Experimental investigation on axial compression behavior of heat-damaged concrete cylinders confined with CFRP sheets

This study focuses on the axial compression behavior of heat-damaged concrete cylinders repaired with carbon fiber-reinforced polymer (CFRP) sheets. A total of 52 specimens were tested to investigate the effects of heating temperature, CFRP layers and cooling methods on the mechanical properties of heat-damaged concrete cylinders. The test results indicated that the residual compressive strength of heat-damaged concrete with water cooling is lower than that of heat-damaged concrete with natural cooling when the exposure temperature is >= 400 degrees C. The confinement of CFRP can enhance the residual compressive strength of heat-damaged concrete. Considering the effect of the heating temperature and cooling method, a combination model was suggested to predict the ultimate strength of heat-damaged concrete confined by CFRP sheets, as well as the accuracy and applicability of the combination model were examined and demonstrated with test results and collected experimental data.