Abstract
Japan has a long history for reclaimed asphalt pavement (RAP), and the number of repeated recycling for the RAP mixtures tends to increase in the future. Therefore, this raises concerns about the poor performance of recycled asphalt mixtures, such as stripping potential of asphalt mixtures. The water-immersion wheel-tracking test (WTT) is widely used in Japan for evaluating the moisture resistance of mixtures. However, recycled mixtures tend to have higher rutting resistance than the conventional mixtures, and this may lead to good results in the water-immersion WTT. Therefore, the stripping performance of recycled asphalt mixtures cannot be evaluated correctly using the water-immersion WTT. This study used the Hamburg wheel-tracking test to evaluate the moisture susceptibility of recycled asphalt mixtures with different contents of reclaimed asphalt pavement and different numbers of repeated recycling. Three indices obtained for the Hamburg wheel-tracking test results were evaluated. The results indicated that SN is more appropriate than SIP (cycles) or SIP (cycles/mm) to evaluate the effect of the number of repeated recycling and the content of RAP on the moisture susceptibility of RAP mixtures.
