Effect of the Transition Zone on the Bulk Modulus of Concrete

Abstract

In concrete, non-uniformities in the hydration process, due to the the “wall effect” produeed by the aggregate (inclusion) particles, lead to an interfacial transition zone (ITZ) that is characterized by an increase in porosity near the inclusions. This increase in porosity may in turn be expected to cause a local decrease in the elastic moduli. We have modeled the effect of the ITZ by assuming that the elastic moduli vary smoothly in the vicinity of the inclusions, according to a power law. The exponent in the power law is chosen based on the estimated thickness of the ITZ. For this model, a closed-form expression can be found for the overall effective bulk modulus. The predicted bulk modulus of the concrete depends on known properties such as the elastic moduli of the bulk cement paste and the inclusions, the volume fraction of the inclusions, as well as on the elastic moduli at the interface. By comparing the model predictions to measured data, we can obtain estimates of the elastic moduli at the interface. Application of this inverse procedure to a set of data from the literature on mortar containing sand inclusions leads to the conclusion that the modulus at the interface is about 15–50% lower than in bulk cement paste.

This is a preview of subscription content, access via your institution.

References

  1. 1.

    S. Mindess, in: Materials Science of Concrete, edited by J. P. Skalny (American Ceramic Society, Westerville, OH, 1989), pp. 163–180.

  2. 2.

    P. K. Mehta and P. J. M. Monteiro, Concrete: Structure, Properties, and Methods, 2nd ed. (Prentice-Hall, Englewood Cliffs, NJ, 1993).

    Google Scholar 

  3. 3.

    A. U. Nilsen and P. J. M. Monteiro, Cement Concr. Res. 23, 147–151 (1993).

    CAS  Article  Google Scholar 

  4. 4.

    T. J. Hirsch, J. Amer. Concrete Inst. 59, 427–451 (1962).

    Google Scholar 

  5. 5.

    Z. Hashin and S. Shtrikman, J. Franklin Inst. 271, 336–341 (1961).

    Article  Google Scholar 

  6. 6.

    K. L. Scrivener and E. M. Gartner, in Bonding in Cementitious Composites, edited by S. Mindess and S.P. Shah, (Mater. Res. Soc. Proc. 114, Pittsburgh, PA, 1988) pp. 77–85.

    CAS  Google Scholar 

  7. 7.

    G. T. Kuster and M. N. Toksöz, Geophysics 39, 587–606 (1974).

    Article  Google Scholar 

  8. 8.

    M. P. Lutz and R. W. Zimmerman, submitted for publication.

  9. 9.

    P. S. Theocaris, in: Composite Interfaces, edited by H. Ishida and J. L. Koenig (North-Holland, Amsterdam, 1986), pp. 329–345.

  10. 10.

    T. Mori and K. Tanaka, Acta Metall. 21, 571–574 (1973).

    Article  Google Scholar 

  11. 11.

    R. W. Zimmerman, M. S. King, and P. J. M. Monteiro, Cement Concr. Res. 16, 239–245 (1986).

    Article  Google Scholar 

  12. 12.

    R. W. Zimmerman, Mech. Maters. 12, 17–24 (1991).

    Article  Google Scholar 

  13. 13.

    K. L. Scrivener, in: Materials Science of Concrete, edited by J. P. Skalny (American Ceramic Society, Westerville, OH, 1989), pp. 127–161.

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to Melanie P. Lutz.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Lutz, M.P., Monteiro, P.J.M. Effect of the Transition Zone on the Bulk Modulus of Concrete. MRS Online Proceedings Library 370, 413–418 (1994). https://doi.org/10.1557/PROC-370-413

Download citation