Interfacial stress calculation of prestressed CFRP sheet reinforcing steel-concrete composite beam under uniformly distributed load

The interfacial stress is mainly affected by the thickness of adhesive layer and CFRP(carbon fiber reinforced polymer) sheet, initial prestress, connector stiffness. The calculation formulas of interfacial stress about the steel-concrete composite girders reinforced with prestressed CFRP sheet are derived basing on the elasticity theory. The results of calculation show that the mid-span interfacial stress is minimum and approaches to zero, which is the nonlinear from the mid-span to the end. The interfacial stress decreases with increasing thickness of CFRP sheet and connector stiffness, while it increases with increasing of initial prestress. Thickness of adhesive layer has little effect on the shear stress and normal stress of the steel beam and concrete slab.