Experimental and numerical study of strengthening and repairing heat-damaged RC circular column using hybrid system of CFRP

This study aims to investigate the behavior of heat damaged reinforced concrete RC circular column considering effect of heat and repair technique. Six RC circular column with diameter of 185 mm and 800 mm in height were cast, heated at 400 °C and 600 °C for 3 h, strengthened and repaired with hybrid system of CFRP and then tested under concentric load. Also, four RC circular columns from Obaidat et al. (2020) [3] were used for comparison. Complementary to the experimental investigation, a finite element modeling (FEM) was developed to simulate the compression behavior of heat damaged RC circular column. The result showed that specimens strengthened and repaired with hybrid system SC-H23-COMP and (DC-H400-COM and DC-H600-COM) exhibited the higher improvement in compression capacity about 100.4% and (86.7% and 53%), receptively, more than the control specimens. It was concluded that as the temperature increases the strength of the specimen decreases. Moreover, the strength in repaired specimens by hybrid system increased by 64.9% and 48.85% more than unheated control RC column specimen CC-COM. Finally, the FEM results provides a good agreement with experimental results and the model capable to predict the compression behavior of the RC circular column.