Stability Properties of Waste Engine Oil Modified Asphalt Mixtures

Abstract

Nigerian automobile industries generate over 200 million liters of Waste Engine Oil annually. They cause environment pollution in terms of their disposal and soil degradation. Several studies have discussed the reuse of waste materials in road paving to minimize the use of bitumen. In this study, waste engine oil was used at 0,2,4,6,8% to modify 20/30 penetration grade bitumen, the modified bitumen samples were then used to produce dense graded asphalt mixtures and the stability and volumetric properties of the mixtures were evaluated. The addition of WEO to bitumen changes the properties of bitumen with penetration, softening point, flash point, fire point and viscosity changing by 44, -22, -16.8, -15.7, -9% respectively. The covariance between WEO and bitumen properties has positive value with penetration while it has negative covariance with all other properties. The modified bitumen becomes softer and this type of bitumen are primarily used in cold climates. The relationship between stability properties of the mix and WEO percentage has a strong coefficient of determination across all properties. The stability, flow, voids in total mix, VTM , voids filled with bitumen,VFB of the mixtures produced from neat bitumen changed by 2.05, 15.2, -134.01, -32., 27.08% respectively at 8% WEO replacement. Based on stability, VFB and VTM, the optimum binder content that yields best results is at 8% WEO replacement. This study can serve as a preliminary laboratory experiment for evaluating its potential.