FR2636651A1 - EXPANSION JOINT FOR CONCRETE FLOORING - Google Patents

Abstract

The seal consists of a hollow plastic profile having an inverted T-shaped section, with a lower part 22 forming a base from which vertically protrudes a part 24 forming a rule having side walls 24a, 24b which have, on the side outside, longitudinal ribs 28a, 28b intended in particular to allow the attachment of concrete to these walls. The joint can constitute both a lost formwork element for pouring concrete, a rule for leveling the poured concrete, and an expansion joint that can, by its deformation capacity, follow the expansions and contractions of the hung concrete. to the side walls. The side walls 24a, 24b of the seal have, on the inside and at their upper part, longitudinal notches 34a, 34b capable of giving the seal a capacity for elastic vertical deformation at its upper part.

Description

The present invention relates to an expansion joint for concrete paving.

  an expansion joint for concrete paving, and more particularly a joint formed by a hollow plastic profile having a cross section

inverted T shape.

  Such an expansion joint is known and has been described in patent FR 2 292 907 filed on November 27, 1974. As shown in FIG. 1, which is a sectional view of a known joint of this type, the joint 10 comprises a lower part 12 forming a base from which protrudes vertically a part 14 forming a rule having

  side walls 14a, 14b converging towards each other in the direction

  tion of the upper edge 16 of the joint. The lateral walls 14a, 14b have on the outer side longitudinal ribs 18a, 18b intended in particular to allow the attachment of concrete to these walls. In this way, the seal 10 constitutes both:

  - a lost formwork element placed on the surface of the

  wearing the paving, before pouring the concrete, which then remains permanently in the paving, - a rule for leveling and compacting the poured concrete, for example by means of a vibrating rule resting on the upper edge of the joint, and - an expansion joint which, thanks to the deformation capacity of

  its side walls, is able to follow the movements of dilata-

  tion and contraction of the concrete adhering to these walls.

  With the seal 10 of the prior art described above, the passage of the vibrating rule, or of a similar device, over the edge of the seal, during compacting and leveling of the

  concrete, causes the joint to sag due to its deformability

  lity. When the joint then regains its initial shape by its elasticity, it drives the concrete attached to the side walls 14a, 14b, as shown diagrammatically in FIG. 2. This results in the

  rippling of the concrete along the joint.

  To avoid this drawback, the resistance to vertical forces can be improved by providing, in the base 12, reinforcing spacers 12a, 12b situated in the extension of the side walls 14a, 14b, as shown in FIG. 3. The seal 10 is no longer deformed vertically during the passage of the vibrating rule. However, it turns out that the upper edge of the joint is often smeared, or even covered with concrete after it has been leveled. It is then necessary to clear the upper edge of the

  joint otherwise, after setting the concrete, it forms on-

  face a crack which, even if it is located at the joint, does not necessarily follow the straight line defined by the edge of the

  joins and produces a completely unsightly effect.

  The object of the present invention is therefore to improve

  tion the joints of the prior art described above to obtain perfectly rectilinear joint lines without undulations of the concrete, without requiring any additional operation such as cleaning or clearing the edges of. joints after leveling

concrete.

  This object is achieved by means of an expansion joint of the type described above and in which, in accordance with the invention, the side walls have, on the inner side and at their upper part, longitudinal notches capable of giving the joint a capacity of elastic vertical deformation at its upper part. The notches are formed at a level equal to or greater than that of the outer ribs closest to the edge of the

attached.

  Thus, during the passage of the vibrating rule on the edge, a vertical deformation of the joint is authorized in a limited way, in the upper part thereof. The return of the joint to its initial shape is not accompanied by a entrainment of the concrete attached to the external ribs of the side walls since the vertical deformation of the joint does not affect the part of it.

  carrying these ribs. In addition, the return of the seal to its original form

  tiale results in a slight rise in the edge after the step-

  wise of the vibrating rule, which allows an automatic release of this edge and the formation of a clean and perfectly straight joint.

  The invention will be better understood on reading the

  description made below, for information but not limitation, with reference to the accompanying drawings, in which: - Figures 1, 2, 3, already described, illustrate expansion joints of the prior art, and - Figure 4 is a cross-sectional view of a mode

  for producing a seal in accordance with the invention.

  In the same way as the joint 10 in FIG. 3, the joint illustrated in FIG. 4 consists of a hollow section having an inverted T section. The seal 20 is formed in a single

  part by extrusion of a plastic material such as PVC.

  The seal 20 comprises a substantially horizontal base 22-

  slab intended to be placed on a surface on which concrete paving is to be carried out. From the central zone of the base 22 projects vertically a portion 24 forming a rule whose side walls are slightly inclined relative to the vertical in

  converging on the edge 26 of the joint.

  On the outer side, the side walls 24a, 24b present

  try longitudinal ribs 28a, 28b. These ribs participate in the reinforcement of the walls 24a, 24b and also have the function of allowing the concrete to be hooked to the side walls of the joint on either side of the latter. For this purpose, the ribs 28a, 28b have an appropriate profile, for example in L or, as shown in Figure 4, in T or in dovetail. In the example illustrated, the ribs formed on each wall are 3 in number regularly spaced. Of course, the number of ribs on each wall may be different from 3, while being at least equal to 2, and the spacing between the ribs may be irregular. The resistance of the joint to crushing under the effect

  of forces exerted laterally on the walls 24a, 24b is reinforced

  forced by means of internal longitudinal spacers horizontally joining these walls. These spacers are for example two or three in number. In Figure 4, two spacers are shown, one 32a at the base of part 24 and the other 32b

  substantially in the middle part thereof.

  Other reinforcing spacers 22a, 22b are provided in the base 22, in the extension of the walls 24a, 24b, to increase the resistance of the seal to crushing under the effect

efforts exerted vertically.

  According to the invention, longitudinal notches or grooves 34a, 34b are formed in the walls 24a, 24b at their upper part and on the inner side. The notches 34a, 34b are two in number, one in each wall, and are located at the ribs 28a, 28b closest to the edge 26. The notches 34a, 34b have a depth at least equal to the thickness walls 24a, 24b. The arrangement of these notches at the ribs 28a, 28b makes it possible to take advantage of the extra thickness of the walls 24a, 24b due to the presence of these ribs. In particular with a view to reserving the space necessary for the notches, the ribs 28a,

  28b closest to edge 26 may have a different shape

  close to that of the other ribs 28a, 28b.

  The notches 34a, 34b allow a slight sagging of the edge 26 under the effect of a vertical force exerted on

  this one. The deformation of the joint is limited to its upper part.

  higher than the level of the notches, and does not affect the rest of the joint. The elasticity of the material of the joint allows it to return to its original shape when the vertical force

ceases to be exercised.

  Figure 4 shows on an enlarged scale the detail of the profile of one (28a) of the two ribs 28a, 28b closest to the edge. The outer wall 28a2 of this rib 28a is connected to the wall 24a, on the one hand, on the upper side, by an inclined part 28a1 forming a chamfer and, on the other hand, on the lower side by a hooking part 28a3 with profile in L reversed. The wall 28a2, which delimits the bottom of the notch 34a, has a thickness less than that of the wall 24a, thus creating a critical point or weak point favoring the deformation of the seal at the level of the notch. The chamfer-shaped upper part 28a1 prevents

  that the joint, returning to its original shape, entrains concrete.

  Concrete paving with joints

  according to the invention comprises the following steps.

  Joints are arranged to form a grid on the support surface of the paving. The joint bases are placed on fresh concrete studs so that the joint edges lie in the same horizontal plane corresponding to the upper OS surface of the paving to be produced. The joints are easily cut with a saw to the desired lengths. Two joints placed end to end can be joined by means of a concrete iron introduced into the

  upper part of each of them. A joint is connected per-

  pendulum to another in place by sawing its end at an angle so that its base comes to abut against that in place and that

  The tops of the joints are at the same level.

  The concrete is poured between the joints put in place then is compacted and leveled by means of a vibrating rule, or other similar device, resting on the upper edges of the joints and causing a slight sagging of these edges due

the presence of the cuts.

  - After the vibrating rule has passed, the edges of the seals return to their initial position. The formation of the notches in the vicinity of the edge of the joint, at the lowest at the level of the outer ribs closest to the edge, means that the return of the edge to its initial position is not accompanied by an increase.

  concrete hanging on the side walls and therefore not pro-

  not the formation of a concrete ripple. Furthermore, the raising of the edge after passage of the vibrating rule allows the clearance of the edge and the formation of a clean and straight line of joint.

  The joints then remain permanently in the paving

  read. The deformation capacity of the side walls allows

  follow the expansion and contraction movements of the bonded concrete

  rant to these walls thanks to the external ribs with which they are provided.

  Finally, note that the interior of the seals can be used

  Read for the passage of cables inside the paving.

Claims (5)

  1. Expansion joint for concrete paving consisting of a hollow plastic profile having an inverted T-shaped section, with a lower part (22) forming a base from which protrudes vertically a part (24) forming a rule having side walls (24a, 24b) converging towards each other in the direction of the upper edge (26) of the seal (20), said side walls having on the outer side longitudinal ribs (28a, 28b) intended in particular to allow concrete attachment to   these walls, so that the joint can constitute both an ele-   formwork lost for pouring concrete, a rule for leveling the poured concrete, and an expansion joint which can,   by its capacity of deformation, follow the dilations and contrac-   of concrete hanging on the side walls,   characterized in that the side walls (24a, 24b) of the pre-   feel, on the inner side and at their upper part, longitudinal notches (34a, 34b) suitable for giving the joint a   capacity of elastic vertical deformation at its upper part.   2. Joint according to claim 1, characterized in that the notches (34a, 34b) are formed at a level equal to or greater than that of the outer ribs (28a, 28b) closest to the edge (26) of the seal.   3. Seal according to any one of claims 1 or   2, characterized in that reinforcing spacers (22a, 22b) are arranged in the base (22) in the extension of the walls side (24a, 24b) of the seal.   4. Seal according to any one of claims 1 to 3,   characterized in that the notches (34a, 34b) are formed at the level of the outer ribs closest to the edge of the joint, and these ribs are connected to the lateral walls (24a, 24b) of the joint, on the upper side, by inclined parts (28a1) in the shape of a chamfer.   5. Joint according to any one of claims 1 to 4,   characterized in that the notches (34a, 34b) are formed at the level of the outer ribs closest to the edge of the joint, and these ribs have an outer wall (28a2) which delimits the bottom of the notch whose thickness is less than that of the Side walls (24a, 24b) to form a weak point or point   critical promoting the vertical deformation of the joint.