Experiment Study of High-Temperature Stability of SMA

The high temperature stability of SMA is affected by many factors. Some factors that may affect the high temperature stability of SMA (stone mastic asphalt) analyzed by the way of Marshall and rutting testing, in the laboratory. The results show that the high temperature stability of SMA is closely related to its gradation,asphalt content,testing temperature,the number of rolling. This paper will only discuss the above factors. Study results indicated that adding proper coarse aggregate (diameter4.75mm ) and mine dust contents would play occluding and wedging role in aggregate mixture. The rolling times of SMA asphalt mixture should be Strictly controled, in order to improve the compaction density. When the experiment temperature was increased up to 67°C, high-temperature stability of SMA can not meet the requirement of standards. The optimal dosage of asphalt in rutting test is 5.0%, which is more 0.3%~0.4% than that in marshell-test. Key words: road engineering; SMA; rutting testing; Marshell test; high temperature stability