US3800492A - Reinforcement for reinforced-concrete structures - Google Patents

Abstract

A reinforcement for reinforced-concrete structures is divided into at least two separate, standardized reinforcing sections, which can be combined with each other and consist each of a set of rigidly connected rods extending parallel in one direction. The sections belong to a modular system of sections having graded lengths and graded steel cross-sections and are adapted to be assembled to form two-dimensional reinforcements having crossing reinforcing rods of any desired length and any desired steel cross-section.

Description

United States Patent Oroschakoff Apr. 2, 1974 REINFORCEMENT FOR REINFORCED-CONCRETE STRUCTURES [76] Inventor: Georgi Oroschakofl',

Simon-Denk-Gasse 7/7, Wien lX, Austria [22] Filed: June 7, 1971 [21] Appl. No.: 150,579

[30] Foreign Application Priority Data June 10, 1970 Austria 5236/70 [52] US. Cl. 52/662, 52/664 [51] Int. Cl. E04c 5/01 [58] Field of Search 52/664, 730, 662, 677, 52/660 [56] References Cited UNITED STATES PATENTS 3,475,876 11/1969 Oroschakoff 52/664 X Dubno FOREIGN PA'I'HNIS ()R APPLICATIONS 1,003,778 1965 (ircat Britain 52/664 Primary Examiner-Henry C. Sutherland Assistant Examiner garl D F rie d n an M I ,7 Attorney, Agent, or F irm-Karl F. Ross and Herbert [57] ABSTRACT A reinforcement for reinforced-concrete structures is divided into at least two separate, standardized reinforcing sections, which can be combined with each other and consist each of a set of rigidly connected rods extending parallel in one direction. The sections belong to a modular system of sections having graded lengths and graded steel cross-sections and are adapted to be assembled to form two-dimensional reinforcements having crossing reinforcing rods of any desired length and any desired steel cross-section.

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Georgi OROSCHAKOFF INVENTORI BYI Attorney REINFORCEMENT FOR REINFORCED-CONCRETE STRUCTURES CROSS-REFERENCE TO RELATED APPLICATIONS This application is related to my application Ser. No. 141,614 filed May 10, 1971 and copending with application Ser. No. 93,822 which was filed Nov. 30, 1970.

FIELD OF THE INVENTION This invention relates to a reinforcement for reinforced-concrete structures, such as slabs, beams, columns or the like, which reinforcement comprises at least two separate, standardized, two-dimensional and- /or angled reinforcing sections, which belong to a modular system of sections having graded lengths and heights and are adapted to be assembled to form twodimensional or basketlike reinforcements of any desired dimensions and any desired steel cross-sections in such a manner that the reinforcing sections, which are two-dimensional, angled and/or of different shape, are adapted to be assembled so that they extend one into the other in non-positive engagement to form selfsupporting reinforcements which have any desired shape and are rigid at least in one direction.

BACKGROUND OF THE INVENTION In the known slab reinforcements which comprise mesh reinforcements that are welded or bonded otherwise, difficulties arise at the joints which are formed at least in one direction. If in slabs which are prestressed in one direction the lengths of the mesh reinforcements were selected in accordance with the respective building, this would hinder industrial manufacture and it will nevertheless be impossible to select also the width of these mesh reinforcements in view of the specific load conditions.

In slabs having crossing reinforcements, the latter carry loads in both directions. In this case it is even more inconvenient that the reinforcements must be joined at least in one direction because the total loadcarrying reinforcement is interrupted in one direction in the section of the joint and because the degree of reinforcement must be as large as desired in both directions and the connections between one mesh reinforcement to reinforcements surrounding the same is extremely difficult since cross-rods will always be caught at the stirrups. For this reason, additional strip reinforcements are placed at the edges, as a rule, or the connection is established by a placing of individual reinforcing rods. Both measures result in joints in the reinforcement and any joint will involve a loss of material because an overlap is required. Additional material is lost because it is difficult to select the steel crosssections in accordance with the moment curve where mesh reinforcements are used.

When it is desired to use one of the known staggered patterns, at least three tiers of reinforcements are formed and twice as many tiers adjacent to the joints. In this case, part of the transverse load-distributing members lie under the load-supporting reinforcement although it is essential that they should like above the same. With slabs having crossing reinforcements, the transverse load-distributing members also carry load so that in one direction the load-carrying reinforcement is not only entirely interrupted but is also placed in two adjacent planes.

The applicant has previously proposed an arrangement such as is shown in FIGS. 1, 2 and 3 of the accompanying drawings in order to avoid some of the disadvantages mentioned hereinbefore. Particularly with slabs having crossing reinforcements, that arrangement involves a larger steel consumption than is required and necessitates a connection of the reinforcing sections in the transverse direction.

SUMMARY OF THE INVENTION In order to avoid these steel losses and to enable a satisfactory connection to the several sections in all directions, the complete reinforcement, which is nonstandardized, is not divided into at least two separate sections but is divided according to the invention into sections which consist of sets of load-carrying rods which extend in one direction and are rigidly held together only by transverse holders. The relation of the length of the load-carrying rods to their steel crosssection, is selected in accordance with the grid line spacing of the modular system. An adaption of the sections to the dimensions of the slab in the longitudinal direction is enabled by a displacement of the assembled two dimensional reinforcements relative to the beamreinforcement surrounding them rather than by a displacement of the two reinforcing sections relative to eachother. It is no longer difficult to provide for any desired width because the reinforcing sections consist only of rods which extend in one direction and the holding members extending transversely to the rods may be interrupted as desired.

Hence, it is a feature of the invention that rods extending only in one direction are assembled to form a rigid set of rods or a rigid reinforcing section. The grading of the length of the assembled rods of a given section is important because the sum of the steel crosssection of all rods should be graded and envelop a parabola. These reinforcing sections can be combined with each other. Finally, a series of these reinforcing sections may constitute a modular system in such a manner that the sum steel cross-section is selected in dependence on the length.

DESCRIPTION OF THE DRAWING Further features and advantages of the invention will become apparent from the following description of illustrative embodiments of the invention with reference to the accompanying drawings, in which FIG. 1 is a top plan view showing a reinforcing section of the previous type;

FIG. 2 is a corresponding elevation and FIG. 3 is a top plan view showing a reinforcement consisting of two sections shownin FIGS. 1 and 2;

FIGS. 4, 5, 6, 7 and 8 are top plan views of embodiments of sets of parallel rods which are rigidly connected according to the invention;

FIGS. 9, 10, l1, l2 and 13 are top plan views showing illustrative embodiments of reinforcing sections according to the invention used as modules in the embodiment of FIG. 5;

FIGS. 14, 15, 16 and 17 are top plan views showing by way of example an assembly of modules of the preferred embodiment shown in FIG. 4;

FIG. 18 is a top plan view illustrating the placing of the reinforcing sections according to the invention shown in FIGS. 14 and 16;

FIG. 19 is a sectional view showing a one-field slab carrying an eccentric load.

FIG. 20 shows the corresponding moment diagram;

FIG. 21 shows how two reinforcing sections such as are shown in FIGS. 15 and 17 may be combined so that even eccentric moments can be taken up without requiring an additional consumption of steel;

FIG. 22 shows by way of example a reinforcement of a slab which is prestressed in one direction;

FIG. 23 is a corresponding side elevation, partly in section;

FIG. 24 shows a detail of FIG. 23;

FIG. 25 shows by way of example a slab having crossing reinforcements;

FIGS. 26, 27 and 28 are, respectively, a top plan view and two side elevations showing a pallet which may be used to stack the sections;

FIG. 29 is a side elevation showing a detail of said pallet.

SPECIFIC DESCRIPTION FIGS. 1 and 2 show a reinforcing section M;, of the previously proposed type. This section consists of alternating longitudinal rods 31 and 32 having different lengths and of transverse load-distributing members 33, which extend at right angles to the longitudinal rods and are joined to the latter at the crossings. FIG. 3 shows a reinforcement consisting of two sections M and M, of FIGS. 1 and 2, which sections have been pushed one into the other.

In accordance with FIG. 3, reinforcing sections M M, must be placed one beside the other with overlapping transverse rods 33 to provide a reinforcement having the desired width of the slab. It is difficult to connect the reinforcement to the beam which defines the slab field.

To avoid a joining of the reinforcement also adjacent to the transverse rods and to ensure that the connections to the elements in thetransverse direction are as simple as those in the longitudinal direction, the complete reinforcement consists of at least two reinforcing sections, as before, but these are spaced in the direction of the rods. As a result, the reinforcing sections according to the invention consist of rigidly connected rods which extend only in one direction. Again, each reinforcing section does not constitute a self-contained reinforcement but can be combined with a similar section or with other sections of the modular system. The complete reinforcement is provided by assembling at least two of these reinforcing sections.

FIGS. 4 to 8 show some embodiments of the reinforcing sections according to the invention. The section shown in FIG. 4 consists of reinforcing rods 1, which are of equal length and rigidly connected by two transverse holders 2. This reinforcing section and all others have been designed in accordance with a grid having a grid line spacing M. The width B of the reinforcing sections may be as large as desired, preferably a multiple of the grid line spacing M. The length L of the reinforcing section is preferably a multiple of the grid line spacing M. The holders 2 need not lie on a grid line. It is essential that the distance e (FIG. 4) or e, (FIGS. 5, 6) from the holder 2 to the associated end of the respecing Table 1.

TABLE 1 Steel cross- Lengths of the reinforcing sections section Fe L,,=nM cm /m L, L L,, L, L

Fe, E, E E,, Fe E, E E E Fe E, E E, E,, Fe, E, E, E

It is apparent that the modular system comprises three sections E,, E and E having lengths L,, L and L and the steel cross-section Fe, cm /m and four reinforcing sections E,, E E,, and E having lengths L,, L L and L, and the next steel cross-section Fe cm /m. There is no reinforcing section which has a length L, and the third steel cross-section Fe, but one reinforcing section having the length L,, and the steel cross-section Fe This grading may be logically extended in dependence on the intended use and static considerations. The section shown in FIG. 5 consists of alternating rods 1 and 3 having different lengths; these rods are again rigidly connected by at least two holders 2.

The embodiment shown in FIG. 6 consists of a set of parallel rods 1, 3 and 3. The rod 3 is shorter than rod 1 and the rod 3 is shorter than rod 3. In this case there are three different steel cross-sections so that an adaptation to a parabolic moment curve can easily be accomplished. Four holders 2 have been provided so that the rod 3 can also be rigidly connected to the reinforcing rods 1 and 3.

The embodiment shown in FIG. 7 consists of rods 4 which have equal lengths and are relatively staggered so that alternate rods extend from one end of the reinforcing section and the other. The reinforcing rods 4 are again connected by two holders 2 to form a rigid section.

The embodiment shown in FIG. 8 is particularly desirable for the provision of the slab reinforcement which consists of at least two separate sections which are spaced in the longitudinal direction and each of which is shorter than the span of the slabs. The section consists of the rods 5 and 6 which have different lengths and the ends of which lie one beside the other on one side and are spaced different distances from the edge in alternation on the other side. The rods 5 and 6 are also rigidly connected by holders 2. With this embodiment of the sections, two identical or different reinforcing sections of this kind may be relatively displaced to provide three different steel cross-sections and to enable an even closer adaptation to the dimensions of the slab.

In the embodiments shown in FIGS. 5 and 6, at least one-half of the rods extend throughout the span of the floor slab. The sections shown in FIGS. 7 and 8 may be used in a complete reinforcement which comprises two offset sections which have been joggled in such a manner that alternating longitudinal rods extend from opposite supports for the slab and terminate in the slab before the respective opposite support.

Sections as shown in FIG. 4 may be assembled to form any desired reinforcement, such as that shown in FIGS. 5 and 6 or that shown in FIGS. 7 and 8. It is common to all embodiments that each of these sections can be combined without restriction with equal or different sections and all embodiments may be combined in accordance with a modular system. This has been shown by way of example in FIGS. 9 to 13 for the sections shown in FIG. 5 and in FIGS. 14 to 17, for the sections shown in FIG. 4.

The reinforcing section E, comprising rods 7,8 and shown in FIG. 9 has a length L nM. The section E comprising rods 9, 10 and shown in FIG. 10 has a length L (n-2)M, etc., up to section B, which comprises rods 11, 12 and is shown in FIG. 13 and has a length L, (n-8)M. The steel cross-sections Fe cm /m are graded in accordance with Table 1. In these FIGS. 9 to 13, rods having equal designations have the same length.

The same grading has been repeated in the sections E shown in FIG. 4, which comprise the rods 12 and have been assembled in accordance with FIG. 14, in the sections E, having rods 13.and assembled as shown in FIG. 15, in sections E comprising rods 14 and assembled as shown in F IG.16 and in sections E having rods 15 and assembled as shown in FIG. 17.

FIG. 18 shows how reinforcements can be placed in which sections E and E, are combined. The sections E, are placed first so that their holders 2 with their holders 2 underneath and then the reinforcing sections E, with holders 2 on top. The complete reinforcement (without transverse load-distributing members) has one grading step, which conforms to the moment curve.

FIG. 19 shows a single-field slab which is eccentrically loaded with a uniform load ql per unit of area and another uniform load q2 per unit of area. FIG. 20 shows the corresponding bending moment curve. It is shown in FIG. 21 how two reinforcing sections, in the present case B, according to FIG. 15 and E according to FIG. 17, can be combined to provide the steel crosssections required in view of the moment curve shown in FIG. 20. The reinforcing section B, is placed first with its holders 2 underneath. The reinforcing rods of this section extend from one support to the other. The reinforcing section B, is then placed below the peak rnornentM with its holders 2 on top and in such a manner that the longitudinal rods of B9 are disposed between those of E1.

FIG. 22 shows by way of example a reinforcement for a floor slab which is prestressed in one direction, which is indicated by the arrow Pf.l. The floor slab is surrounded on all sides by beams, which are indicated by dotted lines. The beams T, carry loads and actually support the slab whereas the beams T are merely frame members adjoining the slab. In an arrangement which is similar to that of FIG. 18, two reinforcing sections E, are placed one beside the other to extend parallel to the beam T and in such a manner that the ends of the longitudinal rods are gripped at least adjacent to the beams T, or protrude beyond the outer edge of the beams T,. The distance X, by which the two reinforcing sections E, are spaced apart may be as large as the rod spacing M. This results in a tolerance which permits of an adaptation of the reinforcing sections to the width of the "slab. Another tolerance is afforded by the distance X, between the outermost reinforcing rod of section E and the inner edge of beam T If the sum of these tolerances is not sufficient, the holder 2 may be cut off so that the required number of rods of a section B, can be added. Whenthe reinforcing sections B, have been placed, the reinforcing sections E designed in accordance withstatic requirements will be placed parallel to the sections E,, as shown in FIG. 18. As is apparent from Table l a modular system having a total of eight sections makes six combinations and a modular system having a total of fourteen sections makes twelve combinations available to the designing engineer. The reinforcing sections E extend only in the middle portion of the slab. Finally, the reinforcing sections E having holders on top are placed to extend transversely to the sections E and E and serve as transverse loaddistributing'members. The connection of the sections E to the beams T can be established just as easily as the connection of reinforcing sections E to the beams T, and in such a manner that one end is first pushed between the stirrups of one beam to such an extend that the other end of the reinforcing section lies before the basket-shaped reinforcement of the opposite beam and is then pushed back between the stirrups of said opposite beam. To enable this, the distance between the rod ends and the holders 2 must be at least twice the bond length of the reinforcing rods plus one grid line spacing M.

FIG. 23 is a side elevation showing the reinforcement of FIG. 22 partly in a section taken through the beams T,. To show more clearly the arrangement of the reinforcing rods when placed, FIG. 24 shows a detail A of FIG. 23 on an enlarged scale. The carrying rods 3 of sections E and E lie in a common plane throughout the width of the slab. Only the holders 2 of sections E lie below said plane. The holders 2 of sections E and the intervening carrying rods 3 of E like above said plane. The carrying rods 3 of E serve in this case as transverse load-distributing members and are provided with holders 2, on top. Analogous tolerances X and X, are provided for. 7

FIG. 25 shows an example of a floor slab having crossing reinforcements. The remarks made in connection with the slab which is prestressed in one direction and shown in FIG. 22 are also applicable. Besides, the reinforcement cross-section may be graded in the di-, rection of its width. The reinforcing sections E, are placed first. The reinforcing sections which contact the beams T, have the steel cross-section Fe, cm /m. Reinforcing sections E, having the steel cross-section Fe cm /m are placed in the middle portion of the floor slab. In accordance with the standard, the steel crosssection Fe, may be smaller by one-half than Fe,. The tolerances which are available in the transverse direcetion are again designated X,, X Besides, the section E,/n has been provided at the end of reinforcing sections E, to show that any desired number of rods may be provided if the holders 2 are interrupted or cut off whereas there are no unusable waste portions as with all previous mesh reinforcements. After the reinforcing sections E,, the reinforcing sections E are placed transversely to E,. The steel cross-section is again graded to Fe, and Fe.,, Fe, being equal to 0.5 Fe, Particularly with small diameters, reinforcing sections E according to the invention are preferably threaded onto prefabricated pallets for storage and transportation. An illustrative embodiment of such pallets is shown in FIGS. 26, 27 and 28.

As is apparent from FIG. 27 showing an exploded view, the rod 17 is bent to have two U-shaped arms and short, straight end portions. The rod 17 is connected to two rods 18 disposed on opposite sides adjacent to the portions from which the arms protrude, as is shown in FIG. 29. Longitudinal rods 16 are then joined by welding above the rods 18 between the sides of the arms of rods 17 to complete the pallet. The reinforcing sections E are stacked on the arms of rods 17, as is shown in FIGS. 28 and 29. Parting strips 19, consisting, e.g., of plastics material, must be inserted between adjacent reinforcing sections. A filled pallet can be lifted by means of a crane engaging the free ends of the arms of the rods 17.

The invention has been explained with reference to illustrative embodiments comprising reinforcing sections comprising each a set of straight carrying rods. These straight carrying rods may be replaced by rods which have been angled or reversely bent before or after the connection of the set of rods to the holders so that sections of any desired three-dimensional configuration may be provided, e.g., sections which are angled or U-shaped or have the shapeof a closed basket or the like.

I claim:

1. A concrete reinforcement system comprising a plurality of reinforcement sections having a common unit dimension, each of said sections comprising a plurality of mutually parallel coplanar transversely speced longitudinal rods of a length equal to an integral number of such units and at least two transversely extending longitudinally spaced holders affixed to said longitudinal rods along one side thereof, at least some of the iongitudinal rods of each section projecting at an end thereof beyond a respective holder to a distance at least equal to twice the bond length of the rods plus said unit dimension, at least some of said longitudinal rods of each section having ends offset in the longitudinal direction from other longitudinal rods of the respective section, said sections having different overall lengths but substantially equal widths and being juxtaposed to form a composite reinforcement body, some of said longitudinal rods of each section being shorter than other longitudinal rods thereof are disposed between the longer longitudinal rods wholly within the length thereof are disposed between the longer longitudinal rods wholly within the length thereof and spaced inwardly from the end thereof by a multiple of said unit dimension, all of said longitudinal rods having a length equal to a multiple of said unit dimension.

2. The system defined in claim I wherein each of said sections includes a short longitudinal rod of a length shorter than that of the shortest longitudinal rod set forth above and disposed between a pair of relatively long longitudinal rods.

g 33 I UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. I 00,492 Dated 2 April 1974 Inventor (s) Georgi OROSCHAKOFF It is certified that error appears inthe above-identified patent and that said Letters Patent are hereby corrected as shown below:

Read claim 1, line 4 (co1.8, line 2) as follows:

for "speced" read spaced Claim 1, Cline '19 (co1.8, line 17) through line 21 I (c'o1.8, line 19) delete :"are disposed between 7 the longer longitudinal rods wholly within the length thereof Signed and sealed this 9th day of July 1974.

I (SEAL) Attest:

Y c. MARSHALL DANN Commissioner of Patents

Claims (2)

1. A concrete reinforcement system comprising a plurality of reinforcement sections having a common unit dimension, each of said sections comprising a plurality of mutually parallel coplanar transversely speced longitudinal rods of a length equal to an integral number of such units and at least two transversely extending longitudinally spaced holders affixed to said longitudinal rods along one side thereof, at least some of the longitudinal rods of each section projecting at an end thereof beyond a respective holder to a distance at least equal to twice the bond length of the rods plus said unit dimension, at least some of said longitudinal rods of each section having ends offset in the longitudinal direction from other longitudinal rods of the respective section, said sections having different overall lengths but subStantially equal widths and being juxtaposed to form a composite reinforcement body, some of said longitudinal rods of each section being shorter than other longitudinal rods thereof are disposed between the longer longitudinal rods wholly within the length thereof are disposed between the longer longitudinal rods wholly within the length thereof and spaced inwardly from the end thereof by a multiple of said unit dimension, all of said longitudinal rods having a length equal to a multiple of said unit dimension.

2. The system defined in claim 1 wherein each of said sections includes a short longitudinal rod of a length shorter than that of the shortest longitudinal rod set forth above and disposed between a pair of relatively long longitudinal rods.

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