建築用外装仕上材の中性化抑制効果の評価方法および評価基準に関する研究

In this study, we examined the evaluation method and evaluation criteria for evaluating the carbonation suppression effect of finishing materials used for the exterior of reinforced concrete buildings, and obtained the following findings. For 17 types of finishing materials with different materials and specifications generally used for the exterior of reinforced concrete structures, accelerated carbonation test are conducted up to the age of 52 weeks of test materials, and the carbonation ratio of each was determined. For finishing materials with a large carbonation ratio, it was confirmed that the carbonation ratio tends to increase with the passage of the test time. As a test method for evaluating the carbonation-suppressing effect of finishing materials, we improved the test method by Kawamura et al. We proposed the manufacturing method of the specimen and test container, the test procedure, the calculation method of the test time and the test result, and measured the carbon dioxide transmission rate of each finishing material. The relationship between the carbonation ratio and carbon dioxide transmission rate was obtained, and it was confirmed that there was a strong positive correlation between the two. It was also confirmed that even if the same material is used, the carbon dioxide transmission rate may increase if the construction specifications are inappropriate. The carbon dioxide transmission rate was measured after the accelerated weathering test. According to the results of this study, the carbon dioxide transmission rate of the thin coating E is large even when the xenon lamp is not irradiated, and it does not change significantly even after the irradiation. Carbon dioxide transmission rate did not increase in the range where continuity was maintained, but for gloss paint, signs of deterioration of the coating film were confirmed at an irradiation time of 2500 hours. Based on the results of the past outdoor exposure test, the evaluation criteria of the carbonation suppression effect considering the influence of deterioration of the finishing material were examined, and as a finishing material having the carbonation suppression effect shown in JASS 5. We proposed that the carbon dioxide transmission rate was 0.5 [mol/(m²･24h)] or less.