The employment of thermodynamic and mechanical methods to evaluate the impact of nanomaterials on moisture damage of HMA

摘要

In this paper, by applying the surface free energy (SFE) method and dynamic modulus test, an attempt has been made to assess the impact of two types of nanomaterials, namely nano Calcium Carbonate and nano Zinc Oxide, as an asphalt binder modifier on moisture sensitivity of HMA. The percentage of the aggregate surface exposed to water (P index) has also been computed using the measured SFE and dynamic modulus results, and assessed as an index for the moisture damage potential of HMA. The results of the SFE method show that nanomaterials increase the wettability of the asphalt binder over the aggregate and the adhesion between the asphalt binder and aggregate. The results of the mechanical tests indicate that treatment of the asphalt binder with nanomaterials increases the ratio of wet/dry values of the dynamic modulus. This indicates that nano-treatment of the asphalt binder decreases the moisture susceptibility of the mixes.