ACCELERATED CARBONATION OF FRIEDEL'S SALT IN CALCIUM ALUMINATE CEMENT PASTE

Knowledge of the stability of Friedel's salt is important due to its capacity for binding chloride. Free chloride is one of the more aggressive ions for steel embedded in concrete, contributing greatly to corrosion. This article reports on a study in which the stability of Friedel's salt with respect to carbonation has been investigated in calcium aluminate cement (CAC) pastes containing NaCl (3% of Cl- by weight of cement). Carbonation was carried out on a powdered sample in flowing 5% CO2 gas at 65% relative humidity to accelerate the process. At an intermediate carbonation step, a part of the sample was washed and dried up to 10 cycles to simulate a dynamic leaching attack. The authors then analyzed the simulated pore solution, with X- ray diffraction (XRD), pH and Cl- analyses. The authors conclude that the carbonation of Friedel's salt does not produce a significant increase of soluble chloride, thus the chloride is trapped in another solid phase. Chloride is effectively eliminated from the carbonated sample after 10 cycles of simulated semidynamic leaching.

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    Elsevier

    The Boulevard, Langford Lane
    Kidlington, Oxford  United Kingdom  OX5 1GB
  • Authors:
    • Goni, S
    • Guerrero, A
  • Publication Date: 2003-1

Language

  • English

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  • Accession Number: 00986453
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Feb 8 2005 12:00AM