Shotcrete and gunite are a mixture of sand, cement, and water.
Shotcrete also known as ‘wet mix,’ is concrete (or sometimes mortar) which is conveyed through a hose and projected at a high velocity onto a surface, as a construction technique. Conventional steel rods, steel mesh, and/or fibers reinforce the shotcrete. Fiber reinforcement (steel or synthetic) is also used for stabilization in applications such as slopes or tunneling.
In addition to shotcrete and gunite we also apply pressure grout.
The shotcrete is pneumatically applied around the interior of the pipe to the thickness predetermined by the engineer, leaving behind a high-strength, fully structural pipe. The wet-process procedure generally produces less rebound, waste (when material falls to the floor), and dust compared to the dry-mix process.
Gunite is the ‘dry mix’ which is applied through a rubber hose and is hydrated in a special mixing nozzle. Hydration begins as the material leaves the chamber and the resulting mixture is shot into place under air pressure.
The pressure application permits shotcrete and gunite to be applied to practically any surface at any angle and at a specified thickness.
When properly mixed and applied, Shotcrete has a wider range of applications and is less expensive than concrete that is applied by any other method. It is extremely strong, dense and is highly resistant to weathering and many forms of chemical attack.
The ease and speed at which the material can be applied has resulted in the method’s ever-increasing use in construction, maintenance, and refurbishment. It is used to resurface and rehabilitate damaged or deteriorated sewers, bridges, dams, culverts, and many other types of masonry construction.
Sanitary and storm lines under city streets and residential areas should be inspected to determine if voids exist.
The filling of these voids by internal pressure grouting will not only increase the load-bearing capacity of the structure but also will prevent infiltration and ex-filtration.
DefinitionPressure Grouting is the process of injecting a specified grout material under pressure to: