Effect of Filler Type on Moisture Susceptibility of Asphalt Mixtures Using Mechanical and Thermodynamic Properties

In order to evaluate the influence of filler type on the moisture susceptibility of asphalt mixtures, this study examined the thermodynamic properties of mastic and the mechanical properties of hot-mix asphalt subjected to multiple freeze-thaw cycles. Furthermore, the potential of using waste concrete aggregates as filler material was particularly evaluated using the moisture damage properties of asphalt mixtures. To fulfill these objectives, recycled concrete aggregates, limestone filler, and portland cement were used as filler materials in asphalt mixtures and siliceous stone powder was used as filler in control samples. The indirect tensile strength and resilient modulus tests were performed as commonly used experiments to assess the moisture sensitivity of asphalt mixtures. Furthermore, the surface free-energy components of mastics as well as the cohesion and adhesion of the mixtures were determined. The results of mechanical and thermodynamic experiments suggest that asphalt mixtures containing the portland cement filler outperform those containing other types of filler at all freeze-thaw cycles in terms of moisture susceptibility. However, recycled concrete aggregates are a sustainable alternative for the aggregate filler and, based on results, they can improve the moisture resistance of asphalt mixtures, particularly at increased freeze-thaw cycles. (c) 2019 American Society of Civil Engineers.