Journal of the Korean Asphalt Institute ISSN:2234-0785(Print) 2635-9553(Online) 한국아스팔트학회지

This study is to evaluate the field performance of reclaimed asphalt pavement mixed with 70.0% of recycled aggregate. Mix-design was conducted to determine the proper aggregate gradation and optimum asphalt contents. Reclaimed asphalt mixtures were produced to meet the criteria of WC-5 described on KS F 2337 and mixed with 1.27% of asphalt, 26.5% of 25mm mineral aggregate, 70.0% of recycled aggregate, 1.89% of filler and 0.315% of recycling agent by weight. Test section was constructed on national highway #38 and opened on September 2015. Field performance such as crack, rutting and roughness was measured by means of automated pavement evaluation vehicle for three times on July 2017, 2019 and 2021. Crack ratio of the test section increased up to 20.45% for six years since it opened in 2015. More crack was developed on the second lane than the first lane due to the higher heavy vehicle ratio on the second lane. The difference of crack ratio between the reclaimed asphalt pavement and the mineral aggregate asphalt pavement was less than 2% for six years. More rut depth was developed on the mineral aggregate asphalt pavement than the reclaimed asphalt pavement and the statistical significance was verified by t-test. Longitudinal roughness was increased more on the mineral aggregate asphalt pavement than on the reclaimed asphalt pavement and the statistical significance was also verified by t-test. From the field test for six years, it is concluded that the field performance of reclaimed asphalt pavement was not reduced by using the recycled aggregate and the service life of reclaimed asphalt pavement showed no difference comparing to the mineral aggregate asphalt pavement.