Measurement of Rheological Properties of High Performance Concrete: State of the Art Report.
Measurement of Rheological Properties of High
Performance Concrete: State of the Art Report.
(408 K)
Ferraris, C. F.
Journal of Research of the National Institute of
Standards and Technology, Vol. 104, No. 5, 461-478,
September/October 1999.
Available from:
Available Online:
Website: http://www.nist.gov/jres
Keywords:
building technology; rheology; cement paste; mortar;
concretes; rheology test methods; flow properties;
suspension; workability; measurement; prediction; models
Abstract:
The rheology or flow properties of concrete in general
and of high performance concrete (HPC) in particular,
are 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.
Predictions of the flow properties of concrete from its
composition or from the properties of its components are
not easy. No general model exists, although some
attempts have been made. This paper gives an overview
of the flow properties of a fluid or a suspension,
followed by a critical review of the most commonly used
concrete rheology tests. 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.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899