Design and construction state-of-the-art superflat

When selected by Du Pont to provide design and construction management services for a new Duluth, Georgia distribution center, Lockwood Greene Engineers and Architects opted for a design that, in all ways feasible, would be state-of-the art. Some of the unique features of the Du Pont facility's floor make it significantly different from typical warehouse floors, and even from many previously constructed critical-tolerance floors. The final design specified 116,000 ft2 with superflat floors, the design and construction of which incorporated the most advanced techniques available. Superflat floor specifications generally utilize F-numbers to specify minimum floor flatness and levelness. F-numbers, which usually are determined by special measuring devices and statistical methods of analysis, are referenced in several ACI, ASTM, and CAN (Canadian standards) documents. This article discusses layout design post-tensioning design, concrete mix requirements, concrete placement, and other aspects of the subject.