Behavior of two-way RC slabs externally bonded with steel plate

Although a great deal of research has been carried out in recent years on the use of plate bonding for strengthening reinforced concrete (RC) structures, so far this work has generally been limited to RC beams and one-way slabs, with little work on two-way slabs. This paper presents the results of a recent study on the behavior and strength of two-way square RC slabs bonded with a steel plate. Experimental load-deflection curves, failure modes, and strengths of plated slabs under a central concentrated load are first reported. These results show that debonding failures are unlikely in these plated slabs, contrary to the case of plated beams, and there are significant strength gains due to the bonded steel plate as a result of a modified yield line pattern. Yield line analyses are then described for these slabs, and the results are found to match experimental results closely. The yield line method is thus suitable for practical use to determine the strength of these plated slabs.