Leading underground mining shotcrete specialist Putzmeister is adding new products to its range of underground construction equipment at this year’s world-leading construction machinery fair, bauma in Germany.

The company is extending its portfolio with the launch of the new top-of-the-range mechanised shotcrete spraying machine for small sections, WETKRET 3, and a compact shotcrete batching plant, BATCHKRET 20, specially designed for underground mines.

WETKRET 3 concrete spraying unit for small tunnel sections

WETKRET 3 is ideal for smaller tunnel sections. Perfect for the rugged, uneven terrain of the mine, the equipment is mounted on a compact rubber-coated crawler chassis to facilitate manoeuvring, even in jagged worksites.

It features a telescopic spraying arm with a vertical reach of 9m and a horizontal reach of 7m, which can be deployed in a minimum section of 2.5m. It can run both on diesel and on electricity, boosting on-site mobility away from the mains.

The unit has hydraulically-operated support legs with an optional tilting system of +/-30º that adds to its stability and safety profile on-site. For upward slopes, there is an optional rear stabiliser blade; and an optional electronically-operated 50m winch cable with a 6.803kg tractive force for downward slopes.

The engine, support legs, tilting system and the blade stabiliser can also be operated in electric or diesel mode. A proportional remote control can be used either by cable or wirelessly via bluetooth to operate the crawler carrier, support legs, spraying arm and head as well as the optional elements.

WETKRET 3 has couplings for concrete piping on both sides for greater flexibility, while the additive and air lines run internally so no external hoses are required. The machine works well with Putzmeister’s stationary concrete pump SPM 715 SYNCHRO, which combines large-scale pumping technology with compact design and easy operation.

BATCHKRET 20 compact batching plant for underground mining

BATCHKRET 20 is a compact batching plant that completes Putzmeister Underground’s shotcrete offering for a fully-integrated, streamlined shotcrete application process.

Designed for the challenging operating environment of the mine, the new BATCHKRET 20 allows clients to bypass costlier shotcrete transporting systems, by taking the production of concrete to the heart of their operations underground and optimising logistics.

Batching plants are processing units where these ingredients are weighed and mixed in a way that will deliver a homogeneous, consistent shotcrete formula that meets stringent quality requirements. BATCHKRET 20 has a compact footprint with an elevated production capacity of up to 20m³/h.
The central mixing set has a cylindrical pan with 750l capacity, and a vertical axle with rotating blades and scrapers.

The plant also features aggregate storage hoppers with belt feeders, a 14m long cement conveyor belt and a batching booth that houses the control equipment and protects it from the harsh working conditions of the underground mine.

It can be configured with three different feeding systems, including a big bag, silo or bag cutter to match the project’s requirements. Optional equipment includes a hydroprobe sensor for sands.