Service-Load Deflection Behavior of Reinforced Concrete Beams with Recycled Concrete Aggregate

摘要

This paper investigates the immediate and long-term service-load deflection behavior of reinforced concrete beams using recycled concrete aggregate (RCA) as replacement for natural coarse aggregate (e.g., crushed limestone, gravel). Test results from eighteen large-scale, simply-supported beams are discussed, incorporating the effects of reinforcement details and varying amounts of RCA up to the full replacement of the coarse aggregate by direct volume replacement. The beams were subjected to service-level loads both above and below the cracking limit while remaining within the linear elastic range of the steel in tension and concrete in compression. Data from companion creep and shrinkage cylinder tests are also presented. The results show significant increases in both the immediate and time-dependent deflections with increased amounts of RCA. The measured immediate beam deflections compared reasonably well with ACI-318 and Eurocode predictions; however, there were significant discrepancies in the time-dependent deflections.