FR2537632A1 - CONNECTING MEMBER FOR TWO REINFORCED CONCRETE CONSTRUCTION ELEMENTS - Google Patents

Abstract

IN A JOINT BODY OF TWO REINFORCED CONCRETE CONSTRUCTION ELEMENTS, PARALLEL GROOVES 9 ARE DEVELOPED IN THE MAIN FACE 2 OF A SUPPORT BAR 1 REMOTE FROM THE PROJECTING TRUNKS OF THE JOINING RODS 4, 4A. HOLES 8, 8A EACH THROUGH A RESPECTIVE JUNCTION STEM 4, 4A ARE DRILLED ALONG THE SAID BARRETTE AND EXTEND FROM THE BOTTOM OF SAID GORGES 9 TO THE OPPOSITE MAIN FACE 3. ANGLED BRANCHES ABOUT SAID STEMS 4, 4A LODGED AND RETAINED RIGIDLY IN THE SAID GORGES 9.

Description

i

  LINK FOR TWO BUILDING ELEMENTS

REINFORCED CONCRETE

  The present invention relates to a connecting member of two reinforced concrete construction elements, which consists of a support bar securing several connecting rods, sections of these rods projecting at mutual intervals from one side of said bar, however that bent branches of said rods are trapped

  inside the support strip.

  Connecting members of this type are known from patent AT-342 396 These known members have several connecting rods which, bent in the shape of stirrups and used to connect two neighboring building elements in reinforced concrete shaped for example in plates, each consisting of a curved loop substantially U-shaped, the branches

  of the U-bent part - being bent at right angles to

  worn in the plane of the loop at a predetermined distance from the transverse wing, and being embedded in a bar of

  support consisting of hardened foam.

  When in use, the hardened foam bars are nailed, in the formwork of the first of the two construction elements in such a way that the loops c of said concrete foam bars of this first element i After taking the l are broken and extracted of the surrounding surrounding, after i junction which have been drowned <reinforced concrete to be connected, protruding junction rods can be taken in the

construction.

concrete, foam bars

concrete of the building element

  which the branches of the rods in said bars are bent perpendicular to the connection surface of the first reinforced concrete element, so that they form anchoring bars for the second reinforced concrete construction element to be secured to the first L extraction of the bars by rupture is just as tedious and long as the manufacture of the connecting rods themselves which must be bent in space, that is to say in

  two planes, which presupposes two separate work passes.

  In other known connecting members intended to fulfill the same function, a profile strip made of metal, plastic or wood of U-section, which is pierced with holes, is used as a support bar for the connecting rods. which can be plugged right through the branches of stirrup-shaped connecting rods, these branches being bent so that they converge towards each other and engage, overlapping partially in the longitudinal direction of the bar, in the cavity of this profiled bar possibly closed first of all by a cover plate (see for example patent DE-A-2 944 739) Instead of -20 consist of a single profiled bar, each support strip can also consist of two integral U-shaped strips, the cavities of these two profiled strips then receiving a respective branch of the connecting rods in the form of stirrups (see for example the patent

CH-626 676).

  The use of metal or plastic bars profiled in a U shape as support bars for the connecting rods is expensive, especially since these

  support bars are non-reusable elements

  sands that remain in the concrete of the building elements

  On the other hand, when using

  wood as the material of the support strips

  port, a large amount of material must be removed by milling to save the cavity of the U-profile, which amounts to a waste of material and causes a considerable reduction in the resistance torque of the wooden element which very adversely influences its resistance failure while it is not yet embedded in the concrete, so during its

handling and transport.

  Admittedly, in the connecting members described above, the converging bent branches of the connecting rods in the form of stirrups make it possible to arrange these stirrups at

  small mutual spacings because the bent branches-

  adjacent stirrups may partially overlap like fishbones in the longitudinal direction of

  support bars, but these branches require inter-

  complicated bending portions and elastic deformation of the stirrups when said branches are inserted into the holes of the bars In addition, in the presence of support bars which receive the branches of the connecting rods in common cavities, the positions of said connecting rods are not not precisely determined when we don't have

  provided for additional retaining parts of the-

  said rods passing through the holes In addition, the characteristic

  common tick of all known types of linkers is poor adaptability to different

  lengths of the surfaces of two construction elements

  reinforced concrete sins which must be connected to each other.

  The object of the invention is to simplify the overall embodiment of connecting members of the aforementioned type and thus to offer the possibility of filling the gaps in the

  known connecting members described above.

  According to the invention, this object is achieved by the fact that, on the main face of the support strip remote from the protruding sections of the connecting rods, two or more of two mutually parallel grooves extending at least approximately in the region are produced. the longitudinal direction of said support strip, the width of which is approximately equal to the diameter of the connecting rods and the depth of which is at least equal to this diameter; by

  the fact that holes each crossed by a respective rod

  ve of junction are produced at intervals along the support bar and extend from the bottom of the grooves to the opposite main face of this bar; and by the fact that the bent branches of said junction rods are

  rigidly housed and retained in said grooves.

  This gives simple basic configurations.

  ples both connecting rods as support bars, these parts can also be easily assembled since it is not necessary to provide stirrups

  with converging branches The resistance torque of the.

  section of the support bar is only reduced small-

  ment by the presence of the grooves, while the bent branches of the rods can be easily rigidly retained in the parallel grooves In addition, after the parts of the connecting rods projecting beyond the support bar have been embedded in a first concrete element

  armed, the branches of said connecting rods which have been-

  previously bent can be very easily bent-

  outside the grooves on the external face of the support bar and, possibly after the extraction of this bar, be embedded in the second reinforced concrete element to be

connected to the first.

  The invention will now be described in more detail by way of non-limiting examples with reference to the drawings

annexed on which: -

  Figure 1 is a side elevation of a connecting member according to the invention;

  FIG. 2 a is a fragmentary longitudinal section

  shut up of a connecting member according to the invention;

  FIG. 2 b is a fragmentary plan view,

corresponding to figure-2 a;

  FIG. 3a is a longitudinal fragmentary section.

  keep quiet from another liaison member in accordance with the invention;

  FIG. 3 b is a fragmentary plan view,

  corresponding to Figure 3a; Figure 4 is a fragmentary cross section on an enlarged scale corresponding to Figure 2a or 3a and showing a groove in which is incorporated a branch of the connecting rod; - Figures 5 a and 5 b are respectively a section

  fragmentary longitudinal and a corresponding cross section

  laying down, showing another embodiment of the invention

  tion; Figure 6 is a plan view of an alternative embodiment of the side face having grooves; Figure 7 is a side elevation illustrating

  another embodiment of the invention ;.

  Figure 8a is a side elevation on an enlarged scale of the right end of a connecting member of the type shown in Figure 7; Figure 8b is a corresponding fragmentary plan view of the underside of said connecting member;

  Figure 9a is a side elevation of the end

  left side of said connecting member Figure 9b is a corresponding fragmentary plan view of the underside of this connecting member; Figure 10 is an axonometric view of another connecting member according to the invention; Figures 11 and 12 are respectively, on an enlarged scale, a fragmentary longitudinal section and a cross section of the connecting member of Figure 10;

  FIG. 13 represents another variant of embodiment.

  sation of the invention; and Figure 14 is a scale cross section

  enlarged corresponding to figure 13.

  FIG. 1 illustrates a support strip 1 comprising, opposite one another, a main face 2 and a main face 3 beyond which protrude end regions of junction rods 4 which are bent for example in hook shape Separation grooves 6 and 7, preferably arranged at equal mutual spacing, form rupture zones in the support strip

  programmed which allow to easily adapt said bar-

  support rette at different lengths of the joint of two

  concrete building elements To facilitate subdi-

  vision in sections, these separation grooves are pre-

  ference shaped in the two main faces 2 and 3 of the support strip, in particular the external groove 6, however, must be made as narrow as possible to prevent as much as possible the penetration of concrete poured on site. rod or compressed cardboard (presspan) can be cut by means of a saw in the programmed rupture zones; in the case of concrete support bars lubricated metal strips in the programmed failure zones can be placed

in the formwork.

  Figure 2a is a fragmentary section of a connecting member according to the invention, comprising alternatively

  connecting rods 4 bent only at right angles.

  Each rod 4 passes through a cylindrical hole 8 of circular section visible in FIG. 2 b, the diameter of which only exceeds that of said rod 4 so that this rod can be pushed right through without any resistance in said hole. the connecting rod 4 in

the hole is thus guaranteed.

  A bent branch 5 of each junction rod 4 rests in a groove 9 open in the direction of the lower main face 2 of the support bar 1 and the depth of which is, in this case, substantially greater than the diameter of the rod increased junction of the radius of curvature of this rod in the bending zone The branch 5 of the rod 4 is held firmly in this groove 9, for example by means of staples 10 When the depth of the groove is selected in this way, the elbow of the connecting rod 4

is located in said groove 9.

  Figures 3a and 3b show an embodiment

  very similar In this case, however, the depth of the groove 9 is only slightly greater than the diameter of the rod. To this end, the hole 8 is produced in the form of an oblong hole whose plane of symmetry xx coincides with the longitudinal median plane of the groove 9 oriented in the longitudinal direction of the support bar 1, and which is also perpendicular (plane yy) -to the main faces 2 and

  3 mutually parallel of said strip 1 Again, -

  the width of the oblong hole 8 is substantially equal to the diameter

  meter of the rod, the length of this oblong hole being, on the other hand, approximately equal to the radius of curvature of the junction rod increased by the diameter of this rod in the region of the elbow. Thus, in this exemplary embodiment, the elbow of

  the connecting rod 4 is in the hole 8.

  As shown in Figure 4, the anchor, in

  the support bar 1, of the branch 5 of the rod

  tion 4 housed in the groove 9 can also be ensured by the fact that this groove 9 is produced substantially narrower than the diameter of said junction rod, the bent branch of this rod being pressed inside said groove

  9 and being retained there by jamming.

  FIGS. 5 a and 5 b show a member de-liai-

  its in accordance with the invention, carrying two grooves 9 and 9 a parallel to the longitudinal axis of the support bar and in which there are connecting rods 4 and 4 a Along each groove, several holes 8 drilled at distances a connect the bottom of said groove to the main face 3 of the bar 1 free of grooves In this case, the holes 8 are in the form of oblong holes whose length is dimensioned so that the rectilinear parts of the primed junction rods by bending can pass through a hole 8, be brought to a position parallel to the groove

  9 by a rotation of 90 of the rod in the median plane lon-

E 7632

  gitudinal of the hole, then be force-fitted into said groove The connecting rods 4 and 4 has associated respectively

  at each individual groove 9 or 9 a (or else the holes

  pective 8 or 8 a receiving these rods) have a mutual distance a, but the holes of the neighboring grooves are offset from each other by the distance a divided by the number of grooves (therefore by a distance a / 2 in the case of two gorges

  In this way, for a given length of branches

  ches 5 junction rods 4 housed in the respective grooves

  tives 9 or 9 a, it is possible to increase the number of connecting rods relative to the unit of length, as well as

  the force that can be transmitted along the sharp joint of the two.

  building elements to be connected.

  It also appears from FIG. 5 b that the support bar 1 advantageously has a trapezoidal section,

  the main grooved face 2 of said strip 1 being -

  wider than its main face 3 free of grooves Thanks to this embodiment, after the branches 5 of the connecting rods 4 housed in the grooves of the support strip have been bent to a position perpendicular to the main face 2 , said support bar can be easily extracted from the concrete which surrounds it in the first of the two construction elements to be connected, which

  forms a connection between the two building elements -

  Grooved and spring type To further facilitate extraction

  tion of the support bar 1 when desired, this bar can also, for example, be impregnated with formwork oil. Another possibility of producing a connecting member in accordance with the invention is illustrated in FIG. 6. In this type of embodiment, the support bar 1 is pierced by several grooves 9 a, 9 b, 9 cec which are mutually parallel, extend at an acute angle with respect to the longitudinal median plane of said strip and with which respective holes 8 a, 8 b, etc. are associated,

  as shown, these holes are made as holes-

  oblong, the longitudinal median plane of each oblong hole must again coincide with the longitudinal median plane

  associated throat This embodiment of the invention

  Another possibility is to provide, for each unit of length of the support strip, a number of connecting rods greater than the number which can be obtained when all of said connecting rods are arranged one behind the other in one and

single throat.

  In the embodiments according to the invention de-

  so far, it is compulsory to provide an asymmetrical arrangement, with respect to the center of the support strip, of the curved sections of the connecting rods projecting beyond said support strip, and this because of the length considerable of the bent branches of said junction rods trapped in the grooves of the support bars, length necessary for the mechanical connection of two neighboring reinforced concrete construction elements When, for example, the branches of the junction rods retained in the grooves of the bar support all extend to the left from the holes through which said connecting rods, the first curved section of a connecting rod located at the right end of the support bar can be arranged very close to this end on the right of said strip On the other hand, the last curved section of a connecting rod situated at the left end of the support strip must have, with respect to -this left end, a distance whose length is at least equal to the branch of this junction rod which is firmly retained in a groove of said support strip Therefore, the last bracket located at the right end of the support bar can be considerably closer,

  the end of said bar which is contiguous to it, that -

  the last bracket at the left end of said bar.

  This asymmetry produces negative effects when several connecting members have to be aligned with each other

  along the elongated joint connecting two elements of-

  neighboring reinforced concrete construction because, in each zone where two support bars meet, mutual spacing

  of neighboring connecting rods or their stirrups is notable-

  ment larger than in the internal region of said support bars Thus, the reinforcement is irregularly distributed the

  along the connection joint of the two construction elements.

  Figure 7 shows a connecting member

  ment to the invention, in which the aforementioned gaps are filled, so that it is also possible to obtain a uniform distribution of the reinforcement in elongated connection joints which require mutual alignment

  two or more of two connecting members.

  FIG. 7 again shows a support strip 1 having main faces 2 and 3 opposite to each other, sections 4 a, 4 b and 4 c of connecting rods 4 formed in stirrups projecting beyond said main face 3 In this example, the stirrups 4 a, 4 b and 4 c are U-shaped, so that each stirrup has an arm 15 with back bending and with parallel branches, the rectilinear part of each junction rod 4 crossing each time the support bar passing through holes 8 a, 8 b and 8 c made of oblong shape (and shown only in FIGS. 8 b and 9 b), which connect the main face 3 to grooves 9 ag 9 b, and 9 c produced in the main face 2 of the support bars The arms 15 of the stirrups are located

  fully outside the support strip 1.

  As is further apparent from FIGS. 8 b ′ and 9 b,

  bent branches 5 a and 5 b of the connecting rods 4, imprisonment

  born in the grooves 9 a and 9 b, both extend from the holes 8 a and 8 b, towards an end El of the support bar located on the left, observing the

drawing.

  The third groove 9 c produced in the support bar 1 communicates with the main face 3 of this bar 1 via the hole 8 c located near the left end El of said bar A junction rod 4 crosses this strip 1 passing through said hole 8 c As shown in FIG. 9 b, a bent branch 5 c of this connecting rod leaves from said hole 8 c and extends in the direction of a straight end E 2 of the strip support, so in a direction opposite to that of the branches

  cubits 5 a and 5 b in grooves 9 a and 9 b.

  As shown in the left part of Figure 7, this measurement allows, in the meeting area of two adjacent support bars, 1 and 1 ', to have connecting rods 4 and 4' (forming stirrups 4 c and 4 a ') at a mutual distance a which is the same as in the internal region

  said support bars 1 and 1 '.

  When the stirrups protruding beyond the support strip have a U-shaped arm 15 bent back, the simplest arrangement consists in that the curved arms 15 remaining entirely outside the bar 1, as well as the branches 5 a, 5 b and 5 c of the connecting rods considered 4, trapped in the grooves 9 a, 9 b and 9 c, are on the same side of the straight parts of the said

  connecting rods which cross said strip 1 (case shown

  felt by solid lines in FIGS. 8 a, 8 b and 9 a, 9 b).

  However, to achieve perfect uniformity of

  force transmission, a preferred embodiment

  of the invention provides that, when the stirrup and the bent branch of each connecting rod are in a plane, the parallel curved arm of the U-shaped stirrup relegated to the outside of the support bar 1 and the branch 5 c trapped in the other groove 9 c are, on the junction rod associated with said other groove 9 c, arranged on opposite sides of the straight part of the junction rod 4 passing through the hole 8 c of the bar support 1, as represented by -

253763-2

  dotted lines in the case of a 4 c 'stirrup and a 15' arm

in Figure 9 a.

  In the exemplary embodiments of the invention

  hitherto described, each connecting rod forms at one end a single section stirrup and at the other end a bent branch, this rod being bent only in one plane, that is to say that the stirrup and the branch are found

in the same plane.

  Also known are connecting members provided with connecting rods in the form of double-section stirrups placed transversely, in which the two branches are bent perpendicular to the plane of the stirrup.

  such connecting rods bent in this way in the es

  pace and having double-section stirrups require a greater amount of work when bending them, because the latter must be carried out in two mutually perpendicular planes, but, with respect to connecting rods bent in one plane and comprising single section calipers, such rods have various advantages In particular, due to the very good anchoring effect of double section calipers, these rods require a lesser amount of material for an equal force to be transmitted per unit of length of the joint of two reinforced concrete construction elements and, in addition, these rods also facilitate the fixing of the connecting member to the formwork of one of said elements to be connected, fixing obtained by means of a wide support strip which must be incorporated into the formwork and includes double-section stirrups, or by means of

  two narrower support bars secured at a distance

  tance by said double section stirrups.

  Thus, as illustrated in FIGS. 10 to 14, connecting members in accordance with the invention can also be equipped with connecting rods curved in space and forming double-section stirrups. In the exemplary embodiment according to FIGS. 10 at 12, stirrups 4 B and 14 B with double section, standing transversely on the support strip 1 at longitudinal intervals, are formed by connecting rods 4 and 14 bent in space and alternate in the direction of each other longitudinal of said support bar Each connecting rod consists of five sections 4 a to 4 e and 14 a to 14 e, respectively The corresponding sections 4 b and 14 b or

  4 d and 14 d of respective connecting rods 4 or 14 follow one another

  dant cross respective holes 8 b, 18 b or 8 dp 18 d drilled in the support bar and arranged alternately, at equal mutual spacings, on a respective one of two associated lines of coincidence 8 B, 8 D, 18 B, 18 D, which extend

  parallel to the longitudinal axis of the support bar.

  The sections 4 b, 4 d and 14 b, 14 d of the rods, which project from the support bar 1 perpendicular to its main face 3, are completed by transverse wings 4 c and 14 c, respectively, to form the stirrups. 4 B and 14 B with double section extending transversely and substantially offset, alternately, towards the respective right edge or

to the left of said bar.

  Respective gorges 9 a, 9 e and 19 a, 19 e, developed

  in the main face 2 of the support strip 1 au-

  below the lines of coincidence 8 B, 8 D and 18 B, 18 D of the holes of this bar, accommodate bent branches 4 a, 4 e and 14 a, 14 e of the connecting rods 4 and 14, respectively (see in particular Figure 14) The internal width of these grooves corresponds approximately to the diameter of the connecting rods The bent branches of these rods are firmly retained in the grooves either by wedging or using

of staples or the like.

  As shown in FIG. 10, the fact of providing individual grooves for the branches of successive connecting rods makes it possible to arrange the stirrups 4 B and 14 B, along the support strip 1, at spacings which are smaller that the length of the respective bent branches

  4 a, 4 e and 14 a, 14 e, because these branches can overlap

  expensive without hindrance in the neighboring grooves.

  As is shown in particular in FIG. 11, the two respective branches 4 a, 4 e and 14 a, 14 e of each of the connecting rods 4 and 14 can, at the same time, be engaged in the respective associated holes 8 b, 8 d and 18 b,

  18 d of the support strip, made of oblong shape.

  To transmit large thrust forces, we

  obtains particularly favorable circumstances when

  that we use, instead of a relative support strip

  wide, two weaker and separate support bars, which are joined at a predetermined distance

  by the connecting rods forming stirrups with double sec-

  tion because, when pouring concrete, it is then simul-

  temporarily formed, for each junction, two connections of the grooved and spring type Although two support bars are used, the rigidity of such a connecting member is very high in comparison with a mutual displacement of the parallelogram type of the two bars because of the bent sections of the branches which are trapped in the gorges without

no pivoting possible.

  In the embodiment according to FIGS. 13 and 14, provision has been made, in the same order of ideas, for a

  common support bar, two bars 1 and 1 'parallel

  them at a distance from each other, presenting main faces

  respective blades 2, 2 'and 3, 3', and between which a gap is reserved 20 During casting, this gap is filled with concrete, which gives rise to two bonds

  of the grooved and spring type in the surface of solidarisa-

  tion of reinforced concrete building elements to be connected. In addition, the arrangement of grooves 9 a, 9 e and 19 a, 19 e, holes 8 b, 8 d and 18 b, 18 d, as well as rods

  junction 4 and 14 with their stirrups 4 B and 14 B and their branches

  respective angled ches 4a, 4e and 14a, 14e, is identical to that of the example of embodiment according to FIGS. 10 to 12. The examples of embodiment described can undergo different modifications Thus, instead of connecting rods mutually identical and forming double-section stirrups of the same width, it is possible for example to use two types of connecting rods forming double-section stirrups of different widths Next, these stirrups of

  different widths are arranged in an alternating succession

  born in the longitudinal direction of the support bars and symmetrically with respect to the center of these bars, the bent branches of the rods forming the wide stirrups and the bent branches of the rods forming the narrow stirrups then being engaged and locked in the grooves respectively

  external and internal support strips.

  It goes without saying that many modifications

  can be made to the link member described and shown

  felt, without departing from the scope of the invention.

Claims (14)

  1 Linking body of two construction elements   tion in reinforced concrete, which consists of a support bar securing several connecting rods, sections of these rods projecting at mutual intervals from one side of said bar, while bent branches of said rods are trapped in the interior of the support bar, connecting member characterized in that, on the main face (2) of the support bar (1) remote from the protruding sections of the connecting rods (4, 4 a), two or more are produced more than two grooves (9, 9 a; 9 a,   9 b, 9 c) mutually parallel extending at least approximately   matively in the longitudinal direction of said strip of   support, the width of which is roughly equal to the diameter of the   said connecting rods (4, 4 a) and whose depth is at least equal to this diameter; by the fact that holes (8; 8 a) each traversed by a respective connecting rod (4; 4 a) are produced at intervals along the support strip   and extend from the bottom of said grooves to the main face   opposite blade (3) of this bar (1); and by the fact that the bent branches (5) of said connecting rods are   rigidly housed and retained in said gorges.   2 connecting member according to claim 1,   characterized by the fact that all of the grooves (9, 9 a) extend   tooth parallel to the longitudinal median plane of the support bar (1), several holes (8; 8 a) made at a distance   each other being associated with each groove.   3 connecting member according to claim 1, characterized in that the grooves (9 a, 9 b) form acute angles with the longitudinal median plane of the bar   support (1), a single hole (8 a; 8 b) being associated cie at each throat.   4 Liaison organ according to any one of   Claims 1 to 3, characterized in that the branches   ches (5) connecting rods (4) are held firmly in place in the grooves (9) by means of staples (10) or similar elements.   Liaison organ according to any one of   Claims 1 to 3, characterized in that the width   grooves (9) is slightly smaller than the diameter of the connecting rods (4); and by the fact that the branches (5) of said connecting rods are held firmly in   place in the grooves by wedging.   6 connecting member according to one of claims   2, 4 and 5, characterized in that the holes (8, 8 a) the   along all the grooves (9, 9 a) are made at distances   these equals (a), the holes of each groove being offset, relative to the holes of the other grooves, by the distance (a) between   holes divided by the number of grooves.   7 Liaison unit according to any one of   Claims 1 to 6, characterized in that the holes   (8) are made in the form of oblong holes whose plane   longitudinal median (x-x) coincides with the median longi-   tudinal of the associated throat (9) and stands perpendicularly   cular on the main parallel faces (2, 3) of the support bar (1); and by the fact that the width of the holes is substantially equal to the diameter of the connecting rods (4), the length of these holes being, however, at least equal to the radius of curvature of said connecting rods increased by diameter of these rods.   8 Liaison unit according to any one of   Claims 1 to 7, characterized in that the bar   support (1) consists of wood, compressed cardboard, rod or the like.   9 Liaison body according to any one of   Claims 1 to 8, characterized in that the bar   support (1) has in a known manner a cross section   pezoldale, its main face (2) having grooves being wider than the main face (3) free of grooves, which is parallel to it.   10 Liaison unit according to any one of 18 2537632   Claims 1 to 9, characterized in that, on its   longitudinal extent, the support bar (1) is subdi-   targeted in sections by programmed rupture zones (separation grooves 6, 7).   11 connecting member according to claim 1, characterized in that, at least in two grooves (9 a, 9 b) of the support bar (1), the bent branches (5 a, b) of the connecting rods ( 4) extend from the hole (8 a; 8 b) of   said strip (1) crossed by the connecting rod considered   ree, in the direction of the same end (El) of said support strip, while, conversely, in at least one groove   additional (9 c) having near said extremi-   tee (El) at least one hole (8 c) crossed by a rod   tion (4), the bent branch (5 c) of this connecting rod extends from said hole (8 c) towards the other end (E 2) of said support bar 12 Connecting member according to claim 11 ,   comprising connecting rods each forming, through the   middle of an arm bent back, a U-shaped bracket located in the same plane as the bent branch of the same connecting rod, connecting member characterized in that, in the case of connecting rods (4) whose bent branches   (5 c) are trapped in the additional groove (9 c), the-   said branches (5 c) and said curved arm (15 ') are oriented towards opposite sides while, in the case of the other connecting rods (4), the curved arms (15) and the branches   cubits (5 a, 5 b) are oriented towards the same side.   13 connecting member according to claim 1, characterized in that two respective sections (4 b, 4 d; 14 b, 14 d) connecting rods (4, 14), projecting beyond a main face ( 3) of a common support bar (1) or beyond the mutually corresponding main faces (3, 3 ') of two individual support bars (1, 1'), together form a transverse wing (4 c;   14 c) a stirrup (4 B; 14 B) with a double cross-section located   Lement to the longitudinal axis of the support bars, corresponding sections (4 b, 14 b; 4 d, 14 d) of the successive connecting rods (4, 14) passing through holes (8 b, 18 b; 8 d , 18 d) of said support bars, which are located alternately and at a distance from each other on the respective one of two associated lines of coincidence (8 B, 18 B; 8 D, 18 D) parallel to the longitudinal direction of said support bars; and by the fact that the branches X 4 a, 4 e; 14 a, 14 e) bent at right angles to said successive connecting rods (4, 14) are firmly retained in associated pairs of parallel grooves (9 a, 9 e; 19 a, I 9 e) produced in the main face opposite (2; 2 ') of the support strip (1) or of the support strips (1, 1 l) o 14 Connecting member according to claim 1, characterized in that the double-section stirrups (4 B, 14 B) of successive connecting rods (4, 14) have the same width and are offset alternately in opposite directions relative to the longitudinal axis of the support bar.