Behaviour of Reinforced Concrete (RC) Infill Frames under Cyclic Lateral Loading

Abstract

Fiber-reinforced polymer (FRP) materials are used in different configration and techniques for strengthening of Reinforced concrete (RC) elements to ensure their longer service life. Use of FRP material as Externally bonded surface is one of the popular strengthening techniques that consists of bonding FRP material using primer and saturant. One specimens of locally available stainless steel wire mesh (SSWM) were selected and tested for finding the tensile strength. The ultimate tensile 770.78 N/mm2 .To check the bond strength between concrete and SSWM (Stainless steel wire mesh), Two dumbbell shaped concrete specimens were prepared and tested. Ultimate bond strength was found to be more than 727.29 N/mm2 because the wire mesh strip got fractured but there was no bond failure between concrete and wire mesh An attempt has been made to investigate the structural performance of simply supported RC beams strengthened with Externally bonded SSWM sheet. Flexural and shear strengthening of RC beams is conducted using SSWM sheet. Total twenty beam specimens are cast and subsequently are strengthened using SSWM sheet. Ten beams are strengthened in flexure, eight beams are strengthened in shear and remaining two beam are Control shear and flexure beam..Size of beam is kept 150mm× 200mm × 2100mm. Beams are designed using IS provisions.The beams are made different for flexure and shear by reducing percentage of tensile reinforcement and required shear reinforcement, respectively. Variables considered in flexure strengthening of beams are change in number of sheet layer and orientation.Variables for shear strengthening of beams include change in number of layers and orientation depth of SSWM sheet. The RC beams are subjected to two point loading during testing. The FEM analysis was performed using ABAQUS software for the comparison with experiment data and also comparison of Strengthened beam wrapped with SSWM sheet with Strengthened beam wrapped with GFRP sheet. Strengthened beam in flexure exhibited increment of 5.89% to 20% in Strength and decrement of 22% to 51.26% in displacement compared to the Control flexure beam.The SSWM wrapped flexure beam exhibited increment in Strength compared to GFRP wrapped flexure beam. Strengthened flexure beam with two layer of SSWM sheet give increment in one layer of SSWM sheet.The U-shaped with two layer of strengthened beam give significant increment compared to other strengthened in flexure. Strengthened beam in shear exhibited increment of 33.5% to 44.82% in Strength and decrements of 12.57% to 39.92% in displacement compared to the Control shear beam.The SSWM wrapped shear beam exhibited increment in Strength compared to GFRP wrapped shear beam. Strengthened shear beam with two layer of SSWM sheet give increment in one layer of SSWM sheet. SSWM bonded full depth at sided gives lesser increment in ultimate load compared to partial depth The two layer side wrapping over full depth give significance performance then other Shear strengthened beam.