Precast Concrete-Open Web Steel Joists Hybrid Structure

New Hybrid Precast Concrete Building Provides Optimum Solution for Metal Recycler, PCI Journal, January-February 2004, describes a hybrid structural system combining precast concrete wall panels and long span double tees with open web steel joists and metal roof decking, used to construct an industrial metal recycling facility. In comparison to an alternative all-steel structural solution, the precast/steel hybrid was budgeted at an additional $2 per square foot, but with benefits including more open space with fewer interior columns, a more durable, low-maintenance interior, and a reduction of two months in the (fast track) construction schedule.

Structural components include:

• Eight-inch thick flat precast concrete loadbearing exterior wall panels
• Sixteen-inch thick x 72 inches wide interior precast loadbearing double-column bents
• Standard precast double tees, 10 feet wide x 34 inches deep, narrowed to 6 feet

Erection of precast elements was completed in 20 days. The use of precast panels rather than metal panel cladding reduced sitework costs by allowing the panels to act as retaining walls where excavation would otherwise have required expensive rock removal. The owner reports that the precast concrete wall panels offer superior sound absorption properties as well.