Carbonation of filler type self-compacting concrete

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Applicability of durability requirements of the European Standard EN 206-1 to self-compacting concrete

Durability and more specifically carbonation and chloride penetration, is of major importance for reinforced structures. Before using self-compacting concrete (SCC), the carbonation and chloride penetration has to be investigated in order to locate and prevent possible problems. In order to do so, an extended experimental programme was set up simulating real conditions. This project includes laboratory experiments on the carbonation and chloride penetration of 14 self-compacting concrete (SCC) mixtures). For the carbonation study, these concretes were stored alternately one week in a carbonation room at 20°C, 60 % R.H. and 10 % CO2 and one week immersed in water. For the chloride penetration study, cylindrical specimens with a diameter of 230 mm and a height of 70 mm were alternately immersed in a solution containing chlorides and exposed to air. One cycle took approximately 1 hour. In Belgium, no standards are available for self-compacting concrete. For this reason, the results of this experimental study are compared with the European Standard EN 206-1 : 2001 concerning 'Concrete - Specification, performance, production and conformity' and the National Application Document NBN B15-001 : 2004 of this European Standard. Both are only applicable to traditional concrete and combine a maximum W/C ratio and a minimum cement content, both depending on the environment. An optional mimimum compressive strength is mentioned. This comparison leads to the conclusion that self-compacting concrete meets the durability requirements prescribed for traditional concrete. Based on the experimental results, the combination of a maximum W/C ratio and a minimum cement content is also a requirement for self-compacting concrete. The requirement for a minimum compressive strength is also optional for self-compacting concrete. In case of self-compacting concrete there is always a large positive difference between the maximum and real compressive strength