Fiber cement

from Wikipedia, the free encyclopedia
Roof with older asbestos fiber cement covering
Roof with corrugated sheets

Fiber cement is a durable composite of cement and tensile fibers that is used in building and construction products. It was originally made with asbestos fibers extracted from silicate minerals. With the ban on processing, the asbestos fibers were replaced by other fibers; after around 90 years of massive use in the construction industry, asbestos-containing old building materials are now considered expensive hazardous waste to be disposed of . Fiber cement is manufactured and sold under various brand names. For curved fiber cement panels (roof corrugated sheets), the term is used colloquially often corrugated asbestos used.

history

Asbestos was already known in ancient times. However, the knowledge of the mineral's abilities has been lost over the millennia. It was not until the beginning of the 19th century that the properties of this material, which is extremely strong and resistant to heat and acids, were rediscovered. After initially smaller applications, asbestos was processed into fire-resistant clothing for firefighters, for fire-resistant roofs or for thermal insulation in steam engines. In general, the year of the Paris World Exhibition of 1855 is considered the starting point for the development of asbestos into an industrially used material.

The Briton Richard Lloyd influenced the invention of fiber cement in 1857 with the idea of ​​an asbestos- based stuffing box packing as a sealant for steam engines. The New York building contractor Henry Word Johns took advantage of the heat-resistant properties of asbestos and invented a flame-retardant roofing felt in 1860. The development reached its climax with the inventions for the production of asbestos cement panels. The Austrian Ludwig Hatscheck applied for a patent in Austria in 1899 and in Germany on March 30, 1900 for a wet process for the factory production of asbestos cement. For the first time, he combined all components from outside the industry into a large-scale technical solution that made it possible to satisfy the need for inexpensive, stable roof panels. Because of its low cost, high fire resistance, low weight and other properties, the building material should subsequently become the preferred building material for facade cladding. From the 1960s to the 1990s, for example, fiber cement panels were a preferred building material to give half-timbered houses a “modern” appearance.

Fiber cement and asbestos

After asbestos was increasingly recognized as harmful to health in the 20th century, the processing of the fibers was banned at the end of the 20th and beginning of the 21st century in Europe, Japan, Saudi Arabia, large parts of Latin America, Malaysia, New Zealand, Australia and Vietnam. because the asbestos fibers that can penetrate the lungs can be released during the production, processing and decomposition of aging materials. In Germany, the sale of newly manufactured asbestos products has been prohibited since 1993, in Switzerland since March 1, 1989. In fiber cement in these countries, asbestos was replaced by other fibers, e.g. B. alkali-resistant (AR) glass , carbon , water-insoluble polyvinyl alcohol and homopolyacrylonitrile fibers (pure PAN) replaced.

Eternit process in Italy

From 2009 to 2012 the so-called Eternit process was negotiated in Turin . Two entrepreneurs were charged, the Swiss Stephan Schmidheiny and the Belgian Baron Jean-Louis de Cartier de Marchienne . Both were sentenced in absentia to 16 years imprisonment each. They were found guilty of being responsible for an environmental disaster and asbestos death of around 3,000 people because they failed to take precautionary measures and suppress information about the health hazards caused by asbestos at the Eternit SpA factory in Casale Monferrato between 1966 and 1986. Stephan Schmidheiny then had his spokesman, Peter Schürmann, announce in a press release that the judgment would be challenged and taken to the next higher instance. In November 2014, the Italian Court of Cassation overturned the guilty verdicts due to the statute of limitations.

Manufacture and properties

Cement is a substance that reacts chemically with water and hardens to form cement paste. Fiber cement contains a fiber reinforcement that improves the bending, tensile and breaking strength of the material. After a curing time of 28 days, fiber cement consists of around:

  • 40% binder
  • 11% additives
  • 02% reinforcement fibers
  • 05% process fibers
  • 12% water
  • 30% air (pores)

The density is 1600 to 1850 kg / m 3 . Fiber cement containing asbestos usually contains 10 to 15% asbestos.

The process fibers are made from cellulose and waste paper. They serve to bind the powdery components to a pulp during production with water ( thickener ). Water can then flow off in the draining phase after shaping. In contrast to the reinforcement fibers, they are of no importance for the strength of the fiber cement.

use

The material is used in all construction areas. a. Used for structural parts for interior work, facade cladding, roof coverings (e.g. corrugated sheets), water pipes, flower boxes , window sills and garden furniture. In the 1960s, entire houses were made from fiber cement materials.

In interior construction, the material is z. B. used in wet rooms, for ventilation pipes, for fire protection cladding and partition walls. In the outdoor area, it is used to manufacture facade cladding, eaves, roof coverings (including artificial slate ) and sub-roof structures.

Manufacturer

A list of the most important manufacturers of fiber cement, which is by no means exhaustive.

  • AMROC Baustoffe GmbH (cement-bonded wood chipboard)
  • Cembrit
  • Etex Group (Belgian holding company of Jean-Louis de Cartier de Marchienne )
    • Eternit GmbH (German Eternit licensee, company of the Etex Group)
  • James Hardie Europe GmbH
  • Swisspearl Group AG (Swiss cement composite holding by Bernhard Alpstaeg, part of the Swisspor Group)
  • Müller Aluminum GmbH
  • Toschi GmbH & Co. KG
  • Landini SpA (Italy)
  • LTM (ТД ЛТМ, Russia, formerly Finnish)
  • Otto Wolff Group
  • SVK (Belgium)
  • Facade design-hm2

See also

literature

  • Jan R. Krause: Fiber cement. Technology and design. Birkhäuser, Basel 2007, ISBN 978-3-7643-7590-4 .
  • Hünerberg, Kurt: Handbook for asbestos cement pipes. Springer Verlag, Berlin, Heidelberg, New York 1968

Web links

Commons : Fiber cement  - Collection of images, videos and audio files

Individual evidence

  1. ^ Darnieder GmbH & Co. KG: Well asbestos renovation and disposal. Retrieved September 5, 2015 .
  2. ↑ Corrugated roof sheets. In: www.lfu.bayern.de. Bavarian State Office for Environmental Protection, accessed on September 5, 2015 .
  3. ↑ a b Corrugated asbestos restoration and disposal. In: www.darnieder.de. Darnieder GmbH & Co. KG, accessed on September 5, 2015 .
  4. ↑ Harald Klos: Asbestos cement . Ed .: Springer Verlag Wien GmbH. Vienna 1967, ISBN 978-3-7091-8170-6 , p. 12 f .
  5. ^ A b Wolfgang E. Höper: Asbestos in the modern age. Industrial production, processing, prohibition, substitution and disposal . Waxmann Verlag GmbH, Münster / New York / Munich / Berlin 2008, ISBN 978-3-8309-2048-9 .
  6. ^ Eternit Aktiengesellschaft Berlin: Die Asbestzementtechnologien, in: 50 Jahre Eternit Aktiengesellschaft. 75 years Eternit in Germany, Berlin 1979 . Ed .: The patent was granted under the Austrian patent number 5970 on June 15, 1901. 1979, p. 6 .
  7. ↑ Werner Catrina: The Eternit Report. Stephan Schmidheinys, difficult legacy. Schwäbisch Hall, Zurich 1985, p. 19 .
  8. ↑ Asbestos. In: Chemical substances. Federal Environment Agency, November 8, 2017, archived from the original on September 18, 2018 ; accessed on August 8, 2019 .
  9. ↑ Asbestos ban. In: Protection regulations. Forum Asbestos Switzerland, accessed on August 8, 2019 .
  10. ↑ Walter Loy: Chemical fibers for technical textile products. 2nd, fundamental revised and expanded edition. Deutscher Fachverlag, Frankfurt am Main 2008, ISBN 978-3-86641-197-5 , SS 96, p. 93, p. 70, p. 83.
  11. ^ Asbestos trial in Italy - "Now everyone is sick" , Der Spiegel , December 10, 2009
  12. ↑ Schmidheiny fears unbalanced proceedings - secondary plaintiff admitted to trial for asbestos victims in Turin , NZZ, March 1, 2010
  13. ↑ 16 years imprisonment each for Schmidheiny and de Cartier , nachrichten.ch, February 13, 2012
  14. ↑ 16 years in prison: Schmidheiny moves on to judgment. Handelszeitung, February 13, 2012, accessed December 25, 2013 .
  15. ^ Eternit trial: acquittal for Stephan Schmidheiny. NZZ, November 19, 2014, accessed on November 21, 2014 .
  16. ↑ Material fiber cement. Eternit (Schweiz) AG, accessed on December 25, 2013 .
  17. ↑ Large-format fiber cement panels for facade cladding. (PDF 48 KB) Physical and chemical properties. In: Safety data sheet according to 1907/2006 / EG, Article 31. Eternit AG, August 26, 2011, accessed on August 8, 2019 (from dachbaustoffe.de).
  18. ↑ Günter Schnegelsberg: Manual of the fiber - theory and systematics of the fiber. Deutscher Fachverlag, Frankfurt am Main, 1999, ISBN 3-87150-624-9 , p. 592.
  19. ↑ Products + Solutions. Eternit (Schweiz) AG, accessed on December 25, 2013 .