The gunite alias shotcrete or sprayed concrete is formed by mixing cement and sand, in the ratio of 1:3. It refers to mortar or small-aggregate concrete that is employed through a wet or dry process. It is conveyed through a hose and pneumatically projected at high velocity onto a surface under a pressure of about 20 to 30 N/cm2.
Guniting is mostly recommended for repairing concrete work that has been defective because of substandard work or other reasons. It is applied for delivering a watertight layer. Gunite is sprayed pneumatically onto the surfaces at a high velocity surface under.
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| Shotcreting in progress |
Gunite is very effective for tunnels, underground structures, slope stabilization, structural repairs, and pools. It is normally reinforced with traditional steel rods, steel mesh, or fibers. When the gunite is used it starts a instantaneous method of compression and settling.
Shotcrete is normally a comprehensive term for both the wet-mix and dry-mix versions. In pool construction, however, shotcrete stands for wet mix and gunite to dry mix. In this respect, these terms are not exchangeable.
Shotcrete is arranged and consolidated simultaneously, because of the force with the nozzle. It is sprayed into different types of shapes or surfaces along with vertical or overhead areas.
Categories of Shotcrete : Dry Shotcrete and Wet Shotcrete
The shotcrete may be used in dry or wet condition. In dry condition, the components are set in a hopper and driven pneumatically via a hose to the nozzle. The inclusion of water at the nozzle is restricted that is mixed up as soon as the material touches the surface. With dry shotcrete or guniting it is possible to modify the water content that should be provided into the mix immediately. It facilitates superior placement process devoid of the inclusion of accelerators. Dry application is suitable when the process entails repeated stops throughout the process of application.
Prepared concrete or the ready mixed concrete is utilized in wet-mix shotcrete. Application of compressed air is prepared at the nozzle that moves the wet mixture over the receiving surface. Less rebound and less dust with regards to dry application of shotcrete has transformed the wet-mix application as the most common process. The benefit of the wet-mix process is to arrange greater volumes in less time.
Benefits of Guniting
- Setting and compression takes place at the same time.
- Shotcrete will follow surfaces better than that of regular concrete.
- Shotcrete is also applied with steel fibers to be utilized as a substitution of welded wire mesh. It allows greater flexural strength, ductility and toughness.
- It is inexpensive with reference to conventional concrete.
- It offers lowered shrinkage and permeability.
Use of gunite
Gunites are mostly found in slope stabilization, tunneling, retention walls, water tanks and pools, artificial ponds, ditches and channels as well as structural reinforcement and mining applications.