Development of Sustainable Asphalt Pavement Mixture Using Recycled concrete aggregate, Crumb Rubber and Waste Engine Oil

The incorporation of crumb rubber derived from waste tires into asphalt mixtures is an effective strategy for improving the fatigue resistance of asphalt pavement. This research focused on hot mix asphalt (HMA) mixtures that replaced 40% of natural aggregate (limestone) with recycled concrete aggregates (RCA) treated with waste engine oil (WEO). Two types of asphalt binders were used: traditional AC60-70 and the same binder modified with 3%, 4%, and 5% crumb rubber (CR) by the weight of bitumen. The study aimed to investigate the influence of CR polymers on asphalt pavement performance and explore the feasibility of using WEO for asphalt modification. Various asphalt mixtures with different CR percentages were tested to evaluate their mechanical properties, including stability, fatigue resistance, permanent deformation, and loss of stability. The durability and resistance of the asphalt mixtures were also assessed through indirect tensile strength testing before and after exposure to water. The study found that the CR-modified mixes showcased several advantages compared to conventional mixes. These included enhanced fatigue and permanent deformation properties, reduced susceptibility to temperature variations, and improved resistance to moisture damage. Overall, the CR-modified mixes demonstrated improved performance compared to the regular mixes. The results indicated that the developed HMA, which included 40% RCA and 4% crumb rubber binder, improved stability and the Percentage of Indirect Tensile Strength Ratio (ITSR). Among the different CR percentages tested, the 4% crumb rubber modification demonstrated the highest fatigue life. Furthermore, the addition of 3% waste engine oil to the modified control mix (MCM) with 40% RCA and 4% CR appeared to enhance the durability of the asphalt mixture. Ultimately, the utilization of MCM with 40% RCA, 4% CR, and 3% WEO was found to enhance the performance of the asphalt pavement mixtures that were developed.