Materials and Structures

, Volume 25, Issue 6, pp 358–365 | Cite as

A two-chamber vacuum cell for measuring the coefficient of permeability to air of the concrete cover on site

  • R. J. Torrent
Experimental Methods and Devices Methodes Experimentales et Appareillage

Abstract

A new testing technique, suitable for on-site, non-destructive measurement of the permeability to air of the concrete cover is presented. The method is based upon applying a vacuum inside a cell placed on the concrete surface and on measuring the rate at which the pressure returns to the atmospheric value. Distinctive features of the method are a two-chamber cell and a regulator that balances the pressure in the inner (measuring) chamber and in the outer (quard-ring) chamber. Thus, unidirectional air flow into the inner chamber is achieved, eliminating any spurious lateral air flow. A simple model is proposed to calculate the coefficient of permeability and the depth affected by the test. Preliminary results fit very well to earlier measurements of the coefficient of permeability to oxygen by the Cembureau method.

Keywords

Permeability Concrete Slab Concrete Surface Permeability Index Outer Chamber 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Resume

On présente une nouvelle méthode d'essai non destructive, utilisable sur site, pour la mesure de la perméabilité à l'air de l'enrobage du béton. Cette méthode consiste à faire le vide à l'intérieur d'une cellule fixée sur le béton et à mesurer la vitesse à laquelle la pression revient à la valeur atmosphérique. La méthode se distingue notamment par une cellule à deux compartiments et un régulateur de pression entre le compartiment (de mesure) intérieur et le compartiment extérieur (anneau de garde). Ainsi, l'écoulement unidirectionnel d'air dans le compartiment intérieur est obtenu par élimination de tout écoulement latéral parasite. On propose un modèle simple de calcul du coefficient de perméabilité et de la profondeur concernés par l'essai. Les essais préliminaires concordent très bien avec les mesures précédentes du coefficient de perméabilité par la méthode Cembureau.

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References

  1. 1.
    Kreijger, P. C., ‘The skin of concrete. Composition and properties,’Mater. Struct. 17(100) (1984) 275–283.Google Scholar
  2. 2.
    Newman, K., ‘Labcrete, realcrete and hypocrete. Where we can expect the next major durability problems,’ ACI SP-100, Vol. 2 (1987) pp. 1259–1283.Google Scholar
  3. 3.
    Meyer, A., ‘The importance of the surface layer for the durability of concrete structures’,, pp. 49–61.Google Scholar
  4. 4.
    Hilsdorf, H. K., ‘Durability of concrete—a measurable quantity?’IABSE Rep. 57(1) (1989) 111–123.Google Scholar
  5. 5.
    Lawrence, C. D., ‘Transport of oxygen through concrete’, in ‘Chemistry and Chemically-related Properties of Cement’, (British Ceramic Society, London, 1984).Google Scholar
  6. 6.
    Gräf, H. and Setzer, M. J., ‘Influence of water cement ratio and curing on the permeability and structure of hardened cement paste and concrete’,Mater. Res. Soc. Symp. Proc. 137, (1989) 337–347.Google Scholar
  7. 7.
    Kropp, J., ‘Relations Between Different Types of Permeability and Selected Durability Characteristics of Concrete’, Draft Report, RILEM TC 116-PCD (November 1990).Google Scholar
  8. 8.
    ‘Permeability Testing of Site Concrete’, Technical Report No. 31 (Concrete Society, London, 1988).Google Scholar
  9. 9.
    Molin, Ch., ‘Evaluation of Field Test Methods for Gas Permeability’, Draft Report, RILEM TC 116-PCD (July 1990).Google Scholar
  10. 10.
    Reinhardt, H. W. and Mijnsbergen, J. P. G., ‘In-situ measurement of permeability of concrete cover by overpressure’, in ‘The Life of Structures. Physical Testing’ (Butterworth, London, 1989) pp. 243–254.Google Scholar
  11. 11.
    Hong, C. Z. and Parrott, L. J., ‘Air Permeability of Cover Concrete and the Effect of Curing’ (British Cement Association, October 1989).Google Scholar
  12. 12.
    Figg, J. W., ‘Methods of measuring the air and water permeability of concrete’,Mag. Concr. Res. 25(85) (1973) 213–219.Google Scholar
  13. 13.
    Kasai, Y., Matsui, I. and Nagano, M., ‘On site rapid air permeability test for concrete’, ACI SP-82 (1984) pp. 501–524.Google Scholar
  14. 14.
    Hansen, A. J., Ottosen, N. S. and Petersen, C. G., ‘Gas-permeability of concrete in situ: theory and practice’, ACI SP-82 (1984) pp. 543–556.Google Scholar
  15. 15.
    Berissi, R., Bonnet, G. and Grimaldi, G., ‘Mesure de la porosité ouverte des bétons hydrauliques’,Bull. liaison Labor. Ponts Chauss. No. 142 (Mars-avr. 1986) 59–67.Google Scholar
  16. 16.
    Schönlin, K. and Hilsdorf, H. K., ‘Evaluation of the effectiveness of curing of concrete structures,’ACI SP-100, Vol. 1 (1987) pp. 207–226.Google Scholar
  17. 17.
    Smith, A., ‘Tightness tester aids quality control investigations’,Concr. Constr. 35(9) (1990) 794–796.Google Scholar
  18. 18.
    Kresse, P., ‘Calculating the capillary radius and surface roughness of concrete by means of the Hagen-Poisseuille law’,Betonwerk + Fertigteil-Technik No. 2 (1990) 72–78.Google Scholar
  19. 19.
    Kollek, J. J., ‘The determination of the permeability of concrete to oxygen by the Cembureau Method—a recommendation’,Mater. Struct. 22 (1989) 225–230.Google Scholar
  20. 20.
    Torrent, R. J. and Jornet, A., ‘“Covercrete” Study-Part I’, Holderbank M. & C. Report MA 90/3815/E (1990).Google Scholar
  21. 21.
    Idem ‘The quality of the “covercrete” of low-medium- and high-strength concretes’, ACI SP-126, Vol. 2 (1991) pp. 1147–1162.Google Scholar
  22. 22.
    Hilsdorf, H. K., ‘In-situ permeability, testing of concrete’, in ‘Testing During Concrete Construction’ (Chapman & Hall, London, 1990) pp. 311–332.Google Scholar

Copyright information

© RILEM 1992

Authors and Affiliations

  • R. J. Torrent
    • 1
  1. 1.Materials Division‘Holderbank’ Management & Consulting Ltd, Technical CentreHolderbankSwitzerland

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