Blast furnace cement

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Blast furnace cement is a product from the normal cement family , which contains between 36 and 95 percent blast furnace slag . The remaining part is Portland cement clinker . Up to 5 percent minor components are possible.

variants

According to the DIN EN 197-1: 2014 standard, blast furnace cement has the abbreviation CEM III . It is divided into:

  • CEM III / A with 36 to 65 percent slag and 35 to 64 percent Portland cement clinker.
  • CEM III / B with 66 to 80 percent slag and 20 to 34 percent Portland cement clinker.
  • CEM III / C with 81 to 95 percent blast furnace slag and 5 to 19 percent Portland cement clinker.

advantages

Due to the lower proportion of clinker in the cement, less heat is generated during hydration . This results in fewer stress cracks in the concrete. Blast furnace cement is also more resistant to salts , which is important e.g. B. in buildings by or in the sea, and carbonic acid, which dissolves lime. It is therefore increasingly used for the construction of massive components as well as containers and systems in the chemical industry, filling stations and sewage treatment plants.

disadvantage

Due to the lower proportion of clinker, concrete made from blast furnace cement has a slightly lower initial strength.

Individual evidence

  1. ↑ Composition of the 27 normal cements according to DIN EN 197-1. HeidelbergCement , accessed on October 19, 2016 .
  2. ↑ a b André Weisner, Thomas Richter: Massive components made of concrete. (PDF file; 530 kB) Concrete Information Center, accessed on October 19, 2016 .
  3. ↑ Diethelm Bosold, Roland Pickhardt: Cements and their production. (PDF file; 151 kB) Concrete Information Center, accessed on October 19, 2016 .