Laboratory Investigation on Nanomaterial Modified Bituminous Concrete Mixes with Reclaimed Asphalt Pavement

In this research article, an attempt is made to develop recycled bituminous concrete mixes comprising of reclaimed asphalt pavement (RAP) and binder modified with nanomaterials such as nanosilica (NS) and nanoclay (NC). The RAP material contains aged binder, which increases the brittleness of asphalt mixtures. Therefore, waste cooking oil is used as a rejuvenator to restore the characteristics of aged binder. The addition of nanomaterial improved the strength and moisture damage resistance of asphalt mixtures. Due to the size reduction from micro- to nanoscale, high surface area and high adsorption intensify the adhesive property of asphalt mixtures. Taguchi's design of experiment methodology was used to reduce the experimental effort. Initially, in the calibration phase, only nine mixes based on Taguchi l-9 orthogonal array were considered, with each of the three input parameters such as RAP at 15%, 30% and 45%, bitumen content (3.7%, 4.9% and 6%) and nanomaterial content of 2% 4% and 6%, respectively, for nanosilica and nanoclay. Prediction equations were developed for the input parameters and responses used for Taguchi analysis, and the same was validated through the test set. The test result revealed that recycled asphalt mixtures exhibit higher Marshall properties, indirect tensile strength (ITS), tensile strength ratio (TSR), resistance to rutting and dynamic stability in contrast with control mixes.