The HRWRA helps in achieving excellent flow at low water contents and VMA reduces bleeding and improves the stability of the concrete mixture.
An effective VMA can also bring down the powder requirement and still give the required stability.
Many researchers have been able to produce self-compacting concrete with locally available aggregate.
It is observed from these studies that self-compactability is achievable at lower cement (or fines) content when rounded aggregates are used, as compared to angular aggregates.
Moreover, the presence of flaky and elongated particles may give rise to blocking problems in confined areas, and also increase the minimum yield stress (rheology terms are discussed in the next section).
Incorporation of aggregate shape in the mixture design would enable the selection of appropriate paste content required to overcome these difficulties.
The Brite-Euram SCC project– has developed specifications and guidelines for the use of SCC that covers a number of topics, ranging from materials selection and mixture design to the significance of testing methods.