Workability: a property of fresh concrete

Published on 31 January 2008 (updated on 14 February 2008)

Fresh concrete has a very specific property: workability. This is a major strong point of the material as regards placement.

Workability is the quality that facilitates the placement of concrete (filling of formwork and covering of reinforcement): it characterizes the fluidity of concrete before it hardens.

THE MEASUREMENT OF WORKABILITY

One of the measurable variables that defines workability is the consistency. It can be measured easily by a slump test using the Abrams cone, so named after its inventor.

The workability of the concrete is measured on the basis of the reduction in height of the concrete after it has been turned out from the cone. The greater this reduction in height (or slump) the more fluid the concrete.

THE INFLUENCE OF COMPOSITION

By adjusting the composition of concrete (mainly by the use of additives) its consitency and the length of time it remains "workable" can be altered..