Textile Reinforced Concrete

Concrete is the material most frequently used in construction industry. Reasons for that are on one hand the low price, on the other hand good mechanical characteristics. Concrete has a good capability of dealing with compressive forces, but its tensile strength is relatively low. For dealing with tensile forces, a reinforcement is applied, for which steel is the primarily used material. In that context, a major problem is the corrodibility of steel in combination with oxygen and humidity. Therefore it is necessary to cover the reinforcement with at least 35 mm of concrete on all sides. That leads to the use of an amount of concrete which is mechanically not necessary.

reinforced concrete with corrosion damage (Source: Wikipedia)

The project's innovative elements are based on the technology of textile reinforced concrete. Here, the steel reinforcement is replaced with alkali-resistant glass-fibre. Through the elimination of corrosion-problems, thin elements can be realized and the use of concrete can be reduced by up to 70%. While conventional ferroconcrete elements require a minimum depth of 70mm, the innovative textile reinforced elements offer the possibility to reduce the thickness to as low as 10 to 20 mm. Compared to glass-fibre reinforced concrete which is already in use today, the innovative textile-reinforced elements offer a higher grade of reinforcement and therefore, a wider field of application. The elements employed in the project consist of 2 shells of textile-reinforced concrete with a depth of 15mm and a supplementarily strengthened frame. The element's specific sandwich structure is generated through the insertion of a PUR-rigid-foam-core between the shells. The lower amount of concrete used in the new elements results in a reduction of CO2-output of about 70% in comparison to a similar element of ferroconcrete. The lower weight results in additional energy and fuel savings as well as a reduced pollutant emission in transport and application. The integration of a layer of thermal insulation offers the possibility to reduce heating costs and consequently improve the element's energy-balance.

Compared with already used in short-fiber-reinforced components of the textile reinforcement offers a higher degree of reinforcement and thus more extensive applications. If you mix the short fibers in the concrete only, they are only omnidirectional in the component. In the TRC, the fibers of the reinforcement structure to the main directions of loading by tensile forces are aligned. Thus, the high potential of the fibers used better and the sustainability of components with lower fiber content even increased.

EXCURSION SFB 532

RWTH Aachen University has 10 years experience in the textile building. In 1999, the Collaborative Research Center was founded in 532 for research on textile concrete. The aim of this research area is to create through interdisciplinary cooperation, the technical-scientific basis for engineering development of a new technology for textile reinforced concrete.

diamond lattice

The research area is divided into various sub-projects and has in recent years, among many publications, many Demonstratorobjekte produced. Long time TRC was only used in curtain wall, making the potential of the textile reinforcement was not fully utilized. With the cafe-Reiff, a student cafe on the campus of the RWTH Aachen University, was established in March 2008, the first building in textile concrete sandwich construction. The building has a floor area of approximately 20 square meters, a height of about 3.30 m and consists of 12 wall and roof panels 4. The facade is composed of two elements, together with coated prepreg fabrics reinforced concrete shells and a rigid polyurethane foam core. It has a total thickness of 20 cm and required at a size of 3.23 m and 0.98 m width of any structure. In further research, it has already succeeded in developing intricate support structures that extend the architectural design options considerably (eg diamond lattice). The research will run until 2012.