- Author
-
Ferraris, C. F.
- Title
- Measurement of Rheological Properties of High Performance Concrete: State of the Art Report.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Report
-
NISTIR 5869,
July 1996,
39 p.
- Distribution
- Available from National Technical Information Service
- Keywords
-
building technology
|
rheology
|
cement paste
|
mortar
|
concretes
|
rheology test methods
|
flow properties
|
suspension
|
workability
|
measurements
|
prediction
|
models
- Abstract
- The rheology or flow properties of concrete in general and of high performance concrete (HPC) in particular, is important, because many factors such as ease of placement, consolidation, durability, and strength depend on the flow properties. Concrete that is not properly consolidated may have defects like honeycombs, air voids, and aggregate segregation. Such an important performance attribute has triggered the design of numerous test methods. Generally, the flow behavior of concrete approximates that of a Bingham fluid. Therefore, at least two parameters, yield stress and viscosity, are necessary to characterize the flow. Nevertheless, most methods measure only one parameter. Prediction of the flow properties of concrete from its composition or from the properties of its components is not easy. No general model exists, although some attempts have been made. This report gives an overview of the flow properties of a fluid or a suspension, followed by a critical review of the most often used tests for concrete rheology. Particular attention is given to tests that could be used for HPC. Tentative definitions of terms such as workability, consistency and rheological parameters are provided. An overview of the most promising tests and models for cement paste is given.