Utilization of cashew nut-shell ash as a cementitious material for the development of reclaimed asphalt pavement incorporated self compacting concrete

This paper focuses on developing sustainable self-compacting concrete (SCC) through the optimization process by incorporating Reclaimed Asphalt Pavement (RAP) as coarse and fine aggregates and also utilizing Cashew Nut-shell Ash (CNA) as a cementitious material. To achieve this optimization technique is implemented in four stages, which are the RAP aggregate treatment process, gradation selection process, RAP replacement percentage, and considering the CNA replacement percentage. RAP has been treated by a novel freeze–thaw cyclic procedure followed by the abrasion treatment method. Bailey's Aggregate Grading Technique (BAGT) has been implemented to line up the aggregate packing gradation. Mechanical and rheological properties have been conducted and analyzed based on compliance requirements of SCC at ambient temperature. Paste properties are analyzed through Field Emission Scanning Electron Microscopy, X-ray diffraction, Energy-Dispersive-Spectroscopy, and Thermo Gravimetric Analysis. Further, quality assessment of SCC has been performed through X-ray μCT (Xradia, XCT-500) and Ultrasonic Pulse velocity tests. In addition, compressive and flexural strength of selected SCC mixes have been performed at 50 °C, 100 °C, and 150 °C. Based on the results, with the incorporation of 75% coarse RAP, 50% fine RAP along 15% CNA as a binder constituent it becomes possible to achieve a sustainable SCC and it was found to be most suitable for real-time practices.