Analysis of the viscosity and self-healing performance of warm-mix recycled asphalt: A method combining molecular dynamics simulations and laboratory tests

Abstract

The technology of warm-mix regeneration has been frequently used in the production of asphalt pavement; however, the viscosity and self-healing properties of warm-mix recycled asphalt (WMRA) need further study. Therefore, the viscosity and self-healing properties of WMRA were analyzed by combining laboratory tests and molecular dynamics (MD) simulations. First, WMRA with different SWA and reclaimed asphalt pavement (RAP) contents were prepared in the laboratory. Then, different simulations, including viscosity simulation and self-healing simulation and Brookfield Viscosity test, were developed to analyze the performance variation rule. Experimental results showed that the Sasobit warm-mix agent (SWA) significantly reduced asphalt viscosity, and the recycled asphalt’s viscosity increased with asphalt aging deeply. In contrast, the addition of 2% SWA made the viscosity of 100% RAP similar to that of new asphalt. Considering the viscosity reduction effect, asphalt performance and economy, a 3% SWA content is recommended. Both SWA and the degree of aging can reduce the healing performance of WMRA. There is little difference between the two factors in reducing self-healing performance. In general, the study's findings serve as a useful guide for the performance analysis of WMRA.

Keywords

• Warm-mix recycled asphalt
• Viscosity performance
• Self-healing performance
• Molecular dynamics
• Laboratory test