Concrete panel systems have been used primarily to provide pre-manufactured walls for residential or small commercial or industrial buildings. Such systems promise a more accurate building, reduced on-site building time and waste, insect resistance and a hedge against rising lumber prices.
U.S. Pat. No. 3,475,529 describes a method of making a prestressed hollow core concrete panel. A first section is formed comprising a slab having a flat outer face and a plurality of ribs extending from an inner face. This first section is then laid ribs down on a second section, which is either a flat slab or a duplicate of the first section laid ribs up. The two sections are joined together. In an embodiment, the cores of the panel are closed.
U.S. Pat. No. 3,683,578 describes a concrete panel building system in which the panels have an inner insulating layer sandwiched between concrete layers. The space between the concrete layers cooperates with a guide nailed to a foundation to align the wall panels on the foundation. Upper portions of adjacent wall panels are secured together by a various bolted connections.
U.S. Pat. Nos. 4,605,529, 4,751,803 and 4,934,121 describe concrete wall panels having vertical ribs extending between horizontal upper and lower beams all attached to a concrete slab which provides the outer surface of the wall. The ribs and beams of the panels are reinforced by longitudinal reinforcing bars and the concrete slab is reinforced by a wire mesh. A “bolting saddle” cast into the ends of the upper beams allows adjacent panels to be bolted together. U.S. Pat. No. 5,656,194 describes an improved assembly jig having hinged sidewalls for use in making such panels.
U.S. Pat. No. 5,493,838 describes a method of constructing a basement from prefabricated concrete panels. The building site is first excavated and footings are positioned in the excavation to define the outline of the building. The footings have a groove in their upper surface to accept wall sections which comprise a slab having a flat outer face and a plurality of ribs on an inner face. Freestanding corner wall sections are placed first on the footings. Flat wall panels are then joined end-to-end between the corner sections to complete a peripheral wall. A conventional wooden floor deck is constructed over the peripheral wall to strengthen the structure before the basement is backfilled.