Trade Journals for the Concrete Industry

The continuously increasing volume of self-compacting concrete (SCC) requires a much more accurate control of the workability than ordinary concrete that will be vibrated in the moulds. The tolerance between a too stiff mix, which will not properly flow in the mould and around the reinforcement, and on the other hand too flowable mix, which will cause detrimental separation of the aggregates and the paste, is very narrow. The use of a high dosage of plasticizers will also make the concrete more sensitive for variations in the cement-admixture interaction. This means that not even a good control of concrete moisture and constant aggregates do guarantee a sufficiently constant workability.