Experimental investigation on R.C.C beam retrofitted with JUTE fibre sheet

Abstract

Recent earthquakes have demonstrated that most of the reinforced concrete structures were severely damaged during earthquakes and they need major repair works. Up gradation to higher seismic zones of several cities and towns in the country has also necessitated in evolving new retrofitting strategies. One of the techniques of strengthening the reinforced concrete structural members is through external confinement by high strength fibre composites which can significantly enhance the strength and ductility. Fibre materials are used to strengthen a variety of reinforced concrete elements to enhance the flexural, shear, and axial load carrying capacity of elements. Beam, being vertical load resisting members in reinforced concrete structures are particularly vulnerable to failures during earthquakes and hence their retrofit is often the key to successful seismic retrofit strategy. The existing reinforced concrete beams which are not designed as per code IS 13920:1993 must be strengthened since they do not meet the ductility requirements. Three exterior reinforced concrete beam specimens was casted, in which one had reinforcement details as per code IS 456:2000(control) and another had reinforcement details as per code IS 13920:1993(control). The remaining specimen had reinforcement details as per code IS 456:2000 retrofitted with JUTE fibre sheets using epoxy resin(retrofitted[1]). The both ends of beam were hinged. Static load was applied at the top of the beam up to a controlled load deflection. The performance of the retrofitted beam was compared with the control beam specimens and the results are presented in this paper.