Concrete as a seal against liquid materials
When manufactured properly, concrete as a building material can provide a very efficient seal against water and other liquid substances. Next to a sufficient wall thickness, this demands the conception of a concrete composition with a sufficiently low pore volume (mainly achieved by a limitation of the water-cement value). When building an impenetrable reinforced concrete structure, the design of the concrete composition has to be complemented by considerations on the limitation of crack widths and joint formation. This applies both to WU constructions, in which the structure is the component that is impenetrable to water, and to the WHG area (Water Resources Act), in which the reinforced concrete structure must hold back such substances that could endanger our groundwater.
DAfStb Directive “Waterproof Concrete Structures”
As well as the generally valid standards, the technical regulations for WU construction are published in the DAfStb Directive “Waterproof Concrete Structures”. For structures in which substances that threaten our groundwater are to be held back, the demands regarding impenetrability are generally much higher than those for the aforementioned WU structures. The naturally high degree of responsibility for our groundwater leads to this increased effort, but also the fact that the substances to be resisted often have a very low viscosity and are able to penetrate the concrete much easier than water.
DAfStb Directive “Concrete construction when dealing with substances hazardous to water”
With regard to the technical regulations for such reinforced concrete structures, reference is made above all to the DAfStb Directive “Concrete construction when dealing with substances hazardous to water”.