Simulation of Volume Changes of Cement Paste at Early Age
This paper describes how the evolution of early age mechanical properties and volume change of cement paste is performed through Finite Element analysis on a 3D computer-generated cement paste. The time evolution of the hydrating microstructure is generated by μic(mike), a vectorial hydration model which takes into account the Particle Size Distribution (PSD) of anhydrous cement particles, the w/c ratio, the filler content and different hydration kinetics mechanisms such as nucleation, growth and diffusion. The microstructure geometry is then discretized into a finite element mesh. At each hydration step, the capillary depression is computed according to Laplace-Kelvin equation and applied on the pore space generated by the hydration model. Then, the autogenous shrinkage corresponds to the overall load-free deformation of the computational volume. Two constitutive models are used. The first one is a purely elastic model where macroscopic stress depends on the total porosity only. The second one is a poroelastic model which takes into account the fluid-solid interaction and the de-saturation effect. In parallel to the modeling work, a systematic experimental study has been performed on series of white cement pastes prepared different finenesses and various water-cement ratios. Many characterization techniques were used in the experimental study: chemical shrinkage, evolution of relative humidity, mercury intrusion porosimetry (MIP), x-ray diffraction (XRD), linear and volumetric autogenous shrinkage and ultrasonic wave propagation measurements. The numerical results are compared with experiment data and it is shown that the poroelastic model provides the best agreement to the experimental results. The remaining gap between the modeling and the experiment is discussed and future developments are outlined.
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Corporate Authors:
American Concrete Institute (ACI)
38800 Country Club Drive
Farmington Hills, MI United States 48331 -
Authors:
- Jaouadi, I
- Guidoum, A
- Scrivener, K
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Conference:
- Transition from Fluid to Solid: Re-Examining the Behavior of Concrete at Early Ages
- Location: San Antonio TX, United States
- Date: 2009-3-15 to 2009-3-19
- Publication Date: 2009
Language
- English
Media Info
- Media Type: CD-ROM
- Features: Figures; References; Tables;
- Pagination: 12p
- Monograph Title: Transition from Fluid to Solid: Re-Examining the Behavior of Concrete at Early Ages
Subject/Index Terms
- TRT Terms: Cement paste; Finite element method; Hydration; Mechanical properties; Shrinkage; Volumetric analysis; Water cement ratio; X ray analysis
- Uncontrolled Terms: Particle size distribution
- Subject Areas: Highways; Materials; I32: Concrete;
Filing Info
- Accession Number: 01142226
- Record Type: Publication
- Report/Paper Numbers: SP-259-12
- Files: TRIS
- Created Date: Oct 20 2009 7:41AM