Effect of LDPE Waste Plastic on Moisture Susceptibility of Asphalt Mixes

Our daily lives are significantly impacted by transportation these days. The asphalt pavement is prone to moisture damage with overloading and bad weather. Due to water and traffic stresses, asphalt pavement would crack, spall, create potholes, and ruts, which would limit pavement life and cause hydraulic erosion. As the reuse and recycling process diminishes in volume, many people discard plastic materials and goods after use, causing environmental and ecological issues. As per Central Pollution Control Board (CPCB) annual report 2019–20, plastic waste generated during the year 2019–20 is approximately 34,69,780 Tonnes. In this research, the primary investigation is to identify the effect of waste plastic in the category of low-density polyethylene (LDPE) in asphalt mixes. The laboratory investigation involved various dosage of waste plastic, i.e., 7.5%, 10.0%, and 12.5% by the weight of bitumen (VG30), was considered in this study. The Marshall mix design properties at OBC of 5.01%, waste plastic was added by following the dry process to produce waste plastic modified asphalt mix samples. The moisture susceptibility of conventional and waste plastic modified asphalt mixes was evaluated by boiling water test and tensile strength ratio (TSR) for the hot mix asphalt mixes. The addition of polymeric material (waste plastic) in asphalt binder can improve the mixture which can resist rutting, cracking, and moisture damage. The ITS test results from this study revealed that with the addition of 7.5%, 10.0%, and 12.5% waste plastic, and the TSR values increased from 84.9%, to 87.64%, 90.42, and 87.04%, respectively. This proves that waste plastic may act as a polymer in asphalt mix and controls the moisture susceptibility.