| Project/Area Number |
06555125
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
土木材料・力学一般
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| Research Institution | The University of Tokyo |
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Principal Investigator |
MAEKAWA Koichi The University of Tokyo, Engineering Research Institute, Faculty of Engeering, Associate Professor, 工学部(試), 助教授 (80157122)
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| Co-Investigator(Kenkyū-buntansha) |
KISHI Toshiharu The University of Tokyo, Engineering Research Institute, Faculty of Engeering, A, 工学部(試), 助手 (90251339)
OZAWA Kazumasa The University of Tokyo, Depeartment of Civil Engneering, Faculty of Engeering,, 大学院工学系研究科, 助教授 (80194546)
下村 匠 東京大学, 工学部, 講師 (40242002)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥13,500,000 (Direct Cost: ¥13,500,000)
Fiscal Year 1995: ¥5,000,000 (Direct Cost: ¥5,000,000)
Fiscal Year 1994: ¥8,500,000 (Direct Cost: ¥8,500,000)
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| Keywords | High Performance Concrete / Durability / Micro Pore Structure / Moisture Transport / Hydration / 細孔組織 / 初期応力 / 養生 / 強度発現 |
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| Research Abstract |
The purpose of this study is to develop a method to evaluate the initial stresses and the micro pore structure formation in self-compacting high performance concrete. For this purpose, a theory of the consumption and transfer of moisture in the pore structure, development of micro pore structure of hydration products according to hydration progress and the production and transfer of thermal energy was constructed based upon thermodynamical concepts. This enables a rational evaluation of the influences of drying, heat and external loads introduced to high performance concrete at early ages in an overall evaluation system.
At first, the hydration heat model of cement based on the arrhenius's law of chemical reaction was proposed under arbitary temperature history, in which the chemical composition of cement used and mix proportion of concrete were adopted as imput data. As next step, the micro pore structure development in concrete was formulated in terms of the hydration progress, where
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the linearity of bulk porosity in the hydrated cluster around the particles were assumed. Also, the moisture transport and distribution model in concrete was proposed by considering the thermodynamic equilibrium of moisture in the pore in a unified adsorption condensation process. Furthermore, the prediction model of volumetric change in concrete due to drying was proposed through the evaluation of maximum pore size saturated by pore water and surface tension given by moisture transport model. Besides, the constitutive law was also proposed to predict the permeability of concrete, considering the random geometrical characteristics of micro-pore structure. Finally, these generalized models of simulation were systematically integrated with rational consideration of relations among them as FEM program "DuCOM3" on the behavior of high performance concrete at early ages. The proposed models were verified through versatile experimental data with respect to time, such as temperature rise, strength development, weight loss, volume change, pore structure distribution and so on. Less
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