F6+ concretes - Concept and practical application

The concept and practical application of a new concrete class F6, which includes a slump flow from 630 to 700 mm tested according to DIM EN 12350-5, is defined. Development of new generation of plasticizers on the basis of polycarboxylate ether (PCE) has made possible the design of concretes with a low w/c ratio and a very soft workability. Self-compacting concrete (SCC) should be used only if the degree of flow provided by an F6 concrete is no longer sufficient. The use of robust F6 concretes with characteristics almost equivalent to those of self-compacting concrete could significantly increase their scope of application. The use of Portland composite cements such as CEM II and CEM II/B-M with several main constituents has led to very good results. The favorable influence on health and safety at the workplace achieved by a casting process without the use of noisy compaction technology is another positive aspect of the new concrete class F6.