Low-temperature thermal cracking performance of waterborne epoxy asphalt emulsion mastic based on bending beam rheometer (BBR)

Abstract

This research experimentally investigated the low-temperature thermal cracking performance of waterborne epoxy asphalt emulsion (WEA) mastic. A total of sixteen WEA mastics were prepared by utilizing two mineral fillers (Portland cement as an active filler and limestone dust as an inert filler) and two WEAs (anionic and cationic emulsions). They were then subjected to the bending beam rheometer (BBR) test. Based on the test results, four parameters, creep stiffness at loading time of 60 s, S(60 s), creep rate at loading time of 60 s, m(60 s), m(60 s)/S(60 s), and the difference in critical low temperature performance grade limiting temperatures, ΔTc, were calculated to evaluate WEA mastics’ low-temperature creep and relaxation properties. The results showed that mineral fillers diminished the susceptibility of WEA material to stiffness growth with testing temperature drop. The charge type of WEA emulsion showed a significant effect on the low-temperature performance grade of WEA-cement mastic. The ΔTc value of anionic WEA-cement mastic was 10℃ more than that of cationic WEA-cement mastic. The creep stiffness master curves fitted by Christensen-Anderson-Marasteanu (CAM) model could better understand the low-temperature creep characteristics of WEA mastics in a wide range of time domains.