Behaviour of Recycled Aggregate RC Columns Wrapped with CFRP Under Axial Compression

Abstract

Over last few decades, number of studies have been carried out which studies the properties of concrete specimen made with recycled aggregates. In general, the focus of these investigations was to evaluate the behaviour of such concrete under uniaxial compression, tensile splitting and flexural by using different percentages of recycled aggregates. Based on these studies declining trend of compressive, tensile splitting and flexural strength was observed as the percentage of recycled aggregates increased. Therefore, if structural columns are to be designed with recycled aggregate concrete (RAC), the decline in compressive strength of RAC should be catered using some strengthening technique. The use of carbon fibre reinforced polymers (CFRP) wraps with columns subjected to uniaxial compressive loads have shown to contribute significantly towards increase in load carrying capacities of columns. This study investigates experimentally, the response of fully wrapped reinforced concrete columns made with RCA with CFRP under uniaxial compression. Twelve 600 mm high reinforced concrete rectangular columns (150 mm × 300 mm) were used in the study. Out of twelve, six specimens were fully wrapped with unidirectional CFRP wraps and six were without wraps. Furthermore, columns were cast using RAC with 0%, 70% and 100% of RCA. It was found from the experimental investigation that the specimens with CFRP wraps performed better than columns without CFRP wraps, both in terms of axial compressive load and the ductility. Furthermore, it was also observed that the declining trend in compressive strength associated with RAC was overcome by the use of CFRP wraps.