Author(s)

A. Vimuttasoongviriya, N. Kwatra & M. Kumar

Abstract

For the purpose of assuring seismic safety in north India, it is necessary to monitor the damaged state of existing reinforced concrete (RC) buildings. Nonductile structures often result in the need of strengthening to increase the lateral load carrying capacity. This paper intends to investigate the effect of lateral load on damage indexes of RC frame model strengthened with fiber reinforce polymer (FRP) sheets. Park and Ang damage theory and stiffness damage index method were used. These damage indexes are expressed as a formula based on deformation, energy dissipation and change in stiffness. The damage indexes based on the change in dynamic characteristics namely modal plastic softening index and modal flexibility damage index were used with the help of impact hammer excitation test. Results of this study show that the use of FRP wrapped for structural strengthening provides significant lateral load capacity increases when compared to original specimen. Damage indexes based on deformation and change in stiffness show a much acceptable accuracy correlation with modal parameters indexes in general. Keywords: strengthened RC frame model, FRP sheets, damage indexes, displacement ductility, non-linear FE analysis. 1 Introduction For the purpose of assuring seismic safety, it is necessary to monitor the damaged state of structures. Many existing buildings in north India are nonductile RC structures. These buildings often result in the need of strengthening or retrofitting to increase lateral load carrying capacity. Un-strengthening building may potentially lead to more seismic damage under future earthquake. The strengthening technique using FRP sheets has been successfully used to prevent

Keywords

strengthened RC frame model, FRP sheets, damage indexes, displacement ductility, non-linear FE analysis