EXPERIMENT AND THEORETICAL RESEARCH ON FLEXURAL PERFORMANCE OF RC BEAMS STRENGTHENED WITH PRESTRESSED AFRP SHEETS

Prestress technology is an effective way to use the high strength of FRP composite. The experimental study onflexural performance of strengthening RC beams using prestressed aramid fiber reinforced plastic (AFRP) sheets isconducted, and the effects of different prestress level on the propertiesof flexural load, stiffness and ductility are analyzed.Results show that, when prestress level is 55%～ 65%, the cracking load, yield load and ultimate load of RC beamsstrengthened with prestressed AFRP sheets are 147%～ 165%, 28%～ 50%, 13%～ 31% larger than that of RC beamsstrengthened with non -prestressed AFRP sheets, validating the effectiveness of prestressed AFRP sheet retrofit.The failurepattern of prestressed AFRP sheets is fracture, but that of non-prestressed AFRP sheets is debonding.Based on theexperimental study, an elastoplastic section analysis method is conducted to predict the loads of beams, the results from thetheoretical predictions and the experiment agree well.