A shotcrete machine pneumatically sprays concrete at high velocity onto a surface. It is commonly used for tunnel lining, slope stabilization, and structural repairs. Available in dry-mix (water added at the nozzle) and wet-mix (pre-mixed concrete) configurations. Outputs typically range from 4 to 30 m³/hr

By Material Mixing Method

• Dry-Mix Shotcrete Machines: Process a dry mixture of cement and aggregates. High-pressure compressed air propels the dry material through the hose, and water is introduced directly at the spraying nozzle. Examples include 10 HP Dry Shotcrete Machines.
• Wet-Mix Shotcrete Machines: Process fully pre-mixed concrete that already contains water. A concrete pump pushes the wet mix through the line, and compressed air is only added at the nozzle to accelerate and disperse the spray.
• Semi-Wet Shotcrete Machines: Handle a concrete mixture with a pre-adjusted moisture content of about 5% to 8%. This damp mix helps minimize airborne dust compared to a purely dry process.

By Material Feeding Mechanism

• Rotor-Type Machines: Utilize a continuously revolving steel and rubber rotor chamber. This setup allows dry or semi-wet concrete to drop from the hopper into the rotor pockets before being blown into the air chamber and hose.
• Pneumatic Twin-Chamber Guns: Feature two pressure chambers working in tandem to enable a continuous feed. One chamber fills with dry mix under normal atmospheric pressure while the other discharges material under continuous system pressure.
• Hydraulic Duplex Piston Pumps: Specifically designed for wet-mix applications. They use dual reciprocating pistons to deliver a highly constant, pulse-free, and continuous flow of heavy concrete.

By Automation and Mobility

• Manual / Handheld Systems: Require a human operator to physically hold and direct the delivery nozzle. They are ideal for tight spaces, small structural repairs, and swimming pools.
• Robotic Boom Sprayers: Feature multi-axis, remote-controlled telescopic arms (such as the Putzmeister Wetkret or Schwing TSR series). These heavy-duty rigs automate concrete spraying to keep workers safe during tunnel excavation.
• Truck or Rail Mounted rigs: Mounted onto rugged heavy-duty truck chassis or rail-guided wheels. These systems provide extreme mobility for long-distance highway slopes, deep mine shafts, and subway tunnels.

• Pneumatic propulsion: Uses compressed air (7–12 bar) to blast concrete onto surfaces at high velocity.
• Dual configurations: Available in dry-mix (water added at nozzle) and wet-mix (pre-mixed concrete) models.
• Continuous feeding: Features a rotating rotor-stator or hydraulic piston pump to maintain uniform material flow.
• Integrated hoppers: Uses vibrating grids and mechanical agitators to prevent material clogging and blockages.
• Additive dosing: Includes synchronized liquid accelerator pumps to inject quick-setting chemicals at the nozzle.
• Variable output: Utilizes frequency inverters to adjust concrete spraying volume based on project thickness.
• Versatile mobility: Available in skid-mounted, wheel-trailer, or rail-guided chassis options for tough terrain.
• Robotic compatibility: Supports remote-controlled telescopic booms to eliminate dangerous manual nozzle handling in tunnels.

• Tunneling and mining: Stabilizes excavated underground rock walls, subway tunnels, and mine shafts instantly.
• Slope stabilization: Sprays onto steep highway embankments, hillsides, and soil surfaces to prevent dangerous landslides.
• Structural repair: Restores damaged overhead concrete bridges, marine docks, columns, and building facades without formwork.
• Pool construction: Creates complex curved shapes easily for swimming pools, skateparks, and decorative artificial rock landscapes.
• Retaining walls: Reinforces deep basement excavations, foundation shores, and temporary earth-retaining barriers.
• Refractory lining: Applies heat-resistant concrete inside high-temperature industrial furnaces, kilns, and metal smelting ladles.
• Water retaining structures: Coats reservoirs, irrigation canals, dams, and storage tanks to ensure structural water tightness.