The following are models that are freely available to the general public. These models have come out of the Sustainable Engineering Materials program and its predecessors including the HYPERCON: Prediction and Optimization of Concrete Performance research program. The technical background for most of these models can be found online in An Electronic Monograph: Modeling and measuring the structure and properties of cement-based materials.
The 4SIGHT computer program was written to facilitate concrete performance prediction under various exposure conditions. An HTML GUI now exists, so users can now use the program. The web page contains entries for the user to specify concrete properties and the boundary conditions (ionic species in contact with the concrete). 4SIGHT uses the cedar++ C++ object code library to perform a transport and reaction calculation based on user input. Currently, relevant user input includes concrete mixture proportions, cement properties, crack properties, and concrete member dimensions.
Cement Hydration Modeling
Computer programs for modeling cement hydration and percolation processes.
Version 3.0 of CEMHYD3D (released in June of 2005), a three-dimensional cement hydration and microstructure development modelling package.
Chloride-Exposed Steel-Reinforced Concrete Service Life Prediction Program (Prototype)
A prototype program that addresses the service life prediction of steel-reinforced concrete exposed to chloride ions.
Computation of Water-to-Cement Distance Function
A menu-based system for computing the water-to-cement distance (proximity) function for user selected values of w/c and cement particle size distribution.
Finite Element/Finite Difference Programs
The software contains programs for computing the linear elastic and linear electric properties of digital images in 2-D and 3-D. These digital images can be of random materials, acquired experimentally or generated by models, or of any other kind of material, whether random or not. The programs are all in simple Fortran 77, and read in the "microstructure" file they are using. There are programs for DC and AC electrical conductivity, linear elasticity, and thermal elasticity.
A three-dimensional concrete microstructure modelling package.
Internal Curing with Lightweight Aggregates
A series of models and publications concerned with mixture proportioning and other aspects of internal curing.
A computer application for automatically calculating a range of microstructural properties from an indexed 2D image. Among the properties calculated are the volume fraction, mass fraction, and surface area fraction of each phase in the image, as well as two-point correlation functions for quantifying the spatial distribution of the phases throughout the structure. The application also enables the user to package the data obtained on cement powders for uploading to the Virtual Cement and Concrete Testing Laboratory Consortium (VCCTL) software.
Stokes Three-Dimensional Permeability Solver
In 2007, the Fortran and C language computer codes developed in the Inorganic Materials Group at NIST are being made publicly available for the first time. The codes allow for the computation of the permeability of any digitized porous microstructure, consisting of voxels of solids and pores.
A user-friendly software for computing the resistance of concrete to sulfate attack. It is a continuum model, which means that it solves coupled partial differential nist-equations for transport and reactions subject to known boundary conditions, without resolving microstructural details.
These software packages were developed at the National Institute of Standards and Technology by employees of the Federal Government in the course of their official duties. Pursuant to title 17 Section 105 of the United States Code this software is not subject to copyright protection and is in the public domain. These software packages represent experimental systems. NIST assumes no responsibility whatsoever for their use by other parties, and makes no guarantees, expressed or implied, about their quality, reliability, or any other characteristic. We would appreciate acknowledgement if the software packages are used.
These software packages can be redistributed and/or modified freely provided that any derivative works bear some notice that they are derived from these original packages, and any modified versions bear some notice that they have been modified.