Influence of Long-Term Aging on the Engineering Properties of WMA Mixtures Containing Petroleum Wax and Natural Zeolite

Several studies were performed to assess the mechanical performance of warm-mix asphalt (WMA) mixtures prepared with petroleum wax (PW) and natural zeolite (NZ) without considering the effects of aging. In this study, the influence of long-term aging (LTA) on the mechanical properties of WMA mixtures containing PW and NZ additives is studied and compared with those of hot mix asphalt mixtures. AASHTO R30 was used to simulate the LTA of the laboratory-prepared PWWMA and NZWMA mixtures. The ratio of PW and NZ added to prepare the WMA mixtures was 1.5% of the total asphalt mass. Marshall stability, indirect tensile strength at 25 °C and 60 °C, flexural strength at − 10 °C and creep compliance at 40 °C tests were conducted. The durability performance of the mixtures was evaluated by calculating the tensile strength ratio (TSR) to investigate the moisture susceptibility of the mixtures. The results indicated that LTA significantly affects the performance of the mixtures. NZWMA mixture showed higher resistance to moisture and permanent deformation with lower cracking resistance compared to PWWMA. Also, at the same optimum binder content, NZWMA and PWWMA mixtures satisfied the minimum ASTM requirements of stability, flow, voids in mineral aggregates, and TSR.