INFLUENCE OF INSUFFICIENT BOND LENGTH OF CFRP BONDED STEEL PLATE ON STRENGTHENING EFFECT

Abstract

 As a repair and strengthening method for steel structures, a method of bonding CFRP with resin has begun to be applied. Generally, in the CFRP bonding method, since the steel and the CFRP are designed on the premise of behaving as a complete composite in section, bonding lengths for transmitting loads to the CFRP are required on both sides. In some cases, the required bonding length becomes longer due to the rigidity of the CFRP layer, the thickness and the shear modulus of elasticity of the adhesive layer. In addition, corrosion of steel bridges often occurs in narrow parts and complicated shapes parts, and in some cases, it is difficult to secure required bonding lengths on both sides of the section to be reinforced.

 In this research, the authors focused on the case which the required bonding lengths cannot be obtained to be a complete composite in section, the tensile tests were conducted on the test specimens in which CFRP was adhered to a steel plate with insufficient bond length, and the influence on reinforcing effect was investigated. In addition, the experimental value compared with the theoretical value and proposed method of determining the reinforcement amount when the bond length is insufficient.