Construction superintendent Kurt Baer was astounded to learn that his latest project, the world's largest structural testing facility at Lehigh University, Bethlehem, Pennsylvania, required nearly 1,000 tons of rebar. That's the average amount needed for a 20-story apartment building. But Baer's structure is less than five stories. The Lehigh University facility is designed to test six-story building sections, dams, bridge spans, and other large structures for their ability to withstand almost any natural or man-made force. The project requires more than 500,000 linear feet of steel cables running through the rebar network that must be post-tensioned after the concrete is poured. Hundreds of hold-down points in the floor and walls must be anchored between the rebar and cable and set flush with the concrete surface.