Effects of applied environmental conditions on the pull-out strengths of CFRP-concrete bond

This paper presents observation and results of an experimental study undertaken to investigate the time dependant behaviour of bond between external Carbon Fibre Reinforced Polymer (CFRP) reinforcement and concrete subjected to temperature cycles, wet-dry cycles and outdoor environment separately. Single shear tests (pull-out test) were conducted to investigate bond strengths (pull-out strengths) of control (unexposed) and exposed specimens. Based on the results, the most significant degradation of bond strength was observed in specimens exposed to outdoor environment, whereas no significant deterioration due to temperature cycles was found probably due to the nature of applied cyclic temperature where the temperature was below the glass transition temperature of epoxy resin and the difference between the upper and lower boundary of the temperature envelope was small.