Effect of production process parameters on high temperature stability of rubber asphalt mixture

Abstract

This study aims to improve the high-temperature stability of rubber asphalt mixtures. Single factor analysis was used to compare and analyze the results of rutting test before and after rubber asphalt equipment reformation and indoors. The influence rule of various production process parameters on high-temperature stability was determined and analyzed through gray correlation theory. The dynamic stability of rubber asphalt mixtures significantly improved after reformation. Prolonged mixing time benefitted mixing uniformity and swelling reactions. With increasing developing temperature and time, the dynamic stability first increased and then decreased. In actual production, the optimal temperature and time are 185-190°C and 1-1.5 h, respectively. Under horizontal axis stirring, the dynamic stability increased by 16% relative to that under vertical shaft stirring. The dynamic stability improved with increasing rubber powder content, and the optimal rubber powder content in terms of construction workability is 20-22%. Experimental results of mass production after reformation are consistent with the laboratory test results. The gray correlation analysis results show that rubber powder content, developing temperature, developing time, and stirring technique are key control parameters. Furthermore, control accuracy should be enhanced, and fluctuation should be reduced.