Pre-cast concrete construction is widely used for food plants, but the technique leaves pock marks that serve as excellent nesting places for insect larvae. For the Tolleson plant, concrete specialists at Younglove Construction Co. recommended using self-compacting concrete to eliminate the bug-hole problem and speed completion.

Self-compacting concrete relies on super-plasticizers in the mix to create concrete weighing two tons per cubic yard. Beefy metal forms are required, and the engineered panels must be pre-cast off site. For the Tolleson project, Younglove relied on Coreslab Structures Inc. in Phoenix to deliver 360 panels measuring up to 10 ft. by 65 ft.

With traditional doube T-roof construction, a haunch is created, providing a ledge for dirt and dust to settle. The tops of self-compacting panels were notched and dovetailed with the roof panels, eliminating the haunch, according to Younglove project superintendant Steve Johanson. “The panels cost more, but the labor savings in not having to fill pockets more than compensated,” he says. The self-leveling pre-cast panels only required caulking to complete.