COUPLINGS IN EARLY-AGE CONCRETE - FROM MATERIAL MODELING TO STRUCTURAL DESIGN

Authors
Citation
Fj. Ulm et O. Coussy, COUPLINGS IN EARLY-AGE CONCRETE - FROM MATERIAL MODELING TO STRUCTURAL DESIGN, International journal of solids and structures, 35(31-32), 1998, pp. 4295-4311
Citations number
26
Categorie Soggetti
Mechanics
ISSN journal
00207683
Volume
35
Issue
31-32
Year of publication
1998
Pages
4295 - 4311
Database
ISI
SICI code
0020-7683(1998)35:31-32<4295:CIEC-F>2.0.ZU;2-O
Abstract
Couplings in early-age concrete are the cross-effects between the hydr ation reaction, temperature evolution and deformation which can lead t o cracking. They involve complex chemo-physical mechanism that operate over a broad range of scales, from nanometer to meter. This paper exp lores these thermo-chemo-mechanical cross-effects from the macroscale of engineering material modeling (the typical scale of laboratory test specimens) to the level of structural design. Set within the framewor k of chemoplasticity, the cross-effects in the constitutive model are derived from Maxwell-symmetries, and characterize the autogeneous shri nkage, hydrate heat and strength growth due to the chemo-mechanical, t hermo-chemical and chemo-plastic couplings. These couplings at a mater ial level can be determined from standard material tests. provided tha t the order of coupling is known. This is shown by considering adiabat ic calorimetric experiments and isothermal strength growth tests, whic h lead to identify an intrinsic kinetics function that characterizes t he macroscopic hydration kinetics of concrete. Finally, an example of application of the model to large-scale finite element analysis of con crete structures is presented, which clearly shows the consequences of thermo-chemo-mechanical couplings for the engineering design of concr ete structures at early ages. (C) 1998 Elsevier Science Ltd. All right s reserved.