SHEAR FORCE AND CAPACITY IN REINFORCED CONCRETE BEAMCOLUMNJOINTS WITH GOOD BOND ALONG BEAM AND COLUMN BARS

摘要

The effect of good bond along beam and column bars within a joint on shear strength in reinforcedconcrete interior beam-column joints was investigated. Five interior beam-column joint specimens withone-half scale were tested. The bond along beam and column bars within a joint and loading history werechosen as the test parameters. All specimens eventually failed in joint shear. To study on horizontal andvertical shear forces input to joint panel, concrete compressive stress distributions acting on beam andcolumn critical sections were researched through measuring concrete normal strains by gauges stuck onbeam and column surfaces. The depth of the concrete compressive zone at beam and column criticalsections exceeded a half of the beam and column depth respectively. This means that all concretecompressive force at critical section is not necessarily introduced to joint panel as a shear force. Thedecrease in either horizontal or vertical joint shear force, which was computed using measured tensileforces of steel bars and accounting for non-contribution of the concrete compressive force to joint shear,resulted in the degradation of story shear force.