Referring first to
Each deck module 11 includes a hollow core element 13 of the type described and manufactured in accordance with the method disclosed in my above identified patent application. The hollow core element 13 includes a stack of long, narrow corrugated paperboard strips 14, each of which in the embodiment shown comprises a fluted web 15 and a smooth web 16 joined with a suitable adhesive. The webs 15 and 16 may be made of many suitable materials, but resin-impregnated paper is presently preferred.
In accordance with the hollow core lay-up method of my above-identified application, flutes are formed in the fluted web 15 of a substantially larger size than typically used for corrugated paperboard. The flutes may have a height of about ½ in. and, in order to provide a stack of strips 14 to make a module 11 with an 8 ft. width, approximately 180 to 200 strips would be required. The strips are 16 in. wide and 50 ft. long. The method and apparatus of my above-identified application are capable of forming up hollow core elements of the required size.
Each of the rectangular hollow core elements 13 has plan dimensions of 8 ft. by 50 ft. Steel sheets comprising an upper skin 17 and a lower skin 18 are attached to the respective upper and lower surfaces 20 and 21 of the hollow core element 13. The upper skin 17 may be, for example, ⅛ in. in thickness and the lower skin 18 may be ¼ in. in thickness. Although high modulus steel is preferred, other materials may be utilized, particularly for the upper skin where tensile strength and high modulus of elasticity are not major concerns. The skins 17 and 18 may be secured to the hollow core element 13 with any of a number of suitable adhesives, including epoxies. The resulting deck module 11 is attached to like modules to fabricate the deck 10 shown in
The upper surface of the upper skins 17 are provided with an array of upstanding projections 24, preferably short steel posts 25 which are welded to the skin 17. The height of the posts 25 depends on the thickness of the concrete slab 12, but for a 4 in. slab, posts having a height of about 3 in. are satisfactory. Once the modules 11 are welded together, concrete is poured onto the upper skin surfaces to form a slab 12 of a desired thickness. Any necessary utility connections, such as electric power conduits, piping and the like are placed on the upper skin surface and embedded in the subsequently poured concrete.
The exposed core elements 13, along the outer periphery of the fabricated deck 10, are closed with suitable close-out panels 26. The panels 26 may be made of any suitable material and glued, welded or otherwise secured to the exposed core elements 13 or the edges of the skins 17 and 18.
Although the composite structural support of the present invention has been described with respect to the fabrication of a floor for a building or a deck for a bridge, the present invention lends itself well to the fabrication of structural supports of a wide variety of shapes and sizes. For example, a much narrower module, namely one using a much smaller number of strips 14 (say 16 strips stacked to form a hollow core element about 8 in. wide) can function as a beam.
A floor, deck or beam member made in accordance with the present invention could be provided with a camber as is sometimes done in long span beams. The inherent flexibility of the fluted paper core element 13 will permit the necessary flexure to be imparted to provide a camber. For example, one of the skins 17 or 18 could be applied to the core element, the element then flexed to the desired camber and the other skin attached to the core in the bowed orientation.