Strengthening of Reinforced Concrete Bridge Columns with FRP Wrap

A compressive strength model for confined concrete wrapped with fiber-reinforced polymer (FRP) has been developed which is an extension of Mohr’s strength theory. This model explicitly relates the confined compressive stress, fcc′, to the confining pressure, fl′. It is shown that in the general form this model requires information about the uniaxial compressive strength, fc′, the uniaxial tensile strength, ft′, and a quantity, n, relating to the shape of Mohr’s envelope of ultimate strength states. A second-order parabolic model, developed analytically, is proposed for use with FRP-confined concrete. The proposed model has been verified using existing tests of normal strength concrete (fc⩽8000psi) specimens confined by FRP wrap and tube previously reported in the engineering literature. For comparison, an empirical model using the same data was also developed. An application example for strengthening a reinforced concrete bridge column is also provided.