US1974730A - Steel girder for concrete structures - Google Patents

Description

Sept. 25, 1934. F. ZOLLINGER 1,974,730

' STEEL GIRDER FOR CONCRETE STRUCTURES Filed Sept. 17, 1952 2 Sheets-Sheet 1 in V672 for.

Patented Sept. 25, 1934 PATENT? OFFICE STEEL GIRDER FOR CONCRETE STRUCTURES Fritz. Zollinger, Merseburg, Germany Application September 17, 1932, Serial No. 633,642

InGermany September 17, 1931 .3 Glaims.

My invention relates to improvements in; the erection of metalframed. and reinforced concrete floors, walls, roofs and othersupportingand enclosing parts. of buildings, bridges, silos etc.,

and more particularly toimprovements inspecial shaped steelgirders or beams of the type. which are made of relatively thin steel sheeting and. which are in many cases preferredas framing-supporting-studding-and bracing elements inconcrete structures where extreme lightness combined with strength and-speedy erection are the chief consign thetimproved girder; that itcanbe quickly cut into the proper lengthseven by handoperated tools,. without the use of heavy; machinery; andthatsitisw an. easy task even for not highly trained welders tojoin for re-use short remnant length which otherwise would :be useless, by autogenous welding or; other weldingaor soldering processes, so that practically nowaste, occurs.

Another "feature of importance of the steel sheet girders ofimproved. design-. according, to thisdnvention is the fact. that they can .be closely. piled up uponeach: other so that largenumbers of girders canrbe 1 packed: into. relatively small boxes, as lar as their crosssection: isrconcemed; and that they can. be easily shippedonaccountoftheir small total weight even intorremote districts. far from railroad trafiic.

stillrother objects aimed at. by. this invention and advantages obtained therebywillibecomeapiparent it hereinafter to' practitioners in l the ferroconcrete building; trade;

The nature and scope of the. invention are briefly: outlined: in the: appended claims and will be more. fullyunderstood tromlthe' .tollowing speciflcation takentogether with the accompanying drawings in which Figs. 1 and 1a are cross sections, taken along Fig. 4 isa cross section through a shipping box showing anumber ofgirders piled up therein;

Fig. 5' shows perspectively the lower tubular flange portion of the girder with a reinforcing rod 23. running therethrough and being embedded in afilling of concrete.

Fig. 6 shows a cross section, Fig. 7 a side view, and Fig. 8 a plan of another example of construction. r

Fig. 9 shows a perspective View of another example of application of the invention.

Fig. 10 shows a perspective view of a further applicationof the invention.

Fig-11 is across section of a detail of Fig. 9 to a larger scale.

Figs. 1245 showconcrete floors supported by girders, which. aredesigned'according to this inventionsaid floors serving to support a ceiling. The girder or improved design consists of a web 10 of thin metal sheeting, preferably of mild. steel; the lower-edge of the web isformed with a tubular flange 20, while the upper edge is provided with tongues30, 30 adapted to bebent away fromthe web preferably towards alternate sides, asbest seen in Fig. 3, was to act as bracingmembers when the upper section of theweb "is embedded intoa layer of concrete 40.

The construction of a ferro-concrete floor ina building can be carriedrout with great speed and economy by means-of the improved girders described above, in the following manner: The girders are placedupon the supporting walls in upright positionby means ofdistance rods and screw:bo1ts 51 extending through holes 11 of which a number are provided in thegirder in alignment to'each other at a suitable distance from its tubular flange 20. In erecting the mold for the concrete floor brackets 60, for supporting the sheeting boards 61, 61 are attached to the girdersby means of clamping bolts 62 which extend through holesbelongingto the set of: holes 11-.refer-redto above.

Whenever required according to" static calcu= lations viz. inconsiderationof the maximum load on the floor, reinforcing rods are placed. into position on'thez indented'upper edge of the girders and other rods 82 may be passed through holes 12 provided for this purpose, whereupon the mold is ready for receiving the mixture of concrete.

After the concrete has become hardened and the sheeting has been removed, the lower section of the girders which is not embedded in the concrete may be suitably covered with fire resisting material, as diagrammatically indicated in dot and dash lines in Fig. 1a; or a cei1ing-not ably rectangular shape may be provided in the body of the web and supporting tongues 16, 16, laterally projecting from the web 10 at alternate sides of same as seen in Figs. 1-3. 7

Instead of forming the tubular flange 20 with a flattened edge portion 21 abutting against the web 10 as shown in Fig.--la and being'joined thereto by electric welding, a flange of modified design which is cheaper to make may be applied to advantage.

My experimental work has shown that a flange the extreme edge 22 ofwhich extends into its tubular cavity, as shownin Figs. 1 and 5, possesses such stiffness that welding or otherwise joining the edges concerned can be dispensed with.

In Fig. 2 it is indicated by dotted lines how the bracing tongues 30, 30 may be temporarily bent upwardly so that sheets of expanded metal 90, wire netting or the like can be lowered onto the system of girders as reinforcing elements of particularly light weight, an important factor e. g. in case of solid roofs where a minimum of thickness and weight are desired.

Various other ways of using girders of the improved design as supporting, reinforcing, stiffening, bracing elements in floors, walls, roofs, columns, and like concrete structures will suggest themselves to practitioners and-a few applications are shown by way of examples in Figs. 611.

In Figs. 6 to 8 the tongues 30, 30 are shown bent at different angles from those shown in the preceding figures, whilst the holes 15 and their corresponding tongues 16 are made longer, and tongues are also provided adjacent the holes 12 for the passage of the rods 80. A rod 82 is also shown as passing through one of the holes 15.

In Figs.'9 and 11 a T-iron 91, provided with spaced notches in its upper flange passes through the holes 11, in which it is secured by wedges 92, and serves to support the sheeting boards 61. Wires or rods may also be passed through the holes 11 to ensure a better hold of fire resistin material when this is applied.

Fig. 10 shows an arrangement wherein some of the tongues 30, 30 are bent vertically up wards, whilst others serve to hold sheets of expanded metal 90 in position. The reinforcing rod 23 is also curved upwardly at its free end so as to increase its engagement in the surrounding concrete.

Fig. 12 is a cross section of a floor in which the layer of concrete 40 of the girder supports a concrete floor 98. From this floor depend suspension rods 94, which together with the wires or rods 93, serve to support expanded metal 95 for a ceiling.

Fig. 12a shows in longitudinal section the use of a girder according to the invention associated with a girder of I-section, this figure being at right angles to Fig. 12, but the wires and rods 93, 94 are omitted.

Figs. 13, 13a, 13b show in cross section, plan, and in section on the line II of the plan another application of the arrangement described in connection with Figs. 6 to 11. The spaces between the ribs of reinforced concrete may be left open or if desired filled in with bricks 98, preferably apertured bricks, known as Hourdis.

In Fig. 14 the concrete 40' of the girder supportsa reinforced plaster floor 99, Whilst the rods 93 serve to support expanded metal sheets provided in a ceiling. Fig. 15 shows a floor in which the girder is completely embedded in concrete.

What I claim is:

'1. In a concrete structure a slab of concrete, which is reinforced by. and structurally associated with a girder of special design, the latter comprising a sheet metal Web, presenting a lower zone, adapted to take up tensile stresses, and an upper zone, the latter beingembedded in the said slab of concrete and being provided along its'top edge with bracing tongues, laterally extending therefrom, the tension zone of the girder which downwardly projects from underneath the slab of concrete, being provided along its lower edge with a tubular'flange.

2. In a concrete structure a slab of concrete, which is reinforced by and structurally associated with a girder of special'design, the latter comprising a sheet metal web, presenting'a lower zone, adapted to take up tensile stresses and an upper zone, the latter being embedded in the said 'slab of concrete and being provided along its top edge with bracing tongues laterally extending therefrom, the tension zone of the girder, which downwardly projects from underneath the slab of concrete, being provided along its lower edge with a tubular fiange,s paced holes being provided in the upper section of the compression zone of the girder for the insertion of reinforcing rods, crosswisely extending therethrough.

3. ma concrete structure-a slab of concrete, which is reinforced by and structurally associated with a girder of special design, the latter comprising a sheet metal web, presenting a lower zone, adapted to take up tensile-stresses, and an upper zone, the latter being embedded in the said slab of concrete and being provided along its top edge with bracing tongues laterally extending therefrom, the tension zone of the girder,'which downwardly projects from underneath the slab of concrete, being provided along its lower edge with a tubular flange-spaced holes being provided in the upper section and in the lower section of the compression zone of the girder for the insertion of reinforcing rods, crosswisely extending therethrough,--the holes in the said lower section being of substantiallyrectangular shape and being formed with auxiliary tongues. outwardly extendingfrom the base of said holes.

FRITZ ZOLLINGER.

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