Simulating mixing processes of fresh concrete using the discrete element method (DEM) under consideration of water addition and changes in moisture distribution

Abstract The article presents a new model for the use in the framework of the Discrete Element Method to simulate the mixing processes of fresh concrete. The model provides a representation of liquid transfer from fluid entities or moist solid particles to dryer solid particles, including volume adaptation and mass conservation. The parameters and laws of force interactions between two particles are defined locally and depend on the amount and the properties of the liquid phase in the contact area. If two dry particles are in contact, friction and elastic forces are computed based on the Hertz-Mindlin model. If two particles with low moisture content are in contact, additional liquid bridge forces act on the particles. When the suspension state is reached, a Bingham-based model is applied. The simulation enables realistic estimation of the moisture distribution during the mixing processes, the corresponding changes in forces acting on the particles and consequently the effect on the rheological properties of the concrete mixture.

[1]  Russell G. Shepherd,et al.  Correlations of Permeability and Grain Size , 1989 .

[2]  E. C. Bingham.  An Investigation of the Laws of Plastic Flow , 2018 .

[3]  Hongming Li.  IMPACT OF COHESION FORCES ON PARTICLE MIXING AND SEGREGATION , 2005 .

[4]  Chiara F. Ferraris,et al.  Testing and Modelling of Fresh Concrete Rheology , 2017 .

[5]  Benjamin J. Glasser,et al.  Mixing characteristics of wet granular matter in a bladed mixer , 2010 .

[6]  Viktor Mechtcherine,et al.  Accurately meeting quality specifications using the virtual fresh concrete laboratory : Interaction of fresh concrete, process engineering and design , 2009 .

[7]  Phillip Frank Gower Banfill,et al.  THE RHEOLOGY OF FRESH CEMENT AND CONCRETE - A REVIEW , 2003 .

[8]  Daichao Sheng,et al.  A saturated discrete particle model and characteristic‐based SPH method in granular materials , 2007 .

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

[10]  Liberato Ferrara,et al.  Numerical simulations of concrete flow: A benchmark comparison , 2016 .

[11]  Nicolas Roussel,et al.  A Theoretical Frame to Study Stability of Fresh Concrete , 2005 .

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

[13]  Phillip Frank Gower Banfill,et al.  Rheology of fresh cement and concrete , 1991 .

[14]  Masayuki Horio,et al.  Numerical simulation of cohesive powder behavior in a fluidized bed , 1998 .

[15]  Viktor Mechtcherine,et al.  Simulating the behaviour of fresh concrete with the Distinct Element Method – Deriving model parameters related to the yield stress , 2015 .

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

[17]  Raymond D. Mindlin,et al.  Compliance of elastic bodies in contact , 1949 .

[18]  W. vom Berg,et al.  Influence of specific surface and concentration of solids upon flow behaviour of cement pastes , 1979 .

[19]  Viktor Mechtcherine,et al.  Developing a Discrete Element Model for simulating fresh concrete: Experimental investigation and modelling of interactions between discrete aggregate particles with fine mortar between them , 2013 .

[20]  Colin Thornton,et al.  A Theoretical Study of the Liquid Bridge Forces between Two Rigid Spherical Bodies , 1993 .

[21]  Thomas J. Dougherty,et al.  A Mechanism for Non‐Newtonian Flow in Suspensions of Rigid Spheres , 1959 .

[22]  Nicos Martys,et al.  The Rheology of Cementitious Materials , 2004 .

[23]  Hertz.  On the Contact of Elastic Solids , 1882 .

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

[25]  Winslow H. Herschel,et al.  Konsistenzmessungen von Gummi-Benzollösungen , 1926 .

[26]  James K. Cable.  Evaluation of Mix Time on Concrete Consistency and Consolidation , 1998 .

[27]  N. Li,et al.  Influence analyses of mixing approaches on properties of conventional and interlocking-dense concrete , 2016 .