YG Machinery

For the First-Time Buyer: What Does This Machine Actually Do?

Shotcrete is concrete that is sprayed onto a surface, usually in a tunnel, mine, or slope.

There are two kinds:

• Dry shotcrete — water is added at the nozzle, at the point of spraying.
• Wet shotcrete — the concrete is fully mixed before it is pumped and sprayed.

This page is about wet shotcrete. It is generally preferred in tunnel lining and support work because it can give better bonding, lower dust, and less rebound, though the final method must be confirmed against the design and the approved process.

The shotcrete machine robot for tunnels is a truck-mounted wet shotcrete machine. It mixes, pumps, and sprays from the same vehicle, and uses a powered spraying arm instead of a hand-held nozzle. This matters because with a hand gun, the operator stands close to the spraying face; with the truck, the arm does the reaching, and the operator controls it from the cabin or with a remote, so the nozzle work is farther from the operator.

• Pumping — moving the wet concrete from the mixer through a hose up to the nozzle.
• Accelerator — a chemical added at the nozzle that makes the concrete stick and set faster on the surface.
• Boom/spraying manipulator — the powered arm that holds and moves the nozzle to different points.

On this truck, mixing, pumping, and spraying, plus the accelerator dosing, all sit on one chassis. They are designed to work together as a system. But the truck is only one part of the system — you also need the concrete supply, compressed air, accelerator, and cleaning water lined up on site.

Contact us now to learn more about hydraulic wet-mix shotcrete machines.

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Technical Specifications for the Concrete Spraying Robot for Tunnels

Model	YG-3016	YG-4016
Overall length	7770mm	7880mm
Overall width	2460mm	2460mm
Overall height	3180mm	3380mm
Rated weight	14T	15T
Minimum turning radius	10.8M	11.5M
Maximum gradeability	≥40°	≥40°
Engine power	85KW	103KW
Wheelbase	3900mm	4100mm
Front axle track	1870mm	1870mm
Rear axle track	1870mm	1870mm
Boom and Outrigger Parameters
Spraying height	16m	16m
Spraying width	25m	25m
Main boom luffing angle	0°~65°	0°~65°
Secondary boom luffing angle	-110°~90°	-110°~90°
Boom slewing angle	310°	310°
Nozzle axial rotation angle	360°	360°
Nozzle vertical oscillation angle	240°	240°
Nozzle sweeping angle	360°	360°
Front outrigger ground contact center distance	2480mm	2480mm
Rear outrigger ground contact center distance	2480mm	2480mm
Front-to-rear outrigger center distance	5850mm	5850mm
Pumping System Parameters
Concrete output	30m³/h	40m³/h
Hopper capacity	0.4m³	0.4m³
Concrete discharge pressure	7.5Mpa	7.5Mpa
Accelerator pump maximum discharge pressure	1.8Mpa	1.8Mpa
Concrete pipe diameter	Φ90mm	Φ90mm
Nozzle outlet diameter	Φ50mm	Φ50mm
Main oil cylinder	Φ100mm*Φ70*1000	Φ100mm*Φ70*1000
Conveying cylinder	Φ180mm*1000	Φ180mm*1000
Electric motor	55KW	75KW

Reference specifications from the YG public page; final configuration and suitability depend on the selected model, tunnel section, concrete mix, pump setup, and site conditions.

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6 Key Features of the YG Robotic Shotcrete Spraying System

1. Integrated wet shotcrete system. All key parts: concrete pumping unit, accelerator dosing, compressed air interface, robotic shotcrete arm, and mobile truck chassis are assembled on one wet shotcrete truck. No need to assemble separate large pumps on site.
2. Hydraulic robotic arm control. Hydraulic wet shotcrete robot delivers stable, smooth nozzle movement. Remote operation lets operators stand outside the high-risk spray face. Arm positioning covers tunnel crown, side walls, and invert when matched to your tunnel size.
3. Rugged off-road chassis for underground sites. YG-3016 and YG-4016 chassis support steep climbing ≥40°. The truck body is compact for tunnel travel.
4. Controllable accelerator dosing. Adjustable accelerator flow matches your concrete mix and rock conditions, helping reduce rebound and improve lining quality.
5. Easy site transfer and cleaning design. The whole unit drives between tunnel faces. After each shift, the pipeline and nozzle need full cleaning to prevent concrete blockages inside hoses.
6. Safety-focused layout. Operator separation from the spray zone cuts dust and impact exposure. This machine still requires site ventilation, escape routes, and trained staff; remote control is not unmanned operation.

Where This Shotcrete Machine Robot Is Used (Applications)

This shotcrete machine robot for tunnels is built for permanent and temporary tunnel support projects.

• Highway & railway tunnel primary lining, tunnel crown and side wall shotcrete support
• Metro/subway underground tunnel rock stabilization
• Hydraulic tunnels, water diversion caverns
• Underground mine drift and stope rock reinforcement
• Slope stabilization, rock cut protection for open sites
• Small underground cavern and utility tunnel shotcrete works

Best fit: Medium to large tunnel sections with continuous shotcrete tasks. For very small cross-sections or short tunnels, YG can review whether split, smaller handheld wet shotcrete equipment is a better option.

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How the Tunnel Concrete Spraying Robot Works (Working Principle)

The working process can be understood in six steps.

1. Prepare the Surface

Before spraying, the surface should be inspected and prepared.

Loose rock, dust, water, and unstable material should be addressed according to the project requirements. Steel arches, rock bolts, mesh, and other support elements should also be checked.

Surface condition affects adhesion and rebound. A clean, stable surface helps the sprayed concrete bond better.

2. Mix the Concrete

Wet shotcrete uses concrete that has already been mixed with water.

The concrete mix must suit the project specification, pump, delivery distance, and spraying method. Aggregate size, workability, and consistency affect pumping and spraying.

The concrete should be delivered in a sequence that matches the spraying schedule.

3. Pump Concrete to the Nozzle

The pump moves wet concrete through delivery lines toward the nozzle.

Pumping distance, hose condition, line routing, and concrete workability all affect operation. A longer or more complex route may require additional planning.

Blockages can interrupt work. Proper mix design, clean lines, correct hose arrangement, and planned cleaning help reduce avoidable interruptions.

4. Add Accelerator at the Nozzle

Accelerator is added near the nozzle, not into the entire concrete batch.

It helps the sprayed concrete adhere to the surface and begin setting faster. The correct accelerator setting depends on the concrete mix, spraying distance, layer thickness, and project requirements.

Accelerator should be handled according to the manufacturer’s instructions and the approved safety procedure.

5. Spray Through the Robotic Arm

The hydraulic arm positions the nozzle against the tunnel crown, sidewall, or other support surface.

Compressed air helps shape the concrete stream as it leaves the nozzle. The operator controls the spraying process from the cabin or remote-control position, subject to the selected configuration.

Nozzle distance, angle, layer thickness, and movement pattern affect adhesion and rebound.

6. Clean and Inspect

After spraying, the system should be cleaned according to the operating procedure.

Delivery lines, pump components, nozzle parts, and accelerator equipment may require cleaning. Inspection should also cover the sprayed surface, equipment condition, hoses, and control system.

Cleaning is part of maintaining reliable operation. It should be planned into the work schedule, not treated as an optional task.

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Frequently Asked Questions About Tunnel Shotcrete Trucks

Send Your Tunnel Cross-Section, Concrete Mix and Site Layout

We will review your tunnel net width, net height, cross-section drawing, tunnel length, slope, support design, concrete mix, pumping distance, accelerator, power supply, destination port, and purchase schedule, then recommend a suitable shotcrete machine robot for the tunnel configuration and provide a technical proposal.