Workability of Self-Compacting Concrete.
Workability of Self-Compacting Concrete.
(2554 K)
Ferraris, C. F.; Brower, L.; Ozyildirim, C.; Daczko, J.
High Performance Concrete International Symposium.
Economical Solution for Durable Bridges and
Transportation Structures. Proceedings. PCI/FHWA/FIB.
September 25-27, 2000, Orlando, FL, 398-407 pp, 2000.
Keywords:
concretes; test methods
Abstract:
The slump test is widely used to evaluate the
workability of Concrete. However it has serious
drawbacks, especially for self-compacting concrete
(SCC). Other flow characteristics such as viscosity or
filling capacity or time of flow through an orifice are
needed to characterize flow in SCC. The goals of this
study were multiple: 1) to test flow characteristics of
SCC using various devices: two concrete rheometrers,
several standard tests, and the widely used V-flow and
U-flow tests; 2) to determine the correlation between
the two rheometers; and 3) to attempt to determine the
rheological characteristics of SCC. Thirteen mixes were
prepared with varying dosages of viscosity modifying
admixture (VMA) and high-range water-reducing admixture
(HRWR) to achieve a wide range of flow behavior. It was
found that the plastic viscosities, measured with the
two rheometers were correlated at 84% and that a SCC
mixture is not defined by the high slump and slump
spread alone.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899