Effects of epoxy-silicone resin on chemistry, morphology and rheology of SBR- modified emulsified asphalt

Emulsified asphalt (EA) exhibits limited performance in pavement maintenance and cold mix applications due to the inadequate high-temperature stability, cohesion strength, and durability. To enhance the performance of EA and elucidate the modification mechanism of epoxy silicone resin (ESR) and styrene-butadiene rubber latex (SBR) composite modification, EA with varying ESR/SBR dosages were prepared. The chemical evolution during modification process, high- and low-temperature rheological performances, phase microstructure of EA residues were investigated. Results indicated that SBR enhances the penetration, softening point, and ductility, whereas ESR reduced the ductility. SBR improved the toughness by forming a physical network film, while ESR enhanced the high-temperature stability via a chemically crosslinked high-strength network. However, excessive ESR content adversely affected the low-temperature crack resistance. Furthermore, increasing ESR content promoted the interpenetration of the ESR and SBR networks, yielding a denser and more stable three-dimensional structure. Based on the comprehensive performance evaluation, optimal performance was achieved at 3% SBR and 6% ESR content.