This guide presents information on the use of recycled concrete aggregate (RCA) in portland cement concrete. The demolition, removal, and processing procedures of turning hardened concrete structures into RCA are introduced. A detailed summary of various characteristics of RCA in comparison to virgin aggregate is presented. Different fresh properties, mechanical properties, and durability considerations of RCA concrete are subsequently discussed. Fifteen case studies on the use of RCA concrete in pavements and other structures are presented at the end of the guide.