Gunite and Shotcrete

Gunite is used for dry-gun concrete, while Shotcrete refers to wet-gun concrete. Gunite and Shotcrete are applied using different processes developed as construction solutions for various applications such as tunnels, underground structures, slope stabilization, structural repairs, and swimming pools.

The process involves spraying a mortar or small-aggregate concrete with air power onto high-pressure surfaces, consolidating and compacting the material, and ensuring it adheres to the surface. This is the concrete mixture to be placed in areas that are hard to reach with conventional concrete placement methods, such as steep slopes or irregularly shaped structures. The high velocity at which the mixture is projected onto the surface helps to compact and bond the concrete, producing a dense and durable finished surface.

In the Gunite process, dry concrete ingredients are placed in a hopper and pushed pneumatically through a hose to a nozzle. At the nozzle, the operator adds water, turning the dry ingredients into thoroughly mixed concrete that hits the surface. This process provides better control over the water content and is recommended when frequent stops during application are necessary.

Wet-mix shotcrete uses mixed concrete sent through a hose and nozzle without additional water. This process is commonly used because it produces less rebound and dust than dry-mix Gunite. Additionally, the wet-mix process can place more significant volumes of material in less time, making it more efficient. Shotcrete is commonly used in the construction of tunnels, mining operations, and other underground structures, as well as in the repair and rehabilitation of existing concrete systems.