2018 Fiscal Year Final Research Report
Acceleration of calcium leaching in concrete and evaluation of the influence on mechanical properties
| Project/Area Number |
16K06446
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Civil engineering materials/Construction/Construction management
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| Research Institution | Hokkaido University of Science |
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Principal Investigator |
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| Research Collaborator |
Schwotzer Matthias
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Keywords | 凍結防止剤 / カルシウム溶脱 / EPMA / 断面分割法 / ヤング係数 / 曲げ強度 |
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| Outline of Final Research Achievements |
In order to investigate the effect of various deicing agents to promote calcium leaching, the immersion test was carried out. It was shown that the degree of calcium leaching was different depending on the deterioration of the hardened cement paste surface. Based on this result, the bending test of hardened cement paste which caused calcium leaching was conducted. After that, chemical analysis of hardened cement paste was carried out to investigate the calcium concentration on the cross section. Then, using a statistical method, the calcium concentration distribution was modeled. Furthermore, the modeling results were used for numerical analysis, and the influence of the decomposition of calcium hydroxide and calcium silicate hydrate, which are the main compounds of the hardened cement paste, on the mechanical properties was discussed.
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| Free Research Field |
コンクリート工学
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| Academic Significance and Societal Importance of the Research Achievements |
ヨーロッパでは，放射性廃棄物の地層処分として岩塩坑が使われることがあり，各種の塩がカルシウム溶脱を促進する作用について様々な研究が行われている．一方，日本において，構造物が各種の塩の水溶液に曝されるのは寒冷地に限定される．すなわち，凍結防止剤が溶けた水に曝される道路構造物である．それらの劣化は凍害として扱われることが多く，カルシウム溶脱の影響はさほど重視されていないと思われる．本研究の成果は，寒冷地の道路構造物の補修計画に対して，カルシウム溶脱の影響を考慮する一助になったと考える．
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