| Title |
Two-step synthesis of low-lime cement and its hydration / |
| Authors |
Siauciunas, R ; Eisinas, A ; Rubinaite, D ; Gedeike, I |
| Full Text |
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| Is Part of |
16th international congress on the chemistry of cement 2023 (ICCC2023) “Further reduction of CO2 -emissions and circularity in the cement and concrete industry”, September 18–22, 2023, Bangkok, Thailand: congress proceeding, Vol. 2.. Duesseldorf : ICCC Permanent Secretariat. 2023, PF0107, p. 254-257 |
| Keywords [eng] |
low-lime cement ; hydrothermal synthesis ; α-C2SH and katoite activation ; heat flow |
| Abstract [eng] |
Ordinary Portland cement (OPC) industry is responsible for 5–7% of global annual greenhouse gas emissions. The search for alternative cementitious materials with a lower CO2 footprint is one of the major challenges that the cement industry and the scientific community have been facing in the past decades. Thus, this work examines the possibility of creating environmentally friendly (low lime) binders by combining hydrothermal synthesis and mechanochemical/thermal activation at low temperatures. The work aimed to obtain a complex effect: to increase the reactivity of Ca/Si/Al composite compounds and the stability of their active modifications. In the course of activities, calcium silicate hydrate (α-C2SH, Ca2(HSiO4)(OH)) and calcium aluminate (katoite; Ca3Al2[(OH)4]3) were synthesised under hydrothermal conditions. For the initial mixtures, the prepared precursors were blended (90-100% of α-C2SH and 0–10% of katoite) and quartz sand (1:1 by mass) was added. The mixtures were activated: 1) mechanically (5 min, 950 rpm) or 2) mechanochemically/thermally (30 min, 450 °C), and used for further research. The mineral composition of the formed complex binders, its physical and chemical properties, as well as the values of the heat flow and cumulative heat during hydration, were determined. The results demonstrate that this technology allows for the loosening of additional molecular bonds and increases the reactivity of the compounds. |
| Published |
Duesseldorf : ICCC Permanent Secretariat |
| Type |
Conference paper |
| Language |
English |
| Publication date |
2023 |
| CC license |
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