Wuhan Ligong Daxue Xuebao (Jiaotong Kexue Yu Gongcheng Ban)/Journal of Wuhan University of Technology (Transportation Science and Engineering)

Bitumen supplies into Australia have become more diverse as importation of bitumen has become common and Australian refineries have been closed or reduced in their capacity. The products on which empirical links between bitumen properties and field performance were established are likely to have changed over the years. This has undermined the effectiveness of the empirical bitumen specifications used in Australia. Similar experiences in New Zealand and South Africa prompted the introduction of performance-based testing. In the USA, the multiple stress creep recovery (MSCR) test was developed as a high-temperature performance grading criterion. The MSCR test is performed using a dynamic shear rheometer. A number of these devices are already available in Australia. The test is simple and takes about 15 minutes to complete. The MSCR test was adopted by the USA for high temperature performance grading of binders because of its advantages over the traditional |G*|/sin δ. The MSCR was used to evaluate three samples of multigrade M1000 bitumen retained from a number of airport overlays. The M1000 samples assessed were found to be unsuitable at 76°C but suited to very heavy and extreme traffic loadings at 70°C and 64°C respectively. The MSCR testing of binders is recommended for high shear stress asphalt applications, such as airport surfaces.