| Project/Area Number |
12650461
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
土木材料・力学一般
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
KAWAI Kenji Graduate School of Engineering, Hiroshima University, Associate Professor, 大学院・工学研究科, 助教授 (90224716)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2001: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2000: ¥2,700,000 (Direct Cost: ¥2,700,000)
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| Keywords | Cement / Municipal Solid Wastes / Chloride / Calcium Aluminate / Friedel's Salt / Fixation / Carbonation / Pore Solution / 塩化物含有量 |
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| Research Abstract |
The aim of this study is to investigate behavior of chloride in cement manufactured from municipal solid wastes (EC) during hydration and carbonation and to discuss on the applicability of this cement to reinfoced concrete members through the experiments regarding the relationship between chloride content of cement and steel corrosion.
EC whose target chloride contents were 0.05%, 0.07% and 0.1% were used as cement in addition to normal portland cement. Cement pastes with a water cement ratio of 0.40 were prepared for the analysis of pore solution and hydration products. Concretes with a water cement ratio of 0.60, where a D13 steel bar was embedded, were also prepared for an acceleration corrosion test (repetition of 3 day immersion in NaCl 3% solution and 4 day exposure in air)
From the results of pore solution composition analysis, most of chloride ions were fixed with cement minerals and/or cement hydration products within 1 day after mixing when EC was used, while most chloride ions were also fixed within 3 days after mixing when normal portalnd cement whose chloride content was equal to that of EC by adding NaCl was used. The ratio of chloride ion and hydroxide ion concentrations of pore solution was extremely lower than 3 to 5 that is said to be a threshold value of steel corrosion even when a specimen was carbonated. From the results of acceleration corrosion tests, steel corrosion derived from internal chloride could not be found when either of cement was used. In conclusion, it is thought that cement manufactured from municipal wastes has a capacity enough to fix internal chloride with cement mineral and/or cement hydration products.
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