FR2711385A1 - Mechanical bonding of concrete reinforcing bars, device for the establishment of this mechanical connection and method of fixing mechanical connection of reinforcing bars. - Google Patents

Abstract

A mechanical connection for concrete reinforcing rods lacking a threaded end or the like comprises - a sleeve (11) with a cylindrical hollow body into which is introduced axially the end of the reinforcing rod (7) which has no connecting element; - a coaxial threaded portion (8) on the end of the sleeve (11); - the outer material of the sleeve (11) having undergone deformation by necking-in in the area of the end of the reinforcing rod so that - the material of the ribs (10) on the reinforcing rod also deforms in order connect the reinforcing rod and the sleeve. This deformation may be produced by a piston (21) and die (23) of a jack screwed on to thread (8). After removal of the jack, the further reinforcing rod is attached via thread (8).

Description

The invention relates to a mechanical connection of reinforcing bars. She

  a mechanical connection of concrete reinforcing bars, a sleeve with a hollow body, as well as a

  device for the establishment of this mechanical connection.

  The invention also relates to a method for fixing

  mechanical connection of concrete rings.

  It will find particular application in the field of construction of buildings using concrete such as buildings in a city or works

port or road.

  In these fields of application, it is known to use mechanical links to bind concrete reinforcing bars in order to ensure the continuous transmission of a

tensile stress.

  The mechanical connection according to the invention can be used on construction sites in order to bond parts that have been subject to industrial preparation in the workshop with other concrete reinforcing bars available on site. These rounds that are used on the site may have a rectilinear end or be in the shape of a stick and the round has in known manner on its outer surface ribs or ribs whose dimensions are quite irregular but are naturally proportioned compared to the diameter of the round. All these elements are calculated to give the link a certain resistance and according to the work implemented, we can have rounds of large diameter with large ribs or small diameter

with smaller ribs.

  These ribs are generally arranged on the outer surface of the round, for example helically with a regular spacing or not, which will also depend on the diameter

  the round used and the desired resistance.

  In certain circumstances, it will sometimes be necessary to bond concrete reinforcing bars embedded in a mass of old concrete with new concrete reinforcing bars, to carry out a construction extension or a modification. Thus, in many cases, concrete reinforcing bars have not been provided by construction with a mechanical connection such as a thread to facilitate the connection or on the contrary has a thread that would have been

  damaged for example by corrosion or seawater.

  Thus, in many cases, the ends of bars embedded in the concrete to be bonded do not have by construction a sufficient mechanical connection. The ends of unprepared concrete reinforcing bars are free and thread-free and therefore it is not possible to easily connect

butt two round concrete.

  Sometimes, the absence of threading on the end of a bar rather than being due to the construction of the bar is due to an impossibility

  to use this thread because it is corroded.

  The absence of threading may also be caused by a construction site accident, for example if such a previously threaded bar had been sawed accidentally. It may still be that on a site liaisonner a series of vertical bars with a concrete slab such as a floor made industrially in the workshop and which would present at the exit of the concrete a series of horizontal bars, these bars can be rectilinear or cross-shaped but it is their end that is necessary on the site liaisonner with vertical concrete rings which will constitute

the vertical concrete element.

  There is also on the site sometimes a significant concentration of steel when the bars of the floor and the vertical bars are very close together and it is sometimes difficult to be able to reach it easily

with big tools.

  It is known today for example to bond such bars by means of a tubular sleeve which is crimped to the press. For this, it is necessary to implement large external jaws which are cumbersome since the system which implements an enveloping jaw by external pressure must be powerful. This bulk is a significant disadvantage when the concentration of steel and concrete reinforcing bars is high because, if the two bars are too close together,

  It is no longer possible to intervene quickly on the site.

  The pressing elements and the environment of the tools are heavy and bulky. It is then necessary to have a large spacing between the axes of the concrete reinforcing bars to be able to crimp them and there are here at least fifteen

centimeters of center distance.

  The daily performance of the operator on the site is very modest and it takes from four to eight connections per hour for a heavy weight material, by

  example of the order of one hundred and sixty kilograms.

  It should also be noted that, when the jaws are engaged by external pressure to crimp the two bars end to end, it is not possible to check and test if the operation is correctly

  performed and the operator must be trusted.

  The devices and dies used are very heavy because one is obliged to obtain a reaction of the force on the tooling. The punch, the matrix and the significant force used make it necessary to use a heavy and bulky external frame because the force must be transmitted to the frame. For example, pressures of up to two hundred tonnes are used and it is not easy to intervene quickly and efficiently with complete safety in all areas.

crimps.

  The object of the present invention is to provide a mechanical connection of reinforcing bars, which overcomes the aforementioned drawbacks and allows to bond a concrete round whose end has no connection means such as a thread. This lack of threading may be due to corrosion or simply because no mechanical connection has been provided to the construction. It is also possible that this mechanical connection was cut on the site

inadvertently.

  Another purpose of the mechanical connection of reinforcing bars according to the invention is to be able to operate rapidly on

  the yard and therefore with light and handy tools.

  Another object of the mechanical connection of reinforcing bars according to the invention is to be able, precisely because of the small size of the tool, to operate on concrete reinforcing bars in a very large concentration, that is to say very

closer together.

  Another object of the mechanical connection of reinforcing bars according to the invention is to be able to be tested by applying to it after bonding a stress for example

  equal to 90% of the yield point.

  Another purpose of the device for the establishment of a mechanical connection according to the invention is to allow the realization of bonds tested so that all the links manufactured will be completely safe in terms of the quality of crimping by spinning the bushing on

the end of the circle.

  Another object of the present invention is to be able to intervene quickly on the job site to bond an element that has been manufactured industrially with concrete reinforcing bars with other concrete reinforcing bars usable on

the yard.

  We can for example prepare all the horizontal slabs at the same time industrially and then link them with vertical bars which will all be set at the same height for example by means of a coppice

  preliminary of the end of the bars.

  Another advantage of the device according to the invention is to be very manageable and easily used on site. The device is provided with an opportunity to test the work that has just been done to have proof that the link is functional, which will naturally be very advantageous since previously, it was not possible to have, using crimping with

  jaws, a quality control of the manufactured link.

  Another purpose of the device according to the invention is to be able to greatly increase the quantities of treated bonds that can grow to four cents per day instead

forty today.

  According to the present invention, the mechanical connection of reinforcing bars, which will find particular application in the field of the construction of concrete elements on site, intended to fit on a straight end or butt, the round with ribs on its outer surface, is characterized in that it comprises: - a sleeve with a cylindrical hollow body into which is introduced the end of the round which is devoid of connection element, - a thread at the end of the bushing, - the hollow body and the thread being coaxial in order to be able to bond two rounds placed end to end, the outer material of the bushing having undergone a deformation by spinning at the end of the round, - the material of the ribs of the round deforming by spinning and penetrating into the hollow body of the sleeve,

  to bond the round and the socket.

  The device for the implementation of the mechanical connection on a concrete bar whose end is devoid of connecting element, for connecting two round butt, is characterized in that it comprises: - a body a double-acting cylinder, - a threaded extension tube fitting on the thread of the end of the sleeve and fixed to the body of the jack, - a hollow piston of the cylinder moving between the body and the extension, - a tool for spinning disposed at the end of the piston can move vertically to deform the outer material of the sleeve and deform the ribs of the concrete round inside the sleeve, to cause the connection and spinning the bushing on the end of the circle. The method for fixing a mechanical connection of concrete reinforcing bars, particularly usable on site, using the connection according to the invention, is characterized in that it consists in: covering the end of a concrete slab without connecting element by means of a bushing, - cause the bushing to spin and crush on the end of the round by vertical movement of a tool, - choose a material for the bushing more malleable than the material of the round to cause the deformation of the ribs of the round inside the hollow body of the sleeve,

  - refer to the round the forces induced by the tool.

  The present invention will be better understood in

  reading of the following description, which is given only

  indicative and not intended to limit it. It is accompanied by the annexed drawings which form an integral part thereof. FIG. 1 shows the mechanical connection of reinforcing bars according to the invention implemented on a bar

  vertical and a horizontal bar in stock.

  Figure 2 is a view of the device according to the invention actuating the mechanical connection of a concrete ring on a round whose end is devoid of connection element. FIG. 3 is a sectional view of the socket

  showing the form obtained by spinning.

  FIG. 4 shows a variant of the spinning tool which, instead of being staggered grains, such as

  shown in Figure 2, will be ball.

  Referring to Figure 1 which shows a mechanical connection of a concrete iron, generally designated (1). This concrete round known to Man of Art is widely used today on construction sites to strengthen buildings. We will seek to bond the concrete round (2) with another round (3) which will be arranged coaxially and end to end with the round (2). The link (1) thus ensures a transmission of the traction force in a continuous manner

between the round (2) and the round (3).

  There is shown in Figure 1 a single round (3) but it could for example be part of a horizontal floor (4) but which would include a multitude of round arranged substantially parallel. Each round (3) can come out of the floor (4) rectilinearly or on the contrary have a butt-shaped end (5) such that

shown in Figure 1.

  The structure also comprises a vertical part in which will be integrated a series of rounds (2) arranged in parallel. It is therefore necessary to connect

  the end (6) of the round (3) with the end (7) of the round (2).

  It should be noted that this end (7) of the concrete bar is devoid of connecting element, that is to say it does not include threading or tapping because then it would be

  easy for the skilled person to operate a mechanical connection.

  We saw that the absence of threading could come from construction or be due to corrosion or sawing

unfortunate on the building site.

  The mechanical connection (1) according to the invention, when it has been secured to the end (7) of the round by the method according to the invention, may be connected to the round (3) for example by screwing. The thread (8) provided at the end of the connection may engage in a tapping

(9) provided at the end (6).

  Referring to Figure 2 which shows the concrete ring (2) with its end (7) devoid of any connecting element and in particular threading. This concrete round of appropriate diameter has on its outer surface ribs (10) arranged for example in a circular or helical manner. These ribs may be irregular but in known manner facilitate the maintenance of the round in the concrete when subjected to significant traction. These ribs have different width and height dimensions and

  adapted according to the diameter of the round.

  Given the method of construction, the diameter of the round is not very regular and these ribs are not distributed very precisely on the outer surface of the round. The mechanical connection of reinforcing bars according to the invention comprises a sleeve (11) with a cylindrical hollow body into which the end of the round (7) is inserted.

through the orifice (12).

  In a preferred embodiment, the sleeve (11) has a cylindrical shape over a large part of its height but it still has inclined planes (13), the end of the sleeve (11) has beyond the planes

  (13) a thread (8) also shown in Figure 1.

  The mechanical links of reinforcing bars are B constituted by the cylindrical sleeve (11) which fits on the unthreaded end (7) of the round (2) and which comprises a thread (8). It should be noted that the round (2) and the thread (8) are arranged coaxially along the axis (14) to be able to make an end-to-end connection of the rounds (2 and 3). The different elements of the mechanical connection are naturally made of metal, but it will advantageously be possible for the sleeve (11) to choose a material that is more malleable than the material constituting the concrete slab (2) and this for the purpose of causing the deformation of the ribs ( 10) inside the bushing (11) when pressure is exerted on the outer surface of this sleeve. This deformation may be carried out for example at the end (7) of the round causing by spinning and crushing of the sleeve on the end of the round. This can be achieved for example by moving a tool vertically

generally designated by (15).

  The material of the ribs of the concrete slab deforms by spinning and penetrates into the inner zone of the bushing.

  look with the round to connect the round and the socket.

  FIG. 2 shows the device (15)

  for setting up the mechanical connection (1).

  This device is provided with a threaded extension tube (16) comprising at one of its ends a thread (17) and a thread (18) which is screwed onto the thread

(8) of the link (1).

  The thread (17) of the extender is fixed in the end (18) of the body of the hollow cylinder used preferably dual effect. The body (19) of this cylinder defines with the extension (16) a zone (20) in which is likely to move a hollow piston (21). The end (22) of this piston is secured to a spinning tool operating in a known manner with offset grains or with balls. These devices may, in some cases, be adjustable according to the diameter of the round to be bonded. We can adjust the setting by adjusting the number of balls. FIG. 4 shows the detail of this tool equipped with balls. Balls deformations (27) on the outer portion of the sleeve (11). Longitudinal crimping is caused during the vertical descent of the tool with a grip on the outer surface of the sleeve, which causes a controlled penetration and a possible adjustment through the balls. This setting

  is for example obtained by means of screws schematized in (28).

  When the piston is lowered in the direction of the arrow F, the end of the tool (23) moves vertically by a distance D. The base (24) of the tool (23) comes into contact with a rotated element (25). This element is itself placed on a rotated plate (26) with a washer

Neoprene intercalated.

  The spinning tool (23) is applied first on the planes (13) and then on the entire outer periphery of the sleeve (11) a large pressure communicated by the piston. It is this pressure and the simultaneous deformation of the periphery of the sleeve, as shown in Figure 3, which cause the connection of the end (7) of the concrete ring with the sleeve. The spinning tool produces threads (27) in the outer portion of the bushing in sufficient number, preferably uniformly distributed over the entire periphery. The number of nets will naturally function

the diameter of the round to be bonded.

  The spinning tool during its vertical displacement on the distance D will dig threads on the outer periphery of the sleeve and by pressure, will also cause the deformation of the ribs (10) of the concrete bar at its end (7). This deformation will naturally be made possible by the choice of the material constituting the sleeve (11) which will be more malleable than the

round material in (7).

  It will thus be possible to bond the bushing with the end of the concrete slab and crimp them by spinning the bushing. The material of the ribs of the round at its end (7) will spread in the internal material of the sleeve

to cause this link.

  Referring to Figure 2, it is seen that the device (15) is operated by the piston (21) when the pressurized oil is sent. The sleeve (4) which is integral with the extension (6) is fixed to the cylinder body (8). There is a reaction on the hollow piston which goes down on the distance D and causes the spinning. The drawings (10) on the outer surface of the round penetrate into the material in the inner area of the bushing which is more malleable. At the end of the operation, the face (24) of the tool comes to bear on the rotated element and is tested at the predetermined value, for example 99% of the elastic limit of the concrete ring. This test will be considered as good if, during the raising of the tool from the low position to the high position,

  the sleeve remains connected to the round.

  If the spinning has not been done under good pressure and application conditions, the linkage will come off during the test, and it is better that it is at this time to avoid further inconvenience on the

  construction site. It will either be redone or replace.

  It can be seen that the device for setting up the mechanical connection which has been described is very compact and acts vertically on the circle. It can therefore be used easily in areas where the footprint is reduced or

  if there is a significant concentration of concrete reinforcing bars.

  It should be noted that we refer on the sleeve (4) and the round (3) the forces induced by the tool (15). The reaction of the room is used. The force induced by the cylinder is returned by the part. This effort contained in the room is not dispersed and it is not necessary to have a large press frame to cushion it. The force dispersed by the cylinder is returned and taken over completely by the part. It is the inertia of the parts which totally tolerates the force of the jack, something which was not possible with the previous devices because the piece did not play this role of reaction during crimping. The sleeve and the end of the round play a functional role of reaction during spinning and can be worked in the air without important tools or support

  acting by vertical push on the end of the circle.

  The value of the distance D on which the spinning will be practiced will naturally depend on the density of the ribs and the protuberances on the circle as well as the diameter of the circle. For example, good results have been obtained with a distance D of 120 millimeters for a diameter of 40 and it is possible for this distance D to indicate a value of the order

from 1 to 5 times the diameter.

  The present invention can also be applied to products other than concrete reinforcing bars and by

  example of smooth crimping bars.

  Naturally, other implementations of the present invention, within the reach of the skilled person, could also have been envisaged without departing from the scope

of it.

Claims (6)

  1. Mechanical connection of reinforcing bars, which will notably find its application in the field of the construction of concrete elements on site, intended to fit on a rectilinear end or butt, the round having ribs on its outer surface , characterized in that it comprises: - a sleeve (11) with a cylindrical hollow body into which is introduced the end of the round which is devoid of connection element, - a thread (8) at the end of the bushing (11), the hollow body and the thread being coaxial in order to be able to bond two rounds placed end to end, the outer material of the sleeve having undergone a spinning deformation at the end of the round, the material of the ribs (10) of the round being deformed by spinning and penetrates into the hollow body of the sleeve (11),   to bond the round and the socket.   2. Mechanical connection of concrete reinforcing bars, particularly usable on building sites in the field of construction, according to claim 1, characterized in that inclined planes (13) are produced on the outer surface of the bushing (11). ) between the thread and the part cylindrical of the socket.   3. Device for the implementation of the mechanical connection on a concrete bar whose end is devoid of connecting element, for connecting two end-to-end rings, is characterized in that it comprises: - a body (19) of double-acting jack, - a threaded extension tube (16) fitting on the thread of the end of the sleeve and fixed to the body of the jack, - a hollow piston (21) of the jack moving between the body (19) and the extension (16), - a spinning tool (23) disposed at the end of the piston that can move vertically to deform the external material of the sleeve (11) and deform the ribs (10) the concrete ring inside the bushing, to cause the connection and crimp the bushing on the end of the circle.   4. Device for the establishment of a mechanical connection according to claim 3, characterized in that it comprises a rotatable element (25) on which abuts the periphery of the spinning tool in the end phase.   down the cylinder, to test the connection.   5. A method for fixing a mechanical connection of reinforcing bars, especially used on site, implementing the connection according to claim 1, characterized in that it consists in: - covering the end of a round to concrete without connection element by means of a bushing, - cause the bushing to spin and crush on the end of the round by vertical movement of a tool, - choose a material for the bushing which is more malleable than the material of the round to cause deformation of the ribs of the round inside the hollow body of the sleeve,   - refer to the round the forces induced by the tool.   6. Method for fixing a mechanical connection of concrete reinforcing bars, particularly usable on site, according to claim 5, characterized in that once the connection is made, for example, a value is tested.   pre-established the elastic limit of the concrete ring.