Textile-reinforced concrete
Concrete is an artificial textile composite material, which is similar to the concrete of the two components of concrete and reinforcement. It is suitable for the production of new as well as for the strengthening of existing components. The concrete is very fine and generally strong, which distinguishes it from the usual normal concrete. As in reinforced concrete structures and the relatively low tensile strength of the concrete is compensated by tensile reinforcement. At TRC, technical textiles, usually scrim used. Proven as fiber material have alkali-resistant glass fibers and carbon fibers. TRC was mainly developed since the mid-1990s at the Universities of Dresden and Aachen and explored in the context of two collaborative research centers of the German Research Foundation (DFG) in its basics.
History
The biggest drawback conventional reinforcing steel is its susceptibility to corrosion. Alternatives are sought for some time. The use of textile-reinforced concrete was first tested in Dresden in 1994. Since 1999, the development of this new material in two by the German Research Foundation ( DFG) Collaborative Research was - SFB 528 ( emphasis gain, Speaker: Prof. Manfred Curbach ) in Dresden and SFB 532 ( emphasis new components, Speaker: Prof. Josef Hegger ) in Aachen - driven. In the Dresden Collaborative Research Center, the focus was mainly on ways to repair and strengthening of solid structures with textile reinforced concrete. At RWTH Aachen was the use of textile-reinforced concrete for new components in the forefront of research. With the help of approvals in each individual case, even during the term of special areas of research first implementation projects were realized.
On 1 October 2007 the German center of textile reinforced concrete ( DZT) was founded in Dresden. Under the umbrella of TUDAG - the marketing company of the TU Dresden - the DZT is intended as a platform for the transfer of knowledge about textile concrete from the basic research into practice.
In September 2008, the brand TUDALIT by the German Patent and Trademark Office has been entered in the register of trade marks by the TUDAG. Under the trademarked name TUDALIT the manufacture and application of TRC based on predetermined quality standards for the components of the composite material, the method of their production, developed from or with the composite material and products used, their method of preparation, and methods for strengthening and repair is protected.
On 26 January 2009 the foundation of the TUDALIT eV was carried out, together with its current 24 members of the Union makes the German center of textile reinforced concrete under the brand TUDALIT products or known with textile reinforced concrete and promotes opportunities for strengthening and repair of textile reinforced concrete. A first General Technical Approval is requested from the German Institute for Building Technology DIBt.
Components and composition
Textile-reinforced concrete made up of two components: the reinforcement fabric for receiving the tensile forces, and a special high-strength concrete for the precision removal of compressive stresses, the production of the composite and the mechanical protection of the fabric. Typical layers are only 1-3 cm thick.
Textiles made of high performance continuous fibers such as glass or carbon made from alkali have the great advantage of not rusting. A textile nest consists of yarns, which in turn are made up of many continuous fibers ( filaments) composed and processed on textile machines to the grid-like structures. Can vary both the fiber material as well as Production and geometry of textiles. Thus textiles can be tailored provided for various applications.
The high-strength fine-grained concrete generally has a maximum grain size maximum diameter of 2 mm and is optimized for use with technical textiles. Especially for reinforcing structural components, the aim is to apply textile concrete in thin layers, which only works when using a fine grit. Are larger layer thicknesses allowed to concretes have already larger maximum grain size (up to 4 mm) proven.
Applications
TRC is distinguished primarily by its lightness and high load carrying capacity. He is also ideal for the manufacture of free-form layers and components since the nest is flexible and the first plastic concrete can preserve any form after solidification.
The reinforcement of concrete structures with textile-reinforced concrete allows high load capacity increases and is a serious alternative to conventional methods such as spraying concrete or fiber reinforced plastics. In addition to the load increase is also a limitation of deformations and a reduction of crack widths are very positive. Completed projects include the upgrading of a lecture hall roof at the FH Schweinfurt, a listed tons of roof and a monumental dome in Zwickau, from ceiling in a commercial building or a sugar silos. These measures would not have been possible without textile concrete.
Also for new components TRC is well suited. Established building materials has already in mild facade panels. Another field of application are light bridges. The world's first bridge made of textile reinforced concrete was created in 2005 for the State Garden Show in Oschatz. She was awarded several prizes, including the Special Encouragement Award of the fib ( fédération international du béton ). In the fall of 2007 was presented to the public a second, around 17 meters long pedestrian and bicycle bridge in Kempten, which, in contrast to the bridge in Oschatz may also carry a bulldozer next to the pedestrian load. This is currently the world's longest bridge segment in textile reinforced concrete. Currently the longest bridge in textile reinforced concrete crosses the highway 463 in Albstadt- Lautlingen. This was completed in November 2010 bridge has a length of 97 meters with individual spans of up to 17 meters.