Experimental study on deformation properties of square concrete columns confined with CFRP at low temperatures

An investigation of deformation properties of square concrete columns confined with CFRP sheets at low temperatures were carried out experimentally. The experimental results showed that the CFRP sheets can increase the bearing and deformation capacity of concrete columns effectively at low temperatures. And the experimental curves show that area of plastic deformation increases, the curves become more stable and slow, and the peak strain increases with increasing usage of the CFRP sheets. The curves of N/N_u vs. strain of steel and CFRP at different temperatures are almost the same, which indicates that the temperature has little effect on the deformation of steel and CFRP. However, the curves of N/N_u vs. strain of concrete are different, which indicates that the temperature has an obvious effect on the deformation of concrete.