Ultimate shear capacity of FRP-reinforced concrete beams: Test database and an improved design model

The current design provisions for fiber-reinforced polymer (FRP)-reinforced concrete beams under shear actions are demonstrated to be too conservative. To this end, a total of 576 test results of FRP-reinforced concrete beams experiencing shear failures were collected in this study. The test results were categorized into three databases. Database D1 contains 390 datasets without FRP stirrups, which was used to study the concrete contribution ( V c ). Database D2 includes 59 datasets which were retrieved from experiments on specimens with or without FRP stirrups, allowing for the separation and investigation of the FRP stirrup contribution ( V s ). The performance of current design codes was assessed against the 127 datasets with FRP stirrups in Database D3 which is independent of D1 and D2. Assessment results revealed that CSA S806–12 has the best performance among the design codes in predicting V c , probably because it considers the arch effect, while it may be inappropriate to adopt constant stirrup strain limits ( ε fv ) in computing V s . In this light, based on the shear design philosophy of CSA S806–12, the arch effect factor and a more accurate equation for ε fv are proposed. Assessing against D3, the proposed model outperformed current design codes with a least error (19 %) and a smallest dispersion.