New Prediction Models for Creep and Shrinkage of Concrete
H. S. Miller
Appears on pages(s):
coefficient of variation; creep properties; models; temperature; modulus of elasticity; shrinkage; stresses; Design
The Comite Euro-International du Beton (CEB) has prepared a new model code for the design and analysis of concrete structures (CEB-FIP Model Code 1990) which includes new prediction models for creep and shrinkage of concrete. These models have been derived and optimized on the basis of a computerized data bank. For the prediction of shrinkage, a diffusion theory-type model has been chosen. The prediction of creep is based on a simple product-type approach. Though the new creep model resembles some of the features of the model presented by ACI 209, various basic improvements could be achieved. The coefficients of variation for shrinkage and creep have been found to be approximately 33 and 20 percent, respectively. The developed prediction models, both for creep and shrinkage, represent a reasonable compromise of accuracy and simplicity. They meet the requirements for presentation in a code. In this paper, both models are presented and some comparisons with test data are shown.