Self-compacting
concrete (SCC) was first
developed in Japan
(in the mid to late 1980s
)
as a means to create uniformity in the quality of concrete by
controlling the
ever present problem of insufficient compaction by a workforce that was
losing
skilled labour and by the increased complexity of designs and
reinforcement
details in modern structural members. Durability was the main concern
and the
purpose was to develop a concrete mix that would reduce or eliminate
the need
for vibration to achieve consolidation.
Self-compacting
concrete achieves this
by its unique fresh
state properties. In the plastic state, it flows under its
own weight and maintain homogeneity while completely filling any
formwork and
passing around congested reinforcement. In the hardened state, it equals
or
excels standard concrete with respect to strength and durability.
The
use of SCC concrete has been increasing in the United States
also during the last
5 years. Currently the technology is being primarily applied to the
precast
industry. Other segments being targeted are flatwork, columns and wall
construction. The applications of SCC are many, limited only by the
industry's
knowledge of it, ability to produce it and acceptance of it.
The
usual
self-compacting concretes have compressive strengths in
the range of 60-100N/mm².
However Ultra High
Performance Self-Compacting Concrete (UHPSCC) with
a strength about 150
N/mm² have also been successfully developed.