Abstract: The ever-increasing volume of construction and demolition waste and the growing demand for sustainable construction practices have spurred extensive research on incorporating Recycled Concrete Aggregates (RCA) in various construction applications. Among these, the use of RCA in Thin Concrete Overlay Slurry (TCOS) for road repairs has emerged as a promising solution to address both environmental concerns and the need for cost-effective infrastructure maintenance. The first segment focuses on the properties and characteristics of RCA, comparing them with natural aggregates and the importance of the criteria for TCOS in terms of mechanical properties, durability, crack prevention, and skid resistance. The key environmental advantages identified are the reduction of construction waste, conservation of natural resources, and energy savings during production. Cost savings on aggregates, reduced waste disposal costs, and lower transportation expenses are highlighted as key economic advantages. The paper emphasizes how RCA may be used in TCOS for sustainable road repairs. A viable sustainable method for building roads has been demonstrated by the integration of RCA in TCOS. However, introducing RCA may lower the TCOS compressive strength. Research suggested that a lower water-to-cement ratio of 30% to 35% may increase the compressive strength of TCOS-RCA. Likewise, the blending of fibers as reinforcement might increase the wear resistance and decrease surface spalling. Further, the flexural strength and crack resistance of TCOS can be enhanced by combining fibers.