Random aggregate model for mesoscopic structures and mechanical analysis of fully-graded concrete

Mesostructure models of three-phase fully-graded concrete are generated.A convex extension method is described to construct crushed coarse aggregates.An occupation and removal method is proposed to improve the efficiency of packings.A mesoscopic FEM is adopted to the flexural failure process of fully-graded concrete.The numerical results show a good in agreement with the experimental data. The realization of approximate practical aggregate models is a crucial link to the mesoscopic mechanical analysis for fully-graded concrete. This study systematically presents the establishment of mesostructure models of three-phase fully-graded concrete composed of anisotropic high-contented aggregates, cement paste, and interfaces bonding between them. A convex extension method is demonstrated in details to construct convex polygons and polyhedrons represented as crushed coarse aggregates in two- and three-dimensional spaces. The Walraven formula combined with the definition of an equivalent diameter is adopted to ensure the equivalence between the gradation and content of circle and spherical aggregates and that of the actual anisotropic geometric aggregates. We also propose a so-called occupation and removal method (ORM) to improve the efficiency of generating mesostructure models with a high aggregate content. Combining the ORM, the inter-particle overlap detection, and the random sequential packing scheme, random aggregate models (RAMs) of polygonal and polyhedral particles are realized to characterize the mesostructure models of concrete. Moreover, by the present RAMs applied, we implement a mesoscopic finite element simulation to investigate the flexural failure process of fully-graded concrete. The numerical results for dynamical flexural strength and dynamic increasing factors show a good in agreement with the experimental data reported in the literature. The proposed RAMs can simulate and explain qualitatively the effects of the mesoscopic structural properties on the macroscopic dynamic characteristics of fully-graded concrete.

[1]  Huisu Chen,et al.  Effects of particle size distribution, shape and volume fraction of aggregates on the wall effect of concrete via random sequential packing of polydispersed ellipsoidal particles , 2013 .

[2]  Huisu Chen,et al.  Aggregate shape effect on the diffusivity of mortar , 2014 .

[3]  M. Stroeven,et al.  Assessment of packing characteristics by computer simulation , 1999 .

[4]  Shunying Ji,et al.  Analytical effective elastic properties of particulate composites with soft interfaces around anisotropic particles , 2016 .

[5]  Peter Wriggers,et al.  An Introduction to Computational Micromechanics , 2004 .

[6]  Hamid Sadouki,et al.  Simulation and analysis of composite structures , 1985 .

[7]  Josef Eibl,et al.  STRAIN-RATE-SENSITIVE CONSTITUTIVE LAW FOR CONCRETE , 1999 .

[8]  Adnan Ibrahimbegovic,et al.  Failure of heterogeneous materials: 3D meso‐scale FE models with embedded discontinuities , 2010 .

[9]  S. H. Perry,et al.  Compressive behaviour of concrete at high strain rates , 1991 .

[10]  P. Wriggers,et al.  Mesoscale models for concrete: homogenisation and damage behaviour , 2006 .

[11]  Huaifa Ma,et al.  Interfacial effect on physical properties of composite media: Interfacial volume fraction with non-spherical hard-core-soft-shell-structured particles , 2015, Scientific Reports.

[12]  Huisu Chen,et al.  Quantitative characterization of the microstructure of fresh cement paste via random packing of polydispersed Platonic cement particles , 2012 .

[13]  A. Kwan,et al.  Sphericity, shape factor, and convexity measurement of coarse aggregate for concrete using digital image processing , 2000 .

[14]  Wen Chen,et al.  Theoretical estimation for the volume fraction of interfacial layers around convex particles in multiphase materials , 2013 .

[15]  Z. M. Wang,et al.  Mesoscopic study of concrete I: generation of random aggregate structure and finite element mesh , 1999 .

[16]  E. Garboczi.  Three-dimensional mathematical analysis of particle shape using X-ray tomography and spherical harmonics: Application to aggregates used in concrete , 2002 .

[17]  Yong Lu,et al.  Mesoscopic analysis of concrete under excessively high strain rate compression and implications on interpretation of test data , 2012 .

[18]  Ignacio Carol,et al.  3D meso-structural analysis of concrete specimens under uniaxial tension , 2006 .

[19]  Joost C. Walraven,et al.  Aggregate interlock: A theoretical and experimental analysis , 1980 .

[20]  Carsten Könke,et al.  Mesoscale modeling of concrete: Geometry and numerics , 2006 .

[21]  T I Zohdi,et al.  Genetic design of solids possessing a random–particulate microstructure , 2003, Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[22]  M. Tabbara,et al.  RANDOM PARTICLE MODEL FOR FRACTURE OF AGGREGATE OR FIBER COMPOSITES , 1990 .

[23]  L. J. Sluys,et al.  Mesoscopic Modeling and Simulation of the Dynamic Tensile Behavior of Concrete , 2013 .

[24]  Jörg F. Unger,et al.  Multiscale Modeling of Concrete , 2011 .

[25]  P. Stroeven,et al.  Capabilities for property assessment on different levels of the micro-structure of DEM-simulated cementitious materials , 2015 .

[26]  Chun’an Tang,et al.  NUMERICAL SIMULATION ON SHEAR FRACTURE PROCESS OF CONCRETE USING MESOSCOPIC MECHANICAL MODEL , 2002 .

[27]  Linhua Jiang,et al.  Prediction of transport behaviors of particulate composites considering microstructures of soft interfacial layers around ellipsoidal aggregate particles. , 2014, Soft matter.

[28]  A. Munjiza,et al.  The modelling of particle systems with real shapes , 2004, Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[29]  Kefei Li,et al.  Numerical and statistical analysis of elastic modulus of concrete as a three-phase heterogeneous composite , 2014 .

[30]  A. Ibrahimbegovic,et al.  Anisotropic constitutive model of plasticity capable of accounting for details of meso-structure of two-phase composite material , 2012 .

[31]  Huisu Chen,et al.  Numerical investigation of effect of particle shape and particle size distribution on fresh cement paste microstructure via random sequential packing of dodecahedral cement particles , 2013 .

[32]  Mohammadreza Yaghoobi,et al.  Mesoscale finite element prediction of concrete failure , 2011 .

[33]  T. Zohdi,et al.  Numerical estimation of effective electromagnetic properties for design of particulate composites , 2016 .

[34]  Erik Schlangen,et al.  Experimental and numerical analysis of micromechanisms of fracture of cement-based composites , 1992 .

[35]  Huisu Chen,et al.  Evaluation of Mesostructure of Particulate Composites by Quantitative Stereology and Random Sequential Packing Model of Mono-/Polydisperse Convex Polyhedral Particles , 2013 .