Shear Fatigue Response Of Cracked Concrete Interface

摘要

The shear fatigue behavior of cracked concrete interface was experimentally investigated on a single crack plane to quantify the degree of deterioration per load cycle.A simple experimental setup was used,in which a finite lateral stiff-ness was provided to the crack interface by using unbonded steel bars.The effects of loading amplitude,loading pattern and water exposure were examined.Time-dependent behavior of shear transfer under sustained shear load was also in-vestigated.The shear fatigue response of cracked concrete interface was found to be characterized by gradual increments of shear slip and dilation and majority of the incremental displacements to occur in the first few cycles.The degree of deterioration was found to be highly sensitive to the load amplitude level and loading pattern.The relative extent of deterioration in the case of reversed cyclic loading was much larger than that of single-sided fatigue loading.Worse yet,the downward flow of water through the crack interface was found to accelerate the shear fatigue degradation.The ex-perimental results are summarized and a simplified phenomenological model is proposed to quantify the degeneration of shear stiffness in terms of intrinsic accumulated normalized slip with respect to crack opening.