Maintenance Building

Project summary provided by submitting company.

The top three reasons why this project should be considered for an award are: the size and weight of the panels; the complexity of the rigging and lifting; and the sandwich-insulated panels.

Security is paramount for the owner, so few details can be shared about this maintenance building project. We have been asked to keep the owner's name, the location and purpose of the structure confidential.

The project required heavily reinforced tilt-up construction. These were the heaviest tilt-up panels installed on any Rudolph Libbe project in our 60-plus years in business. Because of the size, thickness and weight of the panels dictated by the project requirements, tilt-up was more economical than pre-cast panels. The panels averaged 16 feet wide by 40 feet tall and 85,000 pounds. The largest of the 72 panels measured 32 feet wide by 40 feet tall, and weighed 140,000 pounds.

For this project, the structural steel was erected before the panels - very unique compared to the customary process of erecting panels with temporary bracing, followed by steel erection. The size and weight of the panels required two lifting beams and two separate sets of rigging for the face and the top. Each tilt-up panel was picked up from its face and once lifted, was picked up from the top. When all face-lifting lugs were removed, the panel would hang straight down from the top. The crew would then swing the panel into place to be welded to the structural steel. A 300-ton crawler crane was used to erect the panels.

The project required each panel to have 4 inches of insulation, twice the standard 2 inches. Each panel also had 10 inches of structural concrete and a 2 3/4-inch concrete skin with wire mesh. This gave the panels an unusual thickness of 16 3/4 inches.

The project initially required dual-colored panels. To create the sandwich panels, the crew poured the face, then the brick face form liner. Two separate skin pours were made to create the two different colors - the dark first, then the light, then the structural panel with the heavy reinforcement was poured. Ultimately, however, the panels were painted a single color to best serve the project. Mark Remmetter, of MER Engineering in Dayton, Ohio, provided key design and support on the tilt-up portion of the project, which required complex engineering/design work.

Door, window and louver openings were framed with 10-inch-wide channels.

The maintenance building includes a 60,000-square-foot, two-story office area.