1999 Fiscal Year Final Research Report Summary
Development of Long Lifecycle of Concrete Structure and Environmental Preservation
| Project/Area Number |
09650515
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
土木材料・力学一般
|
|---|
| Research Institution | Waseda University |
|---|
Principal Investigator |
SEKI Hiroshi Waseda University, School of Science and Engineering, Professor, 理工学部, 教授 (40120919)
|
|---|
| Project Period (FY) |
1997 – 1999
|
| Keywords | Hydration reaction rate / Flocculation structure / Percolation / Mass transport / Deterioration of concrete / Long lifecycle / Simulation |
|---|
| Research Abstract |
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.
|
