Reversed Cyclic Experiments on Shear Stress Transfer across Cracks in Reinforced Concrete Elements

An experimental study on 14 reinforced concrete membrane elements was performed to investigate shear-stress transfer across cracks. The variables were loading conditions (cyclic or reversed cyclic), concrete strength, and applied tension-to-shear loading ratio. During each experiment, shear and normal stresses across the main crack, crack widths, and crack slips were continuously monitored. All specimens failed in shear along the main crack plane. The results demonstrate that crack behavior is highly nonlinear and path-dependent. Load reversals have the effect of weakening the crack shear stress transfer mechanisms both in terms of strength and stiffness. Concrete strength plays a relatively minor role in crack behavior while reducing the tension-to-shear ratio results in narrower cracks and, thus, an overall crack response that is both stronger and stiffer.