Development of Long Lifecycle of Concrete Structure and Environmental Preservation
Grant-in-Aid for Scientific Research (C)
|Allocation Type||Single-year Grants|
|Research Institution||Waseda University|
SEKI Hiroshi Waseda University, School of Science and Engineering, Professor, 理工学部, 教授 (40120919)
|Project Period (FY)
1997 – 1999
Completed(Fiscal Year 1999)
|Budget Amount *help
¥2,900,000 (Direct Cost : ¥2,900,000)
Fiscal Year 1999 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1998 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1997 : ¥1,000,000 (Direct Cost : ¥1,000,000)
|Keywords||Hydration reaction rate / Flocculation structure / Percolation / Mass transport / Deterioration of concrete / Long lifecycle / Simulation / 一括練混ぜ法 / 分割練混ぜ法 / セメント粒子 / 凝集構造 / 気体移動 / 酸素拡散係数 / 混合セメント / 混和材 / 水和反応 / 細孔構造 / 耐久性 / 遷移帯 / 導電率|
The main objective of this study is an establishment of long lifecycle of concrete structure system for enviromental preservation measures. The system is developed by the lifecycle simulation of mixture proportion of concrete from placing until the concrete structure became deterioration due to the results of physical and chemical processes. And the output is the mixture proportion of concrete with the best perfomance, the most economical cost and the easily maintenance operation. Therefore, this study investigated the dispersion of cement paricles in freshly-mixed condition, the bleeding mechanism, the hydration reaction rate mechanism, the hydration product and pore structure mechanism, the mass transport mechanism based on percolation theory and the deterioration mechanism for developing the basic model.
The following conclusions were obtained from the results of investigation in this study.
1. The bleeding ratio decreased with increasing dispersion of cement particles in freshly-mixed condition.
2. The hydration reaction rate increased with increasing dispersion of cement particles in freshly-mixed condition.
3. The hardening paste became more homogenous with increasing dispersion of cement particles in freshly-mixed condition. However, the transition zone had more porous in high water-to cement ratio.
4. Model of the hydration reaction rate with different dispersion of cement particles gave a good accuracy.
5. Model of the mass transport in concrete based on percolation theory gave a good accuracy.
The final objective of study is development of simulation program based on combination of the results of investigation of this study with all deterioration mechanisms and lifecycle cost to determine the economical and suitable mixture proportion.
Research Output (26results)