Publication detail

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.

Original Title

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

English Title

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

Type

journal article in Web of Science

Language

en

Original Abstract

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).

English abstract

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).

Keywords

Calcium Aluminate Cement; Ca3Al2O6; Hydration; pH; Hydration Products

Released

04.04.2016

Publisher

Springer-Verlag GmbH Heidelberg

Location

Germany

ISBN

1388-6150

Periodical

Journal of Thermal Analysis and Calorimetry

Number

124

State

HU

Pages from

629

Pages to

638

Pages count

10

URL

Documents

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"
}