US1798925A - Floor construction - Google Patents

Description

March 31, 1931. K. P. BILLNERA FLOOR CONSTRUCTION Filed May 19, 19:50

INVENTOR ATTORNEY III/11111111! Patented Mar. 31 1931 PATENT OFFICE KARL P. BILLNER, NEW YORK, N. Y.

FLOOR CONSTRUCTION Application filed Kay 19,

In ap lication for Letters Patent of the United tates, filed February 7, 1930, Serial No. 426,519, I disclosed certain improvements in floor construction in which light steel '5 girders or bar joists are employed, running crosswise of the floor and embedded in and supported and reinforced by a filling of porous concrete or so-called aerocrete. My present invention relates to a floor construction of the same general type but embodies improvements by reason of which the con struction will be substantially stronger and more rigid for the same weight of materials.

With the arrangement described in m pending application, as well as with all floor constructions in which steel girders or beams have been used, so far as I am aware, the

construction has always been what is tech nically referred to as the single span type. By this is meant that the strength of each span is independent of other s ans. For this reason in making calculations based upon assumed loads, the dimensions and sizes of the girders or beams are based upon the load intended to be carried by each span, wholly independent of the other spans.

With my present improvements, I employ a continuous construction through two or more spans, as I will explain, whereby the girders or beams are not independent, and in consequence a very much lighter type, of girder or beam can be employed to resist the same load. In a sense the advantage secured in this direction is somewhat cumulative, for the reason that the dead weight of the floor is reduced whereby a saving in steel results from this fact.

In order that the invention may be better understood attention is directed to the accompanying drawing forming a part of this specification and in which Figure 1 is a cross section ment of floor construction employing light weight girders or bar joists, and

Figure 2 is a similar view of a floor construction employing transverse I beams.

In both of these views corresponding parts are represented by the same numerals of reference.

With the arrangement shown in Figure 1,

of an arrange- 1930. Serial No. 453,679.

I make use of a series of longitudinal I beams 1, or other form of beam carried in the ordinary way upon posts or pillars (not shown), the beams at the extreme ends being supported by the usual walls of the building as will be understood. The I beams 1 are spaced a proper distance apart, usually not to exceed a maximum of twenty-four feet and extend parallel to each other. Extending crosswise of the I beams and supported by the same are light steel girders or bar joists which can be of any suitable construction,

a number of which are referred to in my said application. These are now well known elements in building construction, differing in detail according to different manufacturers or steel fabricators. Their steel characteristic is that they provide great strength with but small weight of steel. These girders are placed generally from twenty to twenty-four infihes apart and extend parallel with each 0t er.

The form of girder shown in Figure 1 is merely for the purpose of illustration. It consists of one top flange 2, one bottom flange 3, and interposed members 4 welded or otherwise secured between the top and bottom flanges, so that the whole forms a light latticedflgirder. As shown, the ends of the bottom ange of each girder are bent up at an angle of ninety degrees more or less, being welded or otherwise secured to the top flange. The girders so formed rest directly upon the upper flange of the I beams 1.

In the arrangement illustrated, I show a pair of plates 5 and 6 which are welded or otherwise secured to the members 2 and 3 and which also rest upon the upper flanges of the I beams. Preferably these plates are somewhat longer than the width of the upper flange of the I beam as shown, so as to strengthen the ends of the girders in such manner that they will be able to withstand the tension occurring at these points under the effect of loads. The plate 5 of one girder, if used, or the members 2 and 3 of that girder, if said plate is not used, are securely tied to the plate 6 of the adjacent 'rder, if used, or to the members 2 and 3 0 that girder if said plate is not used. This tying of the a heads of the keys 7 not only engage recesses in the plates 5 and 6 but also shallower channels in the flat upper portions of the flanges 3.

By thus rigidly connecting adjacent girders together, it will be seen that any load tending to deform the top flange will be resisted, not only by the flange itself, but also by adjacent girders, thus materially increasing the strength of the structure and permitting lighter girders to be used.

With my improved construction I also equip the upturned vertical end of the bottom flange of each girder with an abutment so as to utilize the bottom flange for compression in the vicinity of, the supports or I beams 1, and avoiding any shearing or crushing action at this point. Such an abutment may be a light steel section 8 welded or otherwise secured to the end of the bottom flange of the girder at the point where the bottom flange is bent upwards as shown. The girders are placed in position and a body' of concrete 9 is cast or poured around the lower part of each I beam by means of usual forms or molds not shown. The concrete is so cast that it engages the abutment sections 8 which are thereby embedded in the concrete so as to resist compression strains upon the bottom flanges of the girders. Each section 8 is of sufficient area to take the thrust with out crushing the concrete in which it is embedded.

After the girders have been placed and tied together they are then completely embedded in a layer 1010f porous concrete or so-called aerocrete through the use of forms or molds of usual construction, not shown. This material, when the molds are removed, forms a smooth and continuous ceiling for the floor below, which if desired, may e coated with any suitable plaster-like material. The coating 10 extends above the girders and constitutes the floor. It may be covered with a suitable surfacing material.

In casting the porous concrete 10, instead of using a bottom form of wood which re quires to be removed after the aerocrete has set, I may use a form comprising expanded metal lath of well known construction supported at a short distance belowthe bottom anges of the girders. To such a metal lath when used as a form, I may apply a basic coat of plaster on its underside before the pouring of the expanded concrete, thereby preventing the wet concrete from leaking through the lath. After the expanded concrete has set I may then apply a finishing coat of plaster to the metal lath and thus obtain a finished ceiling without having to remove a wooden form and applying plaster to the undersurface of the expanded concrete.

The arrangement shown in Figure 2 is the same as that just described, except that instead of using light weight girders, I make use of I beams 11, each having a bottom flange 12 and an upper flange 13. Such I beams, if of light weight, may be wholly embedded in a layer of porous concrete as in Figure 1, but when such I beams are of ordinary standard dimensions, it will not be necessary to use the embedding porous cement and therefore, in the latter case, I need use only a relatively thin layer of porous concrete 14 to form the ceiling, and a similar layer 15 to constitute the floor, these layers being poured by the use of ordinary forms.

When an I beam is used instead of a girder as in Figure 1, the plates 5 and t are preferably bolted in place as shown. Instead of using an I beam 11 of suflicient strength so as not to require the use of a complete filling of porous concrete as in Figure 1, it will be understood that latticed steel joists may be employed in the same way.

If desired, instead of employing ordinary concrete for covering the I beams 1, any of the light weight concrete may be used, such as cinder concrete, or so-called Haydite con crete, or other concrete in whichthe aggregate is of a light, porous nature. These materials have sufiicient strength for the purpose and have the advantage over ordinary concrete of being relativelg light.

By completely embed ing light weight girders in a mass of porous concrete or aerocrete a very rigid construction is obtained and any tendency of the girders to buckle under the effect of load strains or of heat in case of fire is prevented. At the same time, the arrangement is fire-proof in a very marked de ree, as well as almost entirely sound proo In my said application above identified, I refer to the possibility of using relatively large fillers, such as bags containing a light, cheap. material, thus reducing the amount of porous concrete necessary in forming the floor, and it will be understood that when the arrangement of Fi re 1 is used, these fillers may be employed 1f desired.

Having now described my invention, what I claim is new therein and desire to secure by Letters Patent is as follows:

1. In a floor construction, the combination of a series of longitudinal supporting members, oftransverse members extending across and supported by said members to form the s an, a bottom on each transverse member an a rigid abutment with which the bottom of each transverse member engages to resist the effect of compression strains.

2. In a floor construction, the combination with longitudinal supporting members, of a series of transverse members extending crosswise between and carried by said longitudinal members to form the span, the transverse members of one s an being connected rigidly to the correspon ing transverse members of adjacent spans, a bottom on each transverse member and abutments with which the bottom of said transverse members engage to resist compression strains.

3. In a floor construction, the combination with longitudinal supporting members, of a series of light weight irders extending crosswise between and earned by said longitudinal members to form the span, the girders of one span being connected rigidly to the corres nding girders of adjacent spans, bottom anges on said girders, abutments with which the bottom flanges of said girders en age and a filling of porous concrete in whic all the girdersare embedded.

4. In a floor construction the combination of a series of longitudinal members, a body of concrete surrounding each member, abutments embedded in said concrete, light weight cross girders extending between the lon itudinal members and supported thereby to orm a span, said girders having bottom flanges which engage with said abutments to resist compression strains, and a filling of porous concrete in which said girders are embedded. u

5; In a floor construction, the combination with a series of longitudinal members and a body of concrete surrounding each of said,

members, of a plurality of transverse members extending crosswise and supported thereb to form a span, the transverse members 0 one span being connected to the corresponding transverse members of an adjacent span, and the transverse members having bottom flanges which are engaged with the adjacent concrete covering the longitudinal members to resist compression strains.

6. In a floor construction, the combination with a series of longitudinal members and a body of concrete surrounding each of said members, of a plurality of light weight girders extending crosswise and supported thereby to form a s an, the girders of one s an being connecte to the corresponding gir ers of an adjacent span, the. compression members of all the girders being in enga ement with the adjacent concrete covering t e longitudinal members to resist compression strains, and a filling of porous concrete in "which all the girders are embedded.

KARL P. BHJLNER-

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