Preventive Measures and Mechanisms of Concrete Deterioration due to ASR under Marine Environments
| Project/Area Number |
02650333
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
コンクリート工学・土木材料・施工
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| Research Institution | Kanazawa University |
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Principal Investigator |
KAWAMURA Mitsunori Kanazawa Univ., Faculty of Technology, Professor, 工学部, 教授 (20019730)
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| Co-Investigator(Kenkyū-buntansha) |
IGARASHI Shinichi Kanazawa Univ., Faculty of Technology, Research Associate, 工学部, 助手 (50168100)
TORII Kazuyuki Kanazawa Univ., Faculty of Technology, Associate Professor, 工学部, 助教授 (50115250)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1991: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1990: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Ettringite / Expansion / Exposure Tests / Opal / Alkali-Silica Reaction / Pore Solution / エトリンガイト / 屋外および海岸暴露試験 / 塩化物の影響 / 膨張挙動 / ひびわれの解析 / 細孔溶液の組成 |
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| Research Abstract |
The results obtained in this fiscal year are divided into the two categories, i. e. the one on the reaction products and expansion behavior in opal-bearing mortars immersed in NaCl solutions and an artificial sea water, exposed to a marine environment.
The major results obtained in the former experiments are summarized as follows ;
(1) Great amounts of Ca (OH)2 in all mortars with the opal were dissipated during the immersion in 1 N NaCl solution.
(2) Great amounts of the chloride-bearing ettringite was found in the portions as well as in voids in opal-bearing mortars immersed in 1 N NaCl solution for longer than one vear. It is likely that the greater the expansion of mortars, the greater the amount of ettringite found in the mortars.
(3) The concentration of NaCl solution in which mortar specimens were immersed, greatly influenced the expansion of mortars with relatively low alkali/opal ratio. However, in the range of high alkali/opal ratio, the concentration of the NaCl solution little influenced the expansion of the mortars.
The following new findings were obtained in the latter experiments which have been successively carried out for these several years.
(1) Rapid expansions occurred on the exposed surfaces in reactive aggregate-bearing concrete specimens with the unit cement content of 450kg/cm3. This fact suggests that spray of sea water is influencing the expansion of the concrete due to the alkali-silica reaction.
(2) There is found a trend that the less the alkali content in the concretes, the greater the expansion of the concretes exposed to the marine environment.
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Report
(3 results)
Research Products
(14 results)
