Experimental Test for Evaluation of SCC Static Segregation

Abstract

A Self-Compacting Concrete (SCC) is by definition one that, due to its own weight, pours and sets in place in the most complex reinforced moulds. It is important to note that the material must not undergo any form of segregation, whether “dynamic”, i.e. when it occurs during flowing, or “static”, i.e. when it occurs in the mould after compaction of different materials in the concrete. In this paper, study of static resistance segregation of self-compacting concretes is presented. Experimental assessment of segregation is carried out by procedure, which is realized in this paper. This procedure is similar to column test but different cylinder geometry and splitting is carried out at the end of setting. For each of the different mixtures studied, we also measure the slump flow, the filling ratio (L-box test), the screen stability and the V-funnel flowing time. The results obtained show that in the case of SCC, specific tests must be carried out to assess static segregation, especially when slump flow is above 70 cm. This study also shows that it is possible to obtain high quality SCC (with no risk of segregation) with screen stability test values in the region of 30%, which are much greater than the usual 15% recommended pat the French association of civil engineering AFGC [1].