Experimental study on behavior of Retrofitted with FRP wrapped RC Beam Column Exterior Joints Subjected to cyclic loading

In the last few decades, moderate and severe earthquake have struck different places in the world, causing severe damage to reinforced concrete (RC) Structures. Retrofitting of existing structures is one of the major challenges that modern civil engineering structures has demonstrated that most of them will need major repairs in the near future. Upgradation to higher seismic zones of several cities and towns in the country has also associated in evolving new retro fitting strategies. One of the techniques of strengthening of the RC structural members is through confinement with a composite enclosure. This external confinement of concrete by high strength fiber reinforced polymer (FRP) composite can significantly enhance the strength and ductility and will result in large energy absorption capacity of structural members. FRP material, which are available in the form of sheet, are being used to strengthen a variety of RC elements to enhance the flexural, shear, and axialload carrying capacity of these elements.

An experimental investigation of the behavior of retrofitted FRP wrapped exterior beam column joints with detailing as per IS 13920: 1993 under seismic conditions is presented. The experimental study on exterior beam column joint of a multistory reinforced concrete building (G+ 4 storey) in Salem Zone falling under the seismic Zone – III has been analyzed using STADD.pro. The specimens were designed for seismic load according to IS 1893(PartI): 2002 & IS 13920: 1993. The test specimen is reduced to one fifth model of beam column joint from prototype specimen. Column confinement and beam stirrups are provided closely in joint region according to IS 13920: 1993. Three Specimens were cast and testedto failure during the present investigation. One is Control specimen test up to post ultimate load, and another two Specimen test up to 70% of the ultimate Load. The test specimens were evaluated in terms of load displacement relation, ductility, stiffness, load ratio and cracking pattern. Test results are compared with analytical modeling of beam column joint performed in STAAD.Pro. and ANSYS Software.