Preparation: Before starting the shotcreting process, the concrete mix or mortar is prepared according to the project's specifications. The mixture typically consists of cement, aggregates (such as sand and gravel), water, and sometimes additives to enhance the properties of the shotcrete machine.
Loading the Machine: The prepared concrete mix or mortar is loaded into the shotcrete machine's hopper. The hopper is a large container that holds the mixture and feeds it into the shotcrete machine.
Mixing and Pumping: Inside the shotcrete machine, there is a powerful pump system that pressurizes the concrete mix. The pump propels the mixture through a hose or a series of hoses towards the nozzle.
Nozzle and Air Compressor: The nozzle is the business end of the shotcrete machine. It is where the concrete mixture is ejected at high velocity onto the surface being sprayed. An air compressor is usually connected to the shotcrete machine to provide a steady flow of compressed air.
Application: The shotcrete machine operator holds the nozzle and aims it at the targeted surface. As the concrete mix is sprayed, the operator uses the compressed air to assist in propelling and distributing the material evenly. This process allows the shotcrete to adhere to the surface with minimal rebound (overspray that doesn't stick to the intended surface).
Building up Layers: Shotcrete machine is applied in multiple layers to achieve the desired thickness and strength. Each layer must be allowed to partially set before applying the next layer. This helps create a strong bond between the layers.
Finishing: Once the desired thickness is achieved, the shotcrete surface may be finished using trowels or other tools to create a smooth or textured finish, depending on the project's requirements.
Curing: After the shotcrete application is complete, curing is essential for the concrete to gain strength and durability. Depending on the environmental conditions and the concrete mix used, curing may involve keeping the shotcrete surface damp or applying curing compounds.
