Performance evaluation of dense mixtures with stabilised rubber modified asphalt

Asphalt rubber (AR) has been used worldwide in road engineering not only for improving the performance of asphalt mixtures but also for providing an advantage in environmental protection. Yet the application of AR is greatly restricted in China for its shortcoming of being only possible to be used in a gap or open gradation mixture to ensure stripping resistance as well as anti-rutting performance. Stabilised rubber modified asphalt (SRMA) with lower high-temperature viscosity and better store stability than traditional AR was developed in our previous research and has been widely applied in projects with good results. In this paper, to evaluate the validation of SRMA in dense mixtures, five kinds of dense mixtures commonly used in China were designed with SRMA as binder. Engineering properties, including high-temperature performance, low-temperature performance, moisture stability, fatigue performance and mechanical properties, including dynamic modulus and phase angle were laboratory evaluated and analysed. For the purpose of comparison, a kind of representative styrene-butadiene-styrene (SBS) polymer modified asphalt commonly used in China was selected to prepare samples with the same gradation of SRMA mixtures, and the same performance tests were conducted. In addition, a brief cost analysis among SRMA, SBS-modified asphalt and traditional AR was performed. Results show good performance and economy of SRMA and corresponding dense mixtures, thus it is possible, using SRMA for dense mixture design in practical engineering, to reduce construction cost.