ADMIXTURE QUALITY AND PERFORMANCE
October 28, 2004

New Guidelines have been released by the Cement Admixture Association (CAA) explaining how admixtures not covered by BS EN 934 can show established suitability for use in concrete, in conformity with the requirements of BS EN 206.

The Guidelines cover seven categories of special purpose concrete admixtures that are in widespread use in the United Kingdom but are not covered by BS EN 934-2. These include underwater concrete admixtures, shrinkage reducing admixtures, corrosion inhibiting admixtures, pumping aids, segregation reducing admixtures, foaming admixtures, semi-dry concrete admixtures.

The Guidelines follow the format established by BS EN 934-2. However, in some cases the admixture performance of the primary function is specific to the materials and equipment used on site and can only be demonstrated by purchaser trials. In this situation, the admixture is tested for uniformity and effects on key characteristics including strength, but effectiveness for purpose is required to be established between the manufacturer and purchaser.

It is hoped that these Guidelines will eventually form the basis for a new British Standard to cover these types of admixture. For further information and details of information sheets available from the CAA, contact the secretary John Dransfield, Telephone/Fax 01564 776362.

Archive News