Self-Healing Performance of Rubber-Modified Asphalt

Abstract

To figure out the effect of rubber modifiers on the self-healing performance of asphalt, this study took Eucommia rubber (TPI, trans-polyisoprene) and natural rubber (NR) as asphalt modifiers and employed the molecule simulation software to analyze the self-healing performance of asphalt in the microscale. At first, a model of basic asphalt system was established in the molecule simulation software, and three parameters of density, solubility and mean square displacement (MSD) were used to verify that the established model can act as the representative of asphalt molecules; then, several self-healing models of basic asphalt and rubber-modified asphalt were constructed to compare the properties of TPI and NR. In the experiment, the temperature was set to 303.15K, 313.15K, 323.15K, 333.15K, and 343.15K, respectively, and a 10Å (1Å=0.1nm) vacuum layer was taken as the microcrack of the asphalt, then the entire self-healing process of the models was analyzed, and the diffusion coefficient and energy change of the models were calculated. The experimental results revealed that, the NR-modified asphalt outperformed TPI in self-healing performance; for the NR-modified asphalt, as the temperature rises, the intermolecular non-bond energy changes, the molecule diffusion ability enhances, which can accelerate the self-healing progress of the microcracks in the asphalt.