Title: New Model for Practical Prediction of Creep and Shrinkage

Author(s): Zdenek P. Bazant and Liisa Panula

Publication: Symposium Paper

Volume: 76

Issue:

Appears on pages(s): 7-24

Keywords: building codes; concretes; creep properties; deforma-tion; humidity; mathematical models; shrinkage; strains; structural analysis; structural design; volume change.

DOI: 10.14359/6783

Date: 10/1/1982

Abstract:
A new model for the prediction of creep and shrinkage (which is presented in full detail elsewhere), along with a large scope verification by test data, is outlined in simple terms, explained and illustrated in this paper. In this model, the total creep strain is separated into the basic and drying creep components, but not into "reversible" and "irreversible" creep components. The effect of environmental relative humidity is modeled by vertical scaling of the drying creep term. The effect of specimen size is modeled by a horizontal shift of the drying creep term in the logarithmic time scale, and the basic creep term is unaffected by humidity and specimen size. The effects of humidity and size upon the drying creep are modeled completely analogously to those on shrinkage. The dependence of shrinkage as well as drying creep on the size of the cross section is introduced by means of shrinkage-square halftime, which is the same for both shrinkage and drying creep. Finally, the basic creep component of total creep strain is characterized by double power law.