Publicly Available Computer Models

The following are models that are freely available to the general public. These models have come out of the HYPERCON: Prediction and Optimization of Concrete Performance research program and its predecessors. The technical background for most of these models can be found on-line in An Electronic Monograph: Modeling and measuring the structure and properties of cement-based materials.

For more information, contact:

Dale P. Bentz

E-mail: dale.bentz@nist.gov

For more information, contact:

Dale P. Bentz

E-mail: dale.bentz@nist.gov

Internal Curing with Lightweight Aggregates

For more information, contact:

Dale P. Bentz

E-mail: dale.bentz@nist.gov

Virtual Cement and Concrete Testing Laboratory

For more information, contact:

Jeffrey W. Bullard

E-mail: jeffrey.bullard@nist.gov

Concrete Optimization Software Tool (COST)

For more information, contact:

Dale P. Bentz

E-mail: dale.bentz@nist.gov

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 an article in the December 1996 issue of Concrete International.

For more information, contact:

Dale P. Bentz

E-mail: dale.bentz@nist.gov

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.

For Windows-based PCs, a pre-compiled version of version 2.0 CEMHYD3D may be installed by opening and running the setup program cemhyd3d_setup.exe.

Image files and particle size distributions for use with the 3-D model are available by clicking here.

For more information, contact:

Dale P. Bentz

E-mail: dale.bentz@nist.gov

HCSSMODEL, a three-dimensional concrete microstructure modelling package is available from the pub/bfrl/bentz/HCSSMODEL subdirectory via anonymous ftp at ftp.nist.gov. A postscript version of the user's manual (NISTIR 6265) is available at the same address in the HCSSMODEL/manual subdirectory. The manual is also available online at the Electronic Monograph, Part I, Chapter 6, Sec. (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 P. Bentz

E-mail: dale.bentz@nist.gov

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 from

Edward J. Garboczi

E-mail: edward.garboczi@nist.gov

4SIGHT Computer Program

HTML Interface

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, concrete member dimensions

4SIGHT does not currently model degradation. Rather, it models the reactions, and corresponding changes in transport coefficients, that may occur. Documentation on the 4SIGHT program is also available from NTIS (NISTIR-5612, NISTIR-6747). Additional inquiries may be made via the web or e-mail:

Kenneth Snyder

E-mail: kenneth.snyder@nist.gov

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.

The software is bundled with a User's Manual and a Technical Report describing its use. Further information may be requested by e-mail:

Dale P. Bentz

E-mail: dale.bentz@nist.gov

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.

The software was developed using MathWorks' MATLAB package. It is distributed as a MATLAB file that can be used immediately with MATLAB. For those without MATLAB, the software has been converted to the C programming language and should compile on platforms having a C compiler available. Both the MATLAB version and the C version are bundled in the download, along with installation instructions.

Available downloads:

• sulfate2.zip (for PC)
• sulfate2.tar.gz (for Unix/Linux)

Further information or help may be requested by e-mail:

E-mail: barzin@asu.edu

ACBM/NIST Computer Modeling Workshop

This four-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 20th in this series will be held in the summer of 2009, at NIST. Updated information on this workshop may be obtained at this address . Persons interested in participating in an upcoming workshop may contact the workshop coordinator,

Edward J. Garboczi

E-mail: edward.garboczi@nist.gov

Cement Hydration Modelling

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.

Dale P. Bentz

E-mail: dale.bentz@nist.g ov

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