Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.



(Return to Cement Hydration and Degradation Modeling Software)

Accurate quantitative data on cement and clinker microstructure images can prove valuable for monitoring and controlling the manufacturing of cement-based powders. Furthermore, quantitative characterization of microstructure is an essential input to microstructure-based computer models of cementitious material processing and properties. This document describes the use and operating principles of MicroChar, 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.


This software was developed at the National Institute of Standards and Technology (NIST) 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. NIST assumes no responsibility whatsoever for the use of MicroChar by other parties, and makes no guarantees, expressed or implied, about its quality, reliability, or any other characteristic. NIST would appreciate acknowledgment, such as an appropriate citation in a publication, if the software is used.

The U.S. Department of Commerce makes no warranty, expressed or implied, to users of MicroChar, and accepts no responsibility for its use. Users of MicroChar assume sole responsibility under Federal law for determining the appropriateness of its use in any particular application; for any conclusions drawn from the results of its use; and for any actions taken or not taken as a result of analyses performed using these tools. All results should be critically evaluated by an informed user.

Intent and Use
The computer program described in this guide constitutes a prototype application for quantitative image analysis of cement powder and clinker microstructures. It has been compiled from the best knowledge and understanding currently available, but has some limitations that must be understood and considered by the user. MicroChar is intended for use by persons competent in the field of cement-based materials and having some familiarity with computers.


Created June 23, 2017, Updated November 15, 2019