2007 Fiscal Year Final Research Report Summary
Study on practical system for production and construction of high-performance concrete with help of visualization technique of fresh concrete
| Project/Area Number |
17360205
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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 | 一般 |
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| Research Field |
Civil engineering materials/Construction/Construction management
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| Research Institution | The University of Tokushima |
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Principal Investigator |
HASHIMOTO Chikanori The University of Tokushima, Institute of Technology and Science, Graduate School, Professor (10180829)
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| Co-Investigator(Kenkyū-buntansha) |
MIZUGUCHI Hiroyuki The University of Tokushima, Institute of Technology and Science, Graduate School, Professor (00035651)
UEDA Takao The University of Tokushima, Institute of Technology and Science, Graduate School, Associate Professor (20284309)
WATANABE Takeshi The University of Tokushima, Institute of Technology and Science, Graduate School, Assistant Professor (50332812)
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| Project Period (FY) |
2005 – 2007
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| Keywords | Concrete mixer / Visualization technique / Shear flow / Recycled aggregate concrete / High strength concrete / High performance concrete / Pressure fluctuation / Angle of the blade installed to axis |
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| Research Abstract |
A purpose of this study is to develop the practical system for production and construction such as concrete mixer, concrete agitator and concrete punping machine in order to spread the use of high performance concrete such as high strength concrete, high durable concrete or high-fluidity concrete. After carrying on the investigation, we decided to develop the high performance mixer for manufacturing high strength concrete having more than 100N/mm2 of compressive strength, high durable concrete having more than 200 years of life time or high-fluidity concrete with the self-compacting ability of Rank 1. The bi-axial forced-mixing type of kinds of the mixer is high and the mixing efficiency is the highest. The flow patterns of the bi-axial forced-mixing type mixer are divided into two: the locally crossing flow and the globally circulating flow. We have developed and proposed a visualization technique that makes it possible to measure the degree of mixing with lapse time. At first a model
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concrete was assumed to be a viscous model of one phase system for the model mixer of two types with different area of the locally crossing flow, the mixing efficiency curve of the model concrete of the high viscosity and the low viscosity was a process of becoming uniform with the axial rotation, and quantification was attempted. Secondly we tried the quantification of the crossing flow around the blade generated when two circulating flows crossed by the pressure fluctuation of the pressure sensor installed in the surface of the blade of the mixer was attempted, and the size of the crossing flow generated in the model mixer of two types and the correlation of the mixing efficiency curve were considered. Thirdly we developed the new bi-axial forced-mixing typemixer with oscillation of mixture and mix proportion design based on mix proportion of high strength concrete are carried out to investigate the possibility for increasing properties and durability of concrete incorporating low quality recycled aggregate. As the results of this study, the mixing method with oscillation of mixture has effect on the concrete using low quality recycled aggregate to increase about 20% of compressive strength. Less
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