Bond and Splice Behavior of High Modulus Cfrp Materials Bonded to Steel Structures

Research on the use of CFRP materials for retrofit and strengthening of steel bridges and structures has increased in recent years. In order to implement these types of strengthening systems to longer span members, it is important to establish an effective method to splice adjacent lengths of CFRP laminates. This paper describes an experimental program to investigate the bond behavior of carbon fiber reinforced polymer (CFRP) laminates with the objective of developing an effective bonded splice joint. The experimental program was conducted in two phases. In the first phase, the effectiveness of three different CFRP splice joint configurations was evaluated using double lap shear coupon tests. In the second phase, steel beams were strengthened with CFRP laminates which incorporated a bonded splice joint located at the midspan of each of the beams. The test results demonstrate that debonding of the CFRP splice plate was the primary mode of failure for the tested joints. The research also indicated that the use of a reverse tapered joint configuration can significantly increase the splice joint capacity. The findings indicate that careful detailing can significantly increase the capacity of bonded CFRP splice joints.