FR2555222A1 - CALIPER ARMOR FOR CONSTRUCTION WORKS - Google Patents

Abstract

IN A CALIPER ARMOR FOR CONSTRUCTION WORKS, THE TWO ENDS OF THE CROSS-STICKS2 ARE BENDED DOWN TO FORM LOOPS6. THE ENDS7 OF THESE LOOPS6 ARE WELDED, ON EACH SIDE OF THE ARMOR, TO A JUNCTIONAL STICK5 PARALLEL TO THE LONGITUDINAL STICKS1 OF THE SAID ARMOR. THE LOOPS6 ARE ELBOWED AWAY FROM THE PLANS OF THE SIDE SURFACES OF THE SAID ARMOR.

Description

CALIPER ARMOR FOR CONSTRUCTION WORKS

  The present invention relates to a stirrup armor that can be incorporated into beams of load-bearing structures of reinforced concrete or of prestressed concrete, and constituted by longitudinal or transverse bars or rods connected to each other, preferably joined by welding. Such stirrup armor has been proposed by the utility model DE-U-1 946 135. These armor according to the prior art comprise, near the two ends of the transverse rods forming thrust arches, two

  respective parallel rods which cross perpendicularly

  the rods forming the arches, extend parallel-

  lie to the axis of the beam in the incorporated state, and have as their object

  to anchor said arches in concrete.

  An anchoring of this type is certainly effective, but it is not economical because the rods used exclusively for this anchoring, and extending without interruption over the entire

  length of the armed beam, involve a relative quantity-

  large amount of material used and used only

for a very modest part.

  In addition, it should be noted that simple rectangular beams are relatively rare in concrete construction. In most of the cases, a beam forms an assembly with the plate which it supports, so that a plate-beam combination of T section is obtained. In such T beams, the armor of the plate, very often consisting of welded armor mesh, must be connected to the armor of the beam. It should then be observed that two superimposed layers of armor are necessary inside the plate in the connection zone between this plate and the beam, that is to say a layer of armor which is arranged at the underside of the plate and extends substantially between a marginal support structure (for example a wall) and the T-beam parallel to this support structure, or even between two neighboring T-beams. This armor must absorb the tensile stresses imposed on the underside of the plate. In addition, it is also necessary to provide, in the immediate vicinity of the beam, an upper armor which must absorb the negative torques generated above the beam, as well as the tensile stresses which affect

  the upper face of the plate and result from these couples.

  During the connection of these armor layers with the armor of the beam, the anchoring rods according to the aforementioned prior art, extending parallel to the axis of the beam and requiring a large amount of material, constitute obstacles. The object of the invention is to provide a stirrup armor provided with an anchor for the armor hoops, which saves more on material than the armor described above and which is, moreover, even more effective because it makes it possible to have a larger steel cross-sectional area to absorb the thrust in the vicinity of the maximum thrust stresses, that is to say in the zone in which the

beam connects to the plate.

  In a stirrup armor according to the invention, this object is achieved by the fact that the two ends of the transverse rods forming thrust arches are folded down by bending in the direction of the longitudinal rods to form loops; that the ends of these loops are welded, on each side of the stirrup armor, to a connecting rod extending parallel to the longitudinal rods of said armor; and that said loops are bent away from the planes of the lateral surfaces of the armor

in stirrup.

  According to a preferred embodiment of

  the invention, the loops are bent outward perpen-

  specifically to the lateral surfaces of the stirrup armor.

  The invention will now be described in more detail by way of nonlimiting example, with reference to the figure.

single of the attached drawing.

  The drawing shows longitudinal rods 1 extending in the direction of the support and rigidly connected, preferably by welding, to transverse rods 2

which are perpendicular to them.

  The longitudinal rods 1 extend over the entire length of the support and form a base armor of the latter. Optionally, it is possible to provide other rods which are parallel to the longitudinal rods 1 and which do not extend in an uninterrupted manner from one support structure to the other of the support, but are grouped in the center of this support by forming a reinforcement of armor whose staggerings correspond approximately to

  the look of couples. These rods can still be com-

  filled with additional rods which are tied with the stirrup armor so as to constitute the armor of

  definitive support adapted exactly to the pace of the couples.

  In addition, in the bending zones of the transverse rods 2 or in the immediate vicinity of these zones, it is possible to provide other longitudinal rods 3 which

  can also be incorporated into the armor

  support and prevent breakage of the lower edges

laughs of this support.

  When making the stirrup armor, the transverse rods 2 are first bent into a U of

  two sides, so that they form branches perpendicular

  rings 4 which, in the vicinity of their upper ends, are secured on both sides by at least one rod of

junction 5.

  The end portions of the transverse rods projecting beyond the junction rod 5 are folded down by bending in the form of loops in the direction of the longitudinal rods and towards the junction rods 5, in the plane delimited by the succession of branches 4 and forming a lateral surface of the stirrup armor, then the loops 6 are immediately bent perpendicular to their plane. The ends 7 of the loops 6, folded back by bending, are also joined by welding with the

junction strips 5.

  A spacing a between the area in which the loops are bent outwards, and the joining strip 5 with which the ends situated at the base of said loops are welded, should preferably measure approximately 15 cm, so that the strip junction 5 is usually located below the concrete slab. Thanks to this measure, the parts of the branches of the loops extending parallel to

  the height of the beam can constitute a work arch

  lant in double shear to absorb the maximum thrust stresses in the connection between the beam and

the plaque.

  The loops 6 not only constitute a structure

  excellent support for the upper armor of the plate above

  above the beam, but, moreover, they ensure a secure anchoring of the thrust arch (transverse rods 2) in

the concrete of the slab.

  The spacing between the poles along the stirrup armor can be equal from one end to the other or, in a manner known per se, it can be different insofar as the poles located in the vicinity of the ends of the beam are closer together than those of the central area of this beam. Thus, in a manner known per se, the transverse rods forming said arches are; along the chopsticks

  longitudinal, located at smaller mutual spacings -

  at the ends of the stirrup armor than in the central area

of the latter.

  It goes without saying that many modifications can be made to the armor described and represented, without going out

of the scope of the invention.

Claims (4)

  1. Stirrup armor that can be incorporated into   load-bearing beams of reinforced concrete or precast concrete   constrained, and constituted by longitudinal and transverse rods secured by welding, armor characterized in that the two ends of the transverse rods (2) forming thrust arches are folded back by bending in the direction of the longitudinal rods to form loops (6) ; by the fact that the ends (7) of these loops (6) are welded, on each side of the stirrup armor, to a joining rod (5) extending parallel to the longitudinal rods (1) of said armor; and by the fact that said loops (6) are bent away from the planes of the   lateral surfaces of said stirrup armor.   2. Stirrup armor according to claim 1, character-   laughed at by the fact that the loops (6) are bent outwards perpendicular to the lateral surfaces of said stirrup armor.   3. Stirrup armor according to one of claims 1 and   2, characterized in that the spacing (a) between the bending zones of the loops (6) and the joining strip (5) measures approximately 15 cm.   4. Stirrup armor according to any one of the res-   dications 1 to 3, characterized in that the transverse rods (2) forming thrust arches are in a manner known per se, along the longitudinal rods (1), arranged at smaller mutual intervals at the ends of the stirrup armor only in the central area of this armor.