This course outlines Recycled concrete aggregate (RCA), which is produced by removing, crushing, and processing hardened concrete. It can be substituted for virgin aggregate in a variety of both bound and unbound uses. Concrete pavement is an excellent source of RCA because it is generally comprised of high-quality source materials that have previously met state agency specifications. As virgin aggregate sources and landfill space become limited, the use of RCA is becoming increasingly attractive for both environmental and economic reasons. Over the past several decades, more than 100 pavement projects have been constructed in the United States using RCA as either a full or partial replacement for coarse aggregate, fine aggregate, or both in concrete paving mixtures. Most of these pavements have exhibited satisfactory performance over several decades, and a number of these pavements are still in service today. Topics: Introduction to RCA Current Use of RCA in Concrete Mixtures RCA Basics and the Recycling Process Characteristics and Quality Testing Influence of RCA on Hardened Properties of Concrete Freeze-thaw, Abrasion Resistance, Permeability Mixture Design Using RCA Considerations for Pavement Design Using RCA Production and Use Considerations Publication Source: US FHWA