Sprayed concrete or shotcrete concrete
It is said that concrete action on the pressure and speed on the surface to be sprayed to a dense, robust and resistant to be created. Shot Shot Crete Crete or concrete spray contains two types of dry and wet Crete shot
In fact Shot Crete can be as concrete or mortar through rubber pipes with compressed air pressure to the desired level is sprayed at high speed, defined. In 1914, the first shot Crete word was used in a mine in America.
Then the system was used to cover the surfaces of rocks against weathering. Shot Crete in 1930. The term was used by the Association of Civil Engineers and has been used.
Overall shotcrete used in two ways:
- Shotcrete Dry - Dry Mix Shotcrete
- A more mixed shotcrete - Wet Mix Shotcrete
Disadvantages of dry mix shotcrete is as follows:
- Cement dust from scattering seeds are high in the workshop.
- Because of the pliable mortar (due to lack of hydration) Much of it goes to waste.
- Because water reaching all the grains, there may be some parts remain hydrated.
The benefits of a more mixed shotcrete (WMS) is as follows:
- Does not require formatting
- Better adhesion between the concrete and rebar
- Reduce infiltration and proper sealing
- Recap pier and lining tunnels
- Better mechanical strength than dry mix shotcrete
- The possibility of implementing concrete structures with curved shapes, round and irregular
- Increasing the thickness of concrete pipes in corrosive environments and dangerous against fire
