Compressive strength assessment of normal and self-compacting concrete made with recycled coarse aggregate using in-situ tests

Abstract

There is an increasing trend in construction for using recycled coarse aggregate (RCA) concrete, which is a more sustainable approach for reducing natural resource consumption. One typical method for developing more environmentally friendly structures is to partially substitute natural aggregate. limited studies investigated the use of in-situ tests to assess the compressive strength of concrete made with RCAs. In this study, ultrasonic pulse velocity (UPV) and core sampling (CST) tests were used to evaluate the compressive strength of normal vibrated (NVC) and self-compacting (SCC) concretes made with recycled coarse aggregates (RCAs). Four different compressive strengths ranging from 25 to 55 MPa were adopted for each concrete type to consider the effect of replacing 0, 20%, 40%, 60%, 80%, and 100% of the required natural coarse aggregates (NCAs) with (RCAs). Exponential relationships were adopted to relate the UPV values with the compressive strength for both RCA-NVC and RCA-SCC. Also, suggested factors were adopted to correct equivalent core strengths for both RCA-NVC and RCA-SCC. The results of both test methods (UPV) and (CST) showed good correlations to estimate the compressive strength of RCA-NVC and RCA-SCC with confidence limits of 93%.