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Pore Structure and Moisture Properties of Cement-Based Systemsfrom Water Vapour Sorption Isotherms

Published online by Cambridge University Press:  21 February 2011

Veronique Baroghel-Bouny
Affiliation:
Laboratoire Central des Ponts et Chaussées, 58 bd Lefebvre, F-75732 Paris Cedex 15, France
T. Chaussadent
Affiliation:
Laboratoire Central des Ponts et Chaussées, 58 bd Lefebvre, F-75732 Paris Cedex 15, France
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Abstract

This paper presents results obtained for hardened cement pastes and concretes, ordinary and very-high-performance materials, concerning pore structure and moisture properties.

Because of the inadequacy of classical pore investigation methods (mercury intrusion, nitrogenadsorption) to provide the exact pore network characteristics of cement-based systems, notably in the case of very-high-performance materials, a more pertinent type of experiment was carried out: water vapour desorption and adsorption measurements.

From these experiments, isotherms were determined at hygrometrical equilibrium and at constant temperature (T = 23 °C) for every desorption/adsorption path. The analysis of these curves gives textural parameters in the mesopore range, not accessible by most of other methods. Thus, from the adsorption curve, the specific surface area accessible to water molecules was calculated by the B.E.T. method. The statistical thickness of the water film adsorbed on the solid surface was also determined. And finally, application of the B.J.H. method on the desorption branch provides relevant porosity values and pore size distribution of the hardened materials, and especially intrinsic characteristics of C-S-H hydrates.

This makes it possible to point out the similarities and the differences between the materials, regarding microstructure and moisture properties, and to quantify the influence of mix parameters such as water-cement ratio or silica fume content.

Type
Research Article
Copyright
Copyright © Materials Research Society 1995

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References

1. Baroghel-Bouny, V., PhD thesis, Ecole Nationale des Ponts et Chaussées Paris, 1994.Google Scholar
2. Feldman, R. F., in Proceedings of the “5th International Congress on the Chemistry of Cement” Edited by Cement Association of Japan, Tokyo, Vol. 3, pp. 5366, 1968.Google Scholar
3. Brun, M., Lallemand, A., Quinson, J. F. and Eyraud, C., Thermochimica Acta 21, 5988, (1977).Google Scholar
4. Barrett, E.P., Joyner, L.G. and Halenda, P.P., J. Amer. Chem. Soc. 73, 373380 (1951).Google Scholar
5. Baroghel-Bouny, V. and Chaussadent, T., Bull. de Liaison des LPC 187, 6975, (1993).Google Scholar
6. Brunauer, S., Emmett, P.H. and Teller, E.J., J. Amer. Chem. Soc. 60, 309 (1938).Google Scholar
7. Young, D.M. and Crowell, A.D., in Physical adsorption of gases Edited by Butterworths, London, 1962, pp. 137246.Google Scholar
8. Rouquerol, F., Techniques de l'ingénieur P 3645, 14 p. (1968).Google Scholar
9. I.U.P.A.C. (Recommendations 1984). Sing, K.S.W., Everett, D.H., Haul, R.A.W., Moscou, L., Pierotti, R.A., Rouquerol, J. and Siemieniewska, T., Pure and Applied Chemistry 57 (4), 603619 (1985).Google Scholar
10. Boer, J. H. De and Lippens, B.C., Journal of catalysis (USA) 4, 319323 (1965).Google Scholar
11. Hagymassy, J. Jr, Brunauer, S. and Mikhail, R.Sh., Journal of Colloid and Interface Science,29 (3), 485491 (1969).Google Scholar
12. Badmann, R., Stockhausen, N. and Setzer, M.J., Journal of Colloid and Interface Science 82 (2), 534542 (1981).Google Scholar
13. Pierce, C., J. Phys. Chem. 57, 149152 (1953).Google Scholar
14. Powers, T.C. and Brownyard, T.L., Bull. Portland Cem. Association 22, 276287 (1948).Google Scholar