Evaluation of foam-based warm mix asphalt modified with nano-sized hydrated lime using multiple creep and recovery tests

© 2014 American Society of Civil Engineers. One of the objectives of this paper is to evaluate the effectiveness of Nano-sized Hydrated Lime (NHL) modification on the creep and recovery behavior of foam-based Warm Mix Asphalt (WMA) produced using Advera®. Also, the study investigates the creep and recovery behavior at multiple testing conditions. NHL with a particle size of 50-nm and Regular Hydrated Lime (RHL) were added to the asphalt binder at the ratios of 5% and 20%, respectively. The creep and recovery behavior was investigated based on: 1) the Multiple Stress Creep and Recovery (MSCR) test, and 2) ten cycles creep and recovery proposed tests performed at different conditions: 3Pa (creep for 100 sec. and 600 sec. recovery), 10Pa (creep for 20 sec. and 600 sec. recovery), and 50Pa (creep for 1 sec and 300 sec. recovery). Advera® foaming slightly increased the non-recoverable compliance (Jnr) of the original binder. Adding NHL in smaller amounts can produce asphalt materials with improved creep and recovery behavior in comparison to RHL. Comparing the MSCR test and proposed creep and recovery methodology, the Jnr seemed dependent on the creep and recovery times

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.</p