Experimental Study On Performance Of Composite Crumb Rubber-HR Modified Asphalt Mixture

Appeared in recent years, the high grade highway traffic of large-area pavement early damage, the rutting attack majority, thus, improving the high-temperature performance of asphalt mixture is the current focus in the study of pavement materials. To a certain extent, the emergence of the rubber powder modified asphalt mixture alleviates the problems, and effectively solves the pollution caused by waste tires. The study found that in the high-temperature performance, compared with the matrix asphalt, mixture performance of rubber powder modified asphalt mixture has obviously improved, but still can’t completely adapt to the current road environment requirements, especially in the highway of Banks and under the condition of the overload transportation needs. Therefore, greatly enhancing the high-temperature performance of asphalt mixture to improve service quality, prolong the service life of asphalt pavement of asphalt pavement has very important significance.The article selects the appropriate compound for composite modified rubber modified asphalt mixture. For rubber powder-HR composite modified asphalt mixture composition structure characteristics to the Marshall mix design, find out the reasonable aggregate gradation and the optimum proportion, and road performance is studied, especially the research and evaluation of the high-temperature performance, and analyzes its modification effect and the comprehensive benefit.The pavement performances of composite modified asphalt mixture was studied in the paper. Experimental results show that compared with SBS modified asphalt mixture, the high-temperature performance of rubber powder-HR composite modified asphalt mixture is significantly improved, low-temperature crack resistance and water stability at the same level. Fatigue performance, but with the increase of strain levels, the fatigue resistance attenuation of rubber powder composite modified asphalt mixture is slow, strain level has reached 650 mu-epsilon began to both fatigue performance almost at the same level.The high-temperature performance of composite modified rubber-HR modified asphalt mixture was studied in rutting test and dynamic creep test, which we change the temperature and load. Rutting test results show that compared with the SBS modified asphalt mixture, the anti-rutting performance of the rubber powder-HR composite modified asphalt mixture under the condition of high temperature and overloading has significantly improved;Dynamic creep results show that under the same experimental conditions, the cumulative number of the powder composite modified asphalt mixture increases, which reaches the stage of creep damage. After adding compound, the high-temperature performance of rubber powder modified asphalt mixture improved significantly, the temperature and load is bigger, the more obvious improvement effect.Through analyzing the modification effects of rubber powder composite modification, relative to the SBS modified asphalt for only to improve the performance of asphalt, compound to the double improve effect of asphalt and mixture can improve and improve the pavement performance of the more.Using the rubber powder-HR composite modified asphalt mixture has outstanding economical benefit、environment benefit and social benefit.The conclusions of this paper provides reference and promotion for the application of rubber powder-HR composite modified asphalt mixture, which has certain research significance and practical value and innovative.