Detail publikace

The influence of pH buffers on hydration of hydraulic phases in system CaO-Al2O3

ŠOUKAL, F. KOPLÍK, J. PTÁČEK, P. OPRAVIL, T. HAVLICA, J. PALOU, M. KALINA, L.

Originální název

The influence of pH buffers on hydration of hydraulic phases in system CaO-Al2O3

Anglický název

The influence of pH buffers on hydration of hydraulic phases in system CaO-Al2O3

Jazyk

en

Originální abstrakt

The present paper deals with the study of pH buffer influence (pH + ions) on hydration course of tricalcium aluminate (C3A), monocalcium aluminate (CA), monocalcium di-aluminate (CA2) and dodecacalcium hepta-aluminate (C12A7). These calcium aluminate phases were synthesized at 1450°C (CA and C3A), 1600 °C (CA2) and 1360 °C (C12A7) respectively. The purity of synthetized products was controlled by XRD. Then, different calcium aluminate phases were hydrated at 25 °C in excess of water at pH 6 and with buffers to kept the pH values at 9, 11 and 13. The evolution of hydration heat was monitored by isothermal calorimetry during 48 hours. After this period, hydration was stopped and the products were cross-characterized with different techniques: X-ray diffraction (XRD), high-temperature X-ray diffraction (HT-XRD), combined differential thermal analysis - thermogravimetry - effluent gas analysis (DTA-TG-EGA). It was found out that the hydration course and the nature of hydration products of different calcium aluminate phases are strongly dependent on the hydration environment (pH + ions).

Anglický abstrakt

The present paper deals with the study of pH buffer influence (pH + ions) on hydration course of tricalcium aluminate (C3A), monocalcium aluminate (CA), monocalcium di-aluminate (CA2) and dodecacalcium hepta-aluminate (C12A7). These calcium aluminate phases were synthesized at 1450°C (CA and C3A), 1600 °C (CA2) and 1360 °C (C12A7) respectively. The purity of synthetized products was controlled by XRD. Then, different calcium aluminate phases were hydrated at 25 °C in excess of water at pH 6 and with buffers to kept the pH values at 9, 11 and 13. The evolution of hydration heat was monitored by isothermal calorimetry during 48 hours. After this period, hydration was stopped and the products were cross-characterized with different techniques: X-ray diffraction (XRD), high-temperature X-ray diffraction (HT-XRD), combined differential thermal analysis - thermogravimetry - effluent gas analysis (DTA-TG-EGA). It was found out that the hydration course and the nature of hydration products of different calcium aluminate phases are strongly dependent on the hydration environment (pH + ions).

Dokumenty

BibTex


@article{BUT123535,
  author="František {Šoukal} and Jan {Koplík} and Petr {Ptáček} and Tomáš {Opravil} and Jaromír {Havlica} and Martin {Palou} and Lukáš {Kalina}",
  title="The influence of pH buffers on hydration of hydraulic phases in system CaO-Al2O3",
  annote="The present paper deals with the study of pH buffer influence (pH + ions) on hydration course of tricalcium aluminate (C3A), monocalcium aluminate (CA), monocalcium di-aluminate (CA2) and dodecacalcium hepta-aluminate (C12A7). These calcium aluminate phases were synthesized at 1450°C (CA and C3A), 1600 °C (CA2) and 1360 °C (C12A7) respectively. The purity of synthetized products was controlled by XRD. Then, different calcium aluminate phases were hydrated at 25 °C in excess of water at pH 6 and with buffers to kept the pH values at 9, 11 and 13. The evolution of hydration heat was monitored by isothermal calorimetry during 48 hours. After this period, hydration was stopped and the products were cross-characterized with different techniques: X-ray diffraction (XRD), high-temperature X-ray diffraction (HT-XRD), combined differential thermal analysis - thermogravimetry - effluent gas analysis (DTA-TG-EGA). It was found out that the hydration course and the nature of hydration products of different calcium aluminate phases are strongly dependent on the hydration environment (pH + ions).",
  address="Springer-Verlag GmbH Heidelberg",
  chapter="123535",
  doi="10.1007/s10973-015-5190-z",
  howpublished="online",
  institution="Springer-Verlag GmbH Heidelberg",
  number="124",
  year="2016",
  month="april",
  pages="629--638",
  publisher="Springer-Verlag GmbH Heidelberg",
  type="journal article in Web of Science"
}