Groz-Beckert KG

Newsletter 3 | 2010

An Exciting Landmark Project – Groz-Beckert Hands Over Textile-Reinforced Concrete Bridge to the Town of Albstadt

In November the textile-reinforced concrete bridge in Albstadt-Lautlingen was officially handed over to the Town of Albstadt. Groz-Beckert participated in the project technologically as well as financially, and also assumed responsibility for much of the planning and construction. Find out more about it all here!

From idea to implementation and handover

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In April 2007 the concrete girder bridge on the same site had reached the end of its useful life, and for safety reasons had to be elaborately dismantled. Groz-Beckert had already been considering the use of textile-reinforced concrete as a possible solution for the successor structure. After numerous analyses, together with a feasibility study by the RWTH (Aachen Technical University), it became clear that the use of textile reinforcement promised many advantages. The next stage in this landmark project followed in March 2008: the town of Albstadt and Groz-Beckert co-signed a contract for implementation of the project including assessment of the costs. The agreement was that the outlay for a conventional construction with ferroconcrete would be initially borne by the town, while the additional costs incurred by the textile-concrete design would be assumed by Groz-Beckert. After a period of time required for research and development, construction work on the textile-concrete bridge began in November 2009. The objectives were clear: the new bridge construction was to be given a slender superstructure, while fulfilling increased demands regarding freeze-thaw cycles.

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At the official ribbon-cutting ceremony: Mayor Mänder, Undersecretary Klaiber, Dr. Lindner, District Administrator Pauli, Mayor Gärtner and Senior Mayor Dr. Genevechow.

The official handover to the town of Albstadt took place in November 2010, amid an exclusive circle of invited guests. In their speeches, politicians and project participants - including Baden-Württemberg's Undersecretary Klaiber, architect Professor Hartwig N. Schneider and Prof. Dr.-Ing. Josef Hegger from H+P Ingenieure GmbH - provided information on numerous aspects of the new textile-concrete bridge. It is based on an epoxy-resin-impregnated fiberglass fabric on the upper and lower side of the bridge deck, and a stirrup reinforcement in the ribs.

The world’s longest textile-reinforced concrete bridge – and the technological details

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At roughly 100 metres, the textile-reinforced concrete bridge in Albstadt-Lautlingen is the longest bridge of its type in the world. Designed as a footbridge, it consists of six prefabricated sections, each with a maximum length of 17.20 metres and a superstructure height of just 43.50 metres. In cross-section, the superstructure comprises a prestressed seven-web tee-beam with a width of 3.21 metres. The combination of textiles as reinforcement material and mono-strands for prestressing resulted in an ideal slenderness ratio. As a result of the articulated cross-section, formed reinforcing elements were used for the webs and trusses, and given the desired shape by being coated with epoxy resin. The textile web reinforcement was used strategically to reduce the transversal forces. Because of the minimal concrete cover of 1.5 centimetres, the webs could be applied at the thinnest section, which is only 12 centimetres wide. The cantilever arm at the edges of the bridge narrowed down to just 9 centimetres. The use of fine concrete also made it possible to create a sharp cross-sectional geometry with a homogenous surface.

A connection to the future

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One great benefit of the textile-concrete bridge in relation to conventional solutions is of course that textiles are not susceptible to corrosion. Textile-reinforced concrete slabs also weigh less than armoured concrete. Unsightly spalling is avoided, as are dangerous cracks in the material. This creates the prefect preconditions for a long service life.

All in all, the textile-concrete reinforced bridge is a technological innovation of the first order - and it's also very impressive to look at. This beacon project illustrates the sheer potential of textile production, and is a symbolic landmark for Albstadt and the entire region.