Evaluating the performance of self compacting concretes made with recycled coarse and fine aggregates using non destructive testing techniques

The paper presents the results of an investigation conducted to evaluate the performance of Self Compacting Concrete (SCC) made with different replacement levels of Recycled Concrete Aggregates (RCA) with the use of Non Destructive Testing (NDT) techniques. Non-destructive tests such as Electrical Resistivity, Ultrasonic Pulse Velocity (UPV) and Rebound Hammer were conducted on the various SCC mixes made with different replacement levels of Coarse Recycled Concrete Aggregates (CrRCA) and Fine Recycled Concrete Aggregates (FnRCA) at different periods of curing. Compressive strength tests on all the SCC mixes were also conducted for reference. The results show that increase in the content of RCA as replacement of Natural Aggregates (NA), decreases the electrical resistivity, UPV and rebound numbers for all SCC mixes. The linear regression coefficients depict excellent relationship between electrical resistivity, UPV and rebound numbers with compressive strength at all curing ages. It has been observed that the SCC mixes containing low and intermediate percentage of RCA as replacement of NA do not report any negative effect on the overall performance of SCC. Using waste materials (RCA) in new concrete certainly reduces its cost, encourages the concrete industry and correspondingly leads to the effective management of Construction & Demolition (C&D) wastes.