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Chloride-Exposed Steel-Reinforced Concrete Service Life Prediction Program

Description/Summary:

(Return to Cement Hydration and Degradation Modeling Software)

In the last decade or so, numerous advances have occurred in the field of information technology. Through the use of computers, the amount of available information and the speed at which it can be retrieved have both increased dramatically. The proliferation of the Internet and the World Wide Web (WWW) now allows researchers to rapidly access a wealth of multimedia information on a seemingly infinite variety of topics. The World Wide Web also provides a convenient format for executing computer programs over the Internet, for example through the use of forms and Common Gateway Interface (CGI) scripts or other Internet programming languages.

A computer-integrated knowledge system (CIKS) provides a means of combining this wealth of information into a coherent system that produces useful results for both the academic and commercial communities. A CIKS should provide the knowledge needed for solving problems with a range of complexities, based on an integrated set of knowledge which is interpreted by an underlying intelligent system. For the concrete community, a subject of vital interest is the service life of concrete structures. One common mode of degradation for highway structures and those exposed to seawater is corrosion of the reinforcing steel. The diffusion rate at which chloride ions can reach the steel is one of the controlling factors in determining how long such a structure will last.

The present research addresses the development of a prototype CIKS with the goal of predicting the service life of a steel-reinforced concrete exposed to chloride ions. Starting from the mixture proportioning process, the system proceeds to predict chloride ion diffusivity coefficients and to finally predict the ingress profiles or time to corrosion initiation for a reinforced concrete exposed in a specific environment. This prototype system demonstrates the potential of disseminating knowledge on specific topics in concrete technology to the construction industry through the use of the World Wide Web.

New users must register by providing their name and specifying a password to be used in future sessions. In addition, from this main screen, the user has the option to select either SI or inch-pound units to be used in all subsequent forms. A profile is maintained for each user so that future sessions can restore the parameters last input by that specific user (as long as the same units are selected from the welcome form). Online guidance, via separate help pages of text and graphics, is provided throughout the system as indicated by highlighted Guidance indicators.

Details

Type of software: Service Life Prediction Program for Chloride-Exposed Steel-Reinforced Concrete

Authors:

System/Platform:

Hypertext markup language (HTML/JavaScript)

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References/Credits/Disclaimers:

This software was 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. This software is an experimental system. NIST assumes no responsibility whatsoever for its use by other parties, and makes no guarantees, expressed or implied, about its quality, reliability, or any other characteristic. We would appreciate acknowledgement if the software is used.

This software can be redistributed and/or modified freely provided that any derivative works bear some notice that they are derived from it, and any modified versions bear some notice that they have been modified.

Contact

General Information:
Dale P. Bentz, Chemical Engineer, Inorganic Materials Group 301-975-5865 Telephone

100 Bureau Drive, M/S 8615
Gaithersburg, MD 20899-8615