Uniaxial Tensile Stress-Strain Behavior of Carbon-Fiber Grid-Reinforced Engineered Cementitious Composites

Carbon fiber-reinforced polymer (CFRP) grid-reinforced engineered cementitious composites (ECC) have been developed as an alternative to epoxy resin-based FRP plates for the strengthening of concrete structures. To broaden the application of this new composite material for seismic retrofit and strengthening of reinforced concrete elements, an experimental study, including three nonreinforced ECC plates and 30 CFRP grid-reinforced ECC (CFRP-ECC) hybrid plates, was conducted to investigate their mechanical performance under both monotonic and cyclic uniaxial tensile loads. The stiffness of the internal CFRP grid and loading scheme were the two primary test variables. Test results showed that all CFRP-ECC plates failed with a dominate crack in the ECC matrix and rupture of the internal CFRP grid. The envelopes of the cyclic tensile stress-strain curves followed the static stress-stain curves regardless of the cyclic loading scheme adopted. A nonlinear stress-strain model is proposed to model the unloading/reloading paths of CFRP-ECC plates under cyclic uniaxial tensile loading. (c) 2018 American Society of Civil Engineers.