-rubber modified asphalt mixture and its matrix asphalt mixture, at ambient air temperature. In each group, UV-irradiation aged asphalt mixture after ultraviolet irradiation of 300 h and its corresponding non-aged asphalt mixture were trafficked at the same time by the 1/3 model mobile load simulator (MMLS3) till the cumulative loading applications up to 500,000. The test results show that the performance attenuation degree of the crumb-rubber modified asphalt mixture was lower than that of the matrix asphalt mixture, so the rubber additive helps to reduce the effect of the UV-irradiation aging. Rutting deformation, three-dimensional dynamic strain and seismic modulus were measured during the accelerated loading test. The rutting results (including the rutting depth, rutting area and its development rates), the surface dynamic strains, and the decay rate of the seismic modulus from the UV-irradiation aged asphalt mixture were greater than those of non-aged sample, and the difference narrowed after the cumulative loading applications reached more than 100,000. In addition the analysis of the modification rutting factor from the dynamic shear rheometer (DSR) test, the UV-irradiation aging weakened the high temperature stability and mechanical strength. Therefore, the UV-irradiation aging aggregated the performance decay of asphalt mixture and will inevitably shorten its service life.