Static behaviour of steel plate-strengthened reinforced concrete slabs in bending

This paper reports on an investigation on a Reinforced Concrete (RC) strengthening technique carried out by the authors, using Surface Bonding Steel Plates (SBSP). To accomplish this investigation, the tension face of one-way spanning RC slabs was scabbled and bonded with one or two sandblasted steel plate(s) of different thicknesses, using epoxy glue. The steel plate thicknesses were varied in order to determine the width-to-thickness ratios that can promote yielding (and not premature debonding) of the RC slabs before failure. A low flexural reinforcement percentage (≈ 0.314% bh) was used in order to prevent over-reinforcement and to ensure that failure of the slabs under static loading was due to flexure. Static two-point line loading was adopted to simulate the worse loading condition. Based on the deformation response of the slabs, the most appropriate parameters of the steel plates, for strengthening distressing reinforced concrete slabs were determined. The SBSP strengthening technique was found to possess effective composite properties as all the strengthened RC slabs failed essentially by flexural yielding before steel plate separation, with enhanced load carrying capacity of at least 89% above that of control slabs.