Effective Splices for a Carbon Fiber–Reinforced Polymer: Strengthening System for Steel Bridges and Structures

Carbon fiber–reinforced polymer (CFRP) materials have been used successfully to strengthen reinforced concrete bridges and structures. Recently, a new high modulus CFRP strengthening system was developed to increase the allowable load carrying capacity and to enhance the serviceability of steel bridges and structures. Because of the relatively high flexural rigidity of the CFRP materials, the length of the CFRP plates that can be transported to the job site is limited. To implement the proposed strengthening system in longer-span steel bridges, adjacent lengths of CFRP must be spliced. To develop an effective splice joint for the proposed strengthening system, an experimental and analytical research program was conducted to study the bond behavior of the CFRP materials. The parameters considered included plate end geometry, splice length, and the possibility of using mechanical anchorage. The analytical study included a finite element analysis to determine the distribution of the stresses within the adhesive layer for different splice configurations. On the basis of the findings, a simplified method was proposed to design lap splice joints with different reversed taper angles and adhesive properties. The research concluded that, with proper detailing, the proposed CFRP system could be effectively used to strengthen steel bridges and structures.