Textiles made from carbon-fibre rovings are particularly suitable for reinforcing concrete, since carbon fibres weighing approximately 1.8 g/cm3 are four times lighter and, with a load-bearing capacity of 3,000 N/mm2, are six times more efficient than conventional steel-reinforced concrete. This lightweight yet extremely strong material can be shaped into virtually any shape and does not corrode.
This means that the reinforcement does not have to be treated to make it corrosion-resistant, which is usually done by applying a covering layer. This enables the thickness of the structural components to be reduced considerably, and consequently reduces the amount of concrete needed (Figure 1). Reducing the consumption of materials also reduces the environmental load. The use of carbon-fibre-reinforced concrete, therefore, has a huge impact on the consumption of resources and energy and on the CO2 footprint.In view of these exceptional performance features, researchers worldwide are working on using carbon fibres as environmentally friendly reinforcing materials in concrete.
To establish Germany as the world’s leading provider of carbon-fibre-reinforced concrete to the construction industry, the Bundesministerium für Bildung und Forschung (Federal Ministry of Education and Research) is funding the C3-Carbon Concrete Composite Project to the tune of roughly €45 million via funds made available within the framework of the Zwanzig20 – Partnerschaft für Innovation (Twenty20 – Partnership for Innovation) Project. The 134 partners in the project will also contribute up to € 23 million of their own funds. The largest building research project currently running in Germany aims to develop a new composite material made from a carbon-fibre reinforcing material and high-performance concrete.
The project is being led by the Dresden University of Technology and brings together partners from various research establishments, companies and federations. KARL MAYER’s subsidiary, KARL MAYER Technische Textilien, is also taking part. KARL MAYER’s contribution to the project is to focus on the production of biaxial textile structures for reinforcing concrete components. These biaxial textiles have a grid-like construction. The load-bearing, carbon-fibre material is arranged at an angle of 0º as warp yarns, and at an angle of 90º as weft yarns. The structure is fixed by means of knitted stitches. The weft can be inserted in line with the stitches or not in line with the stitches. The two relevant types of machine form the basis of KARL MAYER’s two-part work package.