Moisture susceptibility of warm mix asphalt

Abstract

<span style="mso-ansi-language:EN-US;mso-fareast-language:TR" lang="EN-US">In this study, moisture susceptibility characteristics of wax modified bitumens and warm mix asphalt (WMA) mixtures are determined. The asphalt mixtures are prepared with 50/70 penetration grade unmodified bitumen and modified bitumens with three different types of additives (Fischer Tropsch wax, montan wax and polyethylene wax) by weight of 6%. The moisture susceptibility characteristic of the four bitumens is determined with Sessile drop method and that for asphalt mixtures is determined with Nicholson stripping test on loose asphalt mixtures and Modified Lottman test on compacted asphalt mixtures. Furthermore, Marshall stability with different blow numbers of WMA mixtures are determined. The findings from all of these tests suggest that due to the Fischer Tropsch wax and montan wax modification the asphalt mixture become more moisture susceptible which correlates with the surface energy characterization. Interestingly, polyethylene wax modification shows positive moisture performance.

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