EXPERIMENTAL STUDY ON THE SHEAR PERFORMANCE OF R.C BEAMS RETROFITTED BY BONDING GFRP STRIPS

摘要

This paper presents an experimental study on the shear performance of simply supported beam retrofitted by bonding GFRP strips/sheets. The experiment involves eight specimens: two control beams, four beams retrofitted with closed strips and two beams retrofitted with side sheets. Throughout the experiment, the relationship of load versus FRP strain and strain distribution across the shearing section were measured, and the failure process was observed. Test results showed that FRP rupture failure occurred for specimens with closed strips. However, the stresses of FRP strips developed in different ways, where FRP strips ruptured one after another, but before rupturing the FRP strips debonded from the side face of beams. For the specimens with side sheets, complete debonding failure occurred before the FRP strips reached their ultimate tensile capacity. The paper also discusses the influence of various parameters, such as the amount of external FRP reinforcement, shear-span-ratio and bonding method of FRPs on the shear performance and failing process of shear strengthened beams.