INCLINED STIRRUPS AND INCLINED STUD SHEAR REINFORCEMENT IN ZONES OF HIGH SHEAR

摘要

Inclined shear reinforcement affects the response to shear in reinforced and prestressed concrete members in two ways: it increases the capacity to resist shear and reduces the width of the shear cracks. The increase in shear resistance is the result of the decrease in the compressive stress in the diagonal compression struts - theoretically up to fifty percent - relative to beams with vertical stirrups. The reduction in crack width stems from the interception of the inclined shear cracks by the stirrups approximately at right angle. Associated with the reduced compressive stress in the concrete struts and the smaller crack widths is a reduction in shear deformation, which can be important for heavily loaded transfer girders or deep beams. For the understanding of the internal mechanism in concrete members with inclined shear reinforcement the paper first presents theoretical aspects for beams and relevant experimental verification from the literature, which confirm the above statements. This is followed by evidence from recent tests on punching shear in two-way slabs that the use of inclined headed stud shear reinforcement (HSSR) also increases the punching capacity of slabs.