This book highlights the use of commercially available recycled aggregate concrete (RAC) extracted from multiple construction and demolition sites, considering it as a viable alternative to conventional aggregate. It further describes the advanced techniques, such as, scanning electron microscopy, nanoindentation, thermogravimetric analysis and X-ray microtomography shedding light on the deep-rooted causes of inferior macro-mechanical performance of RAC and the advantages of particle packing method design approach in this regard. It then  describes the improved properties of RAC with the help of macro-mechanical performance studies, microstructural characterization and fracture analysis. The systematic and in-depth presentation of the use of recycled coarse aggregate as an alternative to conventional aggregate for the preparation of structural concrete will guide researchers on subsequent research in RAC and provide assistance to structural engineers and concrete manufacturers for the usage of RAC.