Preparation and properties of polyurethane/epoxy-resin modified asphalt binders and mixtures using a bio-based curing agent

Abstract

The use of bio-based materials to partially replace petroleum-based materials in road engineering can not only reduce the consumption of natural resources but also contribute to environmental protection and sustainable development. In this study, a rosin-based acid anhydride curing agent, maleic rosin anhydride (MRA), was used to prepare a polyurethane/epoxy resin/MRA modified asphalt (PEMMA) binder. The mechanical properties, viscosity characteristics, storage stability, and high- and low-temperature performances were studied, and the appropriate modifier content was determined. Meanwhile, Fourier transform infrared spectroscopy and atomic force microscope were used to explore its microscopic modification mechanism. In addition, the PEMMA mixture was prepared, and its pavement performance was tested and evaluated. The results revealed that the PEMMA binder has satisfactory mechanical properties and storage stability. Except for the PEMMA binder with 60 wt% modifier content, the construction allowable time range for the remaining binders met the specification. Compared to the base binder, the PEMMA binder had excellent high-temperature strain recovery ability but reduced its low-temperature performance. The change of the functional groups in the PEMMA binder verified the occurrence of the curing reaction; its microscopic morphology had changed significantly, with the bee-shaped structure becoming blurred and the roughness increasing significantly. The low-temperature performance of the PEMMA mixture was improved compared to the epoxy asphalt mixture. Overall, the comprehensive performance of the PEMMA mixture was more equitable but inferior to that of the mixture prepared with the petroleum-based curing agent.