Cement Hydration and Degradation Modeling Software
The following are models that are freely available to the general public. They have been developed under the research program HYPERCON: Prediction and Optimization of Concrete Performance. The technical background for most of these models can be found online in An Electronic Monograph: Modeling and measuring structure and properties of cement-based materials.
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 the water-cement mass ratio and cement particle size distribution can be found at http://concrete.nist.gov/cementspacing.html
Stokes Three-Dimensional Permeability SolverThese Fortran and C language computer codes allow the computation of the permeability of any digitized porous microstructure consisting of voxels of solids and pores. The codes are available at ftp://ftp.nist.gov/pub/BFRL/bentz/ and a user manual is available as a PDF document. If you have difficulty reading this document please contact firstname.lastname@example.org.
For more information, contact Dale Bentz (email@example.com)
Internal Curing with Lightweight Aggregates
A series of models and publications concerned with mixture proportioning and other aspects of internal curing are available at http://concrete.nist.gov/lwagg.htmlFor more information, contact Dale Bentz (firstname.lastname@example.org)
Concrete Optimization Software Tool (COST)
Version 1.0 of the FHWA/NIST concrete optimization software tool is available at http://concrete.nist.gov/cost/. The user manual is also available online. COST is a system for optimizing concrete mixture proportions based on response surface methodology experimental design principles and statistical analysis. It provides the user with a matrix of concrete mixture proportions to prepare and test and then performs a statistics-based graphical analysis of the results to determine the optimum mixture proportions based on the user's performance criteria.For more information, contact Dale Bentz (email@example.com)
A Prototype Service Life Prediction Program
A prototype program that addresses the service life prediction of steel-reinforced concrete exposed to chloride ions is available at http://concrete.nist.gov/ciks.html. The system is also described in detail in the December 1996 issue of Concrete International.For more information, contact Dale Bentz (firstname.lastname@example.org)
CEMHYD3D Computer Program
Version 3.0 of CEMHYD3D (released in June of 2005), a three-dimensional cement hydration and microstructure development modelling package is available from the pub/bfrl/bentz/CEMHYD3D/version30 subdirectory via anonymous ftp at ftp.nist.gov. A pdf version of the user's manual (NISTIR 7232) is available at the same address in the CEMHYD3D/version30/manual subdirectory. The manual is also available online at the Electronic Monograph Appendix I-2.
HCSSMODEL Computer Program
HCSSMODEL, a three-dimensional concrete microstructure modeling package is available from the pub/bfrl/bentz/HCSSMODEL subdirectory via anonymous ftp at ftp.nist.gov. A postscript version of the user manual (NISTIR 6265) is availalbe at the same address in the HCSSMODEL/manual subdirectory. The manual is also available online at the Electronic Monograph, Part I, Chapter 6, Section 8.
For Windows-based PCs, a pre-compiled version of HCSS may be installed by opening and running the setup program hcss_setup.exe.For more information, contact Dale Bentz (email@example.com)
Finite Element/Finite Difference Programs
The pub/bfrl/garbocz/FDFEMANUAL/ directory 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. Documentation is available on-line at the Electronic Monograph, Part II, Chapter 2. The pub/bfrl/garbocz/FDFEMANUAL/ directory also contains postscipt and pdf versions of this manual. Hard copies (NISTIR 6269) may be requested.
4SIGHT Computer Program
The 4SIGHT computer program was written to facilitate concrete performance prediction under various exposure conditions. An HTML GUI now exists, so users can now go to the 4SIGHT web page to 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.
4SIGHT does not currently model degradation. Rather, it models the reactions, and corresponding changes in transport coefficients, that may occur. Documentation of the 4SIGHT program is also available from NTIS (NISTIR 5612, NISTIR 6747). Additional inquiries may be made via the web or e-mail.For more information, contact Kenneth Snyder (firstname.lastname@example.org)
CONCLIFE Computer Program
CONCLIFE is Windows-based, user-friendly software for estimating the service life of concrete pavements and bridge decks exposed to sulfate attack and freeze-thaw deterioration. The software was developed jointly between researchers at NIST and the Federal Highway Administration (FHWA). CONCLIFE uses three concrete models and user-specified data on concrete properties and external environmental conditions to estimate the time at which the concrete spalls beyond a user-specified limit. Sorptivity of sulfate ions and water are the primary means of degradation; the software uses a laboratory test for measuring concrete sorptivity, annual precipitation, and estimated rates of concrete spalling.
SULFATE2 Computer Program
SULFATE2 is user-friendly software for computing the resistance of concrete to sulfate attack. The model was developed by Professor Barzin Mobasher at Arizona State University. It is a continuum model, which means that it solves coupled partial differential equations for transport and reactions subject to known boundary conditions, without resolving microstructural details. The response of the concrete (expansion and cracking) is modeled by continuum damage mechanics.
Further information or help may be requested by e-mail: email@example.com
NIST Computer Modeling Workshop
This three-day workshop covers the topics of cement hydration modeling, percolation theory, and computation of transport and mechanical properties along with the key experimental techniques that complement and help validate the models. There is no registration fee to attend the workshop. The 22nd in this series will be held in the summer of 2010 at NIST. Updated information on this workshop may be obtained at this address.
Cement Hydration Modeling
The pub/bfrl/bentz/CMML directory at ftp.nist.gov contains computer programs for modelling cement hydration and percolation processes. Software for IBM and Macintosh-compatible PCs is available in the directories educ-mod/ibmcomp and educ-mod/maccomp respectively, both accessible from the CMML subdirectory. Documentation for these models is available at the Electronic Monograph. Courtesy of Technion, Israel Institute of Technology, a Windows XP-based version of the hydration program is available in the directory educ-mod/windowsxp. Many thanks to Prof. Kostantin Kovler for providing the version and to Semion Zhutovsky for doing the actual programming.For more information, contact Dale Bentz (firstname.lastname@example.org)