Investigating the Effective Laboratory Parameters on the Rutting Behavior of Warm Mix Asphalt: Fid-Bau Portal

Investigating the Effective Laboratory Parameters on the Rutting Behavior of Warm Mix Asphalt

Mazhari Pakenari, Mohammad / Hamedi, Gholam Hossein

In laboratory conditions, neglecting time and temperature as two effective parameters on the mechanical properties of asphalt mixtures may affect the results of experimental tests and mislead researchers in analyzing the results. Therefore, it seems necessary that some of the less considered laboratory conditions in past studies need to be perceived more to minimize the error of results obtained by laboratory tests. Hence, in this study, after examining the research on warm mix asphalt and factors affecting laboratory test results, three parameters of short-term aging (asphalt binder storage in oven), curing time (from construction to placement in the test chamber), and thermal equilibrium time (from placement in the test chamber to test onset) were selected to combine different levels for evaluating their effect on the rutting potential by performing dynamic creep test. Based on the results, by increasing the time of aging, the viscosity of asphalt binder increased, thus increasing the mixture’s stiffness and reducing the slippage of materials over each other and decreasing the final strain. Also, increasing the curing time improved the adhesion between the asphalt binder and aggregate and reduced the rutting potential of the sample. However, by increasing the thermal equilibrium time, the viscosity and power of the asphalt binder’s cohesion were reduced, thus loosening the asphalt binder and aggregates, creating shear strain, and increasing the rutting potential of the warm mix asphalt (WMA). Based on the results of statistical analyses, the parameters considered in laboratory conditions affected the rutting potential of WMAs at a 95% confidence level.