By 1988, the concept was developed and ready for the first real-scale tests.
The first paper on SCC was presented at the second East-Asia and Pacific Conference on Structural Engineering and Construction (EASEC-2) in 1989, followed by another presentation at an Energy Diversification Research Laboratories (CANMET)/American Concrete Institute (ACI) meeting in 1992.
(1) In 1997, a RILEM committee (TC 174) on SCC was founded.
Today, SCC is studied worldwide with papers presented in almost every concrete-related conference.
The dimensions may vary from one country to the other.
A rheometer is a device that applies a range of shear rates and monitors the force needed to maintain these shear rates in a plastic material. A few concrete and mortar rheometers are available on the market and have been and are still used for measuring the yield stress, viscosity and other rheological characteristics of SCC.
A few of them are briefly presented in the following paragraphs.Because conventional concrete is placed using external energy, there is no need for specific rheological characteristics.As a matter of fact, the intensity of energy applied in the consolidation process is adjusted to compensate most plastic property variation.(In rheological terms, even though a significant amount of research tends to show that SCCs viscosity varies with the shear rate and acts as a pseudoplastic material, SCC is often described as a Bingham fluid (viscoelastic) where the stress/shear rate ratio is linear and characterized by two constantsviscosity and yield stress (Table 1).This latter model will be used in the following paragraphs because of its simplicity.)Back to the performance-based definition of SCC, the self-consolidation is mainly governed by yield stress, while the viscosity will affect the homogeneity and the ability to flow through reinforcement (Table 2).