Abstract: 171 test beams reinforced with fiber-reinforced polymer (FRP) bars including with and without FRP stirrups were analyzed by using shear bearing capacity’s formulas recommended by the Technical Code for infrastructure application of FRP composites (GB 50608-2010). By comparing each beam’s predicted shear strength with its corresponding experimental value, the result shows that the method adopted by the code is highly conservative. Therefore, main factors that affected the shear capacity of FRP reinforced concrete members with shear reinforcement were analyzed by adopting the grey relational analysis. The results show that the most important factor is effective depth of the cross section, followed by longitudinal reinforcement ratio, concrete compressive strength, the shear span ratio and so on. Accordingly, it was analyzed that formulas in the code underestimated effect of effective depth of the cross section and ignored impact on shear span ratio and so on. The formulas were revised on the basis of former analyses and then verified their rationality by using aforementioned 171 beams’ test data. Compared with the unrevised provision, the mean of ratio of the test to the predicted shear strength of the beams without shear reinforcement, it turns out, are from 4.78 to 1.49, whereas those of beams with stirrups are from 2.18 to 1.4.

Key words: FRP bars, concrete beams, shear bearing capacity, effective depth of the cross section, shear span ratio