DURABILITY UPGRADE OF CONCRETE STRUCTURES USING HYDROPHOBIC IMPREGNAUT

本文研究了硅烷对混凝土结构的影响。通过测定小混凝土棱镜的重量变化率和浸渍深度，了解硅烷疏水效果的长期稳定性。此外，还测量了大断面混凝土不同深度的相对湿度和温度，以明确硅烷对混凝土结构实际尺度的影响。用所得试验结果模拟水在混凝土中的扩散。从这个项目中可以得出以下结论。(1)硅烷表面处理能在一定程度上长期降低碱-团聚体反应膨胀。然而，含有活性骨料和大量氯离子的混凝土，即使用硅烷处理也会发生膨胀。(2)当混凝土中氯离子含量较大时，硅烷表面处理会加速钢的腐蚀。硅烷处理不能降低钢的腐蚀。(3)有限元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天有效深度为50mm， 180天有效深度为200mm。从180天到360天，有效深度没有增加，到目前为止为200mm。硅烷表面处理对深度大于300mm的混凝土面积没有影响。

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.