The possibility of using solid wastes as an aggregate inconcrete has received increasing attention in recent years asone promising solution to the escalating solid-waste problem.Since gravel concrete is the well known type of concrete inEgypt, its proportion in demolition wastes is substantial andexpected to rise in the future due to demolition of oldconcrete buildings.The recycled-aggregate concretes were produced usingcrushed concrete derived from the original gravel concrete.Recycling of solid wastes is not a new concept. Industrialwastes are the basis of many concrete admixtures, such as, flyash, blast-furnace slags etc.The main objective of this thesis is to investigate theapplicability of recycling gravel concrete as an aggregate.The effects of water-cement ratio and cement content onrecycled-aggregate experimentally werethe physical and mechanical properties of and recycled-aggregate concreteinvestigated.In addition a brief cost estimate of recycled aggregate processing was introduced.