| 研究課題/領域番号 |
16K18130
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| 研究機関 | 埼玉大学 |
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研究代表者 |
欒 堯 埼玉大学, 理工学研究科, 助教 (20725288)
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| 研究期間 (年度) |
2016-04-01 – 2019-03-31
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| キーワード | bulk hydrophobicity / silicone oil / crack / water ingression / chloride penetration / strength / shrinkage |
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| 研究実績の概要 |
In FY2016, we prepared the hydrophobic mortar by adding a type of silicone oil as admixture. The agent was added by two methods, directly mixing into mortar, or spraying it on sand. A good water tightness under cracked condition, compared to normal or surface impregnated mortars, was experimentally confirmed by water absorption test and the contact angle. Furthermore, chloride penetration, under uncracked condition, was investigated by salt water absorption test. The hydrophobic mortar was found with a much lower chloride amount than the normal one, and the value was even almost zero in deeper layer.
On the other hand, strength and shrinkage of the mortar were also studied. Strength was found much lower than that of normal mortar. Analysis of chemical composition, by thermogravimetry and X-Ray diffraction revealed that the hydration degree was little influenced by the silicone oil. Therefore, the decrease of strength was attributed mainly to the increased air content, and weakened interface between sand and cement paste. Besides, the drying shrinkage and autogenous shrinkage of the hydrophobic mortar were found both lower than those of the normal one. This was hypothesized to be related to the changed capillary tension force caused by the higher contact angle, but further study is necessary.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
As written in the research plan, the hydrophobicity should be optimized, and water tightness under cracked condition should be studied by experiment. In the research work of FY2016, such studies for mortar specimens were carried out. A good water tightness under cracked condition was achieved, by adding a new type of hydrophobic agent, and conducting water absorption test. Also, chloride penetration of uncracked specimen was roughly studied, showing that the hydrophobic mortar had a good resistance to chloride. This makes a solid base for the research of FY2017, aiming to understand the chloride resistance under cracked condition. In addition, strength and shrinkage, which are also important properties, were discussed through experiment.
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| 今後の研究の推進方策 |
The research of FY2016 progressed rather smoothly as the plan. Therefore, as written in the plan, in FY2017, the main work will be focused on the permeability test, and the chloride ion penetration test under cracked condition. Furthermore, if this part processes smoothly, the influence of hydrophobic agent on shrinkage behavior will be elucidated experiment. The work in FY2018 will be focused on the numerical analysis of water transport and experiment of corrosion, as the original plan.
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| 次年度使用額が生じた理由 |
For some amount, it was planned to purchase a set of image analysis software to observe water morphology with microscopy. However, in FY2016, it was found that the purchased microscopy was sufficient to observe water droplet, even without appended image analysis software. Therefore, the purchase of software was not conduct.
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| 次年度使用額の使用計画 |
In FY2017, the experiment will be focused on water permeability test partially. To sustain a constant water head in the permeability test, small-scale water pumps are necessary. Therefore, according to the number of specimens in the permeability test, some small-scale water pumps will be purchased.
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