US1336166A

US1336166A - Concrete-reinforcing means

Info

Publication number: US1336166A
Application number: US199544A
Authority: US
Inventors: Smulski Edward
Original assignee: Individual
Current assignee: Individual
Priority date: 1917-10-31
Filing date: 1917-10-31
Publication date: 1920-04-06
Anticipated expiration: 1937-04-06

Description

E. SMULSKI.

CONCRETE REINFORCING MEANS APPLICATION mwocr. 31, 1917.

Patented Apr. 6, 1920.

2 SHEETSSHEET 1.

For:

u M 1 M b M w 6 I12 ven E SMULSKI CONCRETE REINFORCING MEANS.

APPLICATION FILED OCT- 31, 1917. 1,336,166. Patented Apr. 6,1920.

2 SHEETSSHEET 2.

Inven 2. 01.- fl raz W61 Af'orny EDWARD SMULSKI, OF HASTINGS-UPON-HUDSGN, NEW YORK.

CONCRETE-REINFORCING MEANS.

Specifica tion of Letters Eatent.

Patented Apr. 6, 1920.

Application filed. October 31, 1917. Serial No. 198,544.

To all whom it may concern:

Be it known that I, EDWARD SMULsKr, a citizen of the United States, residing at Hastings-upon-Hudson, in the county of Westchester and State of New York, have invented an Improvement in Concrete-Reinforcing Means, of which the following description inconnection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

The invention hereinafter described relates to concrete reinforcing beams, and is an improvement upon the construction shown in Letters Patent, No. 1,245,395 granted to me November 6, 1916.

One important field of use for these beams is in structures having a concrete slab mounted on columns. The beams are embedded in the concrete and may extend from column to column and be connected to the steel beams in and reinforcing the columns. It is a well known factthat concrete, in hardening, shrinks away from any large smooth surface. Consequently, the concrete will shrink from the smooth surfaces of an ii-beain embedded therein, thereby leaving a space or film surrounding the beam. This is a serious defect in the construction, since when subjected to heat or in case of fire, the concrete, loosened from the beam, cracks and breaks away, exposing the beam which it was intended to protect and render fire-proof.

@ne object of the invention is to provide a beam having means for so interlocking the concrete and beam together that the concrete will be unable to shrink from and expose the beam.

It is also a well known fact that when the concrete with the beam embedded therein, is subjected to load, deflection occurs which places the portion of the concrete and beam adjacent the upper surface, under compression, and places the portion of the concrete and beam adjacent the lower surface, under tension, thereby tending to shorten the top flange and elongate the bottom flange of the beam. If the concrete and beam are not properly interlocked, relative slip occurs between them, producing, in effect, separate parts comprising a steel section and a hollow concrete section about the same. As the lower flange of the beam elongates, it develops cracks in the concrete, thereby exposing the steel beam to air and moisture and consequent corrosion. If the concrete had already shrunk away from the beam, the defect is intensified, since the air and moisture entering the cracks continues on into the space between the concrete and beam, and the principal part of, if not the entire beam, is exposed to corrosion.

Another object of the invention is to provide the beam with means for so interlocking the same with the concrete as to prevent relative movement of the concrete and beam longitudinally of the latter, and thereby prevent the occurrence of the objectionable cracks referred to.

In my said Letters Patent, a beam is shown which has a head provided with projections along the length thereof for interlocking the head to the. portion of the concrete under compression, the construction being such that the beam utilizes the compressive strength of the concrete and thus permits the use of a lighter beam than heretofore, with economy of material, but without sacrifice of strength of construction. The means for preventing shrinkage of the concrete from the beam, referred to,desirably cooperates with these head projections in holding the concrete thereto and thus enabling said head projections to maintain effective interlocking engagement with the concrete, so as to always share and utilize the compressive strength of the concrete. Since a permanent bond is obtained between the head and the concrete, the deflection of the beam under load is materially reduced, and consequently the elongation of the lower flange and the tendency to produce cracks in the concrete are materially reduced.

The character of the invention my be best understood by reference to the following description of the construction shown in the accompanying drawings, wherein Figure 1 is a plan of a floor slab and supporting columns therefor provided with reinforcing means embodying the invention;

Fig. 2 i a vertical section taken on line 2-2 of Fig. 1;

Fig. 3 is a perspective view showing the means connecting the horizontal beams with the vertical I-bar of a column;

Fig. 4 on an enlarged scale is a vertical section through a portion of the concrete slab and one of the horizontai reinforcing beams therefor;

Fig. 5 is a side elevation of a portion one of the beams;

Fig. 6 is a plan of the portion of the beam shown in Fig. 5;

Fig. 7 is a perspective view of a portion of the beam; and

Fig. 8 is a perspective view of a portion of a slightly modified form of beam.

Referring to the drawings, the construction shown therein as an exemplification of the invention comprises a concrete floor slab 1 supported by four concrete columns 3. The columns are reinforced by vertical steel I- bars 5, and the slab is reinforced by horizontal steel beams 7 extending between the columns and connected thereto by angle brackets 9 at the sides of the beams 7, and by angle brackets 11 beneath the beams. In the present instance of the invention, the beams 7 are embedded in concrete beams 13 projecting downward from the slab.

The upper surface portion of the slab is strong in compression, and the lower surface portions of the slab and the concrete beams are weak in tension. The beams 7 are constructed to produce the greatest reinforcement in the portions of the concrete which are subjected to tension, and less reinforcement in the portions of the concrete which are subjected to compression, so that the maximum reinforcement may be obtained with a minimum amount of steel. With these purposes in view, each of the beams 7 is formed with a relatively small com ression reinforcing head or flange 15 at t e top thereof, a wide tension reinforcing flange 17 at the bottom thereof, and a shear reinforcing web 19 interposed between and connecting the compression flange and the tension flange.

The compression flange is constructed and arranged to utilize the compression strength of the concrete. To accomplish this, in the present embodiment of the invention, said flange is formed to present a series of lateral undulations 21, a series of vertical undulations 23, and a series of projections 25 and notches 27 at the sides of the flange, the projections. at one side being opposed to the notches on the opposite side. The construction may be such that the flange is of uniform width throughout its length.

The flange constructed as described will interlock with the concrete throughout the length thereof and furnish a strong bond with the concrete, which will enable the beam to utilize the compression strength of the concrete. The flange is located in the upper surface portion of the concrete where the compression strength is the greatest, and thus fully utilizes said strength.

To contribute to the strength of the connection of the compression flange with the web and provide additional bond with the concrete, the beam may be formed to present a series of ribs 29 at the juncture of the compression head with the web: Preferably the ribs are located at opposite sides of the web, the ribs on one side being staggered with respect to the ribs on the other side.

As stated, the concrete in hardening tends to shrink away from the beam. To resist this tendency and interlock the concrete closely to the beam, in the present instance, the tension flange is provided with ridges 31 at or adjacent the outer edges of said flange and on the upper surface thereof. The concrete between these ridges and the web of the beam will engage said ridges throughout the length of the beam and thereby will be held against withdrawal away from the surfaces of the beam.

The load on the beam will tend to deflect or bend the same downward longitudinally thereof, and thereby compress the compression flange and lengthen the tension flange, but the beam cannot be so deflected or bent without relative slip occurring between the concrete and the beam. To prevent this slip and resist the deflection, in the present instance of the invention, the ridges 31 may be provided with series of projections 33 alternating with series of notches 35, and the projections of one ridge may be staggered with respect to the projections of the other ridge.

To further resist relative slip between "the concrete and the beam, the tension flange may have a series of grooves or channels 37 slip between the concrete and the beam longitudinally thereof, but also transversely to the length thereof. Thus, these grooves desirably cooperate with the ridges described in resisting withdrawal or shrinkage of the concrete away from the beam.

To further prevent relative slip between i the concrete and the beam longitudinally thereof, the web may have a series of grooves or channels 39 therein, extending between the compression and tension flanges, and desirably communicating with the grooves 37 in the tension flange.

To strengthen the connection of the web with the tension flange, and assist in preventing relative slip between the concrete and the beam longitudinally of the latter, series of ribs 41 may be formed on opposite sides of the web at the juncture thereof with the tension flange, the ribs at one side of the web being preferably staggered with respict' to the ribs at the opposite side of the We Thus, the projections 33, grooves 37, grooves 39 and ribs 41 distributed and arranged as described, eflectively prevent relative slip between the concrete and the beam throughout the length of the beam along the surfaces of the .web and the tension flange.

. beam, but by the construction described, the

concrete and beam are effectively interlocked at appropriately distributed points along the length of the beam, so that it will be impossible for large cracks in the concrete-to occur. In fact, if any cracks occur, they will be so distributed and so microscopic as to be incapable of exposing the beam, and therefore, areharmless. As a result, the beam will not be exposed to air, moisture and fire, but will always be protected from the injurious action thereof.

The means for preventing the concrete from shrinking or withdrawing away from thesurfaces of the beam desirably cooperate with the projections for interlocking the compression flange to the concrete, since the concrete is held closely to the flange between the projections thereon, and their full area and strength are utilized to maintain the concrete and flange in effective interlocking engagement, so that the beam may fully utilize the compression strength of theupper surface portion of the concrete. Therefore, the resistance to deflection of the beam under load is materially increased and the actual deflection reduced. As a consequence, the tendency of the concrete to crack is materially reduced.

The means for preventing the concrete from shrinking or withdrawing. from the surfaces of the beam also tends to maintain the concrete in contact with the full area of the projections and grooves of the tension flange and web, and therefore, materi ally increases their effectiveness in resisting relative slip between the concrete and the tension flange and web in the direction of the length of the beam.

In some cases the beam may be constructed in its slightly modified form shown in Fig. 8, in which the web is thickened somewhat at its juncture with the tension flange, and provided with a series of undulatory projections 43 instead of the ribs 41, referred to, and'the ridges on the tension flange may be formed to present a series of undulations 45 instead of the projections and notches, referred to. i

To further contribute to the strength of the construction, a series of tension rods 47 may be provided extending across the slab and resting on the beams with portions intermediate the beams adjacent the lower surface portion of the slab, which is subjected to tension.

The grooves in the tension flange and web as shown donot add to the thickness thereof, and thus permit the angle brackets 9 pressive strength of the latter.

and 11 to be readily connected thereto without removal of projections.

It will be understood that the top portion or head of the beam may be variousl formed provided it is given a character such that it will be strong enough to withstand the loads placed thereon during the process of construction of the slab, or provided it is formed to interlock with the concrete and cause the steel and concrete to act together, so that the former shall utilize thecom- The reinforcing beam has been described more particularly with reference to its use in reinforcing conicrete having its upper surface portion under compression and its lower surface portion under tension, but the beam is also adapted to reinforce concrete where the strains are reversed and the upper surface portion is under tension and the lower surface portion is under compression. It will be understood that the invention is not limited to the construction shown, but that various deviations may be made there from without departing from the spirit and sco e of the appended claims.

hat is claimed is: v j 1. A beam for reinforcing concrete comprising a compression reinforcing head eX- tending longitudinally. of the beam, a tension reinforcing flange extendin longitudinally of the. beam, a shear rein orcing web interposed between and connecting said head and flange, a series of anchoring projections integral with said head for locking said head to the portion of the concrete under compression, and projections along the length of the beam for locking the concrete against shrinkage awayfrom the beam, that the projections of the compression reinforcing head may be maintained effectively interlocked with the concrete.

2. A beam for reinforcing concrete comprising a compression reinforcing head extending longitudinally of the beam", a tension relnforcing flange extendin longitudi-' nally of the beam, a shear reinforcing web interposed between and connecting said head and flange, a series of anchoring projections integral with said head for locking said head to the portion of the concrete under compression, and rojections along the tension flange for ring the concrete against shrinkage away from the beam, that the projections of the compression reinforcing head may be maintained effectively interlocked with the concrete.

3. A beam for reinforcing concrete comprising a compression reinforcing head extending longitudinally of the beam, a tension reinforcing flange extendin longitudinally of the beam, a shear rein orcing web interposed between and connecting said head and flange, a series of anchorin projections integral with said head for locklng said head to the portion of the concrete under compression,'and ridges extending longitudinally of the tension flange for locking the concrete against shrinkage away from the beam, said ridges having notches therein for locking the tension flange with the concrete.

4:. A beam for reinforcing concrete comprising a compression reinforcing header:- tendingv longitudinally of the beam, a tension reinforcing flange extending longitudinally of the beam, a thin upstanding shear reinforcing web interposed between and connecting said head and flange, and a series of projections disposed alongthe beam at the juncture of the head with the web thereof for strengthening the upper part of the beam and locking the same with the concrete.

5. A beam for reinforcing concrete comprising a compression reinforcing head extending longitudinally of the beam, a tension reinforcing flange extending longitudinally of the beam, a'thin upstanding shear reinforcing web interposed between and connecting ,said head and flange, and a series of projections at the juncture of the tension flange with the web for strengthening the lower part of the beam and lockin the same and the concrete against relative ongitudinal movement.

6. A beam for reinforcing concrec comprisinga compression reinforcing head ea:- tendin longitudinally of the beam, a tension relnforcing flange extending longitudinally of the beam, a shear reinforcing web interposed between and connecting said head and flange, a series of projections on the head for interlocking the head with the concrete, that the head may utilize the compressive strength of the concrete, a series of projections on the tension flange for locking the concrrte and tension flange against relative movement when under load, and projections on the tension flange for locking the concrete against shrinkage away from the beam, that the concrete may be held to and beam.

8. A beam for reinforcing concrete comprising a portion extending longitudinally of the beam for reinforcing the portion of the concrete under compression, a flange extending longitudinally of the beam for reinforcing the portion of the concrete under tension, and a shear reinforcing web interposed between and connecting said compression reinforcing portion and tension reinforcing flange, and projections along the length of said flange for locking the concrete against shrinkage away from the beam.

9. A concrete reinforcing beam comprising a relatively small head for reinforcing the portion of the concrete under compression, a flange for reinforcing the portion of the concrete under tension, and a web between and connecting said small head and said flange, said small head having its body undulating relatively to said web throughout the length of the beam for securely intel-locking said head with the portion of the concrete under compression.

In testimony whereof, I have signed my name to this specification.

nnwann sMULs Kr.