A proposed strengthening model considering interaction of concrete

Many factors can affect the shear capacity of fiber-reinforced polymer in reinforced concrete beams shear-strengthened with externally bonded fiber-reinforced polymer composites. Undoubtedly, the interaction of concrete-stirrup-fiber-reinforced polymer system is one of the key factors. However, most of the existing fiber-reinforced polymer design guidelines do not take account of this important factor on predicting fiber-reinforced polymer shear capacity. This study provides an advanced strengthening model that comprehensively considers the interaction among concrete, stirrup, and fiber-reinforced polymer for calculating the fiber-reinforced polymer effective strain. The advanced strengthening model provides a more accurate prediction for the fiber-reinforced polymer shear contribution compared with existing design guidelines