Development of sustainable pavement: an experimental study of stone mastic asphalt prepared with warm mix additives and reclaimed asphalt pavement

Abstract

Premature failures in flexible pavements, such as low-temperature stripping, medium-temperature fatigue cracking, and high-temperature rutting, pose significant challenges. In order to address these issues and environmental challenges, the use of Reclaimed Asphalt Pavement (RAP) mixtures surface layers is being encouraged. However, the utilization of RAP in surface layer as Stone Mastic Asphalt (SMA) SMA mixtures results into higher stiffness and fracture failure. In this context, experimental studies were conducted on SMA mixes with varying percentages of RAP (0%, 20%, 30%, and 40%) and cellulose fibers. Warm Mix Asphalt (WMA) technologies are also explored as an alternative to conventional Hot Mix Asphalt (HMA) to reduce energy consumption, carbon emissions, and ensure long-term sustainability. The experimental approach involves the use of Polymer-Modified Binder (PMB 70) modified with warm mix additive and inclusion of cellulose fibers in SMA mixes so as to prevent asphalt drain down. The mixes were prepared using Marshall Mix design, and various techniques, including moisture susceptibility, rutting resistance and resilient modulus (RM) and were employed for comparison with control mixes. The findings reveal that the SMA Mix containing 30% RAP exhibits superior resistance to moisture sensitivity and rut depth. Furthermore, the same mix displays significantly elevated resilient modulus values. Thus, the mix is showing promising results in mitigating premature failures and promoting more sustainable pavement solutions.