Concrete

:This article is about the construction material. For the philosophical term, see Concrete (philosophy). For the comic book, see Concrete (comics). For the film see Concrete (film).

Shotcrete / sprayed concrete

Main article: Shotcrete

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Shotcrete uses compressed air to shoot (cast) concrete to a frame or structure. Shotcrete is mostly used for rock support, especially in tunnelling. Today there are two application methods for shotcrete: the dry-mix and the wet-mix procedure. In Dry-mix the dry mixture of cement and aggregates is filled into the machine and conveyed with compressed air through the hoses. The water needed for the hydration is added at the nozzle. In Wet-mix the mixes are prepared with all necessary water for hydration. The mixes are pumped through the hoses. At the nozzle compressed air is added for spraying. For both methods additives such as plasticizers and accelerators may be used. Shotcrete is normally reinforced by fibers.

Related Topics:
Shotcrete - Tunnelling - Compressed air - Plasticizer - Accelerator

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