Mechanical Properties of Self Compacting Recycled Aggregate Concrete

Abstract

Concrete wastes are generally delivered to the landfill sites for disposal. Due to increasing charges of landfill and scarcity of Natural Coarse Aggregate (NCA), recycled concrete aggregate (RCA) derived from concrete wastes is growing interest in construction industry. In the present study, RCA was used as partial and full replacements of NCA to produce durable Self-Compacting Concrete (SCC). Different SCC mixes were produced with RCA substituting 0%, 25%, 50%, 75%, and 100% NCA by weight, 20% MP and 3% admixture. The water to powder (W/P) ratio are variable after adding water absorption to concrete mixes. The effects of RCA on the key fresh properties such as filling ability, passing ability, and segregation resistance of SCC were investigated and the effects of RCA on hardened concrete such as cube and splitting strength , abrasion resistance , Cantabro test and RCPT test to evaluate durability. The test results revealed that the filling ability and passing ability of SCC were improved for all mixes. All mixes of SCC also possessed adequate segregation resistance. In addition, strong correlations were observed for passing ability, and segregation resistance. The test result of hardened concrete revealed that mixes up to 50%RCA gives normal strength and accepted durability. From the overall test results it could be concluded that RCA can be used to produce SCC substituting up to 50% NCA without affecting the key properties of fresh concrete, give normal strength and accepted durability.

Effect of Recycled Aggregate Concrete and Steel Fibers on the Fresh Properties of Self-Compacting Concrete

“…The results showed that RCA can be substituted for natural coarse aggregate up to 100% without affecting the fresh properties of concrete. Sharubim [13] used RCA as an alternative to natural coarse aggregate (NCA) in SCC. They observed that RCA improves the flow ability of SCC without altering its basic properties.…”