1996 Fiscal Year Final Research Report Summary
Basic Study on the Detriment of Durability and Superficial Condition of Concrete Structures Due to Environmental Pollution by Acid Attack
| Project/Area Number |
06805039
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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 | Kagoshima University |
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Principal Investigator |
MATSIMOTO Susumu Kagoshima University Faculty of Engineering, Professor, 工学部, 教授 (00041567)
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| Co-Investigator(Kenkyū-buntansha) |
TAKEWAKA Koji Kagoshima University Faculty of Engineering, Associate Professor, 工学部, 助教授 (10155054)
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| Project Period (FY) |
1994 – 1996
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| Keywords | Concrete Structure / Environmental Pollution / Acid-Rain / Durability / Superficial Condition / Neutralization of Concrete / Corrosion of Reinforcement / Coating of Concrete Surface |
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| Research Abstract |
In this study, the influence of acid-rain on the deterioration of concrete structures was mainly examined by using both the exposure test in the environment affected by acid-rain originating from the volcanic emission and the deterioration-accelerating test which is newly developed. And the effectiveness of the surface-coating on concrete for preventing the deterioration due to the acid-rain was also clarified. The main results of this study are as follows ;
1. Influence on the superficial condition of concrete
(1) The concrete surface grows yellowish due to the attack of acid-rain originating from volcanic emission and having pH 4.0 or less.
(2) The black colored stains on concrete surface, mainly caused by the mold, is less in the acid-rain environment rather than in the normal rain having pH 5.0 or more.
2. Influence on the durability of concrete structure
(1) The acid rain affects at the early stage of neutralization of concrete but diminish in the long-range.
(2) The influence of the ac
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id-rain on the neutralization of concrete is relatively larger on newly built concrete structures than on the old structures in which concrete has already been neutralized.
(3) The acid rain surely accelerates the corrosion of reinforcing bar in concrete.
3. Effect of coating of concrete surface on prevention against the acid-rain attack
(1) The surface treatment with the water repellent type of impregnant is ineffective on the detriment of neutralization of concrete but effective on the corrosion protection of reinforcement.
(2) Epoxy resin coating on concrete surface has high possibility for the prevention against both the neutralization of concrete and the corrosion of reinforcement, though the surface deterioration of the coating is slightly accelerated by the acid-rain. However, if the coating does not have the proper ductility for following the concrete cracks, the prevention effect of the coating, mentioned above, remarkably decreases at the crack portion, especially under the acid-rain environment. Less
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Research Products
(6 results)
