2000 Fiscal Year Final Research Report Summary
Applicability of high carbon ferrochromium slag as an aggregate for ultra high strength concrete
| Project/Area Number |
09555135
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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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 Engrg., Professor, 工学部, 教授 (20019730)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAGUCHI Soytoaki NKK, Quality Assurance Group, Leader, 富山製造所, 室長(研究職)
IGARASHI Shin-ichi Kanazawa University, Civil Engrg., Assoc.Professor, 工学部, 助教授 (50168100)
TORII Kazuyuki Kanazawa University, Civil Engrg., Professor, 工学部, 教授 (50115250)
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| Project Period (FY) |
1997 – 2000
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| Keywords | high carbon ferrochromium slag / high strength concrete / RPC / late hydration / expansive pressure / volume stability / hydrothermal / tobermorite |
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| Research Abstract |
In order to use high carbon ferrochromium slag as an aggregate for ultra high strength concrete, mineralogical compositions of the slag and its alkali reactivity in cementitious matrix are investigated. Effects of its reactivity and surface texture on mechanical properties of high strength mortars and RPC (Reactive Powder Concrete : ultra high strength concrete) were investigated in terms of characteristic microstructures and microscopic failures. The major outcomes in this study are as follows.
(1) The high carbon ferrochromiurn slag has the potential reactivity with cement paste matrix.
(2) The reaction of the slag with alkaline cement matrix does not result in the deterioration of concrete due to alkali silica reaction.
(3) The reaction and rough texture of the slag particles contribute to the increase in bond strength and crack growth resistance.
(4) When silica fume mortars with an extremely low water/binder ratio were cured in water, shrinkage and swelling occurred simultaneously.
(5) Generation of internal expansive pressure due to the late cement hydration should be taken into account as a mechanism to cause maicrocracks in mortars with low water/binder ratios.
(6) The slag can be used as an aggregate for ultra high strength concrete. However, the optimum mix proportion and the thermal treatment for the concrete with the slag may be different than those for concretes with natural aggregates. Dissolution of silica in the slag affects the growth of crystalline reaction products and their morphology.
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Research Products
(16 results)
