Rubber-Tracked Putzmeister Concrete Trailer Pump Overcomes Rough Terrain September 2004

STURTEVANT, Wis. (September 2004) – A high-pressure Putzmeister concrete trailer pump has been mounted on a rubber-tracked chassis to overcome rough terrain on a job site at Grosslappen, Germany. The unit also is increasing the speed at which concrete can be poured into holes bored for piling foundations.

The construction project involves expanding a sewage treatment plant and constructing four sludge digester towers. Each digester tower has a capacity of approximately 18,965 cubic yards (14,500 m 3). An addition to the treatment plant will be linked to the existing plant by a 510-foot (155m) channel.

Wayess & Freytag Ing.-Bau AG is the project engineer. Bauer Spezialtiefbau is the general contractor.

A special-purpose machine built by Bauer bored a circle of holes for piles as deep as 50 feet (15m). The pilings secure an excavation pit as well as foundations for the digester towers. Reinforced and non-reinforced piles overlap in an alternating manner. The diameter of each pile is 4 feet (1.2m) and 95 piles support each tower.

The compact Putzmeister trailer pump model BSA 1005 D is a standard concrete trailer pump with a maximum hourly output of 70 cubic yards (54m 3/hr). An 82-hp (61 kW) Deutz diesel engine supplies power to operate the unit at two speeds: 1.25 mph and 2.5 mph (2 and 4 km/h).

The rubber-tracked pump has proven maneuverable and, paired with the boring machine, allows for quick change of drills. Unlike truck-mounted concrete pumps often used on such projects, time is not lost by having to set up outriggers, or to unfold or fold up a placing boom.

Furthermore, using the trailer pump eliminates unintentional boom movement, which is important because concrete delivery lines are fixed directly to the boring drill. Finally, pump volume can be adapted quickly to the filling velocity in the drilled hole.

It is important that the pump and drill be synchronized, otherwise the predetermined level of concrete to be poured into each drilled hole can be exceeded.

In porous soils, such as found on the Grosslappen site, concrete may be pressed out into the surrounding subsoil with a resulting loss in quality and strength. Therefore, concrete C20/25, 0/16-grain size and W/C factor 0.56 is used for the bored piles.

The BSA with rubber tracks is linked to the rigid riser on the boring machine with a delivery line approximately 100 feet (30m) long. A flexible hose connects with the drill pipes at the upper end of the riser.

The rising drill spindle process produces a corkscrew movement that brings material from the bottom of the bored holes, which are filled continuously with concrete flowing through the hollow shaft of the spindle.

The project began in June 2003. Completion is scheduled for October 2005 with approximately 7,848 cubic yards (6,000m 3) of concrete to be pumped for the foundation.

The BSA trailer pump is expected to prove valuable in other applications because it can be used in urban areas without damaging asphalt or other pavement surfaces.

Customers may order the rubber-tracked trailer pump through Putzmeister America for applications within the United States, Canada and Mexico.