Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Early age hydration of calcium sulfoaluminate (synthetic ye'elimite, ) in the presence of gypsum and varying amounts of calcium hydroxide
Abstract Suspensions of synthetic ye'elimite () in a saturated gypsum () and calcium hydroxide (CH) solution were examined in-situ in a wet cell by soft X-ray transmission microscopy and ex-situ by scanning electron microscopy. The most voluminous hydration product observed was ettringite. Ettringite commonly displayed acicular, filiform, reticulated, and stellate crystal habits. Additionally, pastes with , 15% , and varying amounts of CH were prepared and examined with X-ray diffraction (XRD) and isothermal calorimetry. The XRD experiments showed that increasing CH content caused more solid solution (SO4 2−/OH−) AFm phases to form at early ages (<1d) and more monosulfate to form at later ages (>1d). Calorimetry indicated that the increased production of solid solution AFm was accompanied with an increase in the initial (<30min) rate of heat evolution, and increasing CH generally reduced the time till the second maximum rate of heat evolution due to the formation of ettringite and monosulfate.
Early age hydration of calcium sulfoaluminate (synthetic ye'elimite, ) in the presence of gypsum and varying amounts of calcium hydroxide
Abstract Suspensions of synthetic ye'elimite () in a saturated gypsum () and calcium hydroxide (CH) solution were examined in-situ in a wet cell by soft X-ray transmission microscopy and ex-situ by scanning electron microscopy. The most voluminous hydration product observed was ettringite. Ettringite commonly displayed acicular, filiform, reticulated, and stellate crystal habits. Additionally, pastes with , 15% , and varying amounts of CH were prepared and examined with X-ray diffraction (XRD) and isothermal calorimetry. The XRD experiments showed that increasing CH content caused more solid solution (SO4 2−/OH−) AFm phases to form at early ages (<1d) and more monosulfate to form at later ages (>1d). Calorimetry indicated that the increased production of solid solution AFm was accompanied with an increase in the initial (<30min) rate of heat evolution, and increasing CH generally reduced the time till the second maximum rate of heat evolution due to the formation of ettringite and monosulfate.
Early age hydration of calcium sulfoaluminate (synthetic ye'elimite, ) in the presence of gypsum and varying amounts of calcium hydroxide
Hargis, Craig W. (Autor:in) / Kirchheim, Ana Paula (Autor:in) / Monteiro, Paulo J.M. (Autor:in) / Gartner, Ellis M. (Autor:in)
Cement and Concrete Research ; 48 ; 105-115
07.03.2013
11 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
| British Library Online Contents | 2013
Calcium sulfoaluminate (Ye'elimite) hydration in the presence of gypsum, calcite, and vaterite
| Online Contents | 2014
Calcium sulfoaluminate (Ye'elimite) hydration in the presence of gypsum, calcite, and vaterite
| British Library Online Contents | 2014