Compatibility of cured phase-inversion waterborne epoxy resin emulsified asphalt

Since the waterborne epoxy resin emulsified asphalt (WEREA) showed many advantages over the epoxy asphalt binder (EAB), it had been studied recently, but the compatibility of cured WEREA had not been paid attention to, which was studied by this paper. Through the analysis of solubility parameter difference, the storage stability and the Fourier transform infrared spectrum (FT-IR), WEREA was firstly turned out to be chemically incompatible. After that, based on fluorescent morphologies of WEREA, by the analysis of parameters of the gray-level co-occurrence matrix, it was found that smaller particle size of the waterborne epoxy resin (WER) in WEREA contributed to better technical compatibility of WEREA. Accordingly, the optimized phase-inversion condition of WER was proposed. Then, from fluorescent morphologies of cured WEREA and scanning electric microscopic (SEM) morphologies of the left skeleton of cured WEREA after the "dissolving-evaporating" process, the "sea island" structure and the "IPN-liked" structure were observed, respectively, and the transformation of the "sea island" structure to the "IPN-liked" structure was also observed when the content of WER in WEREA increased from 20% to 30%. Meanwhile, through the analysis of the angular second moment, the entropy and the entropy-energy ratio of gray-level images of fluorescent morphologies of cured WEREA, it was found that the technical compatibility of cured WEREA becomes better with the increase of WER content in WEREA when the WER content is less than 30%. Finally, through tests of interlayer properties of cured WEREA and pavement performance of WEREA mixture with different WER contents, it was turned out that better compatibility of cured WEREA contributed to better interlayer properties of cured WEREA and the molded strength and high temperature stability of WEREA mixture, and the content of WER where the "IPN-liked" structure forms was verified as between 20% and 25%. (C) 2019 Elsevier Ltd. All rights reserved.