Critical Study of Shear Capacity of Reinforced Concrete Beam Having FRP Reinforcement

Abstract

quotSustainable structures are the need of today where the root cause of deterioration of the structures is corrosion of steel reinforcement. Different forms of FRPs have proved to be a good alternative to the conventional steel reinforcement because of the properties like high tensile strength, noncorrosive, nonmagnetic and light weight. Extensive research is ongoing worldwide and design recommendations are produced by various standards; even though, there are many challenges for using FRPs as primary reinforcement. This study is concentrated on shear capacity of RC beam elements using FRP reinforcement, specifically shear contribution made by FRP shear reinforcement. newline newlineVarious design standards adopt different approaches to predict shear contribution made by the stirrups by keeping permissible strain limit or bend strength as upper limit. The range of permissible strain in FRPs is from 0.0025 to 0.004 in different standards (i.e. ISIS Canada, JSCE and ACI) which are very close to strain limit of steel reinforcement. Marginal difference between theoretical predictions and experimental results in the literature motivated to investigate the shear capacity of the beams with FRP reinforcement in flexure as well as shear. newline newlineAdvance testing on thirteen RC beams of size 230 x 300 x 2000 mm with GFRP as flexural and shear reinforcement is done by data observation of strain development at critical locations as well as deflection at midspan. Different strain gauges like PL-90-11-3L for concrete (surface), BFLA-5-5-3L for composite reinforcement (GFRP) and FLA-3-11-1L for steel made by TML, Japan are used for strain measurement. Multi channel data acquisition system TMR-200 is used for data recording, where the midspan displacement is observed by displacement transducers CDP 100. Perfect beam action was observed as well as all the type of shear failure like diagonal tension, shear compression, shear tension and stirrup failure were observed depending on the reinforcement and loading configuration. It is observed that averag