Monday, February 23, 2009

Self-Compacting Concrete

Self-compacting concrete was first developed in Japan in 1988 and is now available in South Africa. The need for this type of concrete arose as a result of a lack of the skills necessary to achieve sufficient compaction for durable structures.

Self-compacting concrete can be compacted into every corner of a formwork without segregation of coarse aggregate, merely by means of its own weight and without the need for vibrating compaction.

The method of achieving self-compaction involves not only high deformability of mortar but also resistance to segregation between coarse aggregate and mortar when concrete flows through confined zones such as reinforcing steel bars.

The greater expense of self-compacting concrete may however be compensated by several benefits including:
  • Shortened construction period
  • High level of workability
  • Compaction in confined areas where vibration is difficult
  • Rapid placement and consequent enhanced surface finish
  • High strengths – overnight typically reaches 30 – 40 N/mm2 – two day strengths can exceed 100 N/mm2.
  • Health and safety – less noise and danger associated with vibrating machines.
For more information on self-compacting concrete visit the Cement and Concrete Institute website.

Bruce Lyle
Membership Services Manager


No comments: