Title: Creep and Shrinkage of Concrete-Kinetics Approach

Author(s): F. Ulm, F. Le Maou, and C. Boulay

Publication: Symposium Paper

Volume: 194

Issue:

Appears on pages(s): 135-154

Keywords: concrete; couplings; creep; creep dilatancy; in-ternal pressure; kinetics; lateral creep; long term creep; mechanisms; short term creep; shrinkage

DOI: 10.14359/9892

Date: 5/1/2000

Abstract:
This paper discusses possible mechanisms of basic creep and autogenous shrinkage and their couplings. The starting point is a kinetics analysis of the basic creep of different types of concrete, a normal strength concrete and a high performance concrete. This approach reveals two domains: short term creep kinetics, active for some days after loading, and long term creep kinet-ics, characterized by a pronounced and non-asymptotic aging. Then, by ex-ploring the creep-shrinkage interaction under sealed conditions, we confirm that the long term autogenous skrinkage, which cannot be explained by pure hydration effects, can be associated with a matrix creep under internal pore pressure. This pressure seems to depend mainly on the water:cement ratio. Finally, we present some preliminary experimental results on the creep dila-tancy behavior of concrete. The results indicate that the short term creep is characterized by a viscous dilatant behavior (i.e., positive volume increase rate), while the long term creep is of rather non-dilatant nature occurring at constant volume.