Contrast experimental effect between flexural member strengthened with bonding steel plate or CFRP

The effects of two strengthening methods were analysised based on comparing the midspan deflections and the strain changes of original tensile reinforcement, later bonded steel plate or CFRP, original concrete superface and later added concrete superface with bending moment, through two groups of reinforcement testing that simple supported RC beams were preloaded to cracking under the same conditions, and then reinforced by bonding steel plate or CFRP on the tensile side and increasing section area on the pressure side. The results show that the strengthening of bonding steel plate is obviously superior to bonding CFRP in the improvements of the old and new material stress, the beam stiffness and the bending capacity, so the latter is fit for anti-cracking reinforcement, not for the strengthening of increasing bending capacity or resistance to deformation capacity. On the other side, the strengthening of bonding steel plate by daubing is inferior to bonding CFRP in inhibiting cracks development. As to the balanced-reinforced beam, the high strength of fiber is hardly play.