Flow of fresh concrete through steel bars: A porous medium analogy

Although being a very promising area of concrete technology, computational modeling of fresh concrete flow is a comprehensive and time consuming task. The complexity and required computation time are additionally increased when simulating casting of heavily reinforced sections, where each single reinforcement bar has to be modeled. In order to improve the computation speed and to get closer to a practical tool for simulation of casting processes, an innovative approach to model reinforced sections is proposed here. The basic idea of this approach is to treat the reinforcement zone as a porous medium in which a concrete is propagating. In the present paper, the numerical implementation of this concept is described. A methodology allowing for the computation of the equivalent permeability of the steel bars network is suggested. Finally, this numerical technique efficiency is evaluated by a comparison with experimental results of model fluids casting in model formworks.

[1]  François Bertrand,et al.  Rheological behavior of cement pastes from MRI velocimetry , 2005 .

[2]  Martin J. Blunt,et al.  Predictive Pore-Scale Modeling of Single and Multiphase Flow , 2005 .

[3]  Jörg-Henry Schwabe,et al.  Fachtagung Baumaschinentechnik 2003: Ausblick auf den Markt für Betonwaren und Betonfertigteile: Entwicklungstendenzen und -potenziale bei Fertigungsmaschinen zur Herstellung von Betonwaren und Betonfertigteilen , 2003 .

[4]  Nicolas Roussel,et al.  Passing Ability of Fresh Concrete: A Probabilistic Approach , 2009 .

[5]  Taketo Uomoto,et al.  Three-dimensional discrete element simulation of rheology tests of self-compacting concrete , 1999 .

[6]  Hajime Okamura,et al.  Self-Compacting Concrete , 2000 .

[7]  K. Sorbie,et al.  Experimental and modeling study of Newtonian and non-Newtonian fluid flow in pore network micromodels. , 2006, Journal of colloid and interface science.

[8]  Martin J Blunt,et al.  Predictive network modeling of single-phase non-Newtonian flow in porous media. , 2003, Journal of colloid and interface science.

[9]  Jon Elvar Wallevik,et al.  Rheology of Particle Suspensions: Fresh Concrete, Mortar and Cement Paste with Various Types of Lignosulfonates , 2003 .

[10]  Nicos Martys,et al.  Simulation of SCC Flow , 2003 .

[11]  François de Larrard,et al.  The rheology of fresh high-performance concrete , 1996 .

[12]  C. Boutin.  Study of permeability by periodic and self-consistent homogenisation , 2000 .

[13]  Frédéric Dufour,et al.  Computational modeling of concrete flow: General overview , 2007 .

[14]  B. W. Barry,et al.  The rheological properties of carbopol gels II. Oscillatory properties of carbopol gels , 1979 .

[15]  Yasufumi Otsubo,et al.  Time-dependent flow of cement pastes , 1980 .

[16]  D. Feys,et al.  Fresh self compacting concrete, a shear thickening material , 2008 .

[17]  P. Coussot,et al.  Yield stress and elastic modulus of suspensions of noncolloidal particles in yield stress fluids , 2008, 0810.3487.

[18]  Phillip Frank Gower Banfill,et al.  On the viscometric examination of cement pastes , 1981 .

[19]  Phillip Frank Gower Banfill,et al.  The rheology of fresh concrete , 1983 .

[20]  Nicolas Roussel,et al.  Correlation between Yield Stress and Slump: Comparison between Numerical Simulations and Concrete Rheometers Results , 2005 .

[21]  Nicolas Roussel,et al.  Steady and transient flow behaviour of fresh cement pastes , 2005 .

[22]  Philippe Coussot,et al.  Steady state flow of cement suspensions: A micromechanical state of the art , 2010 .

[23]  E. Liniger,et al.  Random loose packings of uniform spheres and the dilatancy onset. , 1990, Physical review letters.

[24]  Nicolas Roussel,et al.  From ordinary rhelogy concrete to self compacting concrete: A transition between frictional and hydrodynamic interactions , 2008 .

[25]  H. H. C. Wong,et al.  Passing ability and segregation stability of self-consolidating concrete with different aggregate proportions , 2006 .

[26]  P. Bowen,et al.  Changes in portlandite morphology with solvent composition: Atomistic simulations and experiment , 2011 .

[27]  Nicolas Roussel,et al.  A thixotropy model for fresh fluid concretes: Theory, validation and applications , 2006 .

[28]  Kamal H. Khayat,et al.  Assessment of Thixotropy of Flowable and Self-Consolidating Concrete , 2003 .

[29]  Thi Lien Huong Nguyen,et al.  General probabilistic approach to the filtration process. , 2007, Physical review letters.

[30]  P. M. J. Tardy,et al.  Models for flow of non-Newtonian and complex fluids through porous media , 2002 .

[31]  Young I Cho,et al.  Non-Newtonian Fluids in Circular Pipe Flow , 1982 .

[32]  K. Sorbie,et al.  The rheology of pseudoplastic fluids in porous media using network modeling , 1989 .

[33]  Nicolas Roussel,et al.  Rheology of fresh concrete: from measurements to predictions of casting processes , 2007 .