- Author
- Bentz, D. P. | Haecker, C. J.
- Title
- Argument for Using Coarse Cements in High-Performance Concretes.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD Wilhelm Dyckerhoff Institut, Wiesbaden, Germany
- Journal
- Cement and Concrete Research, Vol. 29, 615-618, 1999
- Keywords
- concretes | hydration | particle size distribution
- Identifiers
- high-performance concrete; microstructure
- Abstract
- The NIST cement hydration microstructural model and experimental studies are used to investigate the effects of particle size distribution and water-to-cement ratio on hydration kinetics. Cement hydration is limited by the availability of water at the cement particle surfaces. Because a reaction layer forms around each cement particle during hydration, this availability is controlled by two factors: the overall water-to-cement ratio and the particle size distribution of the cement. As the water-to-cement ratio is decreased, the effects of particle size distribution on ultimate degree of hydration become less significant. Thus, in the new generation, high-performance concretes, more coarsely ground cements may provide good performance, resulting in substantial energy savings due to a reduction in grinding time. This implies that cement fineness should be optimized based on the mixture proportions of the concrete in which it will be used.