Prediction of autogenous shrinkage of concrete at early age using percolation

Title: Prediction of autogenous shrinkage of concrete at early age using percolation
Author(s): J.M. Torrenti, F. Benboudjema, L. Stefan
Paper category : conference
Book title: International RILEM Symposium on Concrete Modelling - ConMod '08
Editor(s): E. Schlangen and G. De Schutter
Print-ISBN: 978-2-35158-060-8
e-ISBN: 978-2-35158-076-9
Publisher: RILEM Publications SARL
Publication year: 2008
Pages: 725 - 732
Total Pages: 8
Nb references: 16
Language: English

Abstract: Cementitious materials are subjected to delayed strains and therefore to a risk of cracking at early age, if the boundary conditions are such as these deformations are restrained. At early age, mechanical characteristics of the concrete, such as Young’s modulus and autogenous shrinkage, follow a fast evolution and they represent major parameters when the prediction of cracking is considered. The most accurate modelling of their evolution is thus necessary if one wants to correctly predict the risk of cracking. An approach by the percolation theory, using a forest fire algorithm that allows taking into account the binding role played by the hydrates, displays explicitly a threshold of hydration below which the rigidity of the concrete is negligible. A homogenisation approach (self-consistent scheme), applied to the percolated structure, gives the evolution of the elastic properties around the threshold of percolation.
We assume that the autogenous shrinkage is due to the existence of a capillary pressure, the latter being itself a consequence of the hydration reaction. The pressure is obtained from a model function of the corresponding degree of hydration and it can be applied to the deformable skeleton corresponding to the percolated structure. Using this approach it is possible to consider the autogenous shrinkage and its evolution around the threshold of percolation.

Online publication: 2009-06-15
Publication type : full_text
Public price (Euros): 0.00

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