Experimental study on the shear behavior of RC beams strengthened with cementitious grout

Strengthening the existing damaged RC beams with a layer of cementitious grout can effectively overcome the limitations of the conventional concrete-replacement method, which has been considered as an effective way to improve the performance of damaged RC beams. This study presented an experimental study on the shear behavior of 24 RC beams strengthened with cementitious grout. The effects of replacement positions, replace-ment thicknesses, and shear span to effective depth ratios on the shear behavior of the strengthened beams were discussed. Results indicate that (1) No obvious bonding cracks and peeling failures were observed at the interface between the cementitious grout and concrete. (2) Compared with the beams strengthened on the compressive side, the beams strengthened on the tensile side had a smaller load and deflection index value, which indicated that the beams strengthened on the compressive side had a better reinforcement effect than those on the tensile side. (3) With the increase of the replacement thickness, the load and deflection index value of the specimens with different shear span to effective depth ratios increased gradually, and the increment decreased with the increase of the shear span to effective depth ratio. (4) Calculation methods were proposed to evaluate the shear capacity of RC beams strengthened with cementitious grout based on Code GB 50010-2010 and the truss-arch model, respectively, and verified well with experimental data.