Vibration of self consolidating concrete
Delivery methods include cast-in-place, precast, and tilt-up, and in every case, good appearance is essential.
Achieving good surface characteristics requires thorough consolidation of the fresh concrete and thoroughly filled forms.
Concrete that segregates loses strength and results in honeycombed areas next to the formwork.
A well designed SCC mix does not segregate, has high deformability and excellent stability characteristics Self-compacting concrete produces resistance to segregation by using mineral fillers or fines, and using special admixtures.
The importance of self-compacting concrete is that maintains all concrete’s durability and characteristics, meeting expected performance requirements.
In certain instances the addition of super plasticizers and viscosity modifier are added to the mix, reducing bleeding and segregation.
The need for this technology has grown as designers specify more heavily reinforced concrete members and ever more complex formwork.
This led to the development of self-compacting concrete, primarily through the work by Okamura. The first usable version of self-compacting concrete was completed in 1988 and was named “High Performance Concrete”, and later proposed as “Self Compacting High Performance Concrete”.
Current Developments in Self-Compacting Concrete Introduction Self-compacting concrete (SCC) is a flowing concrete mixture that is able to consolidate under its own weight.
The highly fluid nature of SCC makes it suitable for placing in difficult conditions and in sections with congested reinforcement.
Fortunately, this also leads to a durable material because water, precipitation, and aggressive chemicals or ions are shed by the surface skin.
Conventional concrete is placed using vibrators to fill the forms.
Self-consolidating concrete is required to flow and fill special forms under its own weight, it shall be flowable enough to pass through highly reinforced areas, and must be able to avoid aggregate segregation.