Inventors:
Joe C. Pohlman - Pittsburgh PA
James P. Romualdi - Pittsburgh PA
International Classification:
E04C 310
E04C 334
Abstract:
A composite structural member such as an electric transmission or distribution pole, having a thin-walled metal casing, a core of non-metallic settable rigid material such as concrete, and reinforcing members embedded in the core, and method of constructing the structural member are disclosed. The reinforcing members extend between the ends of the casing and communicate with the case. They are pre-stressed prior to the pouring of the concrete into the casing whereby the applied pre-stress is transmitted to the casing. The reinforcing members are secured to the casing such that the applied pre-stress remains permanently on the casing only. The method of forming the structural member includes securing one of the ends of the reinforcing members to one end of this casing and applying a predetermined stress to the reinforcing members, securing the other ends of the reinforcing members to the other end of the casing, pouring concrete into the casing, and allowing the concrete to set whereby the stress transmitted to the casing remains permanently on the casing only and is not transmitted to the core.