Fatigue properties of shear–peeling debonding between CFRP plates and concrete

This paper presents a study of the fatigue bond behaviour of the bonded interface between carbon fibre reinforced polymer (CFRP) plates and the concrete surface in double-lap shear tests. In total, 12 specimens were constructed and tested. The variables in the test were concrete compressive strength, initial angle of attachment at the specimen centre and different fatigue load levels. Strain gauges were bonded at 50 mm intervals along the CFRP plate surface, and linear variable displacement transducers were used to measure the longitudinal strains and displacements between the CFRP plate and the concrete substrate in longitudinal and perpendicular directions. The relative slip evolution curves of the CFRP plate–concrete bonded interface under fatigue load were calculated and the strain distributions and bond–slip behaviour were analysed. Fitting of the S–N curve showed no influence on fatigue life corresponding to the initial angle induced by fast peeling by peel and shear. The results predicted using the fatigue local bond–slip model were found to agree with the test results.