Punching strengths of flat plates with vertical or inclined stirrups

The shear reinforcement of flat plates involves problems in both design and execution. This paper introduces a novel form of inclined stirrups that is simple to make and to install, and reports the results of tests of slabs w ith such reinforcement. Companion tests of slabs without shear reinforcemen t and slabs with vertical stirrups are also reported. The inclined stirrups are shown to function well and produce punching resistances superior to th ose obtained with vertical stirrups. Comparisons are made between the exper imental results and predictions based on both ACI 318-95 and the CEB-FIP Mo del Code MC90 and proposals are made for improving the fatter design method .