Study On Performance Of Asphalt Mortar Modified By Aluminates Coupling Agent

Asphalt mortar is the most important part of asphalt mixture. The typical elastic-viscous-plastic characteristic of asphalt mixture mainly depends on the bonding asphalt mortar. Therefore, the research investigated the modified effect of asphalt to analyze the effect of coupling agent. Some commonly used methods to improve the performance of asphalt mortar are adjusting the components of asphalt, adding surface modifier and some chemical-physical ways.Based on the previous research, this research used one coupling agent named aluminates coupling agent as the modifier, and stearic acid as synergistic agent. Throughout the research, an orthogonal experiment method was used and both range analysis and analysis of variance were used to investigate the effect of 9 kinds of asphalt mortar added coupling agent. The research analyzed the possible changes of internal structure and evaluated the effect of coupling agent on asphalt mortar.The results found that in terms of high-temperature performance asphalt mortar with coupling agent had a worse performance than asphalt mortar without coupling agent. The rutting factor G~*/sinδand loss tanδdecreased significantly. However, in terms of low-temperature performance, asphalt mortar with coupling agent had a better performance than without coupling agent. The creep stiffness of modified asphalt mortar decreased more obviously than base asphalt mortar while m-value increased more significantly. Meanwhile, the research investigated the internal viscous-elastic characteristic of asphalt mortar by Burgers model. Finally, some relationships between the viscosity of asphalt mortar and rotational speeds, temperatures respectively were analyzed. The regression factor and rheologic index decreased significantly. But the VTS index increased with the temperatures, which showed that the effect of coupling agent on the susceptibility of asphalt mortar decreased.The result of this research was that this coupling agent had a better effect on low-temperature performance of asphalt mortar and was suitable for cold regions to increase the service life of asphalt mixture.