Predicting long-term durability performance of cement systems from the nanost ructure and properties of calcium aluminosilicate hydrate (C-A-S-H) gels
| Project/Area Number |
18K04297
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 22010:Civil engineering material, execution and construction management-related
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| Research Institution | Hokkaido University |
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Principal Investigator |
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2020: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2018: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
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| Keywords | Cement chemistry / C-A-S-H / Modelling / Surface complexation / Phase-equilibrium model / Slag / surface complexation / modelling / Durability |
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| Outline of Final Research Achievements |
The density of the surface groups was determined by analysing the structure of C-S-H and C-A-S-H through 27Al and 29Si MAS NMR. The surface sites of ≡SiOH and ≡AlOH are available in C-A-S-H whereas C-S-H has ≡SiOH groups. The incorporation of aluminium decreases the number of total adsorption sites in C-A-S-H. Furthermore, the site density increased with Ca/(Si+Al). To understand the C-A-S-H/solution interface, a triple-layer surface complexation model was developed and the associated equilibrium constants for deprotonation, calcium, and chloride adsorption were determined by fitting the experimental data of potentiometric titration and zeta potential measurement results. The estimated surface complexation modelling parameters were verified by predicting the experimental data of calcium and chloride adsorption on C-S-H and C-A-S-H.
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| Academic Significance and Societal Importance of the Research Achievements |
This research links C-S-H and C-A-S-H properties to durability of cementitious materials. Therefore, this research provides an excellent embodiment of the concept of material design for required properties and long-term durability in various environments.
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Report
(4 results)
Research Products
(4 results)
