Evaluation of Engineering Properties of Rock-Modified Asphalt Concrete

• Published in: Journal of testing and evaluation 2021-03, Vol.49 (2), p.839-853
• Main Authors: Chang, Shu-Chia, Liao, Min-Chih, Shen, Der-Hsien
• Format: Article
• Language: English
• ISSN: 0090-3973; 1945-7553
• DOI: 10.1520/JTE20180582

The addition of the naturally occurring Buton rock asphalt (BRA) into the asphalt mixtures should be more desirable not only for stiffening the base asphalt but also for the future perspective of pavement recycling. The aim of this article is to evaluate the engineering characteristics of the rock-modified asphalt concrete (RMAC) using comprehensive laboratory tests. Test results showed that the RMAC produced by the wet process generally had better performance in all engineering properties as compared with the RMAC prepared by the dry modification process. The high-temperature performance for the RMACs appeared to be better than that for the unmodified asphalt concrete, but the resistance to raveling of the asphalt mixtures was slightly sacrificed after the addition of the rock asphalt. In addition, it is found that the addition of the rock asphalt stiffened the asphalt to reduce the total viscoelastic response of asphalt mixtures, whereas the polymer modifier increased the elastic component to reduce the viscous component of the asphalt. It is recommended that the percentage of pure rock asphalt (PRA) be no more than 15 % on a weight base of the blend. The BRA content should not be more than 30 % by weight of the RMAC.