There has been considerable progress in the field of concrete technology in recent years, which has expanded the range of application of concrete well beyond the normal limits to date, for example high strength concretes or self-compacting concretes. In the wastewater treatment plants in particular there is an increasing need for concretes with a high durability. Experience shows that the requirements for the durability of wastewater systems are fulfilled by the use of normal concrete only if they carry normal municipal wastewater. The durability of normal concrete is no longer sufficient, however, if the wastewater contains high concentrations of media that attack concrete, or if there is a danger of biogenic corrosion by sulphuric acid. Acid-resistant concretes [1, 2] may be considered as an alternative to corrosion-resistant linings, which are unfavourable in terms of production and are associated with additional costs in the manufacture, installation and operation. In the development of these concretes the focus is not on high strength, but rather on the optimisation of the microstructure density and the minimisation of the binder that participates in a damaging reaction, taking into account conformity to standards. Ideal areas of application for such concretes are monolithic manhole bases, optimally shaped concrete and steel reinforced concrete pipes as well as jacking pipes.
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