DURABILITY UPGRADE OF CONCRETE STRUCTURES USING HYDROPHOBIC IMPREGNAUT

本文研究了硅烷对混凝土结构的影响。为了了解硅烷憎水效应的长期稳定性，测量了混凝土小棱柱的重量变化率和浸渍深度。此外，还测量了大截面混凝土几个深度处的相对湿度和温度，以了解硅烷对混凝土结构实际结垢的影响。试验结果被用来模拟水在混凝土中的扩散。从本项目中可以得出以下结论：(1)硅烷表面处理长期在一定程度上抑制了碱集料反应膨胀。但活性骨料和氯离子含量较高的混凝土经硅烷处理后仍会发生膨胀。(2)当混凝土中氯离子含量较高时，硅烷表面处理会加速钢筋的锈蚀。硅烷处理不能减少钢筋锈蚀。(3)有限元方法可以模拟混凝土截面硅烷表面处理的有效深度。模拟和实验结果表明，硅烷处理后60天的有效深度为50 mm，180天的有效深度为200 mm。经过180天至360天，有效深度没有增加，至今仍为200 mm。300 mm以下的混凝土区域不受硅烷表面处理的影响。

In this study, effect of silane for concrete structures was investigeted. Weight change ratio and impregnauting depth of small concrete prisms were measured to know long term stability of silane hydorophobic effect. In addition, relative humidity and temparature at several depth of concrete of large section were measured so that effect of silane for actual scale of concrete structure could be made clear. Obtained test results were used to simulate water diffusion in concrete. Following conclusions may be drawn from this project.(1) Alkali-aggregate reaction expansion was reduced to some extent in a long term by silane surface treatment. However, concrete with reactive aggregate and significant chloride ion could expand even if treated by silane.(2) Corrosion of steel was accelarated by silane surface treatment if chloride ion was included in the concrete significantly. Silane treatment can not reduce steel corrosion.(3) Finite element method can simulate effective depth of silane surface treatment in concrete section. The simulation and experimental results indicated that the effective depth was 50mm in 60 days after silane treatment, and 200mm in 180 days. After 180 days upto 360 days, the effective depth did not increase and was 200mm so far. The concrete area deeper than 300mm was not given any influences by silane surface treatment.