A Hard Core/Soft Shell Microstructural Model for Studying Percolation and Transport in Three-Dimensional Composite Media

Published: January 01, 1999


Dale P. Bentz, Edward J. Garboczi, Kenneth A. Snyder


This user's manual provides documentation and computer program listings for the three-dimensional hard core/soft shell microstructure model developed at the National Institute of Standards and Technology. The model has been developed to represent the three phase microstructure of a concrete composite consisting of a bulk matrix (cement paste), hard core particles located at random in the bulk (aggregates), and a concentric soft shell surrounding each hard core particle (interfacial transition zone paste). However, this microstructural model is generic in nature and has also been applied to modelling air voids in concrete, macro-defect-free cements, and silica sol gels. Any system consisting of partially overlapping or totally non-overlapping spherical particles can be modelled using the developed computer programs, perhaps with some minor modifications. In addition to generating a representative 3-D microstructure, the programs can also be used to assess the percolation characteristics of the microstructure and estimate a diffusivity (or electrical or thermal conductivity) for the composite media. Complete program listings and example datafiles are provided in the appendices of this documentation and the software is also available for dowloading via anonymous ftp.
Citation: NIST Interagency/Internal Report (NISTIR) - 6265
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Pub Type: NIST Pubs

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building technology, computer modeling, concrete, diffusivity, hard core/soft shell, microstructure, percolation, simulation
Created January 01, 1999, Updated February 19, 2017