2003 Fiscal Year Final Research Report Summary
Alkali Silica Reaction in Concrete Using a New Portland Cement Made from Municipal Waste Incinerator Ash
| Project/Area Number |
14550463
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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 | Kanazawa University |
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Principal Investigator |
KAWAMURA Mitsunori Kanazawa University, Civil Eng., Professor, 工学部, 教授 (20019730)
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| Co-Investigator(Kenkyū-buntansha) |
IGARASHI Shin-ichi Kanazawa University, Civil Eng., Assoc.Professor, 自然科学研究科, 助教授 (50168100)
TORII Kazuyuki Kanazawa University, Civil Eng., Professor, 工学部, 教授 (50115250)
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| Project Period (FY) |
2002 – 2003
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| Keywords | Alkali Silica Reaction / Waste glass / Lithium Ions / Expansive Pressure / Expansion / 膨張圧 / 等価アルカリ量 / リサイクル |
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| Research Abstract |
The results obtained in this study are as follows ;
(1)Measured expansions due to the alkali silica reaction in mortars containing a crushed bottle glass aggregate were far greater than in mortars made with the Pyrex glass aggregate.
(2)The lithia glass powder was conspicuously effective in the suppression of the alkali silica reaction as compared with the bottle glass powder. Great reduction in expansion with the addition of the lithia glass powder appear to be derived from the nature of the glass powder as a pozzolan and the lithium released from the glass.
(3)The addition of as much as 20% fly ash completely suppressed ASR expansion even in high alkali cement mortars with the crushed bottle glass aggregate.
(4)The expansive pressure generated under longitudinal restraint was in proportion to free expansion except that the 15% calcined flint-containing mortars with a high Na2Oe of 2.0 and 2.5% showed high expansions, but low expansive pressures. This exceptional behavior of the alkali-rich mortars appears to be due to the production of alkali-rich ASR gels.
(5)The results obtained in the expansive pressure experiment suggest that, even if concretes containing ASR gels with a high alkali content exhibit great expansions in laboratory expansion tests, damages due to secondary stresses induced by the expansive pressure in concrete members under restraint may not be significant.
(6)The intrusion of lithium ions into mortar with a reactive aggregate could arrest the expansion of mortars shortly after immersion in 0.5 N LiOH solution.
(7)Expansion of mortars started decreasing earlier in mortars pre-cured in sealed in vinyl sacks for longer periods.
(8)The alkalis in most ASR gels not far from interfaces between the cement paste and reactive aggregate particles appear to be replaced by the lithium ions supplied from the external solution
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