Abstract:
Through the test of corroded reinforced concrete columns which were strengthened with carbon fiber reinforced polymer (CFRP) composite strips and glass fiber reinforced polymer (GFRP) composite strips in the erosion environment, the influences of erosion environment on the concrete strength, the ultimate load and the axial load-displacement relationship curve of corroded and FRP strengthened concrete columns were analyzed. The result shows that the strength of the concrete is greatly affected by the freeze-thaw environment and is less affected by the dry and wet environment. The axial ultimate load of FRP reinforced damaged columns is related to the number of freeze-thaw cycles, the corrosion rate of steel bars and the type of FRP composite. With the increase of freeze-thaw cycles from 0 to 25, 50 and 75, the axial ultimate loads of corroded reinforced concrete columns strengthened with GFRP composite and CFRP composite strips are decreased by 10.97%, 13.37%, 16.04% and 5.95%, 4.66%, 4.33% respectively. The load-axial displacement curve of the FRP composite reinforced corrosion column reflects the stiffness and the energy consumption of the column, and both of which are affected by the type of erosion environment, the number of times of the erosion environment, the corrosion rate of steel bars and the type of FRP composite. Through the experimental research, the damage coefficient of concrete strength and the regression equation of the strength of corroded bar in the erosion environment were theoretically analyzed. A method for calculating the axial compression capacity of corroded reinforced concrete columns strengthened with FRP composite strips under erosion environment was presented.