Comparative laboratory evaluation of waste cooking oil rejuvenated asphalt concrete mixtures for high contents of reclaimed asphalt pavement

This study focuses on the ability of waste cooking oil (WCO) to recycle old asphalt pavement into new pavements. The application of WCO was contemplated in the pavement materials to reduce the stiffness effect of reclaimed asphalt pavement (RAP). Following the Marshall's method, a detailed laboratory investigation was conducted to evaluate some of the properties of the WCO rejuvenated mixture and compared with the mixture without any RAP (SM) and the mixtures rejuvenated by a commercial rejuvenator (CR). For this comparison, laboratory tests of indirect tensile strength (ITS), percentage of ITS loss and resilient modulus ((Formula presented.)) were conducted following the respective standard method. Three different percentages (13%, 20% and 27%) of WCO (by RAP binder content) were evaluated for three different percentages of RAP mixture (30%, 40% and 50%). The statistical analysis of variance (ANOVA) was applied to quantify the effect of the WCO and the percentage of RAP on the mentioned properties of the rejuvenated mixture. It is observed that the values for ITS, percentage of ITS loss and (Formula presented.) of the WCO rejuvenated mixtures are compatible with those of the mixtures rejuvenated by CR and SM. However, the compatibility exists till a certain extent of RAP and WCO, and the increase in the percentage of RAP (>40%) and WCO (>13%) in the mixtures results in a deviation from the observed properties.