Self-Compacting Concrete was introduced to the European Market in the mid ’90s’ and has gained acceptance fairly rapidly. Several Guidelines and Recommendations that give practical advice have been published. The Japanese Society of Civil Engineers “Recommendations for Self Compacting Concrete” (1999) foresees 3 types of SCC; the Powder type (P), the Viscosity agent type (V) and the Combination type (C). The powder type is proportioned to give the required self compactability by reducing the water to powder (material < 0.125 mm) ratio (W/P) to provide adequate segregation resistance and the superplasticisers and air entraining admixtures give the required deformability and flow. The viscosity type is proportioned to provide self compaction by the use of a viscosity modifying admixture to provide segregation resistance and the superplasticiser and the air entraining admixture are used for obtaining the desired deformability. This type of self-compacting concrete is usually used in underwater concreting. Self Compacting Concrete has gained wide spread use in the precast industry. Where its advantages are easily verified and put to a profitable use and to enhance the aesthetics and the durability of the precast elements. It is estimated that more than 50% of the concrete used for structural precast elements is now self compacting. But the picture is quite different in the ready mixed concrete industry where less than 1% of the concrete produced is self compacting. Why this big difference?
Subscribe to magazine
BASF Construction Chemicals Italia Spa Viale Vittorio Veneto, 3 31100 Treviso, Italy T +39 0422 304251 F +39 0422 420525 www.basf.com