For shotcrete application, the primary equipment used is a shotcrete machine, also known as a shotcrete gun or concrete sprayer. There are two main types of shotcrete machines based on the method of application: wet-mix and dry-mix machines.

　　1. Wet-Mix Shotcrete Machine

　　In a wet-mix process, the concrete （a mix of water, cement, and aggregate） is pre-mixed and fed into the machine. Compressed air propels the mixture through the hose to the nozzle, where it's sprayed onto the surface. Wet-mix machines are commonly used for projects requiring large volumes of concrete and higher consistency, such as tunnels, pools, and structural reinforcements.

　　2. Dry-Mix Shotcrete Machine

　　In a dry-mix process, the machine feeds dry materials （cement and aggregate） into the hose, and water is added at the nozzle just before the mixture is sprayed. This method offers more control over the water content, making it ideal for smaller, more precise applications like repairs or small structures.

　　Advantages of Using a Shotcrete Sprayer:

　　Employing a shotcrete sprayer comes with several advantages:

　　1. Speed and Efficiency: Shotcrete can be applied rapidly, allowing quick construction or repair processes without compromising strength.

　　2. Flexibility: It can conform to complex shapes and irregular surfaces, making it suitable for diverse applications.

　　3. Structural Integrity: The high-pressure application results in dense and strong structures resistant to weathering and corrosion.

　　4. Cost-effective: Reduces labor costs significantly compared to traditional methods.

　　Shotcrete machines vary in size, from portable units for small jobs to larger, more powerful machines for large-scale construction projects.