EP0621380A1 - Metal reinforcement for the reinforcement of concrete structures, and process and device for making the same - Google Patents

Abstract

The subject of the invention is a reinforcement member comprising a steel strip (10) which can be reeled up and intended to be incorporated in the concrete. The faces of the steel strip each comprise substantially straight ribs (12) arranged in at least one longitudinal row (R), these ribs being substantially parallel to each other and inclined with respect to the longitudinal direction of the strip. The ribs (12) of one of the faces of the strip are symmetrical with the ribs (12) of the other of the faces of the strip with respect to the mid-plane of the strip parallel to the faces of this strip. The subject of the invention is also a process and a device for manufacturing this reinforcement. <IMAGE>

Description

The present invention relates to a reinforcement for reinforcing concrete structures and to a method and a device for manufacturing this reinforcement.

It applies in particular to the manufacture of reinforced concrete slabs or sails intended for the construction of roadways or tracks, in particular motorways.

Already known in the prior art, in particular from FR-A-2,579,651, a reinforcing reinforcement for reinforced concrete slabs intended for the manufacture of roadways, comprising a relatively narrow steel strip of small thickness, the faces are embossed or notched.

The embossing comprises reliefs formed, alternately, by projections delimiting bosses, and by hollows delimiting cells.

This type of embossing makes it possible to obtain a good anchoring of the steel strip in the concrete having the effect of an almost total mobilization of the resistance of the reinforcement, this provided that the concrete used has a very high resistance and that the relative displacements between steel and concrete, during a traction exerted on this tape, are greater than a millimeter.

On the other hand, when a steel strip having the abovementioned type of embossing is sealed in ordinary or lean concrete, it is found that under the effect of a traction exerted on this strip, the total mobilization of the resistance of the reinforcement due to its anchoring in concrete is done only gradually and remains incomplete for relative displacements between steel and concrete of the order of a quarter of a millimeter.

However, in the case of structures such as reinforced concrete pavements, a significant mobilization of the resistance of the ribbons is generally required. steel for relative displacements between steel and concrete remaining less than a quarter of a millimeter.

In addition, the reinforcing tapes are generally packaged in reels so that at the time of their use the unrolled tapes have a residual or residual bending very troublesome during the laying of these tapes for the manufacture of reinforced concrete structures.

The object of the invention is in particular to optimize the mobilization of the resistance of steel ribbons intended to reinforce ordinary or lean concrete structures, when the relative displacements between steel and concrete are very small, this by providing ribbons of armature that can be conditioned in reels and which do not have bending after being unwound.

To this end, the subject of the invention is a reinforcement for the reinforcement of concrete structures, in particular concrete slabs or veils, comprising a coilable steel strip intended to be incorporated into the concrete, characterized in that the faces of the steel tape each comprise ribs arranged in at least one longitudinal row being substantially parallel to each other and inclined at an angle α relative to the longitudinal direction of the tape.

• les nervures d'une des faces du ruban sont symétriques aux nervures de l'autre des faces du ruban par rapport au plan médian du ruban parallèle aux faces de ce ruban ;
• le ruban en acier a une limite d'élasticité élevée supérieure à 650 MPa ;
• les nervures sont sensiblement rectilignes ;
• l'angle d'inclinaison α a une valeur absolue comprise entre 45 et 90° ;
• chaque face du ruban en acier comprend au moins deux rangées de nervures disposées côte à côte suivant la largeur du ruban, les nervures de ces deux rangées ayant des angles d'inclinaison α opposés ;
• chaque face du ruban en acier comprend au moins deux rangées de nervures disposées côte à côte suivant la largeur du ruban, les nervures de ces deux rangées ayant des angles d'inclinaison α identiques ;
• chaque face du ruban en acier comprend un nombre pair de rangées de nervures, ces rangées étant réparties symétriquement par rapport à l'axe longitudinal médian du ruban ;
• chaque face du ruban en acier comprend au moins deux rangées de nervures disposées côte à côte suivant la largeur du ruban, les extrémités rapprochées des nervures de ces deux rangées étant décalées longitudinalement entre elles ;
• chaque rangée de nervures est bordée latéralement par des zones longitudinales lisses ;
• les nervures d'une même rangée sont espacées longitudinalement entre elles suivant un pas constant compris entre 3 et 20 mm, de préférence entre 5 et 10 mm;
• la largeur de la base de chaque nervure est comprise entre 1 et 4 mm, de préférence égale à 2,5 mm environ ;
• la hauteur de chaque nervure est comprise entre 0,1 et 0,5 mm ;
• la section transversale de chaque nervure est délimitée sensiblement par un trapèze isocèle dont les côtés non parallèles forment un angle β d'environ 45° par rapport à la base de ce trapèze ;
• le ruban en acier comprend une lumière et un crochet disposés l'un et l'autre à des extrémités opposées du ruban, formant des moyens d'accrochage de ce ruban notamment avec un autre ruban identique ou avec une bobine d'enroulement du ruban comportant des moyens d'accrochage complémentaires ;
• la lumière a une forme générale rectangulaire et le crochet est formé par un crevé de forme générale rectangulaire ménagé dans le ruban.

According to the characteristics of different embodiments of this frame:

• the ribs of one of the faces of the ribbon are symmetrical to the ribs of the other of the faces of the ribbon with respect to the median plane of the ribbon parallel to the faces of this ribbon;
• the steel strip has a high yield strength greater than 650 MPa;
• the ribs are substantially rectilinear;
• the angle of inclination α has an absolute value between 45 and 90 °;
• each face of the steel strip comprises at least two rows of ribs arranged side by side along the width of the strip, the ribs of these two rows having opposite angles of inclination α;
• each face of the steel strip comprises at least two rows of ribs arranged side by side along the width of the strip, the ribs of these two rows having identical angles of inclination α;
• each face of the steel strip comprises an even number of rows of ribs, these rows being distributed symmetrically with respect to the median longitudinal axis of the strip;
• each face of the steel strip comprises at least two rows of ribs arranged side by side along the width of the strip, the close ends of the ribs of these two rows being offset longitudinally between them;
• each row of ribs is bordered laterally by smooth longitudinal zones;
• the ribs of the same row are spaced longitudinally between them at a constant pitch of between 3 and 20 mm, preferably between 5 and 10 mm;
• the width of the base of each rib is between 1 and 4 mm, preferably equal to approximately 2.5 mm;
• the height of each rib is between 0.1 and 0.5 mm;
• the cross section of each rib is delimited substantially by an isosceles trapezium whose non-parallel sides form an angle β of about 45 ° relative to the base of this trapezium;
• the steel tape includes a light and a hook, both arranged at opposite ends ribbon, forming means for hooking this ribbon in particular with another identical ribbon or with a ribbon winding reel comprising complementary hooking means;
• the light has a generally rectangular shape and the hook is formed by a generally rectangular puncture formed in the ribbon.

• on forme sur les faces d'une tôle ou bande en acier des rangées longitudinales de nervures sensiblement rectilignes et inclinées par rapport à un axe longitudinal de la bande, les rangées étant espacées entre elles suivant la largeur de la bande par des zones longitudinales lisses ; et
• on refend la bande le long de zones longitudinales lisses choisies de manière à former des rubans de largeur souhaitée comprenant au moins un rangée de nervures sur chacune de ses faces.

The invention also relates to a method of manufacturing a steel strip from a reinforcing reinforcement for concrete structures, in particular concrete slabs or veils, the reinforcement comprising a steel ribbon intended to be incorporated in concrete, characterized in that:

• longitudinal rows of substantially rectilinear ribs inclined with respect to a longitudinal axis of the strip are formed on the faces of a steel sheet or strip, the rows being spaced apart along the width of the strip by smooth longitudinal zones; and
• the strip is slit along smooth longitudinal zones chosen so as to form ribbons of desired width comprising at least one row of ribs on each of its faces.

• les nervures sont formées en faisant passer la bande en acier en continu entre deux cylindres de crantage, chacun de ces cylindres étant destiné à former des nervures sur une face correspondante de la bande de manière que les nervures d'une face soit symétriques aux nervures de l'autre face par rapport au plan médian de la bande parallèle aux faces de cette bande ;
• les nervures sont formées par écrouissage à froid d'une bande en acier obtenue par laminage à froid ou à chaud, de telle manière qu'après écrouissage final la limite d'élasticité de la bande soit élevée, de préférence supérieure à 650 MPa ;
• les nervures sont formées à chaud sur une bande en acier de limite d'élasticité élevée, de préférence supérieure à 650 MPa.

According to the characteristics of the different embodiments of this process:

• the ribs are formed by passing the steel strip continuously between two notching cylinders, each of these cylinders being intended to form ribs on a corresponding face of the strip so that the ribs of one face are symmetrical with the ribs of the other face with respect to the median plane of the strip parallel to the faces of this strip;
• the ribs are formed by cold work hardening of a steel strip obtained by cold or hot rolling, so that after final work hardening the elastic limit of the strip is high, preferably greater than 650 MPa;
• the ribs are hot formed on a steel strip of high yield strength, preferably greater than 650 MPa.

The invention also relates to a device for manufacturing a steel strip of a reinforcing reinforcement for concrete structures or, in particular concrete slabs or veils, the reinforcement comprising a steel ribbon intended to be incorporated in concrete, said device being of the type comprising a frame, two parallel notching cylinders, each mounted on a drive shaft carried by bearings, means for adjusting the spacing between the notching cylinders and means of synchronized drive in rotation of said locking cylinders, characterized in that each locking cylinder comprises, on the one hand, a set of independent and juxtaposed discs mounted on the corresponding drive shaft and whose working faces are provided of projecting parts of conjugate shape to produce said ribs on the faces of the strip and, on the other hand, means of relative positioning of the projecting parts d e each disc with respect to the adjacent discs as a function of the distribution of the ribs on the faces of the strip, the discs of each assembly being connected to each other and to the corresponding drive shaft by connecting means.

• les parties en saillie de chaque disque sont inclinées suivant un angle α' par rapport à l'axe du disque ;
• les moyens de positionnement relatif des parties en saillie de chaque disque par rapport aux disques adjacents sont formés par des orifices transversaux répartis angulairement et radialement sur les faces latérales de chacun desdits disques, les axes des orifices étant parallèles à l'arbre d'entraînement et les orifices étant destinés à coopérer avec les moyens de liaison des disques avec ledit arbre d'entraînement ;
• les moyens de liaison des disques de chaque cylindre de crantage avec l'arbre d'entraînement correspondant sont formés, d'une part, par deux plateaux parallèles, enserrant lesdits disques et, d'autre part, par des tirants reliant les deux plateaux et traversant les disques par lesdits orifices, l'un des plateaux portant l'arbre d'entraînement correspondant et l'autre desdits plateaux étant traversé par ledit arbre d'entraînement ;
• les moyens de liaison des disques de chaque cylindre de crantage avec l'arbre d'entraînement correspondant sont formés, d'une part, par deux flasques parallèles, enserrant lesdits disques et solidaires en rotation avec ledit arbre d'entraînement et, d'autre part, par des tirants reliant les deux flasques et traversant les disques par lesdits orifices ;
• le dispositif comporte des moyens de guidage de la bande en amont et en aval des cylindres de crantage par rapport au sens de défilement de la bande pour limiter les effets de sabrage et de ski de ladite bande ;
• le dispositif comporte des moyens de refendage de la bande de manière à former des rubans de largeur souhaitée et des moyens de meulage des arêtes longitudinales des rubans.

According to the characteristics of the various embodiments of this device:

• the projecting parts of each disc are inclined at an angle α 'relative to the axis of the disc;
• the means for relative positioning of the projecting parts of each disc with respect to the adjacent discs are formed by transverse orifices distributed angularly and radially on the lateral faces of each of said discs, the axes of the orifices being parallel to the drive shaft and the orifices being intended to cooperate with the means for connecting the discs to said drive shaft;
• the means for connecting the disks of each locking cylinder with the corresponding drive shaft are formed, on the one hand, by two parallel plates, enclosing said disks and, on the other hand, by tie rods connecting the two plates and passing through the discs through said orifices, one of the plates carrying the corresponding drive shaft and the other of said plates being traversed by said drive shaft;
• the means for connecting the discs of each locking cylinder with the corresponding drive shaft are formed, on the one hand, by two parallel flanges, enclosing said discs and integral in rotation with said drive shaft and, on the other part, by tie rods connecting the two flanges and passing through the discs through said orifices;
• the device comprises means for guiding the strip upstream and downstream of the locking cylinders relative to the direction of travel of the strip in order to limit the effects of sabering and skiing of said strip;
• the device comprises means for slitting the strip so as to form ribbons of desired width and means for grinding the longitudinal edges of the ribbons.

• la figure 1 est une vue de face d'une armature selon un premier mode de réalisation de l'invention ;
• la figure 2 est une vue en coupe suivant la ligne 2-2 de la figure 1 ;
• la figure 3 est une vue en coupe suivant la ligne 3-3 de la figure 1 ;
• la figure 4 est une vue en coupe suivant la ligne 4-4 de la figure 1 ;
• les figures 5 à 7 sont des vues de face partielles d'armature respectivement selon un second, un troisième et un quatrième modes de réalisation de l'invention ;
• la figure 8 est une vue de face du dispositif de fabrication d'une armature selon l'invention ;
• la figure 9 est une vue latérale en élévation du dispositif de la figure 8 ;
• la figure 10 est une vue latérale en élévation d'un disque d'un cylindre de crantage du dispositif de fabrication ;
• la figure 11 est une vue de dessus de plusieurs disques juxtaposés ;
• la figure 12 est une vue partielle en coupe d'un premier mode de réalisation d'un cylindre de crantage ;
• la figure 13 est une vue partielle en coupe d'un second mode de réalisation d'un cylindre de crantage.

Examples of embodiments of the invention will be described below with reference to the appended drawings in which:

• Figure 1 is a front view of a frame according to a first embodiment of the invention;
• Figure 2 is a sectional view along line 2-2 of Figure 1;
• Figure 3 is a sectional view along line 3-3 of Figure 1;
• Figure 4 is a sectional view along line 4-4 of Figure 1;
• Figures 5 to 7 are partial front views of reinforcement respectively according to a second, a third and a fourth embodiment of the invention;
• Figure 8 is a front view of the device for manufacturing a frame according to the invention;
• Figure 9 is a side elevational view of the device of Figure 8;
• Figure 10 is a side elevational view of a disc of a notching cylinder of the manufacturing device;
• Figure 11 is a top view of several juxtaposed discs;
• Figure 12 is a partial sectional view of a first embodiment of a notching cylinder;
• Figure 13 is a partial sectional view of a second embodiment of a notching cylinder.

There is shown in Figures 1 to 4 an armature according to a first embodiment of the invention comprising a steel strip 10 for reinforcing a concrete structure, for example a reinforced concrete pavement slab manufactured continuously.

The strip 10 can be made of galvanized steel.

Referring to FIGS. 1 and 2, it can be seen that each of the faces of the ribbon 10 has rectilinear ribs 12 arranged in two longitudinal rows R. Each row R is arranged in one of the two halves of the ribbon 10 symmetrical with respect to the median longitudinal axis X of the ribbon 10.

The ribs 12 of each row R are substantially parallel to each other and inclined relative to the longitudinal direction of the ribbon 10 at an angle α having an absolute value preferably between 45 and 90 °.

In the example described, the ribs 12 have an angle of inclination α of approximately 60 ° in absolute value.

With particular reference to FIG. 2, it can be seen that the ribs 12 of one of the faces of the ribbon are symmetrical to the ribs of the other of the faces of the ribbon with respect to the median plane P of the ribbon parallel to the faces of this ribbon.

Referring again to Figure 1, we see that the ribs 12 of the same row R are spaced longitudinally between them at a constant pitch of between 3 and 20 mm, preferably between 5 and 10 mm.

The close ends of the ribs 12 of the two rows R are offset longitudinally between them and the ribs 12 of one of the rows R have an angle of inclination opposite to that of the ribs 12 of the other row R so as to form a pattern on the cob.

It can also be seen in FIG. 1 that each row of ribs is bordered laterally by smooth longitudinal zones 14, the smooth zone 14 disposed between the two rows R being aligned with the median longitudinal axis X of the ribbon 10.

Referring to Figures 1 to 3, it can be seen that each rib 12 has an elongated shape and has a cross section delimited by an isosceles trapezoid.

Referring in particular to FIG. 3, it can be seen that the non-parallel sides of the isosceles trapezoid form an angle β of approximately 45 ° with the base of this trapezium.

Alternatively, the upper faces of the nevures may be located in the plane of the ribbon.

The ribs may have other possible shapes which are substantially rectilinear, in particular elongated S-shapes comprising a rectilinear central part and slightly curved ends.

Preferably, the height of each rib 12 is between 0.1 and 0.5 mm and the width of the base of each rib 12 is between 1 and 4 mm.

In the example described, the width of the base of each rib 12 is equal to approximately 2.5 mm.

Referring to Figures 1 and 4, it can be seen that the ribbon 10 further comprises a slot 16 and a hook 18 arranged one and the other at opposite ends of the ribbon.

Preferably, the lumen 16 has a generally rectangular shape and the hook 18 is formed by a generally rectangular puncture formed in the ribbon.

The angles of the light can be rounded.

The light 16 and the hook 18 form means for hooking the ribbon 10 in particular, either with another identical ribbon aligned with it during the manufacture of a reinforced concrete structure, or with a reel for winding the ribbon 10 comprising complementary hooking means of the hook or light.

Preferably, the light 16 and the hook 18 are aligned along the median longitudinal axis X of the ribbon 10.

A method of manufacturing a reinforcing tape according to the invention will now be described.

First, longitudinal rows of substantially rectilinear ribs are formed on the faces of a steel sheet or strip having a high yield strength preferably greater than 650 MPa.

Such a steel strip is obtained for example by hot rolling a steel strip of thickness between 1.5 and 6 mm having a carbon content of less than 0.9% by weight and an elastic limit equal to approximately 500 MPa, then by rolling this cold steel strip by work hardening by imposing a work hardening rate higher than 40%. A steel strip is then obtained having a thickness between 0.8 and 2.5 mm and an elastic limit greater than 650 MPa.

The ribs are preferably formed by passing the steel strip continuously between two notching cylinders, each cylinder comprising juxtaposed discs having, on their contour in contact with the corresponding face of the strip, projecting parts opposite to those which the we want to form on this strip, so that the ribs of one of the faces of the strip are symmetrical to the ribs of the other of the faces relative to the median plane of the strip parallel to the faces of this strip.

The rows of ribs are formed side by side along the width of the strip, being spaced apart by smooth longitudinal zones, for example so as to reproduce over the width of the sheet a series of spiky patterns such as that shown on the figure 1.

The steel strip undergoes work hardening, the rate of which depends on the height of the ribs formed on the faces of the strip.

After formation of the ribs, the steel strip is slit along smooth longitudinal zones chosen so as to form ribbons of desired width comprising at least one row of ribs on each of their faces.

Alternatively, the rib forming operation or the slitting operation may be preceded by a continuous galvanizing operation by dipping the strip.

Preferably, the strip is slit so as to form ribbons with a width of between 30 and 40 mm, comprising two rows of ribs on each of their faces so as to form a spiky pattern as shown in FIG. 1. You can also split this ribbon in half along the middle smooth area.

According to yet another possibility, it is possible to form, as shown in FIG. 5, a ribbon 10A of width substantially identical to that of the ribbon 10 represented in FIG. 1, comprising spike patterns, similar to that of the ribbon 10, formed by four rows R of ribs narrower than the rows of ribs of the ribbon 10.

As a variant, the ribs can be formed by any means of cold work hardening of a steel strip obtained by cold or hot rolling, so that after final work hardening, the elastic limit of the strip is high , preferably greater than 650 MPa.

According to another variant, the ribs can be hot formed on a steel strip of high yield strength, preferably greater than 650 MPa.

In Figure 6 there is shown a reinforcing tape 10B according to another embodiment of the invention.

This ribbon 10B differs from the ribbon 10A in FIG. 1 in that the ribs 12 of each row R have an identical inclination relative to the median longitudinal axis X of the ribbon.

In Figure 7, there is shown a ribbon 10C according to yet another embodiment of the invention.

This ribbon 10C has a width substantially identical to that of the ribbon 10B shown in FIG. 6 but comprises four rows R of ribs narrower than the rows of ribs of the ribbon 10B.

The ribbon 10C comprises, on each side of the median longitudinal axis X, two rows R of ribs 12, the ribs arranged on the same side of the axis X having identical inclinations relative to this axis, and the ribs belonging with two rows arranged on either side of the X axis having opposite inclinations.

In this case, the close ends of two ribs of rows R side by side are opposite one another.

According to other embodiments the ribbon can include any number of rows of ribs, that is to say an even number or an odd number. Preferably, each face of the steel strip comprises an even number of rows of ribs, these rows being distributed symmetrically with respect to the median longitudinal axis of the strip.

The manufacturing device shown in FIGS. 8 and 9 comprises a frame 20 comprising two pairs of columns 21 and 22 supported by a base plate 23 and connected together by crosspieces 24 and 25.

The columns 21 and 22 support the ends of two parallel drive shafts 26 and 27, by means of bearings, respectively 28 and 29.

As shown in FIG. 9, the bearings 28 are each formed by a semi-cylindrical cradle 30 closed by a semi-cylindrical flange 31.

The bearings 29 each have a bearing 32.

The bearings 28 are also each formed by a semi-cylindrical cradle 33 closed by a semi-cylindrical flange 34.

The bearings 29 each include a pad 35.

The bearings 28 are associated with fixed plates 36, mounted on the columns 21 and 22.

The bearings 29 are associated with guide plates 37, mounted vertically displaceable on the columns 21 and 22.

As shown in FIG. 8, each drive shaft 26 and 27 carries a notching cylinder, 40 and 41 respectively.

The drive of the shafts 26 and 27 and the notching cylinders 40 and 41 is produced in synchronism by pinions 38 and 39 respectively secured to the shafts 26 and 27, which mesh with a driving pinion, not shown.

The spacing between the notching cylinders 40 and 41 is adjusted using screws 42 and 43 acting on the upper plates 37.

Stops, not shown, make it possible to limit the descent of the upper plates 37 and consequently of the bearings 29 and of the locking cylinder 41 in order to prevent this locking cylinder 41 from coming into contact with the locking cylinder 40.

As shown in FIGS. 8 and 10 to 13, each notching cylinder 40 and 41 comprises a set of independent and juxtaposed discs 44, mounted on the corresponding drive shaft 26 or 27.

The working faces 44A of the discs 44 are provided, for example, with projecting parts 44B (FIG. 11) of conjugate shape in order to produce the ribs 12 on the faces of the strip.

On the other hand, the manufacturing device comprises means for relative positioning of the protruding parts 44B of each disc 44 with respect to the adjacent discs 44 as a function of the distribution of the ribs 12 on the faces of the strip and means for connecting the discs 44 of each set therebetween and with the corresponding drive shaft 26 or 27.

The means for relative positioning of the projecting parts 44B of each disc 44 relative to the adjacent discs 44 are formed, as shown in FIG. 10, by transverse orifices 45, distributed angularly and radially on the lateral faces of each of said discs 44.

The axes of the orifices 45 are parallel to the axis of the corresponding drive shaft 26 or 27 of the discs 44.

As shown in FIGS. 10, 13 and 14, each disc 44 has a central orifice 46 for the passage of the drive shaft 26 or 27.

Preferably, the projecting parts 44B of each disc 44 are inclined at an angle a 'with respect to the axis of said disc, as shown in FIG. 11.

This angle α 'corresponds to the angle α of the ribs 12 which it is desired to form on the faces of the strip.

Depending on the distribution of the ribs 12 on the faces of the strip, the user may have at his disposal several series of discs 44 whose angular distribution of the orifices 45 is different so as to be able to offset the protruding parts 44B by disc 44 relative to one or two adjacent discs which allows to form on the faces of the strip of rows of ribs 12 offset longitudinally therebetween.

Furthermore, the discs 44 can be inverted with respect to each other, as shown in FIG. 11, so that the projecting parts 44B of each disc 44 relative to the adjacent discs have opposite angles of inclination α '.

Referring now to FIG. 12, there will be described a first embodiment of the means for connecting the disks 44 of the notching cylinder 40 with the drive shaft 26, the means for connecting the disks 44 of the notching cylinder 41 with the drive shaft 27 being identical.

These means for connecting the disks 44 with the drive shaft 26 are formed, on the one hand, by two parallel plates 50 and 51, enclosing said disks 44 and, on the other hand, by tie rods 52 connecting the two plates 50 and 51 and passing through the discs 44 through the orifices 45.

One of the plates, for example the plate 50 carries the drive shaft 26, while the other plate 51 is crossed by said drive shaft 26.

The discs 44 are driven in rotation by the tie rods 52 cooperating with the plate 50.

According to a second embodiment shown in FIG. 13, the means for connecting the discs 44 with the drive shaft 26 are formed, on the one hand, by two parallel flanges 55 and 56, enclosing the discs 44 and integral in rotation with the drive shaft 26 by means of key 57 and, on the other hand, by tie rods 52 connecting the two flanges 55 and 56 and passing through the discs 44 through the orifices 45.

The means for connecting the disks 44 of the locking cylinder 41 with the drive shaft 27 are identical.

According to another embodiment not shown in the figures, the drive shaft 26 or 27 can be formed of two half-shafts each carrying at one end a plate. Each half-shaft is mounted in a bearing supported by the columns 21 and 22. The means for connecting the discs 44 with the plates of the two half-shafts are also formed by the tie rods 52 which pass through the said discs through the orifices 45. In this in this case, the discs 44 only have the orifices 45 for the passage of the tie rods 52.

The device also includes means for guiding upstream and downstream of the notching cylinders 40 and 41 relative to the direction of travel of said strip.

As shown in FIG. 9, one of the guide means is formed by at least two grooved rollers 60 and 61 arranged on either side of the plane of the strip and each carried by an adjustable support, respectively 62 and 63.

Grooved rollers 60 and 61 make it possible to simultaneously counteract the saber effect and the ski effect of the strip.

The device also includes means for slitting the strip so as to form tapes of desired width and means for grinding the longitudinal edges of the tapes.

These means, not shown in the figures, are constituted for example by a conventional cutting tool and by a grinding wheel allowing two adjacent edges to be ground simultaneously resulting from the slitting of the strip of tape.

The invention has many advantages.

Tensile tests on steel reinforcements according to the invention sealed in ordinary or lean concrete have shown that these reinforcements have an optimized mechanical behavior compared to conventional reinforcements, in particular for very small relative displacements between the steel and concrete.

The ribbon shape of the reinforcement according to the invention makes it possible to provide a very long reinforcement which can be packaged in a coil compatible with the manipulations usually carried out on a site.

Due to its high elastic limit, the reinforcing tape according to the invention retains excellent flatness and straightness after unwinding.

supérieur à celui des armatures classiques de sections circulaires. Ce rapport élevé ainsi que les nervures disposées sur le ruban d'armature selon l'invention permettent d'obtenir une très bonne adhérence et un très bon ancrage de cette armature dans les structures en béton habituellement utilisées pour la construction de chaussées d'autoroutes ou de pistes d'aérodromes.The reinforcing tape according to the invention, of small thickness, has a ratio T: $$\text{T =}\frac{\text{adherent surface per unit of length}}{\text{section area}}\text{,}$$

higher than that of conventional reinforcements with circular sections. This high ratio as well as the ribs arranged on the reinforcing tape according to the invention make it possible to obtain very good adhesion and very good anchoring of this reinforcement in the concrete structures usually used for the construction of motorway pavements or aerodrome runways.

This very good anchoring in the concrete results in a total mobilization of the resistance of the steel for relative displacements between the steel reinforcement and the concrete of at least a quarter of a millimeter due to cracks in the concrete of width low generally tolerated, especially for cracks less than 0.5 mm wide.

The reinforcing tapes according to the invention make it possible to obtain adhesion and anchoring in the concrete which can exceed the tensile strength of the reinforcement.

Compared to conventional reinforcements, the reinforcement according to the invention has a very high anchoring capacity and very good mechanical qualities, in particular very good tensile strength.

The reinforcement according to the invention, continuously windable and unrollable can be used simultaneously with an extruded concrete of the "slip form" type for the continuous production over a great length, of slabs or sails, of constant section.

For the construction of a road or a motorway, the reinforcement according to the invention can be unwound for the successive or simultaneous reinforcement of the roadway, the aisles and the track separation walls.

Claims (28)

Reinforcement for the reinforcement of concrete structures, in particular concrete slabs or walls, comprising a steel tape (10; 10A; 10B; 10C) which can be wound up to be incorporated into the concrete, characterized in that the faces of the tape steel each comprise ribs (12) arranged in at least one longitudinal row (R) being substantially parallel to one another and inclined at an angle α relative to the longitudinal direction of the ribbon. Reinforcement according to claim 1, characterized in that the ribs (12) of one of the faces of the ribbon are symmetrical to the ribs (12) of the other of the faces of the ribbon with respect to the median plane (P) of the ribbon parallel to the faces of this ribbon. Reinforcement according to claim 1 or 2, characterized in that the steel strip has a high yield strength greater than 650 MPa. Reinforcement according to any one of claims 1 to 3, characterized in that the ribs (12) are substantially rectilinear. Reinforcement according to any one of claims 1 to 4, characterized in that the angle of inclination α has an absolute value between 45 and 90 °. Reinforcement according to any one of Claims 1 to 5, characterized in that each face of the steel strip (10; 10A; 10C) comprises at least two rows (R) of ribs (12) arranged side by side along the width of the ribbon, the ribs (12) of these two rows having opposite angles of inclination α. Reinforcement according to any one of Claims 1 to 6, characterized in that each face of the steel strip (10B; 10C) comprises at least two rows (R) of ribs (12) arranged side by side along the width of the ribbon, the ribs (12) of these two rows having identical angles of inclination α. Reinforcement according to any one of Claims 1 to 7, characterized in that each face of the steel strip comprises an even number of rows (R) of ribs (12), these rows (R) being distributed symmetrically with respect to the median longitudinal axis (X) of the ribbon (12). Reinforcement according to any one of Claims 1 to 8, characterized in that each face of the steel strip (10; 10A) comprises at least two rows (R) of ribs (12) arranged side by side along the width of the strip, the close ends of the ribs (12) of these two rows being offset longitudinally therebetween. Reinforcement according to any one of claims 1 to 9, characterized in that each row (R) of ribs (12) is bordered laterally by smooth longitudinal zones (14). Reinforcement according to any one of claims 1 to 10, characterized in that the ribs (12) of the same row (R) are spaced longitudinally between them in a constant pitch of between 3 and 20 mm, preferably between 5 and 10 mm. Reinforcement according to any one of Claims 1 to 11, characterized in that the width of the base of each rib (12) is between 1 and 4 mm, preferably is approximately 2.5 mm. Reinforcement according to any one of claims 1 to 12, characterized in that the height of each rib (12) is between 0.1 and 0.5 mm. Reinforcement according to any one of claims 1 to 13, characterized in that the cross section of each rib (12) is delimited substantially by an isosceles trapezium whose non-parallel sides form an angle β of about 45 ° relative to the base of this trapezoid. Reinforcement according to any one of Claims 1 to 14, characterized in that the steel strip comprises a lumen (16) and a hook (18), both arranged at opposite ends of the strip, forming means for hooking this ribbon in particular with another identical ribbon or with a ribbon winding reel comprising complementary hooking means. Reinforcement according to claim 15, characterized in that the opening (16) has a generally rectangular shape and the hook (18) is formed by a generally rectangular puncture formed in the ribbon. Method for manufacturing a steel strip from a reinforcing reinforcement for concrete structures, according to any one of Claims 1 to 16, characterized in that: - On the faces of a steel sheet or strip are formed longitudinal rows (R) of ribs (12) inclined relative to a longitudinal axis of the strip, the rows (R) being spaced apart along the width of the strip by smooth longitudinal zones (14); and - The strip is split along smooth longitudinal zones chosen so as to form ribbons (10; 10A; 10B; 10C) of desired width comprising at least one row of ribs (12) on each of its faces. Method according to claim 17, characterized in that the ribs (12) are formed by passing the steel strip continuously between two locking cylinders, each of these cylinders being intended to form ribs (12) on a corresponding face of the strip so that the ribs on one side are symmetrical with the ribs on the other side with respect to the median plane (P) of the strip parallel to the faces of this strip. Method according to claim 17 or 18, characterized in that the ribs (12) are formed by cold working of a steel strip obtained by cold or hot rolling, so that after final work hardening the limit of elasticity of the strip is high, preferably greater than 650 MPa. Method according to claim 17 or 18, characterized in that the ribs (12) are hot formed on a steel strip of high elastic limit, preferably greater than 650 MPa. Manufacturing device for implementing the method according to any one of Claims 17 to 20, of the type comprising a frame (20), two parallel notching cylinders (40, 41), each mounted on a drive shaft ( 26, 27) carried by bearings (28, 29), means (37, 42, 43) for adjusting the spacing between the notching cylinders (40, 41) and means for synchronously rotating the said cylinders notching (40, 41), characterized in that each notching cylinder (40, 41) comprises, on the one hand, a set of discs (44) independent and juxtaposed, mounted on the drive shaft (26, 27) corresponding and whose working faces (44A) are provided with projecting parts (44B) of conjugate shape to produce on the faces of the strip said ribs (12) and, on the other hand, means (45) of relative positioning of the projecting parts (44B) of each disc (44) relative to the adjacent discs as a function of the rep artition of the ribs (12) on the faces of the strip, said discs (44) of each set being connected together and to the corresponding drive shaft (26, 27) by means (50, 51, 52, 55 , 56) of connection. Device according to claim 21, characterized in that the projecting parts (44B) of each disc (44) are inclined at an angle α 'with respect to the axis of the disc (44). Device according to claims 21 and 22, characterized in that the means for relative positioning of the projecting parts (44B) of each disc (44) with respect to the adjacent discs are formed by transverse orifices (45), distributed angularly and radially over the lateral faces of each of the discs (44), the axes of the orifices (45) being parallel to the drive shaft (26, 27) and the orifices (45) being intended to cooperate with the means for connecting the discs ( 44) with the corresponding drive shaft (26, 27). Device according to any one of Claims 21 to 23, characterized in that the means for connecting the discs (44) of each notching cylinder (40, 41) with the corresponding drive shaft (26, 27) are formed , on the one hand, by two parallel plates (50, 51), enclosing said discs (44) and, on the other hand, by tie rods (52) connecting the two plates (50, 51) and passing through the discs (44 ) through the orifices (45), one of the plates (50, 51) carrying the corresponding drive shaft (26, 27) and the other of said plates (50, 51) being traversed by said drive shaft (26, 27). Device according to any one of Claims 21 to 23, characterized in that the means for connecting the discs (44) of each notching cylinder (40, 41) with the corresponding drive shaft (26, 27) are formed , on the one hand, by two parallel flanges (55, 56), enclosing said discs (44) and integral in rotation with said corresponding drive shaft (26, 27) and, on the other hand, by tie rods (52 ) connecting the two flanges (55, 56) and passing through the discs (44) through said orifices (45). Device according to claim 21, characterized in that it comprises means (60, 61) for guiding the strip upstream and downstream of the locking cylinders (40, 41) relative to the direction of travel of the strip to limit the saber and ski effects of said strip. Device according to claim 21, characterized in that it comprises means for slitting the strip so as to form ribbons of desired width and means for grinding the longitudinal edges of the ribbons. Use of a reinforcement according to any one of Claims 1 to 16, for the reinforcement of roadways or tracks.

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