Behavior of FRP-Wrapped Rectangular Concrete Columns

The bearing mechanism of rectangular concrete column that has been strengthened with fiber reinforced polymer (FRP) wrap under axial load is analyzed, and a predicted modal for the strength of FRP confined concrete is obtained based on the typical model of confined concrete, which takes the restrictionof FRP wraps to concrete as the effective lateral compressive stress. Then, according to the theoretical analysis and experimental results, several key parameters of the proposed modal are analyzed and determined. The parameters include in-section, inheight coefficients of effectiveness and confinement effectiveness coefficient. Moreover, the design formula for the ultimate load of the FPR-wrapped rectangular column under axial load are put forward, good accordance between the calculated results and the experimental ones being revealed. It is thus concluded that the proposed confined concrete strength modal and design formula is feasible to evaluate the ultimate load of the FRP-wrapped rectangular columns.