After honing their skills on the new 33-story Kilbourn Tower in downtown Milwaukee, Potratz Concrete Pumping, Franksville, Wis., discovered the ideal formula for high rise construction.

As the pumper proceeds with the immediately adjacent University Club Tower, Potratz crews are utilizing the same combination of pumping equipment to surpass the Kilbourn Tower as the tallest residential structure in the state.

Potratz first dispatched their S 45 SX and 42-meter Schwing concrete boom pumps to the University Club Tower site in April 2005 to complete a 1,225-cubic yard mat pour on top of drilled piling.

Cliff Gorn, project superintendent for general contractor J.H Findorff & Son, Madison, Wis., said the pour took nine and a half hours.

Careful planning and cooperation with the city of Milwaukee made ready mix truck access a non-issue for Meyer Material Company, Burlington, Wis., which continues to supply the site as construction moves upward.

To complete deck pours on each of the towers' 36 floors, Potratz utilizes a Schwing 5000 trailer pump and 31-meter separate placing boom combination.

The boom's standard tubular mast and floor frames are incorporated into the form system within the structures core wall, designed by Peri Formwork Systems, Inc., Bolton, Ontario.

As decks are completed, the entire form system is raised by a hydraulic jacking system, and the boom goes along for the ride.

Keep It Simple

Gorn appreciates the simplicity behind the mounting system.

"Because it is actually a part of the forming system, it rides right with us. We aren't forced to tie up the crane relocating the boom. We're using the placing boom once every week and it hasn't hindered the carpentry, finishing or other labor schedules."

A 7,000-psi mix was utilized to complete pours to the 20th floor, and a 5,000-psi mix is currently supplied to finish off the remaining 16 floors of the high rise. As of January of this year, the crews had reached the 33rd floor.

The uniform concrete placement accomplished with the 31-meter boom and 5000 trailer pump results in less raking and finishing time, meaning contractors remain on schedule while providing a higher quality product.

The self-climbing system also provides time-saving benefits; the boom remains in the same position throughout the project, with no need for removal and remounting to other locations.

The 31-meter boom covers a wide area from one location, while on-site cranes remain free to complete other work.

In its previous life, the 31-meter boom serviced job sites around the Milwaukee area from a truck-mounted position.

Recently converted to a separate placing boom by Concrete Pump Repair, North Branch, Minn., the boom has become a hot commodity in the pumper's territory, and given Potratz Concrete Pumping an edge in a highly competitive territory.

"As a separate placing boom, it services a specific market, but we made the right decision to convert it," said firm owner Sid Potratz. "It supplies an engineering solution for our contractor clients, and there's a high demand for it."

The University Club tower will contain 36 floors and measure 446 feet high upon completion. Several condominium units within the structure are scheduled for occupation by September of this year.