Evaluation of Polymer-Modified Warm-Mix Asphalt Used for Gobi Road

Abstract

South Gobi road of 240-km flexible pavement was constructed from UKHAA KHUDAG to GASHUUN SUKHAIT in South Gobi, Mongolia in 2011. However, due to the heavy traffic and severe weather condition, early distresses have occurred from a length of 100-km flexible pavements in South Gobi road after one year service life. In order to enhance crack and rutting resistances and to improve paving quality control in South Gobi road, polymer modifier is selected to reduce rutting at high temperature and cracking at low temperature and warm-mix asphalt (WMA) additive is selected to reduce the mixing and compacting temperatures and provide better compaction on the road and the ability to haul paving mix for longer distances. This paper adopted comprehensive asphalt tests to evaluate physical and rheological characteristics, and crack potential at low temperature for use in a South Gobi road. Laboratory tests were performed on asphalt binder with a polymer modifier and warm-mix asphalt additive by conducting the following tests: softening test, ductility test, SuperpaveTMtest and cold bending test. These test results of asphalt binder with SBS polymer modifier and warm-mix asphalt additive were significantly more positive than those of typical asphalt binder. On the basis of test results, it can be concluded that the asphalt binder with SBS polymer modifier and WMA additive is stronger and less susceptible to rutting and crack than typical asphalt binder used in South Gobi.