Evaluation of Properties and Performance Improvement Mechanism of Novel Waterborne Epoxy Modified Asphalt Emulsion with Styrene–Butadiene–Chloroprene Rubber

Abstract

This study aims to investigate the properties of novel waterborne epoxy modified asphalt emulsion with styrene–butadiene–chloroprene rubber (SBR/CR) and evaluate its performance improvement mechanism. To achieve this objective, Brookfield rotational viscometer tests and dynamic shear rheometer tests were first performed to characterize the rheological properties of new emulsion residues with time. Then, penetration, softening point, and ductility tests were adopted to evaluate the conventional performance of the new emulsion residue. Finally, the curing microstructures, functional group changes, and thermal stability of new emulsion were analyzed by using scanning electron microscopy, Fourier transform infrared spectrometry, thermal gravimetric analysis, and differential scanning calorimetry, respectively. The experimental results showed that the new emulsion residue showed an extremely high viscosity, and its viscosity value was more than 40 times that of general asphalt emulsion. The stiffness and thermal stability of new emulsion at high temperatures were significantly improved by crosslinking the epoxy system to form a three-dimensional polymer network. The incorporation of SBR/CR copolymer reduced the effect of waterborne epoxy cured products on the low-temperature elongation performance of new emulsion, resulting in improved thermal cracking resistance of the new emulsion system. The optimum dosage of waterborne epoxy for the new asphalt emulsion determined was 15% by weight of SBR/CR modified asphalt emulsion. Based on these results, it is evident that the waterborne epoxy asphalt emulsion together with the SBR/CR copolymer can form a durable emulsion system in both low- and high-temperature environments.