抄録
Inspection of reinforced concrete is important to ensure durability, and visual test is widely applied to the inspection. In this study, reliability on the result of the visual test for cold joint and sand streak was investigated, and it was clarified that error among the results of visual test comparing with photographs on questionnaires obtained by more than 100 students is fairly small. Then method to predict durability of reinforced concrete based on visual test results is proposed. The following (1), (2) and (3) are main conclusions.
(1) The error in visual test by the proposed method among inspectors is significantly small enough to inspect cold joint and sand streak, even when the inspectors are students who have no experiences.
(2) Relation between the visual test result for cold joint and the diffusion coefficient of chloride ion in hardened concrete is very close, so that the durability of reinforced concrete structure against chloride attack can be predicted based on visual test results. For a example, the method specified in Japan Society of Civil Engineers standard specification can be applied to the prediction.
(3) Relation between the loss of mass under freezing and thawing test and the result of visual test for cold joint and sand streak is close, so that the visual test can be an effective method to predict durability against freezing and thawing and also to judge the requirement for repair.
