This chapter discusses cement and concrete characterization. It covers both microscopy of various kinds (scanning electron and optical) and x-ray diffraction analysis. Images of cement and concrete microstructure are important in their own right, for analysis and characterization. They are also important as a basic input for modelling the microstructure, and as a check as to how well that microstructure has been modelled. X-ray diffraction, especially as interpreted by Rietveld analysis, can give very precise information on phase composition of cements and clinkers. Standard reference materials serve a vital importance in calibrating instruments, and so a link to some of the NIST cementitious reference materials are provided. The particle size distribution of cement can greatly affect its hydration performance, so it has become of importance to routinely measure it.
Much of NIST microscopy expertise and many NIST images have gone into the development of the Concrete Microscopy Library, which provides a basic introduction to concrete microscopy, and many examples of images of materials.
This section describes the use of the Rietveld method for powder x-ray diffraction to analyze the composition of NIST reference material clinkers. The results of this method is compared to optical microscopy results using careful statistical analysis.
(2g) Powder Diffraction Analysis of Hyraulic Cements: ASTM Rietveld Round Robin Results on Precision (P. E. Stutzman, to be published in Proceedings of the 53th Annual Denver X-Ray Conference, Steam Boat Springs, CO, August 2-6, 2004)
This section describes how to prepare specimens for scanning electron microscopy so as to avoid mixing artifacts of preparation with real microstructural features. Some discussion and examples are given of artifacts that can be seen due to incomplete sample preparation. (13 pages of text, 2127 kbytes of figures)
This section covers the scanning electron microscopy and image processing techniques used to obtain starting 2-D images of cement-based materials (cement powder, fly ash, etc.) dispersed in an epoxy resin.
This section discusses the results from a study of pavement concrete problems in Iowa. The study was made using a number of techniques, including scanning electron microscopy, x-ray microprobe analysis, optical microscopy, and image analysis.
Concrete petrography is used to assess damaged concrete in order to determine the probable mechanism of damage. However, using traditional petrographic analyses, it is often difficult to say what mechanisms caused the crack damage, since many deterioration mechanisms produce cracks. This article describes a hybrid imaging-finite element modelling technique that can be used to help determine the mechanism of damage in such cases.
Synchrotron-based X-ray computed microtomography, at a voxel size of about 1 micrometer per voxel side length, was used to examine the microstructure of hydrating cement paste, hardening plaster-of-paris, and a brick material. This section describes the data obtained and how to download data sets for further use.
The results of the Visible Cement database for cements that had only just set were used to extract shape information for thousands of the actual cement particles. This section describes how this shape information was obtained and how it was used to modify the NIST CEMHYD3D model so as to incorporate real shape information into model cement paste microstructures.
A quantitative comparison of real and CEMHYD3D model microstructures has been made utilizing the visible cement data set. The study is based on visual comparisons and analysis of the two-point correlation functions of various components of the microstructures (porosity, unhydrated cement, and hydration products). As indicated in the paper, the comparisons are generally quite favorable.
This section describes the results from an ASTM-sponsored round-robin test on measuring the particle size distribution (PSD) of portland cement. It describes the various methods used and the results obtained by the various operators. This is an on-going research project, so more material will be periodically added to this section.
Go back to Chapter 2. Concrete rheology
(2a) P.E. Stutzman and S. Leigh, Proc. of 22nd International Conference on Cement Microscopy, April 30-May 2, 2000, Montreal, Quebec, Canada (2000).
(2b) P.E. Stutzman and S. Leigh, National Institute of Standards and Technology Technical Note 1441, September (2002).
(2c) Standard Reference Materials Program, National Institute of Standards and Technology, Gaithersburg, MD 20899 (2002).
(2d) Standard Reference Materials Program, National Institute of Standards and Technology, Gaithersburg, MD 20899 (2002).
(2e) Standard Reference Materials Program, National Institute of Standards and Technology, Gaithersburg, MD 20899 (2002).
(2f) P.E. Stutzman and S. Leigh, Accuracy in Powder Diffraction III. Proceedings. National Institute of Standards and Technology, April 22-25, 2001, Gaithersburg, MD Poster #2, (2001).
(2g) P.E. Stutzman, to be published in Proceedings of the 53th Annual Denver X-Ray Conference, Steam Boat Springs, CO, August 2-6, 2004.
(2h) P.E. Stutzman, Proceedings of the 52nd Annual Denver X-Ray Conference, Steam Boat Springs, CO, August 4-7, 2003.
(3) P.E. Stutzman and J.R. Clifton, Proceedings of the 21st International Conference on Cement Microscopy, ed. by J. Jany and A. Nisperos, April 25-29, 1999, Las Vegas, Nevada, pp. 10-22 (1999).
(4a) D.P. Bentz, P.E. Stutzman, C.J. Haecker, and S. Remond, Proceedings of the 7th Euroseminar on Microscopy Applied to Buildings Materials, Eds: H.S. Pietersen, J.A. Larbi, and H.H.A. Janssen, Delft University of Technology, pp. 457-466 (1999).
(4b) D.P. Bentz, and P.E. Stutzman, Petrography of Cementitious Materials, ASTM STP 1215, Sharon M. DeHayes and David Stark, Eds., American Society for Testing and Materials, Philadelphia, pp. 60-73, (1994).
(4c) P.E. Stutzman, Cement and Concrete Composites 26 (8), 957-966 (2004).
(5) P.E. Stutzman, National Institute of Standards and Technology Internal Report 6399, December, (1999).
(6) P.E. Stutzman, D.S. Bright, E.J. Garboczi, Twenty-Third International Conference on Cement Microscopy. Proceedings. April 29-May 4, 2001, Albuquerque, NM, 352-365. (2001).
(7a) D.P. Bentz, S. Mizell, S. Satterfield, J. Devaney, W. George, P. Ketcham, J. Graham, J. Porterfield, D. Quenard, F. Vallee, H. Sallee, E. Boller, and J. Baruchel, Journal of Research of the National Institute of Standards and Technology 107 (2), 137-148 (2002).
(7b) E.J. Garboczi and J.W. Bullard, Cement and Concrete Research 34 (10), 1933-1937 (2004).
(7c) D.P. Bentz, Cement and Concrete Research 36 (2), 238-244 (2006).
(8a) C.F. Ferraris, V.A. Hackley, A.I. Aviles, C.E. Buchanan, Jr., National Institute of Standards and Technology Internal Report 6883, Technology Administration, U.S. Dept. of Commerce, (2002).
(8b) C.F. Ferraris, V.A. Hackley, A.I. Aviles, C.E. Buchanan, Jr., National Institute of Standards and Technology Internal Report 6931, Technology Administration, U.S. Dept. of Commerce (2002).
(8c) V.A. Hackley, L. Lum, V. Gintautas, C.F. Ferraris, National Institute of Standards and Technology Internal Report 7097, Technology Administration, U.S. Dept. of Commerce (2004).
(8d) C.F. Ferraris, V.A. Hackley, and A.I. Aviles, Cement, Concrete and Aggregates 26 (2), 71-81 (2004).
(8e) C.F. Ferraris, W. Guthrie, A.I. Aviles, M. Peltz, R. Haupt, and B.S. MacDonald, NIST Special Publication 260-166.