Trade Journals for the Concrete Industry

… sites, in research and in development The composition of modern concretes has become increasingly more complex in order to cope with requirements in practice. New challenges, such as slender structures and filigree construction elements that imply complex formwork and dense reinforcing, are hastening the trend still further towards self-compacting concretes (SCC) and engineered cementitious composites (ECC) in concrete technology. Utilising highly effective superplasticisers does not just give these concretes higher performance; it also renders them more susceptible to environmental factors and influences. It is thus becoming more problematic to maintain specified fresh and hardened concrete characteristics. Up to now, there has been a lack of rapid, user-friendly methods able to test the sedimentation stability of concretes at a construction site. On account of their pronounced sensitivity, such concretes should be investigated separately, before they are installed, for their tendency to segregate. For this reason, a testing procedure, with which this criterion can be investigated, is currently being developed in particular for soft concretes at the Institute of Construction Materials (ICM) of the University of Stuttgart, Germany. First pre-trials with a simplified procedure have already successfully endorsed the basic ideas behind the test.