Das nachträgliche Abdichten von Massivbauwerken gegen drückendes Wasser ist bautechnisch sehr anspruchsvoll. Als eine sehr nachhaltige Methode ist der Einbau einer Weißen Wanne aus Textilbeton anzusehen. Bei ökonomisch noch vertretbaren Kosten zeichnet sich Textilbeton durch seine Dünnwandigkeit aus, was zu wenig Verbrauch von nutzbarem Raum – und damit auch zu einer Wertsteigerung des Gebäudes – führt. In dem Beitrag wird über das System Weiße Wanne aus Textilbeton und erste Erfahrungen damit berichtet.
Watertight textile-reinforced concrete
Retrospective sealing of solid structures against water under pressure is technically very demanding. The installation of watertight textile-reinforced concrete is regarded as a very sustainable method. Textile-reinforced concrete is characterized by its suitability for thin walls at costs that are still economically viable. These walls then occupy less useable space and therefore increase the value of the building. The article describes the watertight textile-reinforced concrete system and initial experience with its use. Calculations for the proposed system have already been carried out for several projects after successful analysis of the structures. The main cost factors are the special steel anchors and the horizontal barriers under the ground-floor floors required against rising moisture in the masonry. This means that for normal situations and building dimensions the costs exceed those of installing conventional watertight reinforced concrete by a factor of 1.5 to 2. In this respect, watertight textile-reinforced concrete is only economically viable if the additional cost is justified for other reasons. One of these is the retention of usable living space if the cellar is to be used as a living area or for hobbies. The system also offers substantial advantages for sealing underground garages against water under pressure as the effective height can be retained. It is in such cases that purely economic considerations are inadequate. A rise in the groundwater level in Germany is also going to be a future issue for existing buildings so textile-reinforced concrete may well remain an interesting alternative for sealing structures against standing groundwater.