US1994829A - Concrete slab or like structure and reenforcing therefor - Google Patents

Description

CONCRETE SLAB 0R LIKE STRUCTURE AND REENEORCINGEHEREFOR sheets-sheet 1 m G A N H.

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Mam-h m, 1935. H. NAGIN 1,994,829'

CONCRETE SLAB OR LIKE STRUCTURE AND REENFORCING THEREFOR Filed Feb. 1'7, 1954 5 Sheets-Shea?l 2 INVENTOR March 19,*11935. H. NAG|N I 1,994,829

CONCRETE SLAB OR LIKE STRUCTURE AND REENFORVCING THEREFOR Filed Feb. 1'7, 1934 5 Sheets-Sheet 3 Patented Mar. 19, 1935 UNITED STATES PATENT OFFICE CONCRETE SLAB R LIKE STRUCTURE AND REENFORCING THEREFOR Harold Nagin, Pittsburgh, Pa., assignor to Reliance Steel ProductsCompany, Rankin, Pa., a corporation of Pennsylvania This invention relates to reenforced slab and supports previously assembled units consisting of girder members.

T-bars or other shapes held together by cross bars, and to ll the spaces between the bars with concrete. The heads of the T-bars are lowermost and constitute a substantially continuous bottom for the structure which holds the wet concrete in place and eliminates the necessity for forms. The stems of the Ts extend upwardly and at their uppermost portions are joined together by the cross bars. The upper faces of the stems and the cross bars serve as a pavement armoring. Structures of this character may be fabricated and placed at relatively low cost and by their use the dead weight of the bridge may be greatly reduced. However, they are open to certain serious objections which are overcome by the present invention. Notably these prior structures are open to the objection that the heads of the Ts are not adequately protected and must be painted regularly if corrosion is tobe avoided. There is also the danger that water condensing between adjacent Ts and freezing may cause deterioration of the structure. Another serious objection is that the load is not distributed from one T to the next, `and this has proved so serious that attempts have been made to overcome it by welding the Ts together at spaced intervals. Such arrangement, however, is not entirely satisfactory and decidedly expensive. l

I provide a structure wherein the steel is adequately protected from the elements and the tension loads are properly distributed between the My improved structure is relatively simple and inexpensive to build, may be placed with ease, and when filled with concrete or other filling material, is permanent, requiring no painting. Furthermore, my invention provides a structure which can be used with advantage Where preformed blocks or bricks are employed.

In the accompanying drawings illustrating present preferred forms of the invention,

Figure 1 is a transverse view through a composite slab embodying the invention;

Figure 2 is a top plan view thereof;

Figure 3 is a longitudinal section;

Figures 4 and 5 are views corresponding to Figure 1 but showing'modied constructions;

Figure 6 is' a longitudinal section of the embodiment illustrated in Figure 5;

Figure 7 is a top plan view of another form of reenforcing structure;

. the drawings for this purpose. The edges of the Figure 8 is a transverse section through a composite structure using the reenforcement of Figure 7;

Figure 9 is a'longitudinal sectional view, `being in a plane at right angles to Figure 8; and 5 Figure 1'0 is a transverse section through still another form of structure.

Figures 1 to 3 inclusive show a slab consisting of girder bars 2 and tension bars 3 adapted to take the longitudinal loads, these several meml0 bers being connected together by cross bars 4 at the top and cross bars 5 at the bottom. Any suitable type of joint may be made as, for example, by electric pressure welding. It will be noted from Figures 2 and 3 that the cross bars 4 are 15 rather closely spaced, preferably at approximately the same distance as the girder bars 2 are spaced so as to provide a grating surface with substantially square openings, which serves as a pavement armoring when the structure is filled with concrete or other filling material. The cross bars 5 are more widely spaced. They function to hold the parts of the reenforcing structure assembled until the concrete or other filling has set; but, more important, they cooperate with the lling to distribute the tension between the longitudinal members when the slab is loaded. Although these bars are relatively small in cross section and extend at right angles to the longitudinal members, they are nevertheless highly effective for distributing the load transversely of the structure and very eiectively distribute any concentrated loads which may be applied. In consequence, it is possible to use the steel very enciently in designing the slab.

In order to protect the steel from corrosion by the elements it is important that the concrete extend belowthe longitudinal bars and the cross bars 5. For this purpose, I provide a sheet 6` of concrete-retaining material, such as wood, composition board, cardboard, sheet metal, or the like,`and suspend it from the assembled metal structure. Any suitable suspending devices may be employed. I have illustrated wire clips 7 in sheet 6 may be turned up at the sides of the slab, as indicated at 8, and secured to the outside girder -bar in any convenient fashion, or a form board may be employed at the side of the structure and the sheet secured to it for the purpose of retaining the fluid concrete when poured. Similar provision may be made at Athe ends of the slab where necessary, although in general, the structure itself will provide an end wall for the concretereceiving space.

The reenforcing structure is filled with concrete 9, or other material such as'asphalt or like composition, or with precast or molded blocks and/or slabs bonded with or embedded in a cementitious or plastic filler, which mass preferably has its top surface flush with the top of the reenforcing structure, the reenforcing structure providing a pavement armoring. After the concrete or other mass has hardened or set, the structure develops its full strength and, as stated, is peculiarly effective for receiving and distributing concentrated loads. The sheet 6 may be removed if desired but, generally speaking, it will be satisfactory to leave it in place. If it is corrodible material, it can be allowed to orrode away without any concern arising asfto t e slab structure proper.

Figure 4 illustrates a modified construction having longitudinal members 10 Whose lower portions are enlarged as indicated at 41l to provide additional metal for withstanding the tensile forces. It will be noted that the enlargement 11 is not continued at full width to the bottom of the girder bar 10, but that, on the contrary, the metal thickens and is then thinned again so that the bottom section is relatively narrow. This is to simplify the problem of attaching the tension distributing cross bars a. which are secured to the girder bar in its lowermost position 12 of reduced `cross section.

Figure 4 also illustrates a modified form of bottom sheet. 'Ihis sheet, instead of beingflat, has corrugations 13 which are located beneath the girder bars for the purpose of providing additional concrete therebelow. This insures the utmost protection for the girder bars with a minimum of concrete.

Figures 5 and 6 illustrate a modified structure wherein the girder members 14, instead of being solid bars, are of truss-like construction having a continuous top element l5, a continuous bottom element 16, and an intermediate lattice 17. The upper cross bars 4b are connected to the elements 15 and the tension distributing bars 5b are connected to the elements 16.

The reenforcing for my improved slab structure may be pre-,assembled and handled in unit sections. These units may be assembled with the form sheet or it may be placed after the reenforcing sections have been put into place. In either case, the sections may be fabricated and placed at relatively low cost and, when filled withf concrete, provide a concrete slab structure of the highest quality. Moreover, instead of using concrete, asphalt or other paving composition may be employed. It is also contemplated that -ly from precast blocks and/or slabs. V

In the arrangement shown in Figures '7 to 9, inclusive, the reenforcement comprises longitudinally extending bearing members connected at the top by cross members 21 and connected at the bottom by cross members 22. The cross members 22 are preferably out of line with the cross members 21. This structure may be advantageously used in paving, particularly on roadways,

.such as tunnels where the vehicles travel in cere.

tain defined lanes, and the strain on the paving is concentrated along definite tracks.

'Ihis reenforcement may be set on a previously formed foundation 25 and may be embedded in a mass of cement 26. Preformed blocks or bricks 27 are set into the cells between the top cross members 21 and these blocks rest on the bottom cross members 22. The cement material in which the bottom of the reenforcer'nent is embedded extends up around the sides of these blocks, serving to fill the spaces between the blocks and to hold the blocks firmly in place. the main bearing members 20, there-may also be provided small auxiliary bearing members 28, or the longitudinal bearing members 28 may be used in place of the transverse bottom members 22, although the use of the transverse members 22 is preferable.

In the manufacture of the reenforcement, the main grid structure comprising the bearing members 20 and the cross members 21 may first be assembled, after which the cross members 22 can be welded in place. If longitudinal members 28 are used in addition to the cross members 22, the cross members 22 and the longitudinal members 28 can be assembled as a separate grid structure and then welded to the bottom of the first grid structure comprising the members 20 and 21.

Figure 10 illustrates a slight modification of the arrangement shown in Figures 7, 8 and 9. With this structure, there are longitudinally ex. tending main bearingmembers 30 corresponding to the members 20 of Figure 7, and top cross members 31 corresponding to the members 21. At the bottom of the grid structure comprising the members 30 and 31, is a secondary grid structure comprising cross members 32 connecting the bottom edges of the members 30 and carrying longitudinally extending bearing bars 33 in the form of angles, these angles projecting-up into the spaces between the longitudinally extending members' 30. They add increased rigidity to the structure and at the same time form a support for the preformed blocks 34. With this arrangement, it is not necessary that the blocks'have a height or thickness as great as the thickness of the main bearing bars 30. Moreover, this reenforcement can be rmly interlocked with the mass of cement 35 above -thevfoundation 36.

While I have illustrated and described preferred embodimentsof my invention, itvwill be understood that .the same is not limited thereto; but

may be otherwise embodied and practiced within the scope of the following claims.

I claim:

1. Areenforced composite slab structure comprising girder'members, crossv bars connecting the girder members adjacent their tops. tension dis tributing bars extending transversely of the girder members and connecting their bottom portions together, a bottom plate supported by such structure and spaced from the bottoms of the several members, and a cementitious body extending upwardly from the bottomplate and substantially lling the spaces between the several members.

2. A reenforced slab structure comprising girder members, cross bars connecting the girder members adjacent their tops, tension distributing bars extending transversely of the girder members and connecting their bottom portions together, a. bottom plate below such structure and spaced from the bottoms of the several members, and a cementitious body extendingupwardly from the bottom plate and substantially filling the spaces In addition 'to between the several members, the bottom plate having portions extending outwardly beneath the girder members so as to provide a greater depth Aof concrete therebelow.

3. A reenforced structure comprising girder members, cross bars connecting the girder members adjacent their tops, tension distributing bars extending transversely of the girder members and connecting their bottom portions together, the girder members and the cross bars having a common top plane, and a cementitious body substantially filling the spaces between the several members and terminating substantially in such plane.

A4. A reenforced' structure comprising girder members. vsupplemental tension members, lying between the girder members and spaced from the girder members and being near the bottoml portions thereof, tension distribution bars extending transversely of the several members and connecting them together, and a cementitious body substantially filling the spaces between the several members.

5. Avreenforcement for concrete slab and like structures comprising girder members, tension distributing bars extending transversely of the girder members and connecting their bottom portions, and a form sheet lying below the assemblage of members and suspended therefrom.

6. A reenforced structure comprising spaced girder members having their greatest cross sectional dimension in the direction of the thickness of the structure, cross bars connecting the edge portions of the girders at one extremity of the cross section thereof, cross bars connecting the edge portions of the girders at the other extremity, the cross bars being of a considerably smaller cross section than the girders, and a cementitious body in which the girders and cross members are embedded.

7. A reenforcing structure comprising longitudinally extending main members arranged edgewise, cross members at the tops of the main members connecting the main members and dividing the spaces between the main members into cells, and a grid structure secured tothe bottoms of the main members and having elements between the main members and out of line with the top cross members for supporting preformed blocks when such blocks are set into the cells.

8. A reenforcing structure comprising main longitudinally extending bearing members in the form of bars set edgewise, cross members connecting the top edge portions of the main members and dividing 'the space between the main members at the upper portion thereof into individual cells, and a grid structure secured to the bottoms of the main members and providing a support for individual blocks when such blocks are set into the cells.

9. A reenforcing structure of the class described comprising main bearing members in the form of bars set edgewise, cross bars connecting the top edge portions only of the main bars at regular intervals and providing a cell-like formation in the top portion of the reenforcement, cross bars connecting the lower edge portions of the main members, and longitudinally extending auxiliary bars supported by the cross bars between the main bearing members.

10. A reenforcing structure of the class described comprising main bearing members in the form of bars set edgewise, cross bars connecting the top edge portions only of the main bars at regular intervals and providing a cell-like formation in the top portion of the reenforcement, cross bars connecting the lower edge portions of the main members, and longitudinally extending auxiliary bars supported by the cross bars between the main bearing members, said longitudinally extending bars being angle bars.

11. A composite structure of the class described comprising a reenforcing structure comprising main bearing members of rectangular cross section set edgewise, relatively smaller cross members connecting the top portions of the main members at regular intervals, an auxiliary grid structure carried at the bottom of the main bearing members, individual blocks set into the cells formed between the main bearing members and between the cross members, the bottoms of said blocks resting on said secondary grid structure, and a mass of cement embedding the secondary grid structure and surrounding the individual blocks.

` HAROLD NAGIN.

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