Shear Transfer Strength of Uncracked Concrete after Elevated Temperatures

The shear transfer strength (STS) of uncracked concrete at ambient and after elevated temperatures of 350°C, 550°C, and 750°C is investigated. Forty-eight uncracked push-off specimens with different confinement levels were cast with a constant concrete mix having a target compressive strength of 40 MPa. Specimens were heated at different temperatures in an electric furnace and tested for STS after natural cooling. Results revealed that loss in STS was at its maximum for specimens without transverse reinforcement. An increase in transverse reinforcement resulted in a decrease of loss in STS after exposure to elevated temperatures. Elevated temperatures resulted in the reduction of stiffness of the shear stress-crack deformation curves and also increased the crack deformation corresponding to peak shear stress. An equation for the prediction of STS after elevated temperature is also suggested from the experimental results and validated on the specimens reported in the literature.