US2016616A - Reenforced concrete structure - Google Patents

Description

0a. 8, 1935. o. SCHAUB 2,016,616

REENFORCED CONCRETE STRUCTURE Filed July 21, 1953 Patented Oct. 8, 1935 UNITED STATES 2.018.818 scam-0mm CONCRETE srnncrons 'otte stin s, Biel, Switlerland Application July :1, 193:, Serial No. 1,594 In Switzerland July so, i s:

4 Claims. (61. 7 1) The invention relates to reeni'orc'ed concrete structures comprising a concrete slab supported by section irons.

In reeniorced concrete structures, for instance I in ceilings, it is known to utilize iron reeniorcement in lattice iorm in the concrete, whereby the lattice work,'which owing to its bearing power, does away, at least partly, with the necessity of ialsework or centering, prevents sliding 10 in the concrete and ensures the transmission of the shear betweentheiron parts and concrete parts stressed in tensionor compression respectively. With the -so-called Pohlmann-ceiling these latticed girders are replaced by bulb beams is which have a similar effect. The web of these beams is in places provided with apertures so that the concrete penetrating into these apertures causes an intimate connection between concrete and metal. By placing sling-like flat N" beams through these apertures the anchorage between the bulb beams and the concrete in its compression zone may be further increased.

The production 01' such anchorages being resistant to shearing isin many cases very tedious and expensive. The present invention has for its purpose to simplify such structures. cording to the invention at least one metal rod bent in more than one direction is welded to the upper flange of the section girder and is embedded in the concrete plate.

A plurality or metal rods may thus be welded and the rods may be bent to a sinuous or coiled shape. i

Several. constructional examples or the subject matter or the invention are illustrated in the accompanying in which Figs.;1- and,2 show in a cross-section and in a longitudinal section respectively a first constructional example,

Figs. 3 and 4 are a cross-section and a longitudinal section of a second constructional example, and 4 Figs. 5 and 6 similar sections of a third constructional example.

In the constructional example according to Figs. 1 and 2 I-beai ils a are used as reeniorcement for a ceiling needing no ialsework. On

the upper flange 9'; this section-beam two sinuous rods b of circular cross-section are welded staggered to each other and are embedded in the concrete slab e and cause thereby a. connection between beam, and concrete which resists shear.

The ceiling illustrated in Figs. 3 and 4f also comprises girders in the form of I-beams a. to 55 each oi 'which only one sinuous shearing rod bi is fixed, the waves of the latter being alternately inclined by a certain angle to one or the other side of the-vertical centre plane, in order to 'obtain a better distribution of the shearing forces in the concrete slab c and to prevent ll eventual cracking oi. the latter owing to excessive shearing stresses. In order to increase the eil'ective metal reeniorcement cross-section in the zone 01 tension a flat metal plate d may be welded to the lower flange oi. the I-beam a. 10

The third embodiment of the invention shown in Figs. 5 and 6 diflfers from the two constructional examples described above by the helical rod b2 welded to the upper flange oi the l-beam a; I

The diflerent shaped rods bite into the concrete" slab .c and form together with the latter a-rigid anchorage. These shear rods are adapted to prevent mutualdisplacements or distortions between the section-beam and theconcrete slab andto transmit the large shearing stresses occuring when the supporting structure is subjected to a bending moment. Although the section-beamgirder is only in contact with the concretesiab on the upper surface 01' its flange the compound efiect is neverthelessperi'ect owing to the ironrods being-welded to the girders. During the 1 construction of the ceiling and before the hardening or the concrete the section beam Ialone acts as supporting girder. Alter the hardening of the g concrete the lower flange of the girder takes over the tensile stresses of the whole compound structure and flat iron plates may be welded to the underside oi the girder as indicatedin the second constructional example for increasing the eflec- 88 tive cross section it the actualbending moment requires such reeniorcement.

I claim v l. A reeniorced concrete structure of the type described, comprising in combination, a plurality 01' section beams having upper flanges, a concrete slab contacting with the upper flanges oi.- said beams, a plurality of sinuous metal rods, .each

extending longitudinally along the upper flange contacting with the upper flanges of said section I55 Ibeams. and a'metal of helical shape placed section against the upper flange of one of beams-andwelded thereto at places oi contact said rod being embedded in said concrete s s 3. A reeniorced "concrete structureaof the ype described, comprising in combination, a plurality of section beams having flanges, a concrete slab contacting with the upper flanges 'of said se'ction' beams, and a metal 'rod oi-vertically extending sinuous shape placed against the upper-flange of one of said section beams and welded theretouat the places of contact and inclined to diiierent concrete slab:

said rod being embedded in said concrete slab.

'4. A reeniorced concrete structure of the type described, comprising in combination, a plurality or section beams having flanges, a concrete slab contacting with the upper flanges of said section beams, and two ir'on rods of sinuous shape arranged at adistance from each other and staggel-ed, said rods being placed on the upper flange of one or said section beams and'welded thereto 10 at the places of contact and embedded in said

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