Mechanical threshold of cementitious materials at early age

Title: Mechanical threshold of cementitious materials at early age
Author(s): J. M. Torrenti, F. Benboudjema
Paper category : journal
Serial title: Materials and Structures
Abreviated Serial title: Mater. Struct.
ISSN: 1359-5997
Publisher: RILEM Publications SARL
Volume: 38
Issue: 277
Issue date: 2005-04-01
Publication year: 2005
Pages: 299 - 304
Total Pages: 6
Nb references: 14
Language: English

Abstract: At an early age, the mechanical characteristics of concrete behaviour, such as Young's modulus, follow a rapid rate of change.
If strains are restricted or in the event of strain gradients, tensile stresses are generated and there is a risk of cracks occurring.
Change in Young's modulus as a function of the hydration degree is a major parameter for the modelling of this phenomenon.
In this evolution, a hydration threshold has to be taken into account, below which concrete displays negligible stiffness.
For cement pastes, a simplified hydration model shows that percolation of the solid phases depends on the water-to-cement ratio, which is in accordance with experimental results.
For mortar or concrete, on the other hand, the presence of aggregates means that the solid volumetric fraction of is such that percolation is observed before hydration occurs.
Therefore another parameter is introduced: cohesion due to hydrates products.
By coupling our model with a finite-element code (CAST3M), we show that the hydration threshold for Young's modulus in mortar is almost independent of the water-to-cement ratio, which is in accordance with experimental results.

Online publication: 2005-02-15
Classification: Scientific Reports
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/14203