Evolution of kinetics and pore water composition during hydration of a CAC‐Calcite system by addition of Na5P3O10

Rost P, Schramm T, Götz-Neunhoeffer F (2023)

Publication Type: Conference contribution

Publication year: 2023

Publisher: ibausil

Series: Proceedings in civil engineering

Book Volume: 6

Pages Range: 290-296

Conference Proceedings Title: 21st ibausil International Conference on Building Materials

Event location: Weimar DE

Issue: 6

DOI: 10.1002/cepa.2961

Abstract

It was analysed how a low Na5P3O10 (STPP) concentration influences the hydration of a calcium aluminate cement. It is known that the hydration of a CAC-Calcite system precipitates C2AHX as a precursor phase at 23°C during hydration before the formation of hemi- or monocarbonate and the additional formation of CAH10 and AH3. In our study the addition of 0.2 and 1.0 wt.% STPP (bwoc) to a CAC-Calcite system at 23 °C and with a w/b of 0.33 was investigated and is compared with mixes without STPP addition. Heat flow calorimetry data showed that STPP accelerates the main reaction. Moreover, an additional heat flow event within the first 30 minutes was detected by STPP addition. However, from the results of QXRD analysis, crystalline hydrate phases are formed only during the main reaction. These are CAH10, C2AHX, AH3, hemicarbonate and monocarbonate. STPP shows an influence on the amount of crystalline C2AHX, otherwise, no difference in the qualitative phase content is observed. Gillmore-Needle-Testing (IMETER device) could observe an accelerated hardness development during the early heat flow event despite initially reduced viscosity. Pore water studies and thermodynamic modelling (PhreeqC) indicate the formation of an amorphous C-P-H phase during this early heat flow event.

Authors with CRIS profile

Pauline Rost Lehrstuhl für Mineralogie Tillmann Schramm Lehrstuhl für Mineralogie Friedlinde Götz-Neunhoeffer Lehrstuhl für Mineralogie

How to cite

APA:

Rost, P., Schramm, T., & Götz-Neunhoeffer, F. (2023). Evolution of kinetics and pore water composition during hydration of a CAC‐Calcite system by addition of Na5P3O10. In 21st ibausil International Conference on Building Materials (pp. 290-296). Weimar, DE: ibausil.

MLA:

Rost, Pauline, Tillmann Schramm, and Friedlinde Götz-Neunhoeffer. "Evolution of kinetics and pore water composition during hydration of a CAC‐Calcite system by addition of Na5P3O10." Proceedings of the International Conference on Building Materials, Weimar ibausil, 2023. 290-296.

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