Interfacial Interaction of CFRP Reinforced Steel Beam Structures

Abstract

Due to the increase of service life, the phenomenon of performance degradation of bridge structures becomes more and more common. It is important to strengthen the bridge structures so as to restore the resistance level and extend the normal service life. Carbon fiber reinforced polymer (CFRP) materials are thus used for the assembly reinforcement of bridges for the advantages of high strength, light weight, corrosion resistance and long-term stability of physical and chemical properties, etc. In view of this, based on the previous theoretical study and the established formula of the interfacial shear stress of CFRP reinforced steel beam and the normal stress of CFRP plate, this paper discusses the sensitive parameters that affect the interfacial interaction of CFRP strengthened beam structures. Through the analysis, the priority design indicators and suggestions are accordingly given for the design of reinforced beam structures. Young’s modulus of CFRP composite and shear modulus of the adhesive have the greatest influence on the interfacial interaction, which should be carefully considered. It is suggested that CFRP material with Ec close to 300 GPa and thickness no less than 3 mm, and adhesive material with Ga less than 5 GPa and 3-mm thickness can be adopted in CFRP reinforced steel beam. The conclusions of this paper can provide guidance for the interfacial damage control of CFRP reinforced steel beam structures.