US3838931A

US3838931A - Elastic road bridge joint

Info

Publication number: US3838931A
Application number: US00362972A
Authority: US
Inventors: A Valla
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-05-29
Filing date: 1973-05-23
Publication date: 1974-10-01
Anticipated expiration: 1991-10-01

Abstract

An elastic road bridge joint comprising an arcuate member having an arcuate peripheral surface supporting the load of the road pavement and transmitting this load to a pair of adjacent bridge floors to be connected by the joint, said arcuate peripheral surface being supported at a point below its vertex by a section member firmly connected thereto and, if desired, forming a single element therewith, which section member contributes to take off the load from said arcuate peripheral surface, the arcuate means being provided with a resilient watertight coating connecting it to the adjacent bridge floors and being to a limited extent deformable to adapt itself to the deformations of the road pavement and the bridge floors under the influence of ambient temperature fluctuations.

Description

United States Patent 1191 Valla Oct. 1, 1974 [54] ELASTIC ROAD BRIDGE JOINT 3,760,544 9/1973 Hawes 52/403 X [76] Inventor: Angelo Valla, P. 221 Maestri P E N C B r J 7 rzmary xammer- 1 e ye s, r. den Amglanot' Savona Italy Attorney, Agent, or Firm-Pollock, Philpitt & Vande [22] Filed: May 23, 1973 Sande [21] App]. No.: 362,972

[57] ABSTRACT 52 us. c1 404/69, 52/396, 14/16 An elastic road bridge joint comprising an arcuate [51] Int. Cl. E01c 11/02 member having an arcuate Peripheral Surface p 58 Field 61 Search 404/69, 68, 57, 56,47, ing the load of the road pavement and transmitting 404/71, 66, 65, 48, 64, 58; 52/396, 403; 14/1 this load to a pair of adjacent bridge floors to be con nected by the joint, said arcuate peripheral surface 5 References Cited being supported at a point below its vertex by a section member connected thereto and, desired, forming a single element therewith, which section 22322 253 member contributes to take off the load from said ar- 2 198 084 4/1940 Jacobson .111: 2.1:: 404/69 l pe.ripheral.s.rface thefrcuate being. 2:282:335 5/1942 Methuen 104/48 vlded wrth a resilient watertight coatmg connecting it 3,135,176 6/1964 Foulger 404 47 t0 the adjacent bridge floors and being to a limited 3,410,037 11 19 3 Empson 52 403 X tent deformable to adapt itself to the deformations of 3,447,430 6/1969 Gausepohl 404/69 the road pavement and the bridge floors under the in- 3,58l,450 6/1971 Patry 52/403 fluence of ambient temperature fluctuations,

3,677,145 7 1972 Wattiez 404/47 3,724,155 411973 Reeve 1. 52 396 x 19 Claims, 9 Drawlng Flglll'es PATENTEU H974 3,888,931

sum 30? 4 ELASTIC ROAD BRIDGE JOINT This invention relates to an elastic road bridge joint, particularly for road viaducts and the like.

Modern traffic requirements have imposed certain limitations on the extent to which roads may rise and fall and in mountainous regions necessitate the construction of numerous bridges and viaducts formed by a number of spans of varying length and supported by piers having shoulder portions or projecting floors which form a joint whenever a pair of them meets.

The movement produced by the traffic at these joints may cause damage to the pavement which is usually made discontinuous at the joints to permit dilatation and thus to a certain degree hinders the free course of the motor vehicles. Also the water which sometimes is mixed with deicing salt penetrates through the gaps in the pavement and causes damage to the concrete and other materials of which the bridge structure is made, particularly to the beam supports.

It is an object of the present invention to eliminate these drawbacks by providing an elastic road bridge joint for connecting adjacent bridge floors without interrupting the pavement. In this manner a sealing connection is provided between the ends of the bridge floors of each bridge span.

This object is achieved according to the invention by providing an elastic road bridge joint which comprises arcuate means having an arcuate peripheral surface supporting the load of the road pavement and arranged to transmit the load to a pair of adjacent bridge floors to be connected by the joint, said arcuate peripheral surface being supported at a point below its vertex by a section member firmly connected thereto and contributing to take off the load from said arcuate peripheral surface, said arcuate means being provided with a resilient coating connecting it to said adjacent bridge floors and being to a limited extent deformable to adapt itself to the deformations of the road pavement and said adjacent bridge floors under the influence of ambient temperature fluctuations.

In a preferred embodiment of the invention said arcuate means is supported below its vertex by an angle section member firmly connected with its vertex to said arcuate means below the vertex thereof and having a pair of horizontally extending flanges supported by the ends of said adjacent bridge floors and said arcuate means having ends terminating just before and above said horizontally extending flanges.

The section member may be integrally formed or made of a plurality of individual plates placed one upon the other and consisting of plastics material, metal alloys or other appropriate material which is cast, extruded or pressed into the required shape.

The arcuate means and underlying section support member may also be made in a single piece of resilient material provided with a plurality of through holes arranged in an arc of a circle and delimiting the arcuate means and the section support member with the holes forming the boundary line therebetween.

Some preferred embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:

FIG. 1 is a vertical cross section through a first embodiment of an elastic road bridge joint according to the invention, this embodiment of the joint being intended to be constructed together with the construction of the bridge;

FIG. 2 is a vertical cross section through a second embodiment of the elastic road bridge joint intended to be applied to a bridge constructed previously;

FIG. 3 is a cross section through a sectional member made of plastics material for use in the elastic road bridge joint according to the invention;

FIG. 4 is a cross section through a sectional member as in FIG. 3, but made of more than one separate sheet members placed one above the other;

FIG. 5 is a cross section showing a modification of the sectional member of FIG. 3 as mounted in the operative position on a bridge in which the adjacent bridge floors have sufficiently large support surfaces to permit reduction in size of the support flanges of the sectional member relative to the size shown in FIG. 3;

FIG. 6 is a cross section through another embodiment of the elastic road bridge joint;

FIG. 7 is a cross section as in FIG. 6 and showing a modification of the embodiment shown in FIG. 6;

FIG. 8 is a perspective view of another form of sectional member for use in the embodiment of FIG. 6, and

FIG. 9 is a cross section showing the embodiment of FIG. 3 as mounted in the operative position and illustrating the path of drain water flow through the joint.

Referring now to FIGS. 1 and 2 showing the first embodiment of the elastic road bridge joint, the ends of two bridge floors of a pair of adjacent bridge or viaduct sections are indicated by 1 and 2. A gap 3 is provided between the ends 1 and 2 to permit the free expansion of the bridge sections under the influence of heat. However, the gap 3 interrupts the pavement above the ends 1 and 2 of the bridge sections which may be made of concrete or steel.

Conventionally a layer of bituminous conglomerate 4 is arranged above the supporting floors l and 2 and the actual wear-resistant pavement 5 is spread on the conglomerate 4. An intermediate binder layer 6 may be provided between the layers 4 and 5, as shown in FIG. 1.

The width of the gap 3 varies according to ambient temperature and produces a discontinuity in the layers located thereabove resulting in the above-mentioned disadvantages. Therefore, the known protective joints of this type have been little efficient in spite of their excessively high cost.

The joint according to the present invention, indicated generally by 7, comprises an. angle section member 8 placed across the gap 3 on the support floors I and 2 and provided with symmetrically arranged horizontal flanges 9 and 10. The vertex of the angle section member 8 is connected to a channel member 11, preferably of semicircular cross-sectional shape, having its concave side turned downwardly. The two ends of the channel member 11 to not touch the flanges 9 and 10 of the angle section member so that the resilience of the arcuate channel member is not impaired by its connection to the angle section member.

For mounting the elastic road bridge joint of FIG. 1 before application of the pavement the required operations are as follows:

a. An omega-shaped cover plate 12 of resilient material is adhesively connected by bitumen to the two adjacent ends of the floors l and 2 of cement or iron to seal the joint and collect the water which accumulates at the ends of the floors due to their longitudinal inclination. By means of the cover plate 12 the water is removed from the bridge structure due to the transverse inclination of the joints. If the joints have no transverse inclination the cover plate 12 must be arranged in an inclined position.

b. A thin highly resilient and adhesive watertight coating 13 is spread, while it is not, on the floors l and 2, adding, for example, neoprene latex and trying to horizontally align the ends of the adjacent floors.

0. While the coating 13 is still hot the particular section member 7 is placed thereon, if required, in lengths of about 1 yard over the entire width of the bridge structure, making sure that the horizontal flanges 9 and 10 of the section member 7 are well supported on the coating 13. d. The section member 7 thus supported is completely covered with a resilient adhesive coating 14 of the same type as used under point b).

e. The conventional bituminous conglomerate is applied in the usual manner, spreading a first filling layer 4 up to the top of the section member 7 already in position, such layer being almost always required to level the floors l and 2.

If the thickness of the filling layers has to be reduced to avoid overloading of the joint, the flanges 9 and 10 of the section member 7 may be moutned in a cutout provided at the ends of the floors 1 and 2. After application of the first layer 4 has been completed the binder layer 6 is spread thereon with the interposition of a net 15, for example, of multifilament spun polyester, across the joint to reinforce the continuity of the pavement which has been weakened along the axis thereof, the length of the net 15 varying as a function of the extent of the bridge spans. Finally, the wear resistant pavement layer 5 is applied either immediately or when the rest of the pavement of the bridge is applied.

For mounting an elastic road bridge joint of the type shown in FIG. 2 after paving of the bridge has already been completed, the following operations are required:

a. In the existing pavement two

cuts

16 and 17 are made parallel to the axis of the joint to a width determined by the length of the bridge spans. The paving material between the two cuts is removed until the ends of the floors l and 2 are exposed and the cuts in the pavement are made so that the cut surfaces are rough to ensure a solid anchoring of the insert to be made in the existing pavement.

b. A cover plate 12 is adhesively connected to the ends of the floors 1 and 2, the cover plate 12 having the same resilience and properties as mentioned above with reference to the embodiment of FIG. 1.

c. A watertight resilient and adhesive coating l8, 19 is spread, while it is still hot, on the ends of the floors 1 and 2 and the

inclined walls

16 and 17 of the bituminous conglomerate, trying to horizontally align the ends of the floors 1 and 2, as described with reference to the embodiment of FIG. 1.

d. The section member 7 is placed directly on the

coating

18, 19 while it is still hot, the section member 7 being composed of lengths of about one yard which are arranged over the entire width of the bridge structure, making sure that the horizontal flanges of the section member 7 are well supported on the coating l8, 19.

e. The section member 7 thus supported is completely covered with the coating l8, 19.

f. The seat of the joint is completely filled with bituminous conglomerate made elastic with neoprene latex and thoroughly compacted by a road roller in two consecutive working phases so as to make the insert completely continuous with the existing pavement.

g. However, if the pavement is located at the level of the binder layer, as shown in FIG. 2, it is necessary to place the reinforcing net 15, for example, of multifilament spun polyester, on the insert made in the pavement to permit application of the joint, before the upper wear-resistant paving layer is applied, to ensure greater stability of the pavement at the joint.

The principal advantage of the joint proposed according to the present invention consists in that it is capable of taking up the two major stress components to which the pavement is subjected at the joints between two adjacent bridge spans. One of these stress components acts in the longitudinal direction and is produced by the compression or tension caused by the expansion or retraction of the bridge floors as a function of varying ambient temperatures. The other stress component is a vertically acting shearing stress which varies each time a motor vehicle passes over the joint.

The longitudinal stress component is symmetrically absorbed by the semicircular resilient portion of the section member 7 which under the effect of the thrust exerted thereon by the pavement is capable of deforming by about one inch without being damaged. Further deformations, if there should be any, can be easily taken up by the pavement itself.

If the bridge floors retract the semicircular resilient portion of the section member 7 returns to its rest position following the retraction of the pavement.

For mounting this section member on joints of bridges and viaducts on which the pavement has already been completed and to replace other conventional joints it is advisable to carry out the work required for replacement when the bridge spans are in the longitudinally retracted position, i.e., in spring or autumn, or to mount the resilient section member after it has been previously deformed by compression.

When this joint is mounted before the pavement is completed no particular measures are required as during the paving operation the structure is heated and thereby the semicircular resilient portion is compressed and later adapts itself to the pavement when the entire structure cools down. This resilient semicircular portion takes up most of the stress of the pavement produced at the points of contact with the bridge floors and thus avoids breaking of the upper wear-resistant surface of the pavement.

The shearing stress produced vertically of the joint is taken up by the horizontal flanges 9 and 10 which are connected across the centre of the joint and supported on the ends of the bridge floors 1 and 2, the flanges being embedded in the resilient coating 14 and being to a certain extent movable therein as the two floors move toward or away from one another. In this manner each of the flanges is capable of eliminating independently of the other the vertical movement or shearing stress without transmitting any movement to the vertex of the section member 7 thus avoiding breaking of the surface of the pavement.

Referring now to the embodiment shown in FIGS. 3, 4 and 5, the section member of the bridge joint shown in FIG. 3 in cross section comprises an angle section member having an upwardly directed vertex and a pair of

lateral flanges

21 and 22 bent off from the central vertex portion so as to extend horizontally. The two sides of the angle section member 20 are stiffened by a horizontal cross beam 23 and an arcuate member 24 is arranged at the vertex of the angle section member and has a pair of laterally extending end portions spaced from the

flanges

21 and 22 so that the capability of the arcuate member to undergo elastic deformation is not reduced by the presence of the

flanges

21 and 22.

This integrally formed compound member is suitable for making wide connections between the arcuate member 24 and the sides of the angle section member 20. Advantageously this section member is made of synthetic plastics material although alloys and extrudable metals which can be easily formed with complex cross sections may also be used. Mounting of the section member of FIG. 3 to form a bridge joint is similar to the method already described.

Referring now to FIG. 4, the compound section member shown therein comprises an angle section member 25 having an upwardly directed vertex and laterally extending

support flanges

26, 27 connected with wide angles to the inclined sides of the angle section member 25. A similarly wide connection is provided at the vertex of the angle section member 25. With this form of construction the angle section member 25 and the

flanges

26, 27 may be formed integrally, for example by deep-drawing, if this member is made of metal, or by die-casting if this member is made of plastics ma terial, etc.

As shown in FIG. 4, the inclined sides of the angle section member 25 are interconnected by a horizontal cross bar 28 which may be formed integrally with the angle section member 25 or subsequently added and may be continuous or discontinuous according to various requirements and the type of material used.

By way of difference from the preceding embodiments, the embodiment of FIG. 4 has an arcuate member 29 which may be formed of a plurality of sectional plates placed one upon another. These plates may be made of spring steel, plastics material or partly of spring steel and partly of plastics material. In this latter case plates of resilient material such as rubber or the like may be interposed between the arcuate plates. The layers thus formed may then be solidly connected to one another or may be left free to move and deform individually, depending on the type of material used, the dimensions thereof and the various loads which the joint has to support. Obviously the

lower member

25, 26, 27 may also be made, if desired, completely or partly as the upper member 29, Le, of a plurality of plates placed one upon the other and secured together or simply placed loosely one upon the other.

In the modification shown in FIG. 5 the section member has relatively

short support flanges

30, 31. Such a section member may be used in a joint in which the ends 32, 33 of the adjacent support floors of the bridge are in an excellent state of preservation so that they provide a good joint supporting surface even under heavy loads. Therefore, such a section member may conveniently be used in a joint particularly designed for a new bridge in which the ends of the support floors are not yet worn.

Such a form of construction may also advantageously be used when the joint supporting bridge floors are made of steel so that their ends do not easily wear. As seen in FIG. 5, the lower ends of the support coating 34 define a downwardly widening channel in which the section member may be easily inserted from one end of the joint to save work when the bridge structure has already been completed. The upper surface of the arcuate member is covered with a relatively thick and large layer of resilient material 35 on which a layer of wearresistant material 36 is finally spread. The resilient material 35, for example bitumen, is also spread above and below the

support flanges

30, 31 as described in connection with the first embodiment of the invention.

Referring now to the third embodiment of the invention shown in FIGS. 6, 7, 8 and 9,. the assembly of the supporting members of the joint is constructed in a single partially hollow block 37 of resilient material such as plastics, rubber, synthetic rubber or the like. The block 37 is provided with lightening holes 38 which permit to make a distinction between a central support body 39 which is upwardly connected to an arcuate peripheral member 40 having free end edges 41 which are free to bend as the webs 42 between the lightening holes 38 offer little resistance to such bending movement. A pair of lateral flanges 43 extend from the basis of the central body 39 and are designed to be supported by the ends of the bridge floors which are not indicated in FIG. 6. A relatively large hole 44 is provided in the central lower portion of the central support body 39 to serve as a water drain channel for collecting the water arriving from small side channels 45 communicating with the base portion of the upper surface of the support flanges 43 on which the water is collected that succeeds in penetrating the road surface and reach the joint. If desired, the central support body 39 may be provided with a second through hole above the hole 44 to accommodate cables and the like.

In the modification shown in FIG. 7 the assembly of the two main components of the joint is divided by circular holes 48 and connecting webs 49 therebetween into a central support body 46 and can arcuate hollow peripheral member 47. A hole 50 extends parallel to the hole 44 and serves to accommodate cables and the like.

In the modification shown in FIG. 8 the central body 51 of the joint is formed by a sturdy trapezoidal leg traversed by a longitudinal hole 52 for accommodating cables and for lightening the joint structure. The arcuate member 53 has the same general shape as in the previous embodiments with the only difference that it is outwardly provided with a plurality of longitudinally extending parallel ribs 54 designed to improve the anchoring of the arcuate member to the overlying coatmg.

The section member shown in FIG. 8 is designed for the connection of vertical walls and therefore the lateral flanges supporting the central body 51 have been omitted. Instead there are provided short lateral flanges 55 for positioning and centering the section member.

FIG. 9 shows the joint as mounted in the operative position, the joint being indicated generally by 56. Transverse channels 57 are provided for feeding the drain water to the lower central collecting channel 58. If the joint is mounted on an inclined bridge or viaduct advantageously upstream of the higher support flange 59 of the joint a water collecting angle plate 60 is provided to keep off most of the drain water accumulating in the region of the joint. The water collecting angle plate 60 will be connected by ducts leading to the base portion of the support member 61 and the previously described transverse channels 45 (FIG. 6) will feed the water coming from the angle plate 60 to the central collecting channel 58.

Although some preferred embodiments of the invention have now been described in detail and illustrated in the accompanying drawings it is to be understood that the invention is not limited to these precise embodiments and that numerous changes and modifications obvious to one skilled in art may be made therein without departing from the scope of the invention.

I claim:

1. An elastic road bridge joint comprising arcuate means having an arcuate peripheral surface supporting the load of the road pavement and arranged to transmit the load to a pair of adjacent bridge floors to be connected by the joint, said arcuate peripheral surface being supported at a point below its vertex by a section member firmly connected thereto and contributing to take off the load from said arcuate peripheral surface, said arcuate means being provided with a resilient watertight coating connecting it to said adjacent bridge floors and being to a limited extent deformable to adapt itself to the deformations of the road pavement and said adjacent bridge floors under the influence of ambient temperature fluctuations.

2. An elastic road bridge joint as claimed in claim 1, wherein said arcuate means is supported below its vertex by an angle section member firmly connected with its vertex to said arcuate means below the vertex thereof and having a pair of horizontally extending flanges supported by the ends of said adjacent bridge floors and said arcuate means having ends terminating just before and above said horizontally extending flanges.

3. An elastic road bridge joint as claimed in claim 1, wherein a cover plate is arranged between the adjacent ends of said bridge floors symmetrically opposite the vertex of said section member and forms a downwardly concave water drain channel.

4. An elastic road bridge joint as claimed in claim 1, wherein said resilient watertight coating consists of a bituminous conglomerate also used as conventionally to cover the bridge floors and the vertex of the joint is at a level considerably below the upper surface of said resilient water-tight coating and a connection net is placed horizontally above the joint and is embedded in said resilient watertight coating.

5. An elastic road bridge joint as claimed in claim 1, wherein said resilient watertight coating consists of approximately equal quantities of two different types of bitumen and calcium carbonate and about -20 percent by weight, on the basis of the total amount of bitumen used, of neoprene latex, one of said types of bitumen having a penetration index of 4050 and the other a penetration index of 60-80.

6. An elastic road bridge joint as claimed in claim 1, wherein said section member is formed integrally with said means having said arcuate peripheral surface.

7. An elastic road bridge joint as claimed in claim 1, wherein said section member is made of a plurality of individual plates placed one upon the other and consisting of a material selected from the group comprising plastics material and metal alloys formed into the required shape.

8. An elastic road bridge joint as claimed in claim 1, wherein said arcuate means is formed integrally with said section member and the section member has a pair ofinclined sides connected with a relatively wide angle to said arcuate means below the vertex thereof.

9. An elastic road bridge joint as claimed in claim 1, wherein said arcuate means is formed of a plurality of layers of resilient material placed one above the other.

10. An elastic road bridge joint as claimed in claim 1, wherein said section member is made of a plurality of individual plates placed one upon the other with alternate plates consisting of relatively hard material such as spring steel and resilient material such as rubber.

11. An elastic road bridge joint as claimed in claim 2, wherein said angle section member has a pair of inclined sides adjacent its vertex and the inclined sides are connected with a relatively wide angle to said horizontally extending flanges.

12. An elastic road bridge joint as claimed in claim 2, wherein said angle section member has a pair of inclined sides adjacent its vertex and a horizontal cross beam connects said inclined sides to each other.

13. An elastic bridge joint as claimed in claim 2, wherein said horizontally extending flanges extend laterally from the basis of said angle section member.

14. An elastic bridge joint as claimed in claim 2, wherein said horizontally extending flanges extend across the basis of said angle section member.

15. An elastic road bridge joint as claimed in claim 1, wherein said arcuate means and said section member are made of a single piece of resiliet material provided with a plurality of through holes arranged in an arc of a circle and delimiting the arcuate means and the section member with the holes forming the boundary line therebetween.

16. An elastic road bridge joint as claimed in claim 15, further comprising a pair of support flanges extending laterally substantially horizontally from the basis of a central body formed by said section member and said central body is provided in its lower central portion with a water discharge channel extending longitudinally through the joint and connected by smaller transverse channels to the basis of said central body adjacent said support flanges.

17. An elastic road bridge joint as claimed in claim 15, wherein said section member forms a central body of the joint and a hole extends longitudinally through the central body to accommodate cables.

18. An elastic road bridge joint as claimed in claim 15, wherein said section member forms a central body of the joint and a pair of relatively short side flanges extend from the central body for positioning and centering the section member when it is used for connecting vertical panels.

19. An elastic road bridge joint as claimed in claim 15, wherein a water collecting channel is provided upstream of the joint and extends parallel thereto and is connected by transverse channels to a central collecting channel formed below and extending longitudinally of the joint.

*ggggg v e CUNIITEII) STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent o- 3,838,93 Dated October 1. 197 I Inventor (S) ANGELO VALLA' It is'certified that error appears in the above-identified patent and that said Letteys Patent are hereby corrected as shown below:

Foreign Application Priority Data May 29, 1972 Italy. es5-2o7 A/72 october l3, l972 Italy. -12-957-A/72 ned and sealed this 3rd day of December 1974.

(SEAL) Attest: I

McCOY M. GIBSON JR. c. MARSHALL DANN Attesting Officer Commissioner of Patents

Claims

5. An elastic road bridge joint as claimed in claim 1, wherein said resilient watertight coating consists of approximately equal quantities of two different types of bitumen and calcium carbonate and about 15-20 percent by weight, on the basis of the total amount of bitumen used, of neoprene latex, one of said types of bitumen having a penetration index of 40-50 and the other a penetration index of 60-80.

8. An elastic road bridge joint as claimed in claim 1, wherein said arcuate means is formed integrally with said section member and the section member has a pair of inclined sides connected with a relatively wide angle to said arcuate means below the vertex thereof.