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Simulation of 3D cracks propagation in cement paste



Title: Simulation of 3D cracks propagation in cement paste
Author(s): Z. Qian, G. Ye, E. Schlangen
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: 637 - 646
Total Pages: 10
Nb references: 7
Language: English


Abstract: Cracks in concrete can increase the rate of aggressive ion penetration resulting in accelerated chemical attack or corrosion of reinforced steel bar. In concrete structures, accurately predicting the development of cracks could ultimately prevent the possibility of concrete failure.
In this contribution, a three-dimensional (3D) micromechanics model for modeling material properties of cracked cement paste is proposed. The material properties of cement paste are represented by cement hydration model Hymostruc. The cracks of cement paste are predicted using a 3D Lattice fracture model i.e. based on the simulated microstructure. The simulated virtual microstructure is first transferred into lattice beams, where the beams consist of unhydrated cement, low density CSH and high density CSH. The physical properties, including elastic modules, the length and the volume are assigned to each beam element. The cracks caused by external loading are studied. The loads are applied to the lattice structure.
The tensile stress of beam elements can be derived using the Lattice Model. In this model, the local forces for the beam elements are obtained by applying the "minimum potential energy" principle. It means that the element with the highest tensile stress relative to its tensile strength will be removed and assumed to be the first crack. In the next step, the stiffness matrix of the sample without the removed beam element will be determined. By tracing the removed beam element, the 3D crack pattern can be derived.
In the simulation, the development of cracks will be studied in detail. Further investigation will be paid on the development of cracks of concrete caused by internal and external loads based on multi-scale approach.


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