Feasibility of Using Rice Bran Oil as a Rejuvenator in Asphalt Mixtures Containing RAP Material

The use of recycled asphalt pavement (RAP) has been one of the available solutions in road maintenance due to cost reduction and preservation of natural resources. On the other hand,by using RAP materials, aged binder in the RAP causes improper performance of the asphalt mixture, including reducing the cracking resistance. Nowadays, rejuvenators are used to improve the performance of asphalt mixtures containing RAP. Iran is one of the active countries in rice cultivation, while 70% of rice bran is unused. This study investigated rice bran oil as a rejuvenator in asphalt mixtures containing 20%, 30%, and 40% RAP materials by dynamic creep test, resilient modulus test, and semicircular bending (SCB) test. The results show that using rice bran oil in asphalt mixtures as a rejuvenator causes a decrease in the flow number, resilient modulus, and fracture toughness values by an average of 31%, 27%, and 13%, respectively, also increase in fracture energy values by an average of 24%. The results show that using rice bran oil improves the performance of asphalt mixtures containing RAP by reducing the viscosity of aged binder in RAP. As a result, implying rice bran oil as a rejuvenator in asphalt mixture due to the using rice waste and low cost and environmentally friendly, can be a good way to enhance asphalt pavement performance.