2022 Fiscal Year Final Research Report
Creation of high strength concrete secondary products by low temperature autoclave curing
| Project/Area Number |
19K15063
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| Research Category |
Grant-in-Aid for Early-Career Scientists
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| Allocation Type | Multi-year Fund |
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| Review Section |
Basic Section 22010:Civil engineering material, execution and construction management-related
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| Research Institution | Nihon University |
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Principal Investigator |
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| Project Period (FY) |
2019-04-01 – 2023-03-31
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| Keywords | オートクレーブ養生 / 遠心成形 / シリカフューム / メチルセルロース / スラッジ / 高強度コンクリート |
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| Outline of Final Research Achievements |
Autoclave curing is usually performed at 180℃ for manufacturing high strength precast concrete products. The current research is aimed at establishing a new technique of autoclave curing at a reduced temperature of 150℃. In association with the addition of silica fume to enable the low temperature autoclave curing, an experimental study was performed with focus on suppression of material segregation and reduction of sludge generation during centrifugal molding. It was found that adding 2.5% silica fume and 0.01% methyl cellulose resulted in both high strength development and reduction in sludge generation and density by the effect of methyl cellulose. However, there was a large variation in the compressive strength of the specimens after autoclave curing following centrifugal molding. This was likely because methyl cellulose was exposed to high temperatures before it decomposed.
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| Free Research Field |
土木材料
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| Academic Significance and Societal Importance of the Research Achievements |
本研究は，高強度コンクリート二次製品の製造に用いられている180℃のオートクレーブ養生を150℃に低温化した新しい養生技術の実用化を目的としたものである。これを実現可能とするシリカフュームの添加に伴う遠心成型時の材料分離抑制ならびにスラッジ発生量低減に着目した実験を行った。その結果，シリカフュームは2.5%，メチルセルロースは0.01%添加した場合において高い強度発現性が得られたとともにメチルセルロースによるスラッジ発生抑制や密度低下の効果が認められた。しかし，遠心成形後のオートクレーブ養生後の圧縮強度はばらつく結果となった。これは，メチルセルロースが分解前に高温履歴を受けた影響と推察した。
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