| The authors attempted to clarify the durability of the adhesive properties of carbon fiber (CF) sheet reinforcements to concrete, and conducted outdoor exposure and adhesion tests with specimens. Four types of CF sheets were attached to the surfaces of concrete plates and exposed to the elements for 14 years in moderate climatic conditions. The specimens were evaluated mainly with a pull-off and a peel test. The results of the tests showed the following. Firstly, the pull-off adhesion strength of the specimens had decreased slightly in 14 years. However, the modes of failure of both the initial and the 14-year exposed specimens for the pull-off test were concrete substrate failures. Hence, the durability of the pull-off adhesive properties of the CF sheet reinforcements to concrete appears to have been sufficiently maintained for 14 years. Secondly, the configuration of the peel test was similar to actual debonding and the failure modes, unlike the pull-off test, were not limited to concrete substrate failures. Accordingly, the peel test may be a suitable method for evaluating these types of adhesive properties. |
