| Project/Area Number |
11650462
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
土木材料・力学一般
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
SAKAI Etsuo Tokyo Institute of Technology, Faculty of Engineering , Associate Professor, 大学院・理工学研究科, 助教授 (90126277)
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| Co-Investigator(Kenkyū-buntansha) |
OHBA Yoko Tokyo Institute of Technology, Faculty of Engineering, Research Associate, 大学院・理工学研究科, 助手 (50223938)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2000: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1999: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | Concrete / Fluidity / Comb-type superplasticizer / Hydration / Inorganic electrolytes / Adsorption / Dispersion mechanisms / Materials design / 無桟電解質 / セメントコンクリート |
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| Research Abstract |
For the development of self compacting concrete, high strength concrete and high duarable concrete, it is necessary to control the fluidity of concrete with comb-type superplasticizers. This study discusses the influence of graft chain length and dosage of comb-type superplasticizers on adsorption and dispersion mechanisms, and their subsequent effect on the fluidity of concentrated limestone suspensions. Furthermore, the addition of certain soluble salts, which can effect the concentration of Ca^<2+> in liquid phase of CaCO_3 suspensions, has been observed to decrease the adsorption of comb-type polymers on CaCO_3. Thus, the polymer adsorption process on solid surfaces can be selectively influenced by certain types of ions. Early hydration of C_3A is accelerated by adding of comb-type superplasticizers in C_3A-calcium sulfates systems. In the case of comb-type superplasticizers, SO_4^<2-> contents in gel formed around C_3A is decreased. It is necessary to control the early hydration reaction of aluminate phase in order to control the fluidity of the cement with comb-type superplasticizers.
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