FR2574453A1 - METAL REINFORCEMENT FOR REINFORCED CONCRETE - Google Patents

Abstract

1. Metal reinforcement for reinforced concrete of the kind having a web with a convex polygonal section whose apices are slightly frustroconical with oblique ribs on its slightly convex faces and whose section is subtantially inscribed inside a circle, characterized in that the distance separating the most convex part of the ribs (4) and the centre of the web (1) is slightly less than that separating said center and said frustoconical apices (2).

Description

- 1

  The present invention relates to a metal frame

reinforced concrete policy.

  There are known metal reinforcements for reinforced concrete, hot formed, in the form of bars, with an oval cross section, provided with oblique ribs extending

  each on about I80 of the periphery of the bar, the inclination

  the sound of said ribs with respect to the axis being approximately 60.

  Due to their hot production method, these products are delivered to the user in the form of coils whose turns are deformed. It is therefore advisable to straighten the turns using special machines to obtain, after cutting,

  either straight bars or frames, stirrups, etc.

  After folding, it was found that the two extreme strands of the pieces did not remain in the same plane but formed a large angle between them, thus rendering them unsuitable.

  to the function for which they were intended.

  This phenomenon can be explained by the fact that due

  ribs, the outline of the straight section of the bar evo-

  read from one end to the other without presenting an axis of symmetry and deviates significantly from the ideal contour which must be circular. Therefore, during the passage in the blocking blocks of the machines the rollers of these subject the bar to

  torsional forces generating stresses in the latter

  which are released when said bar is submitted later-

lie to a folding effort.

  It was also found that the relief of the ribs was very attenuated after dressing. This is explained by the fact that,

  each series of ribs spanning approximately I800, the con-

  tact with the rollers is effected appreciably at points if-

  killed on the top of said ribs. Therefore, to achieve a good training of the straightening bar it was necessary that the

  drive rollers exert a very significant effort on the

  ribs. This degradation of the ribs is

  core more important on the so-called "rotating frame facing machines. The frame, object of the present invention, which remedies -2-

  these disadvantages, is remarkable in that the soul of the arma-

  ture has a square section and has on each of its

  faces of the inclined ribs extending a little less than 90.

  The invention will be better understood from the description which

  will follow, made with reference to the accompanying drawings by way of indicative example only, in which:

  Figure 1 is an elevational view of a frame

  form of the invention; Figures 2,3 and 4 are sections made by planes passing respectively through lines II-II, III-III and

IV-IV of figure 1.

  Referring to the drawings, it can be seen that the armature pre-

  feels a central core 1, the cross section of which assumes the shape of a square, the vertices 2 of which are truncated, defining four lateral faces 3 each having ribs 4 oblique to the axis X-X! of the reinforcement and extending over a little less than 90. The angle formed between the ribs and the axis

  mentioned above is in the range of 25 to 45.

  As is apparent from Figure 2, the assembly is substantially in a circle and the vertices 2, truncated, are rounded. However and according to a characteristic of the invention, the distance D1 separating the center C of the reinforcement and the top of the rib is slightly less than that D2 separating

  said center and a vertex 2 of the core. In this way, the con-

  tacts between the armature and the V-shaped section rollers or the rotating frames of the straightening machine, are carried out

  at the vertices 2, which avoids the crushing of said nerves

  vures. According to one embodiment, the ribs of two adjacent faces are associated in pairs so that the apex of each rib on one face is contained in an oblique plane passing through the apex of a rib on the other face. The trace of

  one of these planes appears in Y-Y1 in FIG. 1.

  The ribs of the other two faces (dotted on the

  Figure 1) are tilted in reverse.

  According to another characteristic of the invention, the faces

  of the soul are slightly domed.

  -3- As can be seen from the diagrams in FIGS. 2 to 4, the sections of the armature are substantially uniform and are

in a circle.

  Following tests, it was found that the reinforcement passed through the straightening machine without rotating around its axis. It was also found that during a subsequent folding the two end strands remained in the plane in

  which had been folded.

  Of course, the present invention is not limited to

  embodiment described and shown but extends, at the

  milk, in all variants of shapes and dimensions.

  Thus, among other things, the reinforcement bar can have a polygonal section with n sides defining n faces

  each having, or some of them, ana-

logues to those 4.

- 4-

Claims (6)

  1-Metallic reinforcement for reinforced concrete, characterized in that it has a core (1), having a polygonal section whose vertices (2) are slightly truncated, comprising on   its oblique ribs (4) faces, the entire sec-   tion of the armature sensibly in a circle.   2-Metal reinforcement for reinforced concrete, according to the resale   dication 1, characterized in that the faces of the core are slightly domed.   3-Metal reinforcement for reinforced concrete, depending on which one   conch of claims 1 and 2, characterized in that the   distance separating the most curved part of the ribs and the center of the core is slightly less than that separating   said center and the truncated vertices.   4-Metal reinforcement for reinforced concrete, according to one   any one of claims 1 to 3, characterized in that   the inclination of the ribs relative to the core of the reinforcement is in the range of 250 to 450.   - Metal frame, reinforced concrete ottoman, depending on which one -   conch of claims 1 to 4, characterized in that the section of the core is square.   6-Metal reinforcement for reinforced concrete, according to the claim   cation 5, characterized in that the ribs of two faces   are adjacent to each other.   7-Metal reinforcement for reinforced concrete, according to one   any one of claims 1 to 6, characterized in that   the truncated vertices 2 are rounded.