Novel cold pothole patching mixtures utilizing EAF steel slag and pyro-oil from municipal plastic solid waste

Road upkeep is frequently hampered by potholes, and traditional techniques of filling them can be expensive and time-consuming. This research delves into the utilization of plastic-based pyrolysis oil (PPO) derived from plastics in the modification of cutback bitumen. Additionally, it explores the replacement of conventional aggregates (CA) with electric arc furnace (EAF) steel slag, coupled with the incorporation of an anti-stripping agent (ASA) to produce eco-friendly and novel cold pothole patching mixtures. The Brookfield viscosity test was used to assess cutback bitumen with diesel and PP oil, the Marshall method was used to evaluate the mix design properties, the Virginia Department of Transportation (DOT) test procedure for adhesion, the AASHTO TP-44-94 for cohesion, the Texas Department of Transportation (TxDOT) for abrasion resistance, and the modified Lottman test for moisture sensitivity. The results indicate that the viscosity of both the pyrolysis oil’s-based cutback (PC) and diesel-based cutback (DC) cutback bitumen was within favorable values at 60 °C but displayed identical values at higher temperatures. The strength and adhesiveness of cold pothole patching mixtures improved with the use of PC bitumen and EAF steel slag instead of conventional aggregates. Compared to CA-DC, EAF-DC, and CA-PC mixtures, higher material retention was seen in EAF-PC mixtures. Cantabro loss of CA-DC, EAF-DC, CA-PC, and EAF-PC mixtures was within the limits (< 20%). ITS values before and after freeze‒thaw cycling improved with the use of PC cutback bitumen and EAF steel slag instead of conventional aggregates. Furthermore, the tensile strength ratio (TSR) value of the EAF-PC mixtures had the highest value (86%), while the TSR values of the CA-DC, EAF-DC, and CA-PC mixtures were below the limits (> 85%).