Bond behavior of interface between CFL and concrete under static and fatigue load

This paper presents a study on the static and fatigue bond behaviors of the bonded interface between carbon fiber laminate (CFL) and concrete by using double-shear tests. 20 specimens (100 × 100 × 520 mm) were constructed and tested. The variables in the test were: the type of load applied (monotonic or fatigue loading), bond length, CFL width, bond thickness, and different fatigue load levels. Strain gauges bonded along the CFL surface and linear variation displacement transducers (LVDTs) were used to measure longitudinal strains and slip of the interface. The relative slip evolution curves of the CFL-concrete bonded interface under fatigue load were presented, and its strain distributions and bond-slip behavior were analyzed. The fatigue experimental results showed that under the fatigue load, the strain evolution in the CFL and the relative slip of the specimens consisted mainly of three steps: the early rapid development step, the stable step and the instable failure step. The cycle number in second step lasts 95% of the total number of fatigue life cycle. Finally, a fatigue damage model of the CFL-concrete interface is proposed based on the test results presented in this paper.