Demolition crews increasingly specify wet-mix shotcrete machines for tunnel support, with robotic arms delivering 20–30 m³/h of sprayed concrete to keep operators out of unsupported headings [S5].
Output bands now cluster around 30 m³/h (compact YG-3016 class) and 40 m³/h (YG-4016 class), both with 0.4 m³ hoppers, 90 mm concrete pipes, 50 mm nozzles, and 16 m spray height, while pressure-rated units push main-pump pressure to 15–20 MPa for long-distance conveying [S5].
Wet-mix vs dry-mix: the rebound and dust trade-off
Wet-mix shotcrete cuts rebound from roughly 30% (typical dry-mix) to under 10%, and inside tight demolition headings it cuts dust load enough to keep a crew productive without respirator-grade ventilation at every face [S5][S7].
Dry-mix rigs remain useful for small one-off demolition patches: the material is conveyed dry and water is added at the nozzle, so the package is lighter, the compressor (3–15 m³/min) sets the output, and setup is faster when the patch is a few square meters of overhead concrete [S3][S4]. For a full tunnel cross-section, however, dry-mix loses on rebound cost and on consistent quality, which is why wet-mix has become the default in 2026 underground specs [S5].
Conveying reach is a hard separator: the MEYCO Piccola and MEYCO GM 090 each deliver up to 500 m horizontally with 100 m lift, while a mid-size Aliva 262 stops at 40 m horizontal and 10 m vertical, a direct cap on how far a demolition face can sit from the pump station [S2].
Output, pressure, and aggregate: the three number gates
Output target is the first gate: 4–8 m³/h suits patch repair, 20–30 m³/h suits one-boom robotic tunnel crews, and 30–40 m³/h suits truck-mounted or carrier-mounted rigs working full tunnel sections [S4][S5][S6].
Pressure is the second gate. Concrete discharge pressure on a YG-3016/4016 wet-mix rig is 7.5 MPa, but the main pump circuit (the one that pushes concrete to the nozzle, not the accelerator circuit) is rated 15–20 MPa for long-distance and high-altitude pumping [S5]. For a demolition retrofit where the pump sits 200–400 m back from the face, the higher-pressure pump is mandatory; the lower-pressure discharge figure is a downstream rating, not a conveying rating [S4][S5].
Aggregate size is the third gate. Most wet-mix rotors and pumping cylinders accept up to 15 mm crushed stone; pushing 20 mm aggregate through a standard rotor (350–480 mm diameter) raises block risk and accelerates wear-plate consumption [S3][S5]. On demolition jobs where shotcrete must bond to rough, scabbled concrete, mix-design discipline on the 15 mm limit matters more than chasing higher output.
Air, hose, and compressor matching
Dry-mix and small wet-mix rigs are air-thirsty: published data shows air consumption of 3–4 m³/min at 0.4–0.6 MPa for small rotors, 7–8 m³/min mid-size, and 10–15 m³/min for production rotors at the same pressure band [S3].
Hose inner diameter scales with output: 38 mm for the smallest, 51 mm for mid, 64 mm for production rigs, and dual 51/64 mm options on heavier units [S3]. A common demolition mistake is pairing a 40 m³/h pump with a 38 mm hose, which chokes flow and inflates rebound. The right rule is to size the hose to the rotor diameter (350–480 mm) and to the cited m³/min figure, not to the hose already on the truck [S3][S4].
Working air pressure sits in a narrow 0.4–0.6 MPa band for dry-mix rotors and 0.5–0.8 bar for the wet-mix projection circuit, so the on-site compressor must be sized for both peak m³/min and sustained pressure, or the nozzle will starve at the top of every cycle [S3][S4].
Robotic arm vs handheld: where each earns its slot
Robotic shotcrete arms (360° nozzle rotation, 240° swing, 2900 mm boom telescopic stroke, 20 m³/h theoretical pumping, 7.5 MPa pumping output) are now standard for large demolition-support headings because they keep the operator out of the unsupported zone and double output vs handheld [S1][S6].
The Hitech-style demolition robot platform adds a shotcrete attachment alongside breakers, scalers, scabblers, and buckets, so one base machine handles drill-scale-spray in a single mobilization, which is decisive in narrow tunnel sections where bringing in a separate shotcrete pump is logistically painful [S1]. Handheld shotcrete still fits small patch work, repair crews, and confined corners where the boom cannot reach; its motor-power and hose-size limits make it the wrong tool for full cross-section demolition rehab [S10]. For a related take on mobility and output match across road and concrete work, see the shotcrete selection map for concrete work.
Decision matrix: wet robotic, wet handheld, dry handheld, dry robot-mounted
Four configurations cover nearly every demolition shotcrete brief, and lining them up on the same criteria makes the pick straightforward: [S1]
Configuration A, wet-mix robotic (e.g. truck-mounted YG-4016 or 20 m³/h boom unit): output 20–40 m³/h, rebound under 10%, dust low, main-pump pressure up to 20 MPa, reach 16 m vertical / 25 m horizontal, 360° nozzle rotation, best for full tunnel cross-section and slope stabilization where a crew can be kept off the face [S5][S6].
Configuration B, wet-mix handheld: output 4–8 m³/h, low dust, requires a separate compressor at 10–15 m³/min, fits patch repair and overhead detail work in demolition, cheaper to mobilize but bottlenecks on output [S4][S10].
Configuration C, dry-mix handheld (small rotor, 350 mm, 0.4–0.6 MPa, 3–4 m³/min air, 38 mm hose): output 1–3 m³/h, rebound 25–30%, fits very small patches and one-off demolition where compressor air, not pump flow, is the binding constraint [S3].
Configuration D, dry-mix robot-mounted attachment: combines the Hitech-style demolition robot base with a shotcrete attachment for initial tunnel stabilization, output band lower than wet robotic but uniquely useful where a single modular platform must drill, scale, and spray in one pass [S1].
Standards, safety, and what to verify before signing
Noise from a working shotcrete rig is typically specified at ≤90 dB(A) under ISO 4871, and the electrical enclosure is commonly IP54 per IEC 60529, both numbers worth confirming in the OEM data sheet for any demolition tender [S4].
For demolition use, the binding constraints are not exotic standards but four on-paper numbers: theoretical pumping capacity in m³/h, maximum aggregate size in mm, maximum conveying distance in m (horizontal and vertical), and the main-pump pressure in MPa, not the concrete discharge pressure which is a downstream figure [S5][S6]. Get those four in writing, match them to your face area and rebound target, and the machine choice is mechanical, not subjective.
For a cross-check on how output and reach pair with service coverage on road and infrastructure work, the shotcrete selection for road maintenance companion piece lays out the same output/reach logic for a different site profile. For demolition projects that pair shotcrete with heavy cutting and breaking, the demolition hammer reference covers the breaker side of the same workflow, and the broader shotcrete machine category anchors the spec vocabulary used here.
The underlying component specifications are covered under aerial work platform.