Retrofitting of Corrosion Effected Steel Bridge Members using Steel – CFRP Bonding Systems
Keywords:
Control beams, CFRP strengthened beams, ultimate load, extreme exposure, wetting-drying cycles and epoxy adhesive.Abstract
Most steel bridges need strengthening either due to prolonged exposure to severe corrosive environments or increase of live load in due course of time or to improve fatigue performance. The current techniques of retrofit of steel structures need heavy equipment and skilled manpower for installation/implementation of them. The use of fibre reinforced polymer sheets for repair and strengthening of RCC structures is well recognised but the relevance of FRP composites to steel structures has been limited. The use of FRP materials for the repair and rehabilitation of steel members has abundant benefits over traditional method of retrofit by bolting or welding of steel plates. Carbon Fibre Reinforced Polymers (CFRPs) have been preferred over other FRP materials for strengthening of steel structures due to higher stiffness of the former. The emergence of high modulus CFRP plates, which have elastic modulus higher than or comparable to that of steel is helpful in considerable load transfer from steel beams, prior to the yielding of steel. In CFRP strengthened structure, the behaviour of bonding joints between CFRP and steel plays a very important role. In CFRPsteel bonding, the weak link is epoxy adhesive.
In the present study, feasibility and effectiveness of adhesively bonded Carbon Fibre Reinforced Polymer (CFRP) sheets in retrofitting of steel member, with and without end anchor plates, affected by corrosion to be used in bridges, has been determined along with short term effect of further corrosion in extreme exposures.
