A Laboratory Study of Warm Mix Asphalt for Moisture Damage Potential Using Surface Free Energy Method

摘要

The moisture damage potential of an asphalt mix is generally determined using tensile strength ratio test (TSR), according to AASHTO T 283 test method. The basis of evaluating moisture damage potential of a mix using TSR is an empirical approach which does not represent moisture failure mechanism in real life of an asphalt pavement. This shortcoming of TSR method is more of concern when it comes to moisture susceptibility of warm mix asphalt (WMA), which is known for a possibbly higher moisture susceptibility. Recently, surface free energy (SFE) approach has been used as a mechanistic-based indicator of moisture susceptibility of the asphalt mixes.The present study was undertaken to evaluate the moisture susceptibility of Advera~® (synthetic zeolite) modified WMA mix using SFE approach. The SFE components of a selected asphalt binder, modified with different percentages of Advera~® and selected aggregates were measured in the laboratory and different energy parameters were calculated for the aggregate-asphalt binder systems. It was found that addition of Advera~® does not make the mix prone to moisture damage, , however, this additive did not show favourable properties with highly acidic aggregates like granite.