Flexural Strengthening of Reinforced Concrete Columns with Near-Surface-Mounted FRP or Stainless Steel

This paper presents the results of a large-scale experimental program aiming to study the behavior of reinforced concrete (RC) columns under simulated seismic loading, strengthened in flexure (of crucial importance in capacity design) with different types and configurations of near-surface-mounted (NSM) reinforcing materials. The role of different parameters is examined by comparing lateral load-versus-displacement response characteristics (peak force, drift ratios, energy dissipation, and stiffness). Those parameters are as follows: carbon or glass fiber-reinforced polymers (FRP) versus stainless steel, configuration and amount of NSM reinforcement, confinement via local jacketing, and type of bonding agent (epoxy resin or mortar). The results demonstrate that NSM FRP and stainless steel reinforcement is a viable solution toward enhancing the flexural resistance of RC columns subjected to seismic loads. This is especially the case when the retrofitting scheme combines epoxy-bonded NSM bars with local confining jackets (provided in this study with textile-reinforced mortars [TRM]). [PUBLICATION ABSTRACT]