Waste Cooking Oil as Sustainable Rejuvenator in Recycled Asphalt Pavement

Abstract

Abstract: The practice of disposing of traditional asphalt pavements in Pakistan is harmful to the environment and natural resources. Only 15% of old asphalt material has been recycled on Motorway-2 (M2) near Sheikhupura so far, according to existing guidelines. A study aimed to increase recycled asphalt in Pakistan using waste cooking oil (WCO) as rejuvenator. The asphalt mixture containing 50% recycled materials comprising 3.45% recycled binder was investigated for consensus properties, indirect tensile strength, and rutting resistance using WCO. The results showed that WCO of 9% is best for equating the properties of recycled binder and mixture to neat binder and mixture performance, except for ductility. The improved performance of recycled mixtures was attributed to adequate interlocking in the asphalt mixture due to stimulation and mobility of the recycled binder because of effective use of WCO. The recycled asphalt mixture displayed almost equivalent rut and moisture resistance to virgin asphalt mixture at a WCO of 9%. The long-lasting integrity of the rejuvenator in the recycled asphalt mixture containing WCO allowed it to sustain repeated wheel loads when subjected to wheel tracking test. The study's findings could be useful in recycling old asphalt materials for engineering purposes, utilizing WCO, and indirectly benefiting the environment by reducing pollution generated due to dumping of aged asphalt materials because of demolishing of asphalt roads after their service life.