Experimental and analytical investigations on the effectiveness of non-uniform CFRP wrapping on circularised RC columns

This study aims to experimentally and analytically investigate the effectiveness of non-uniform wrapping on circularised reinforced concrete (RC) columns under axial and flexural loads. Sixteen specimens including four square and twelve circularised RC specimens were prepared and tested. Specimens of the first group were square RC specimens. Specimens of the second and third groups were circularised RC specimens fully wrapped with two and three plies of carbon fibre reinforced polymer (CFRP), respectively. Specimens of the fourth group were circularised RC specimens non-uniformly wrapped with CFRP. The experimental results showed that, for an equivalent amount of CFRP, the performance of circularised RC specimens fully wrapped with CFRP was better than the performance of circularised RC specimens non-uniformly wrapped with CFRP. An analytical method was developed for the failure envelopes of the tested specimens. A good correlation between the experimental and analytical failure envelopes was obtained for the tested specimens.