1994 Fiscal Year Final Research Report Summary
Fundamental Study on Flow and Settling Characteristics of Clay Suspensions.
| Project/Area Number |
05660262
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Irrigation, drainage and rural engineering/Rural planning
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| Research Institution | Iwate University |
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Principal Investigator |
FUJII Katsumi Iwate Univ., Fac.of Agr., Assistant Prof., 農学部, 助教授 (30134513)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAISHI Katsuya Ibaraki Univ., Fac.of Agr., Research Assistant, 農学部, 助手 (40180236)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Exapansive Clay / Suspension / Non-Newtonian viscosity / Thixotropic behavior / Bingham yield stress |
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| Research Abstract |
1 (1) Montmorillonite and Kaolinite, famous for those typical properties, were adopted as test clay minerals. Then we measured the viscosities of clay suspensions under constant temperature. using cone-plate type viscometer.
(2) From these experimental data, dependency of viscosities on solid ratio of suspensions could be obtained with high accuracy. Thus experimental formula (viscosity) * Exp (solid ratio) were derived, and those constants were discussed theoretically.
(3) Viscosities of clay suspensions proved to exhibit non-Newtonian, thixotropic flow, as well as high dependency on shear rate.
(4) Then, extrapolating the relationship between shear stress TAU and shear rate gamma to gamma=0. Bingham yield stress TAU_o could be estimated for the clay suspensions.
2 Settling phenomena of dispersed clay particles in suspensions were also measured for several ten days. These results indicate that the friction force f between particles and cylindrical tube wall, especially more than 2% of solid ratio.
3 Bingham yield stress TAU_o and friction force f, estimated for montmorillonite suspensions, take almost the same size in order, and exhibit typical tendency on solid ratio. In general, these two values are too slight to be detected, so this research would be expected to have a significant contribution to experimental and theoretical study on clay mechanics in suspensions.
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