Performance evaluation of microsurfacing with rubber powder

With the rapid increase in the number of vehicles, the use of worn tires that are increasing everyday grows environmental problems. On the other hand, one of the fundamental issues for road agencies is the management and maintenance of the roads. The preeminent practice in this area is to carry out preventive maintenance by methods such as using protective asphalt layers by means of microsurfacing. However, there has not been a study regarding microsurfacing with rubber, the mix design, and its field performance indicators. In this study, the performance of microsurfacing mixtures with different amounts of crumb rubber has been investigated under the ISSA A143 requirement set by the International Slurry Surfacing Association. For this purpose, 0.5-3% of crumb rubber with a grain size of maximum 0.33 mm as a replacement of aggregates has been used. The results from wet track abrasion test excess asphalt by loaded wheel test (LWT), multilayer LWT showed that the best performance among different amounts of rubber powder is obtained at the 14% bitumen emulsion and 0.5% crumb rubber, and the use of this amount of crumb rubber reduced the amount of optimum emulsion needed. Moreover, the rutting on the specimen also decreased compared to the control specimen.