2020 Fiscal Year Annual Research Report
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 Institution | Hokkaido University |
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Principal Investigator |
Y Elakneswaran 北海道大学, 工学研究院, 准教授 (60769090)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Keywords | Cement chemistry / C-A-S-H / Surface complexation / Phase-equilibrium model / Slag |
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| Outline of Annual Research Achievements |
This year of research mainly focused on the development of integrated model to predict durability of cementitious materials. The triple-layer surface complexation model developed to predict calcium and chloride adsorption was combined with phase-equilibrium model to predict chloride binding in slag-blended cementitious materials. The addition of blast furnace slag reduces the calcium to silica ratio and produces more calcium aluminosilicate hydrate (C-A-S-H). Therefore, to predict chloride binding in slag-blended cementitious materials, the adsorption of chloride in calcium silicate hydrate (C-S-H) and C-A-S-H was considered in addition to the formation of Friedel's salt. The integrated model successfully predicts the chloride binding in slag-blended cementitious materials for the replacement of cement up to 70 %. The prediction results indicated that C-A-S-H dominates the chloride adsorption than that is in C-S-H. Furthermore, the chloride adsorption is much higher than the formation of Friedel's salt in slag-blended cementitious materials.
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