The multiple stress creep-recovery test: a detailed analysis of repeatability and reproducibility

The multiple stress creep-recovery (MSCR) test was recently introduced to evaluate bituminous binders at high service temperatures, in particular to evaluate the stress or loading resistance. This test allows classifying binders at the high-performance graded temperature, according to the traffic loading, starting from standard, to heavy, very heavy and extreme traffic loading. It is the intention that this test includes nonlinear binder properties. In this study, five laboratories have participated in a round robin test to evaluate the repeatability and reproducibility of the parameters derived from the MSCR test. Nine different binders were evaluated, including unmodified, slightly and highly modified binders. The MSCR tests were conducted at 50°C, and each laboratory performed testing five times under repeatability conditions. The test results were analysed according to ISO 5725 and observations and reasons for deviating test results are discussed in detail.