SHEAR STRENGTH AND THREE DIMENSIONAL FAILURE OF RC BEAM WITH SUFFICIENT SHEAR REINFORCEMENT

Abstract

The prevailing two dimensional truss model represents experimental results well when shear reinforcement yields. The model, however, has two weak points when shear reinforcement does not yield. First, flexual deformation of shear reinforcement affect shear failure after flexual yielding. Second, sub-ties affect shear strength before flexural yielding. This paper shows an analysis considering three dimentional failure and the upper bound theorem. The effect of sub-ties on shear strength is studied. The analytical strengths agreed with the experimental ones and with the shear strength equation presented in AIJ Design Guidelines (1997). The calculated three dimensional strain distribution also agreed with the observed crack pattern inside the specimens.