Hydration Description

Cement Hydration and Microstructure Development

In the Cementitious Materials Modelling Laboratory at the National Institute of Standards and Technology, researchers have developed two and three-dimensional digital-image-based computer models for the hydration of Portland Cement. The starting input image can consist of a real image captured using a scanning electron microscope (SEM) or a collection of spherical particles reconstructed in 3-D to match the particle size distribution, phase volume fractions, and phase surface fractions of a real cement. The models use cellular automaton rules to simulate dissolution, diffusion, and reaction processes, as shown in the movie Two-dimensional Cement Hydration. The movie Three-Dimensional Multi-Phase Particles illustrates a flight through a 3-D starting system containing four-phase particles as well as separate gypsum particles.

Output consists of the degree of hydration, phase volume fractions, heat released, and chemical shrinkage under isothermal or adiabatic conditions as well as a detailed 3-D image of the cement microstructure at any degree of hydration of interest. This 3-D structure can then be used in other computational programs to calculate ion diffusivity, phase percolation, or elastic modulus. In general, agreement with experimental data is quite good. Current research is concentrated on extending the model to consider various sources of sulfate (gypsum, hemihydrate, and anhydrite) and provide for a variable C-S-H gel stoichiometry as a function of curing temperature.

Want to learn more about cement. An excellent starting point is the Portland Cement Association.

Recent Publications

Bentz, D.P., , CEMHYD3D: A Three-Dimensional Cement Hydration and Microstructure Development Modelling Package. Version 3.0, NISTIR 7232, U.S. Department of Commerce, June, 2005.

Bentz, D.P., Haecker, C.J., Feng, X.P. and Stutzman, P.E., "Prediction of cement physical properties by virtual testing," Process Technology of Cement Manufacturing. Proceedings of the Fifth International VDZ Congress, Dusseldorf, Germany, September 23-27, 2002, 53-63, (2003) and Cement International, 1 (3) 86-92, (2003). (PDF Version)

Bentz, D.P., Garboczi, E.J., Haecker, C.J., and Jensen, O.M., Effects of Cement Particle Size Distribution on Performance Properties of Portland Cement-Based Materials, Cement and Concrete Research, 29 (10), 1663-1671, 1999. (PDF Version)

Bentz, D.P., Stutzman, P.E., Haecker, C.J., and Remond, S., SEM/X-ray Imaging of Cement-Based Materials, in Proceedings of the 7th Euroseminar on Microscopy Applied to Building Materials, Delft University of Technology, pp. 457-466 (1999).

Bentz, D.P. and Haecker, C.J., An Argument for Using Coarse Cements in High Performance Concretes, Cement and Concrete Research, Vol. 29 (4), 615-618, 1999.

Bentz, D.P., , CEMHYD3D: A Three-Dimensional Cement Hydration and Microstructure Development Modelling Package. Version 2.0, NISTIR 6485, U.S. Department of Commerce, April, 2000.

Bentz, D.P., "Three-Dimensional Computer Simulation of Portland Cement Hydration and Microstructure Development", Journal of the American Ceramic Society, 80 (1), 3-21, 1997.

Bentz, D.P., A Three-Dimensional Cement Hydration and Microstructure Program. I. Hydration Rate, Heat of Hydration, and Chemical Shrinkage, NISTIR 5756, U.S. Department of Commerce, November, 1995.

Bentz, D.P., Coveney, P.V., Garboczi, E.J., Kleyn, M.F., and Stutzman, P.E., Cellular Automaton Simulations of Cement Hydration and Microstructure Development, Modelling and Simulation in Materials Science and Engineering, Vol. 2 (4), 783-808, 1994.

Garboczi, E.J., and Bentz, D.P., "Computational Materials Science of Cement-Based Materials", MRS Bulletin, Vol. 18 (3), 50-54, 1993.

Bentz, D.P., Schlangen, E., and Garboczi, E.J., "Computer Simulation of Interfacial Zone Microstructure and Its Effects on the Properties of Cement-Based Materials", in Materials Science of Concrete IV, Eds. J.P. Skalny and S. Mindess, American Ceramic Society, Westerville, OH, 1994.

Bentz, D.P., and Stutzman, P.E., "SEM Analysis and Computer Modelling of Hydration of Portland Cement Particles", in Petrography of Cementitious Materials, ASTM STP 1215, Eds. S.M. DeHayes and D.Stark, American Society for Testing and Materials, Philadelphia, 60-73, 1994.