IL112821A - Roadway joints - Google Patents

Abstract

The road joint provides continuity between two slabs (1,2) separated by a gap (3) which support or form a road (4). The slabs can be displaced relative to each other along a principal axis (X). The joint comprises rigid horizontal teeth (5), parallel to the principal axis, which are mounted on top of the gap and fixed to the first slab (1). A horizontal road surface (6) covering the teeth has two longitudinal edges (8.1,8.2) fixed to the slabs. This surface comprises a rigid plate (7), extending longitudinally parallel to and supported either side the gap, resting on the teeth fixed to the first slab. The surface also has a deformable plate (8), side by side with the rigid plate, extending longitudinally parallel to the gap and covering the teeth fixed to the first slab. This plate, which can deform elastically along the principal axis, has one edge (8.1) fixed to the rigid plate and the other (8.2) fixed to the first slab.

Description

? Roadway Joints Freyssinet International et Compagnie C. 96852 IMPROVEMENTS TO ROADWAY JOINTS The invention relates to roadway joints intended especially to form expansion joints between the spans of a bridge.

More particularly, the invention relates to a roadway joint for achieving running continuity between two 8labs, namely a first slab and a second slab, which are separated by a gap and which support or form a roadway, it being possible for these slabs to move one with respect to the other at least along a main axis of movement, moving closer together or further apart, the roadway joint including substantially horizontal rigid teeth which point parallel to the main axis of movement and which are mounted in a cantilever fashion above the gap and are fixed at least to the first slab, above the gap.

Roadway joints of this type, known as "comb"-type joints, are known which exhibit interpenetrating teeth fixed respectively to one slab and to the other. These known joints especially exhibit the drawback of permitting a limited amplitude of movement, or distension between the two slabs parallel to the main axis of movement. In effect, the teeth have always to remain substantially imbricated in each other in order to achieve good running continuity, so that the distension is limited to the overhanging length of the teeth.

What is more, these roadway joint may prove dangerous for two-wheeled vehicles owing to the gaps between the teeth, and this is particularly true if the teeth are long.

The object of the present invention is especially to propose a roadway joint which avoids these drawbacks and allows substantial distension, ranging for example from 500 to 1500 mm.

To this end, according to the invention, a roadway joint of the type in question is essentially characterized in that it further includes a substantially horizontal running surface which covers the teeth, this running surface exhibiting, on the one hand, a rigid plate which bears on either side of the gap and rests on one side on the teeth secured to the first slab, this rigid plate extending longitudinally parallel to the gap, and, on the other hand, at least one first defonnable plate which is juxtaposed with the rigid plate and which extends longitudinally parallel to the gap, covering the teeth fixed to the first slab, this first defonnable plate being elastically defonnable at least along the main axis of movement and including two longitudinal edges, one of which is fixed to the rigid plate, and the other of which constitutes one of the longitudinal edges of the running surface and is fixed to the first slab, the roadway joint and the second slab being shaped to allow the teeth to move under the rigid plate beyond the said rigid plate in the direction of the second slab when the two slabs move closer together along the main axis of movement, the roadway joint being shaped to allow the two slabs to move away from each other as far as a point where a substantially horizontal longitudinal empty space parallel to the gap is cleared in front of the teeth, this empty space then being covered by the rigid plate.

Owing to the fact that the teeth of the joint are covered by a running surface, the slabs can move away from each other as far as a point where an empty longitudinal space is left between the teeth of one slab and the other slab, or between the teeth of the two slabs, without danger or discomfort to the vehicles running over the roadway joint since the rigid plate covers this empty space.

Thus, the roadway joint according to the invention can tolerate substantial distension with teeth whose overhanging length above the gap is relatively small by comparison with the length of the teeth which would be necessary in a conventional "comb"-type joint, since the distension here is taken up not only by the length of the teeth but also by the width of the rigid plate of the running surface.

Owing to their shorter length, the teeth can furthermore be less strong, therefore smaller, less heavy and less expensive than in a conventional "comb"-type joint designed to take up the same distension.

Likewise, the joint according to the invention make8 it possible to take up more substantial distensions than the known joints which include a rigid plate forming a bridge over the gap bearing directly on the two slabs and, for equal distension, the joint according to the invention makes it possible to use a narrower and therefore less strong and consequently less thick, less heavy and less expensive rigid plate.

In the preferred embodiments of the invention, recourse is further had to one and/or other of the following provisions: - the teeth are fixed alternately to the first and second slabs respectively, in order to interpenetrate at least when the two slabs move closer together, the rigid plate bearing on either side of the gap on the teeth fixed respectively to the two slabs, the roadway joint exhibiting a second deformable plate which is juxtaposed with the rigid plate and which extends longitudinally parallel to the gap covering the teeth fixed to the second slab, this second deformable plate being elastically deformable at least parallel to the main axis of movement and including two longitudinal edges, one of which is fixed to the rigid plate and the other of which constitutes one of the longitudinal edges of the running surface and is fixed to the second slab; - the roadway joint includes means for limiting the deformation of each deformable plate, so that the deformable plates cannot undergo excessive deformations which could damage them, especially if a vehicle were to break abruptly when positioned above the roadway joint; - each deformable plate includes alternately, on the one hand, thick and relatively rigid parts which extend longitudinally in an overall direction parallel to the gap and, on the other hand, deformable bellows, retaining plates being fixed under at least some of the thick parts and extending as far as under others of the thick parte, the retaining plates including slots under the said other thick parts and the said other thick parts including pegs which penetrate into the said slots, limiting the relative motion between the thick parts parallel to the deformable plate, all the thick parts of the deformable plate thus being linked together in pairs by the retaining plates; - the teeth fixed respectively to the two slabs are separated laterally from one another along a transverse axis which is substantially horizontal and perpendicular to the main axis of movement, and this is true regardless of the relative position of the two slabs along the main axis of movement, so that the roadway joint allows a relative transverse movement between the two slabs; - the teeth consist of rails along which there slide fastening devices which are fixed under the running surface allowing a certain transverse movement between the running surface and the rails; - each fastening device includes a shoe which is fixed under the running surface and a clamp which slides along a rail, the shoe being mounted so it can slide on the clamp parallel to the transverse axis, and the shoe being immobilized with respect to the clamp at least along the main axis of movement; - at least part of the rail is clamped axially between the shoe and the clamp along a third axis which is substantially vertical, by means of wedges in an elastic material which are secured to the clamp and which are interposed between the said part of the rail and the clamp, which allows the play which is due to wearing of the shoe on the rail to be taken up; - a layer of elastomer secured to the shoe is interposed between the said part of the rail and the shoe; - the rigid plate includes two longitudinal edges, this rigid plate being fixed to fastening devices close to each of its longitudinal edges, by means of a fixture which allows a certain degree of pivoting about the transverse axis, the fixing devices which correspond to one and the same longitudinal edge being mounted so they can slide on rails which are all fixed to one and the same slab situated facing the said longitudinal edge, which allows a certain vertical relative movement of the two slabs or a certain relative rotation of the two slabs about the transverse axis; - the fastening devices keep the running surface at a certain distance above the rails, a certain amount of clearance also being left beneath each rail, between the said rail and the slab to which it is not fixed, which allows a certain vertical relative movement of the two slabs one with respect to the other.

Other features and advantages of the invention will emerge during the following detailed description of one of its embodiments, given by way of non-limiting example, with reference to the appended drawings.

In the drawings: - Figure 1 is a cutaway perspective view of a roadway joint according to one embodiment of the invention, - Figure 2 is a diagrammatic vertical section of the roadway joint of Figure 1, - Figure 3 is an elevation of one of the fastening devices which keep the running surface of the roadway joint of Figures 1 and 2 on the guide rails of this joint, - Figure 4 is a section on IV-IV of Figure 3, and - Figure 5 is a diagrammatic plan view which illustrates the way in which the deformations of the deformable plates of the roadway joint of Figures 1 and 2 is limited.

In the various figures, the same references denote identical or similar elements.

As represented in Figure 1, the roadway joint according to the invention is intended to achieve running continuity between two slabs 1, 2 which are separated by a gap 3 and support or constitute a roadway 4, these two slabs belonging in general to the deck of two spans of a bridge.

The two slabs 1, 2 can move apart or closer together along a main axis of movement X, which is substantially horizontal, and which constitutes the longitudinal axis of the roadway. The axis X is generally, but not exclusively, perpendicular to the gap 3. The relative motion of the slabs along the axis X, known as distension, is due mainly to the thermal expansions and contractions of the material forming the two slabs.

Furthermore, the two slabs 1, 2 can move one with respect to the other along a transverse axis Y, which is substantially horizontal and perpendicular to the axis X, generally parallel to the length of the gap 3.

Moreover, the two slabs 1, 2 can move one with respect to the other in terms of unlevelling along a third axis Z perpendicular to the axes X and Y, therefore substantially vertical.

Finally, the relative movements between the slabs 1 and 2 may assume the form of rotations about the second axis Y.

Close to the gap 3, each of the two slabs 1, 2 exhibits a shoulder, l 2j respectively, situated at a level below the level of the roadway 4.

Onto each of the shoulders lx, 21 are fixed metal rails 5 which in the example represented have an I section. Each rail 5 is mounted in a cantilever fashion, with one free end which extends above the gap 3.

When the slabs 1, 2 are as far as possible from each other, the free ends of the rails 5 which are fixed respectively to the two slabs, are separated from one another by an empty space which extends parallel to the gap 3. When the two slabs 1, 2 move closer together, the rails 5 fixed respectively to the two slabs inter-penetrate without lateral contact in the transverse direction Y.

In addition, above and beyond a certain relative mutual moving-together of the slabs 1, 2 in the direction X, the free end of each rail 5 partly covers the shoulder of the slab to which this rail is not fixed. In this position, a vertical clearance remains between the lower face of the free end of the rail and the upper face of the shoulder of the slab to which the rail is not fixed.

In the example represented, this vertical clearance is obtained by a slight unlevelling downwards 12, 22, formed between the rails 5 on the shoulders la, 21 starting from the edge of these shoulders which is close to the gap 3. Thus, there is no interference between the rails 5 and the slabs 1, 2 when these slabs 1 and 2 undergo relative movement in unlevelling or when said slabs undergo a rotation about the axis Y, particularly if the said slabs 1 and 2 are as close as possible to each other.

Moreover, the roadway joint includes a running surface 6 which bears on the rails 5 and which extends the roadway 4 above the two shoulders 11# 2X and the gap 3. This running surface 6 consists of a rigid plate 7 enframed by two deformable plates 8.

The rigid plate 7 can be produced especially in the form of a relatively thick steel sheet, preferably covered with elastomer. This rigid plate 7 extends substantially horizontally, longitudinally, parallel to the gap 3.

Each of the deformable plates 8 extends substantially horizontally and includes two longitudinal edges 8ir 82 fixed respectively to one of the longitudinal edges 7 72 of the rigid plate and to one of the two slabs 1, 2 on one edge 13, 23 of the shoulder of this slab.

The two deformable plates 8 are formed of elastomer, and they include thick zones 83, 84 reinforced by rigid metal inserts and separated by bellows 8S of smaller thickness.

By virtue of the bellows 8S, the deformable plates 8 can deform elastically in the direction of the axis X. During these deformations, the rigid plate 7 is kept centred relative to the gap 3 by virtue of the elastic forces exerted on the said rigid plate by the bellows 85 of the two deformable plates 8.

As represented in Figure 1, the thick parts 8, of the deformable plates 8 extend longitudinally along the axis Y and are continuous, at least over a certain length. These thick parts 83 include polygonal pads which are relatively wide in the X direction and preferably quite elongate in the Y direction, these pads here being joined together in the X direction by zones of the thick parts 83 which are narrower in the Y direction. The polygonal pads give a good running surface and enhance the flexural strength of the plates 8 between the rails 5, owing to the fact that they include inserts made of rigid metal sheet.

The thick parts 84 are relatively narrow in the X direction and extend in the Y direction along broken lines which are continuous at least over a certain length. The thick parts 84 are located on either side of the thick parts 83 following the contour of the said thick parts 83.

The bellows 85 separate the said thick parts 83 and 84: these bellows consequently extend in the Y direction following the broken lines which, in places, are not perpendicular to the axis X, which gives the deformable plates 8 greater rigidity as regards elastic deformations along the axis X.

As can be seen particularly in Figure 2, fastening devices 9 fixed under the running surface 6 are mounted so they can slide on the rails 5.

For the rails 5 fixed to one and the same slab, that is to say situated on one and the same side of the gap 3, fastening devices 9 are fixed underneath the polygonal pads of the thick parts 8, of the deformable plate corresponding to the said slab, and each rail 5 further includes a fastening device 9 which is fixed under the rigid plate 7 close to that lateral edge 7ir 72 of the said rigid plate which is situated on the same side as the said slab.

The fastening devices 9 keep the running surface 6 at a certain distance above the rails 5, so that there is no interference between the rails 5 and the running surface 6 when the slabs 1 and 2 undergo a relative movement in unlevelling or when the said slabs undergo a rotation about the axis Y, particularly if the said slabs 1 and 2 are as close as possible to each other.

What is more, as represented diagrammatically in Figure 2, the fastening devices -6- which are fixed under the rigid plate 7 are connected to this rigid plate by a fixture 16 which allows a certain degree of relative pivoting between the rigid plate and the fastening devices about the axis Y. This figure 16 may be of any known type: it may, for example, consist in a link of the pivot or swivel type.

One particularly advantageous embodiment of the fastening devices 9 is represented in Figures 3 and 4. In this embodiment, the fastening devices each consist of a shoe 12 which is fixed under the running surface 6 and a clamp 13 which slides along the rail 5.

The shoe 12 may be fixed under the polygonal pads of the thick parts 83 of the deformable plates by a rigid link, for example by means of screws, and it may be fixed under the rigid plate 7 by means of the abovementioned pivot-type or swivel-type link.

To allow the motions of relative movement of the two slabs 1, 2 parallel to the transverse axis Y, the shoe 12 is mounted so that it can slide on the clamp 13 parallel to the axis Y. However, the shoe 12 is immobilized with respect to the clamp 13 in the X and Z directions .

In order to do this, the flanks of the clamp 13 include, at the upper part, a guiding cutout 17 which takes the shoe 12 allowing the shoe to slide along the axis Y and immobilizing the said shoe with respect to the clamp along the axis X.

Furthermore, the shoe 12 includes two ribs 19 which extend longitudinally along the axis Y and which are covered by tags 18 of the clamp 13 in order to immobilize the shoe along the axis Z.

Furthermore, the dimension of the shoe 12 along the axis Y is greater than the width of the clamp 13 along the same axis Y, so that there is no risk of the shoe 12 coming out of the clamp 13 during the sliding of the shoe on the clamp.

What is more, the lower face of the shoe 12 is secured to a layer 14 of elastomer, which is vulcanized onto the said shoe and which slides on the upper flange 51 of the rail. Moreover, the clamp 13 includes two folded-over portions 13x which are located under the upper flange 5! of the rail, a wedge 15 of an elastic synthetic material, such as polyurethane foam being interposed and compressed between the upper flange 5X of the rail and each folded-over portion 13x of the clamp.

Thus, the upper flange 51 of the rail is clamped elastically between the shoe 12 and the folded-over portion 13! of the clamp with interposition of the layer 14 of elastomer and of the polyurethane foam wedges 15 between the rail, on the one hand, the shoe and the clamp on the other, so that the fastening device 9 slides along the rail 5 with precision and without play likely to give rise to noise or vibration, and this is true even as the layer 14 of elastomer wears away.

In the example represented in Figures 3 and 4, the wedges 15 are kept in the clamp 13 by means of the tabs 132 of the said clamp. It goes without saying that other retention means could possibly be employed for retaining the wedges 15 in the clamp 13.

As represented diagrammatically in Figure 2 and in more detail in Figure 5, the roadway joint according to the invention further includes means for limiting the deformation of the deformable plates 8.

In the example represented in the drawings, these means are in the form of retaining plates 11 which are interposed between the shoes 12 and the lower face of the polygonal pads of the thick parts 83, and which are secured to these shoes 12 and to these polygonal pads. The retaining plates 11 extend along the axis X as far as under the thick parts 84 adjacent to the pads under which they are fixed. Under these adjacent thick parts 84, the plates 11 include slots lla through which pegs 20 secured to the said thick parts 84 extend vertically downwards.

Thus the relative movement of a thick part 83 with respect to the two adjacent thick parts 84 is limited along the axes X and Y by the pegs 20 abutting against the edges of the slots 112 of the retaining plates 11.

What is more, retaining half-plates lll are fixed under the thick parts 83 which form the longitudinal edges 8X and 82 of the deformable plates 8. These retaining half-plates 111 extend along the axis X as far as under the thick parts 84 adjacent to the longitudinal edges of the deformable plates 8, these thick parts 84 including, as before, pegs 20 which extend vertically downwards through the slots 112 of the retaining half-plates llj.

Thus, all the thick parts 83, 84 of one and the same deformable plate 8 are linked together in pairs by the retaining plates 11 and 112 so that the overall deformation of each deformable plate 8 is limited, both in the X direction and in the Y direction.

The pegs 20 may possibly include horizontal lugs 21 which extend under the plates 11 and llx, to prevent the thick parts 84 from lifting up.

Finally, it will be noted that the retaining plates 11 and llx also have the function of supporting the thick parts 84.

As an option, as represented in Figure 2, it is possible in some cases to provide limit stops 10 at the free end of the rails 5, so as to guarantee that the fastening devices 9 which support the rigid plate 7 cannot come out of the rails in the direction of the gap 3.

As emerges adequately from the foregoing, the roadway joint described hereinabove allows substantial distension, as well as transverse relative movements in unlevelling and in rotation about the axis Y, of the slabs 1, 2.

According to one possible alternative, just one of the two slabs, for example the slab 1, could include a shoulder 1} and rails 5 covered by a deformable plate 8.

The edge 72 of the rigid plate 7 would then be fixed directly to the slab 2, for example by a pivot-type or swivel-type link, and the said slab 2 would include, in its face opposite the slab 1, recesses designed to take the free ends of the rails 5 with transverse and vertical clearance, when the slabs are as close together as possible.

Claims (11)

1. Roadway joint for achieving running continuity between two slabs (J , ii )-, namely a first slab and a second slab f*†, which are separated by a gap and which support or form a roadway {4") , it being possible for these slabs to move one with respect to the other at least along a main axis of movement ^*†, moving closer together or further apart, the roadway joint including substantially horizontal rigid teeth 87 which point parallel to the main axis of movement (X) and which are mounted in a cantilever fashion above the gap fr-*† and are fixed at least to the first slab «(4r) , this roadway joint being characterized in that it further includes a substantially horizontal running surface {·£·) which covers the teeth (4 and which includes two longitudinal edges (^j† fixed respectively to the two slabs, this running surface fr†- exhibiting: - on the one hand, a rigid plate f^† which bears on either side of the gap ( ) and rests on one side on the teeth secured to the first slab Γ) , this rigid plate Ifi) extending longitudinally parallel to the gap fr*t, - and, on the other hand, at least one first deformable plate (<ΘΤ which is juxtaposed with the rigid plate 4<9? and which extends longitudinally parallel to the gap covering the teeth fixed to the first slab, this first deformable plate (*) being elastically deformable at least along the main axis of movement (X) and including two longitudinal edges (¾ff ^), one (9) of which is fixed to the rigid plate, and the other (fcfj of which constitutes one of the longitudinal edges of the running surface {6") and is fixed to the first slab , the roadway joint and the second slab being shaped to allow the teeth (*t to move under the rigid plate (.3·) beyond the said rigid plate in the direction of the second slab when the two slabs move closer together, the roadway joint being shaped to allow the two slabs - 1, 2) to move away from each other as far as a point where a substantially horizontal longitudinal empty space parallel to the gap (4*) is cleared in front of the teeth , this empty space then being covered by the rigid plate 4*†.

2. Roadway joint according to Claim 1, in which the teeth Iffr) are fixed alternately to the first and second slabs respectively, in order to interpenetrate at least when the two slabs move closer together, the rigid plate bearing on either side of the gap on the teeth rf fixed respectively to the two slabs H)f the roadway joint exhibiting a second defonnable plate which is juxtaposed with the rigid plate and which extends longitudinally parallel to the gap («d† covering the teeth 6) fixed to the second slab (·£■) , this second defonnable plate being elastically defonnable at least parallel to the main axis of movement (X) and including two longitudinal edges J?2) , one O) of which is fixed to the rigid plate ) and the other (β^ΐ of which constitutes one of the longitudinal edges of the running surface (4*) and is fixed to the second slab ig^i*

3. Roadway joint according to either one of Claims 1 and 2, including means ( ^f V*T/ f°r limiting the deformation of each deformable plate t&>) .

4. Roadway joint according to Claim 3, in which each deformable plate ^A† includes alternately, on the one hand, thick and relatively rigid parts (^f which extend longitudinally in an overall direction parallel to the gap J>) and, on the other hand, defonnable bellows , retaining plates ( f, being fixed under at least some (fyg) of the thick parts and extending as far as under others (fif) of the thick parts, the retaining plates (>¾Γ, i ) including slots under the said other (&f) thick parts and the said other thick parts including pegs (*β) which penetrate into the said slots, limiting the relative motion between the thick parts (9f, $ ) parallel to the deformable plate , all the thick parts j of the defonnable plate thus being linked together in pairs by the retaining plates ( ¾ 7 l^f ·

5. Roadway joint according to Claim 2, in which the teeth &ή fixed respectively to the two slabs are separated laterally from one another along a transverse axis (Y) which is substantially horizontal and perpendicular to the main axis of movement (X), and this is true regardless of the relative position of the two slabs 2) along the main axis of movement.

6. Roadway joint according to any one of the preceding claims, in which the teeth {/ consist of rails along which there slide fastening devices 4&) which are fixed under the running surface 4£) allowing a certain transverse movement between the running surface (·£) and the rails 4*) .

7. Roadway joint according to Claim 6, in which each fastening device includes a shoe (*F7) which is fixed under the running surface {4† and a clamp (43) which slides along a rail , the shoe (Jifl ) being mounted so it can slide on the clamp (JJ^ parallel to the transverse axis (Y), and the shoe being immobilized with respect to the clamp at least along the main axis of movement (X) .

8. Roadway joint according to Claim 7, in which at least part (jf) of the rail is clamped axially between the shoe ^ld) and the clamp ()&) along a third axis (Z) which is substantially vertical, by means of wedges *5") in an elastic material which are secured to the clamp (^3-) and which are interposed between the said part Off of the rail and the clamp.

9. Roadway joint according to Claim 8, in which a layer («14-) of elastomer secured to the shoe frlB-) is interposed between the said part Of of the rail and the shoe.

10. Roadway joint according to any one of Claims 6 to 9, in which the rigid plate fh) includes two longitudinal edges (^T , the rigid plate being fixed to fastening devices close to each of its longitudinal edges, by means of a fixture which allows a certain degree of pivoting about the transverse axis (Y), the fixing devices which correspond to one and the same longitudinal edge being mounted so they can slide on rails ( f which are all fixed to one and the same slab situated facing the said longitudinal edge.

11. Roadway joint according to any one of Claims 6 to 10, in which the fastening devices ^H keep the running surface †fr) at a certain distance above the rails 9 , a certain amount of clearance also being left beneath each rail , between the said rail and the slab S) to which it is not fixed. For the Applicants DR. EINHOLD COHN 7WD PARTNERS By: ' —