Recycled aggregate concrete (RAC) uses crushed concrete, reclaimed from demolished structures, as a substitute for fresh aggregate in new concrete. The mechanism behind RAC revolves around the processing of demolished concrete, which is crushed, screened, and sometimes treated to reduce contaminants and improve quality. RAC retains the hygroscopic and porous nature of original concrete but often with higher water absorption rates and lower density. These characteristics arise due to residual mortar attached to the aggregate, which affects the mechanical properties and durability of the recycled concrete. The incorporation of RAC in new concrete can significantly affect the fresh and hardened properties of the mix, including workability, compressive strength, and durability.