Abstract
The seismic retrofit concept of using aramid fiber belt with initial lateral prestressing for RC columns was proposed by one of the authors. An important point of this technique is that the lateral prestressing can be initially introduced into column through aramid fiber belts using couplers and thus the benefits of active confinement as well as passive confinement can be captured. To analyze the nonlinear behavior of RC columns retrofitted by the proposed technique, the appropriate constitutive law of confined concrete is essential. Therefore, to establish the constitutive law of confined concrete, axial compression tests of RC columns externally confined by aramid fiber belt prestressing were conducted. The stress- strain relationships of concrete and aramid fiber belts are obtained through the experimental investigation. Finally, an appropriate constitutive law of confined concrete for the mensioned retrofit technique is proposed.
