Bahavior of Reinforced Concrete Flat Plate with Shearhead Reinforcement

An experimental investigation was presented to evaluate static and repeated response of flat plate slabs reinforced by shearhead system. Fifteen panels were cast and tested under centrally point load. The slabs were geometrically similar (1000x1000x80) mm. The studied parameters are divided into shape of shearhead, section depth of shearhead, diameter of shearhead and number of stiffeners. The experimental results indicated that using square shearhead achieved slight increase in punching shear strength about 3% over that circular shearhead with same surface area. When increase the section depth of shearhead is increased from 30 mm to 40mm, the punching shear strength was increased about 32.7%. Increasing the number of stiffeners from one stiffener to two stiffener results a decrease in punching shear strength by about 20.3%. Under repeated load testing, there was an increase in punching shear strength when using shearhead reinforcement with 25%. When comparison between static and repeated load test was made, there was an increase in stiffness and ductility in specimens tested under static loading than specimens tested under repeated load.