1995 Fiscal Year Final Research Report Summary
Fundamental Study on the Prediction of Residual Expansion of ASR Deteriorated Concrete
| Project/Area Number |
06650497
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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 |
土木材料・力学一般
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| Research Institution | Kanazawa University |
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Principal Investigator |
KAWAMURA Mitsunori Kanazawa University, Department of Civil Engineering Professor, 大学院・自然科学研究科, 教授 (20019730)
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| Co-Investigator(Kenkyū-buntansha) |
TORII Kazuyuki Kanazawa University, Department of Civil Engineering Associate Professor, 工学部, 助教授 (50115250)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Alkali-Aggregate Reaction / NaCl / Residual Expansion / Accelerated Test / Pore Solution / Concrete Core |
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| Research Abstract |
The results obtained are diveded into the following two category.
(I) Expansion behavior of concrete cores drilled from the existing ASR deteriorated concrete structures under the two curing conditions and (II) Discussion on the significance of the accelerated testing from the viewpoint of the relation between the expansion of reactive aggregate-containing mortars and pore solution composition. The results of the foamier are summarized as follows ; (1) Relatively large amounts of chloride existed in the ASR deteriorated concrete structures. The chloride may come from NaCl used as a deicing agent.(2) The residual expansion of ASR affected concrete can be predicted during shorter periods by the Danish method than by the usual accelerated testing.(3) The discrimination between ASR affected concretes with and without residual expansiveness is more sharply defined by the Danish method than the usual accelerated testing. The results of the latter are summarized as follows ; (1) OH-ion concentration in the pore solution in mortars immersed in the saturated NaCl solution rapidly increased immediately after immersion. The maximum OH-ion concentration was proportional to the alkali content in the mortars.(2) Expansions of mortars containing reactive flint immersed in the saturated NaCl solution were as large as approximately twice those of the corresponding mortars under a moist environment in the usual accelerated testing. The correlation between both was very good.
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