2002 Fiscal Year Final Research Report Summary
Study on Flow Simulation Method of Fresh Concrete
| Project/Area Number |
13450220
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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 |
Building structures/materials
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| Research Institution | Nagoya University |
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Principal Investigator |
TANIGAWA Yasuo Nagoya Univ., Graduate School of Environmental Studies, Professor, 環境学研究科, 教授 (70023182)
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| Co-Investigator(Kenkyū-buntansha) |
KUROKAWA Yoshiyuki Nagoya Univ., Graduate School of Environmental Studies, Research Assoc., 環境学研究科, 助手 (50242839)
MORI Hiroshi Nagoya Univ., Graduate School of Environmental Studies, Assoc.Professor, 環境学研究科, 助教授 (80157867)
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| Project Period (FY) |
2001 – 2002
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| Keywords | Shear Box Test / Yield Value / Shear Strain Dependent Property / Viscoplastic Finite Element Method / Shape of Aggregates / Viscoplastic Suspension Element Method / Rotational Motion / Virtual Radius of Coarse Aggregate Node |
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| Research Abstract |
The results obtained in this research on the flow simulation method of fresh concrete are summarized as follows :
1. Measurement and Modeling of Rheological Properties by Shear Test
The shear box test, which can be applied to the wide range of rheological properties from wet-mixed to relatively dry-mixed concrete, has been improved. Small sized shear box test was designed for the sake of simple measurement, and the counter weight, which is the cause of influence of inertia, was removed. According to the results of measurement with cement paste and mortar, the shear strain dependent properties of materials were verified especially for the addmixing of fine aggregate or segregation control agent.
Furthermore, according to the result of flow simulation by viscoplastic finite element method with the shear strain dependent model, the phenomenon of shear strain hardening was represented.
Moreover, the influence of pressure or transition was discussed and modelized.
2. Improvement of Flow Simulation by Viscoplastic Suspension Element Method (VSEM)
First of all, VSEM was improved for consideration of rotational motion. According to the result of flow simulation, the evaluation considering rotational motion for the friction on walls and the blockage in narrow space was verified
Furthermore, the virtual radius for 2-dimensional coarse aggregate nodes was introduced in order to let the matrix flow out through a couple of blocking coarse aggregates. According to the result of simulation of segregation test, the change of amount of flow out mortar with mix proportion was represented.
Moreover, the connected aggregate nodes with aggregate suspension elements was introduced in order to discuss the shape of aggregates. According to the result of 2-dimensional simulation of L-flow test, it was clarified that the influence of the shape of aggregates increases with decrease of yield value and plastic viscosity.
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