Evaluation of recycled asphalt mixtures rejuvenated with Madhuca longifolia (Mahua) oil

Reuse of reclaimed asphalt pavement (RAP) material not only leads to environmental sustainability, but also lowers down the of construction cost. However successful addition of RAP is limited to replacement level of 50%, as it is believed that higher quantity of the RAP makes the asphalt more susceptible to fatigue and thermal cracking. Studies on rejuvenation of aged binders recommend that it is possible to use higher percentage of RAP by using recycling agents or rejuvenators. Different types of oils such as vegetable oil, tall oil, cotton seed oil, waste engine oil, pongamia oil and soybean oil etc. have been explored as rejuvenators. In this study, Madhuca longifolia oil (Mahua oil), another oil produced largely in eastern part of India has been assessed as a potential rejuvenator to design recycled Hot Mix Asphalt (HMA) with high RAP content. Suitable dosage of the rejuvenator was decided based on the evaluation of rheological characteristics of the rejuvenated aged binder using a Dynamic Shear Rheometer (DSR). Performance of the conventional asphalt mixture and rejuvenated mixtures containing RAP with varying (30–70%) RAP percentages was assessed in terms of volumetric properties, indirect tensile strength, moisture sensitivity, resilient modulus, rutting, fatigue, low temperature cracking. Results were compared with the performance of recycled HMA made using softer binder grade. Results indicate that recycled mixtures with RAP content up to 60% can be successfully designed with addition of Madhuca longifolia oil to meet the without notably influencing the performance of the pavement.