A DEM hard-core soft-shell model for the simulation of concrete flow

Abstract A new DEM model for the simulation of concrete flow is presented. Fresh concrete is described as an assembly of composite particles made of spherical hard grains representing coarse aggregates surrounded by concentric spherical layers representing mortar. Two kinds of simulations are carried out: rheological simulations performed in a Couette geometry and slump test simulations. Rheological simulations show that the rheological behaviour of simulated concretes can be approximated with the Bingham model. The force model used allows for a direct relation between rheological characteristics of the mortar and rheological characteristics of the simulated concrete. Slump test simulations show that the model is able to describe the shape of concrete during the flow. The yield stresses and viscosities of numerical concretes are then calculated from the slump values and slump times with equations of the literature.

[1]  P. Cundall,et al.  A discrete numerical model for granular assemblies , 1979 .

[2]  Runyu Yang,et al.  Computer simulation of the packing of fine particles , 2000, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[3]  Xavier Chateau,et al.  Homogenization approach to the behavior of suspensions of noncolloidal particles in yield stress fluids , 2008, 1006.2293.

[4]  Surendra P. Shah,et al.  The influence of wall slip on yield stress and viscoelastic measurements of cement paste , 2001 .

[5]  Hiroshi Mori,et al.  FLOW SIMULATION OF FRESH CONCRETE CAST INTO WALL STRUCTURE BY VISCOPLASTIC DIVIDED SPACE ELEMENT METHOD , 1997 .

[6]  Spahn,et al.  Model for collisions in granular gases. , 1996, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[7]  A. Mizrahi,et al.  Simulation of the packing of granular mixtures of non-convex particles and voids characterization , 2008 .

[8]  Edward J. Garboczi,et al.  A Hard Core/Soft Shell Microstructural Model for Studying Percolation and Transport in Three-Dimensional Composite Media | NIST , 1999 .

[9]  S. Rémond.  DEM simulation of small particles clogging in the packing of large beads , 2010 .

[10]  Knut Krenzer,et al.  Simulation of fresh concrete flow using Discrete Element Method (DEM): theory and applications , 2014 .

[11]  F. Larrard.  Concrete Mixture Proportioning: A Scientific Approach , 1999 .

[12]  G. Delette,et al.  Green strength of binder-free ceramics , 2013 .

[13]  James G. Berryman,et al.  Random close packing of hard spheres and disks , 1983 .

[14]  Nicolas Roussel,et al.  “Fifty-cent rheometer” for yield stress measurements: From slump to spreading flow , 2005 .

[15]  F de Larrard,et al.  Modified Slump Test to Measure Rheological Parameters of Fresh Concrete , 1998 .

[16]  P. A. Langston,et al.  Discrete element simulation of granular flow in 2D and 3D hoppers: Dependence of discharge rate and wall stress on particle interactions , 1995 .

[17]  Leslie J. Struble,et al.  Rheology of fresh concrete , 1996 .

[18]  Gilles Pijaudier-Cabot,et al.  Numerical modelling of concrete flow: homogeneous approach , 2005 .

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

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

[21]  H Chu,et al.  EXPERIMENTAL EVALUATION AND THEORETICAL SIMULATION OF SELF COMPACTING CONCRETE BY THE MODIFIED DISTINCT ELEMENT METHOD (MDEM) , 1998 .

[22]  Howard A. Barnes,et al.  A review of the slip (wall depletion) of polymer solutions, emulsions and particle suspensions in viscometers: its cause, character, and cure , 1995 .

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

[24]  Christophe L. Martin,et al.  Compaction of aggregated ceramic powders: From contact laws to fracture and yield surfaces , 2010 .

[25]  Johan Silfwerbrand,et al.  Numerical simulation of fresh SCC flow: applications , 2011 .

[26]  B. Widom,et al.  Random Sequential Addition of Hard Spheres to a Volume , 1966 .

[27]  Hiroshi Mori,et al.  Simulation methods for Fluidity of fresh concrete. , 1992 .

[28]  C. O’Sullivan.  Particulate Discrete Element Modelling: A Geomechanics Perspective , 2011 .