Investigation on the behavior of CFRP-to-steel joint using carbon nanotubes modified epoxy adhesive

In this study, the bond characteristics between Carbon Fibre reinforced polymer (CFRP) laminates and steel with carbon nanotubes modified epoxy (CNT-epoxy) adhesive were studied. A series of experiments with double strap steel joints bonded with pure epoxy adhesive and/or CNT-epoxy adhesive were conducted. Experimental results presented in this paper include bond strength, failure modes, CFRP strain distribution and bond-slip relationship. The results show that failure mode in all specimens was a combination of steel-adhesive interface failure, cohesive failure, epoxy-CFRP interface failure and CFRP delamination. It was found that, CNT-epoxy is more efficient than pure epoxy to transfer the load from steel substrate to CFRP laminates. This paper provides an insight on the application of CNT-epoxy structural adhesive in the strengthening and rehabilitation of steel infrastructures using CFRP.