Olympia Centre, a multimillion dollar residential and commercial building in Chicago, presented many unique forming challenges. With a 63-story building on his hands, the forming subcontractor naturally wanted to avoid handset forms and take advantage of the efficiency attainable with big form table assemblies that could be moved out of the building and lifted by crane to the next level, all in one piece. Adjoining buildings made it impractical to move the forms out the ends of the building, so a way had to be found to do it from the front. But the building facade had deep cast-in-place spandrels and columns defining openings that in many cases were less than 7 feet square. Further complications existed because the building tapered appreciably over several levels. The forming subcontractor called in a custom forms specialist who, in cooperation with the supplier of aluminum forming trusses, worked out a design to meet the needs of the situation.
For typical lower levels of the 7th through 23rd floors, an 18 1/2-foot-wide deck module was developed with a steel joist form built into the center. The slab form was hinged 3 feet 3 inches on either side of the joist, so that the side members or wings dropped down, making a formwork package 6 feet 7 1/2 inches high and 6 feet 6 inches wide, which could be pulled out through the restrictive openings in the building facade.