Sustainable building with technical textiles
It was previously thought that buildings have to have a useful life of at least 100 years. In today’s fast-moving world that has changed. Today it is important to gauge the true quality of a building through consideration of its life cycle. This requires analysis of all the stages in the life of a building according to the different aspects of sustainability. The aim is to determine the optimum use of building materials and components, whilst at the same time minimising the consumption of, for example, electricity, heating, water, waste water and materials etc. Minimising the environmental footprint is also part of this. Ultimately it is process of optimisation through which a high, long-lasting building quality is established. The breadth of the range of applications for technical textiles in building in terms of sustainability is indicated by three new products from research and industry.
This includes the Techtextil Prize-winning ‘Polar bear pavilion’,
a textile membrane that is self-sufficient in energy and has been created at the Denkendorf Institute of Textile Technology and Process Engineering (ITV). Until now membrane structures have been notoriously bad at controlling heat loss and gain, however working with its partners in industry this research project has succeeded in proving that it is now possible to control these insulation properties. In design terms the researchers adopted the principle of polar bear fur and its different fur-related properties: constructed
in Denkendorf, the building has a black coated textile fabric and very porous membrane with a heat transfer layer. When sunlight falls on the building this heat transfer layer assumes the task of heating the air that flows into the space in between. The warm air produced is transported via the roof to an innovative long term heat energy storage system – another new development of this research project. This storage system is able to transform heat energy into chemical energy and to store it with hardly any loss. This development has been patented by project partner TAO and is able to store sufficient heat in the summer to heat the pavilion in the winter. At the ITV solar test stations it has already been possible to achieve a temperature of up to 140 degrees centigrade.
The technical properties of the heat insulation materials used on and in buildings are important.
Ziegler is a manufacturing company and has now received the important German Institute for Building Technology approval for its insulation material made from recycled PET bottles. The insulation material is manufactured from one hundred percent polyester fibres. No chemical binding agents are used and the fibres come from PET bottles that have been appropriately sorted and recycled. It is possible to find these polyester non-wovens in many other technical applications. The non-woven material meets human ecological requirements as evidenced by its Oeko-tex certificate.
Textile concrete is another good example. The use of textile concrete for the protection of historical monuments poses a special challenge also in terms of sustainability. In this case it is more a question of securing valuable building fabric for posterity than it is of energy-related issues. Until now the actions taken were limited to looking for possibilities to protect the building fabric from deteriorating using established technologies – often with the use of chemical products such as impregnating sandstone for surface strengthening. The results were unsatisfactory, since the treatment was not weather resistant and it was not possible to prevent crack formation.
A very interesting solution to the problem is a RWTH Aachen University research project which has been used for preserving historic monuments such as the neo-Byzantine ceiling mosaics of Aachen Cathedral. A crack in the area of the octagonal dome threatened to destroy the mosaic. The bandage made from textile concrete is based on the idea of plate reinforcement. The bandage was manufactured on site by a process of lamination, with the textile carbon reinforcement being incorporated in the same mortar as was used to restore Aachen Cathedral. It has been shown that the crack bandage is able to absorb forces and minimise crack formation. This enables the art historical value of the mosaic to be secured on a sustainable basis.
Background picture: Source – ITV/TAO GmbH