In particular the roadway portions and the kit serve for the production of a construc- tion road, that is to say a roadway on unconsolidated soil or unmade-up ground, on which transport vehicles and passenger vehicles can reach a construction site. Usually construction roads of that kind are in the form of a ballast track. In that case firstly the top soil is dug out or excavated to a depth of about half a metre and put into intermediate storage. Then a non-woven material is introduced and a ballast covering is deposited thereon and compacted so that the ballast track can bear the wheel loads required. After the building and construction operations are concluded the construc- tion road is removed again. Firstly the soiled ballast is removed and transported away. Then the top soil which had been put into intermediate storage is back-filled.

That procedure is relatively time-consuming and also cost-intensive because of the labour costs involved. It will be noted however that when producing a ballast track the material costs incurred are rather low.

For military applications, various apparatuses are known for producing a roadway on unconsolidated subsoil, such apparatuses generally being used for troop transport and for transporting supplies. The production of a so-called log road has been known for decades. For producing a log road beams of wood or tree trunks of approximately equal length are laid in closely mutually adjoining relationship transversely with respect to the roadway on the unconsolidated ground. Road-laying vehicles or tanks have also long been known, on which are arranged temporary roadways which are very quick to lay.

For example DE 32 41 104 concerns a ground covering, which can be rolled up, of a traffic-bearing surface for soft grounds, which comprises individual, pivotably interconnected plate-shaped carrier elements. The pivotal interconnection is

generally required in the case of roadways consisting of plate-shaped elements in order to avoid excessively high flexural moments in the roadway when a heavy transport vehicle causes the roadway to sink locally into the soft ground. That publication proposes plate-shaped carrier elements comprising extruded light metal or alloy profile members which in section in the longitudinal direction of the roadway are of a honeycomb structure. By virtue of the adoption of honeycomb light metal or alloy profile members the individual roadway elements can be rather light so that a large number of such elements can be transported at the same time.

Particularly rapid laying of the roadway is possible by virtue of the fact that the 'roadway elements can be rolled up. The adoption of extruded light metal or alloy profile members however results in the plate-shaped carrier elements involving very high manufacturing costs. The fact that the roadway elements are rolled up also increases the space required for transport of the individual roadway elements. As the individual rigid carrier elements are not flexible, on the one hand they must be rolled on to a core and on the other hand they must have gaps relative to each other.

For that reason only a rather short length of roadway can be transported on a transport vehicle. By virtue of the expensive aluminium extruded profiles and the need to use a special vehicle for transporting and laying the roadway, it is not possible for the apparatus described here to be used to produce a provisional roadway which is similarly inexpensive to a ballast track.

The same applies in regard to the subject of European patent EP 0 134 352 Bl.

Admittedly here the space required for transporting the roadway plates is rather small as they are not rolled but are folded together in a zig-zag shape so that they bear flat against each other. However, this device also involves the use of extruded profile members which involve very high roadway costs. Special apparatuses are also required, in particular a special container for transporting and laying the roadway.

The makeshift roadway disclosed in DE 36 16 671 C2, which comprises roadway panels which are pivotably interconnected in the transverse direction and in the longitudinal direction is also very much more expensive than a ballast track. In addition the roadway portions which are pivotably interconnected in two directions are very heavy to handle so that the operation of laying the roadway is a difficult one and takes up a rather long time.

GB 2 322 150 A describes portable roadway panels which are formed by plastic tubes which are loosely connected together. The plastic tubes are either threaded on to at

least two connecting cables or they are inserted with their ends into mutually oppo- sitely disposed C-shaped members of a frame. The portable panels proposed here, on the one hand by virtue of the use of plastic tubes and on the other hand by virtue of the loose interconnection of those tubes, do not in any way have the necessary stiffness to be able to carry heavy vehicles over a period of several weeks. Only the elements of the frames which hold the plastic tubes and which do not form a closed surface that may support a vehicle comprise metal profile members.

Further structural elements for producing temporary traffic routes are known from the documents US 1 035 927, CH 500 336, US 4 376 596, DE 41 24 837 A1, DE 34 13 790 A1, DE 31 40 222 Cl and US 5 402 941.

The object of the invention is to provide or a roadway portion for producing a roadway, which makes it possible to lay the roadway with sufficient stiffness to carry heavy construction vehicles at very low costs with a small labour force in a short time.

A further object of the invention is to provide a kit for inexpensively and rapidly producing such a roadway comprising said roadway portions.

Another object of the invention is to provide a method of inexpensively and rapidly producing such a roadway while involving a small labour force.

The object of providing the advantageous roadway portion is attained according to the invention in that the roadway portion has a plurality of mutually juxtaposed transverse profile members of metal which form the support surface for the wheels of vehicles, wherein the two ends of each of the transverse profile members are fixedly connected to a respective edge profile member.

In order to produce plate-shaped or slab-like roadway portions with an extremely high load carrying capacity for very low costs, they are made from individual metal profile members, in particular steel profile members, which are very inexpensive to produce in large quantities. The roadway portion comprises two edge profile members which preferably extend at the longitudinal edges and parallel to each other. The edge profile members impart rather high rigidity to the roadway portion in their longitudinal direction. The roadway portion further comprises a plurality of mutually juxtaposed transverse profile members which extend transversely with

respect to and between the two edge profile members. The transverse profile members form the support surface for the wheels of the vehicles which travel on the roadway. The transverse profile members are also preferably made of steel. The ends of the transverse profile members are suitably fixed to the edge profile members, for example by screw means or welding.

In a very simple and efficient embodiment of the invention the roadway portions are simply laid on the soft subsoil without any connecting means. The proper weight of the roadway portions or the load applied by vehicles travelling on the roadway portions causes them to sink into the ground. Thus, the roadway portions are fixed in their position simply by sinking in. However, in a preferred embodiment of the invention described below the several roadway portions form part of a kit further comprising connecting elements for pivotably interconnecting each roadway portion with the adjacent roadway portions.

Each edge profile member of the roadway portion preferably includes at least a vertical and a horizontal profile limb. Preferably the horizontal profile limb is arranged above the transverse profile members and rests on the edge portion thereof. The transverse profile members are preferably either welded or screwed to the edge profile member. When using screw means the horizontally extending limbs of the edge profile members should have through holes for receiving the screws.

The described preferred edge profile members in the form of an inverted L may be steel profile members which are rolled or bent to shape, of a gauge of at least 5 mm.

The transverse profile members can be selected according to the respective loading to be expected on the roadway. They preferably also include at least one horizontal profile limb which forms the support surface for the wheels of the vehicles and generally two profile limbs which are substantially vertical and which in practice are inclined slightly with respect to the vertical direction. The substantially vertical profile limbs ensure that the transverse profile member enjoys a high degree of flexural stiffness. An embodiment of the transverse profile member which can carry very heavy loads comprises for example a horizontal profile limb which is adjoined by two substantially downwardly extending profile limbs. That transverse profile member in the form of an inverted letter'U'is preferably also made of steel. In that arrangement the U-shaped transverse profile members are disposed in mutually juxtaposed relationship as closely as possible and without clearance so that the edges

of two adjacent transverse profile members are in mutually closely adjoining relationship. It is possible in that way to prevent a transverse profile member suffering deformation in the case of temporary overloading thereof. Deformation of that kind would result in the edge of the transverse profile member bulging out, this being prevented by the adjoining edge of the adjacent transverse profile member. In addition this arrangement closes the gap between two transverse profile members.

That prevents soft marshy ground being pushed under the effect of a heavy load on the roadway portion through intermediate spaces between the transverse profile members to the surface of the transverse profile members and soiling the wheel support surface. The edges of mutually adjoining transverse profile members can be joined together by spot welds.

An alternative embodiment of the transverse profile member has two horizontal profile limbs having downwardly angled outer edges. Arranged between the inner edges of the two horizontal profile limbs is a U-shaped central portion with two substantially vertical profile limbs. A steel profile member of that kind is produced in very large quantities as profile members for crash barriers on motorways and expressways. By virtue of the purpose of use as a crash barrier, that profile has a very high level of stiffness. It is further very inexpensive by virtue of the large quantities produced. The use of that profile member thus makes it possible to manufacture rigid roadway portions at extremely low manufacturing costs. In this case also it is advantageous for the adjacent edges of two successive transverse profile members to be disposed in closely mutually juxtaposed relationship so that those edges bear against each other and the edges are prevented from bulging out when a high loading is applied. The mutually adjoining edges of two transverse profile members can also be welded to each other.

Both the edge profile members and also the transverse profile members can be rolled to shape. A very high level of dimensional stability with extremely low production costs can be achieved by both profile members comprising cold-formed steel plates. For example a steel plate with a thickness of about 6 mm (1/4") can be bent over either around one edge or around two edges, in one working stroke. In the former case the result is an L-shaped profile member which can be used as an edge profile member. In the second case the result is a U-shaped profile member which can be used as a transverse profile member. In order to achieve inexpensive manufacture and a long life for the roadway portions, the transverse profile

members and the edge profile members preferably comprise steel plates which are bent over, of that kind.

As mentioned, the edge profile members may be welded to the ends of the trans- verse profile members. This results in very stable roadway portions, at very low manufacturing costs. It will be noted however that it is expensive to replace a transverse profile member if it is damaged in the course of use.

For that reason as an alternative it is proposed that the transverse profile members are screwed to the edge profile members. That permits a damaged transverse profile member to be very easily replaced. It is only necessary to release the screws which join that transverse profile member to the edge profile member. Furthermore, when using screw-fixed profile members, it is possible to ship prefabricated parts for producing the roadway portions of the kit according to the invention, with a very small transport volume. The profile members can be arranged in the non-screwed condition stacked one upon the other on pallets or in containers and shipped to their location of use. It is only at an assembly location near the location of use that the transverse profile members are screwed to the edge profile members. The finished roadway portions are then transported by. any suitable transport vehicle to the location for laying the roadway and can be laid in accordance with the method described hereinafter.

The disadvantage of screwing the profile members together lies in the rather high material and labour costs which are involved when producing the screw holes in the edge profile members and in the transverse profile members and when fitting the screws and screw nuts.

Preferably the roadway portions according to the invention are between 2 and 4 m in width and between 2 and 5 m in length. They can be transported to the building site with any suitable transport vehicle. There is no need for special vehicles as are required for example for laying roadways which are rolled up or folded together, as in accordance with the state of the art. Depending on the respective dimensions of the vehicles and the roadway portions, the roadway portions can either be laid flat on the load surface of the vehicles or they can be placed on edge on the load surface. If the width of the roadway portions is greater than the maximum permissi- ble width of a load on the transport vehicle, the roadway portions can be loaded

with their width in the longitudinal direction of the vehicle, and turned during the laying procedure.

At least one strap or hoop member is preferably welded between two transverse profile members of a roadway portion. A chain or a hook can be fixed to that strap or hoop member in order to lift the roadway portion with a crane jib. Preferably, mounted in the four corner regions of each roadway portion are straps or hoop members to which a hook or a chain can be fixed. That ensures that the roadway portion can be lifted in the required position by the crane jib.

Preferably the roadway portions are laid on the unconsolidated ground in such a manner that the edge profile members extend in the longitudinal direction of the roadway to be constructed. Each pair of wheels on the axis of a vehicle will successively roll over each of the juxtaposed transverse profile members of each roadway portion. However, it is alternatively possible to position the roadway portion in such a manner that the edge profile member extends in the transverse direction of the road. In this case each edge profile member forms a transversely extending front and back edge of the roadway portion. The profile members extending transversely to the edge profile members and forming the support surface then extend in the longitudinal direction of the roadway to be constructed.

Preferably at least the upper support surface of each transverse profile member is provided with a non-skid surfacing. That is preferably applied by sand being sifted into the wet paint on the transverse profile member, to increase the roughness of the surface.

A further aspect of the invention concerns a kit for producing a roadway on unconsolidated ground comprising several of said roadway portions which are to be arranged in succession and further comprising connecting elements which pivotably interconnect two adjacent roadway portions. The connecting elements avoid the danger of displacement of a roadway portion in case of a lateral force applied. They further keep the roadway portions from excessively sinking into soft portions of the unconsolidated subsoil. If one roadway portion is positioned on a particularly soft ground section the vertical forces applied by vehicles crossing this element may be partly carried by the connecting elements.

Particularly with the aim of providing an especially inexpensive and rapid laying method which is described hereinafter, the connecting elements are preferably easily releasably fixed to at least one of the two roadway portions fixed thereto. In that way the roadway portions can be separated from each other for transportation and for easy handling during the laying procedure. They can be arranged in a condition of being stacked one upon the other or bearing flat against each other in the course of transpor- tation. Handling of the roadway portions in the laying procedure is simple as they are not non-releasably connected to further roadway portions but may be moved individu- ally into the laying position. It is only in the laying operation that they are connected to the adjoining roadway portion by the easily releasable fixing.

A connecting element is preferably mounted at each end of an edge profile member to provide the pivotable connection of two adjacent roadway portions. The connect- ing element is connected to the adjoining end of the edge profile member of the adjacent roadway portion. Preferably at least one of the connections is rotatable in that case. In a preferred embodiment the connecting element can be releasably and rotatably fixed to both adjoining edge profile members. The connecting elements should also be produced as inexpensively as possible. Preferably the connecting elements are in the form of steel bars or plates carrying two pins, wherein each end of an edge profile member has a through hole into which one of the two pins can be fitted. The pins are prevented from being pulled out or falling out of a through hole, by securing elements. The securing element used can be any means which can be fixed to a pin and which engages behind the edge of the through hole. For example it is possible to use securing split pins. The pins on the plates may also have screwthreads on to which securing nuts can be screwed. Finally, resilient securing elements can be fixedly mounted to the pins on the plates, which when the pins are fitted into the through holes spring outwardly and engage behind the edges of the through holes. It is sufficient for only one pin to be provided with a securing element. In practice, a roadway portion is lifted by a crane jib and lowered until its lower edge is located closely above the free edge of an adjacent roadway portion that lies on the ground. The pins on the connecting element are inserted in the through holes of both the roadway portion on the ground and the lifted roadway portion. The bottom side of the lifted roadway portion is well accessible for a worker. Therefore, the securing split pin may be exclusively mounted to the pin on the connecting element which is fixed to the lifted roadway portion.

It is not necessary to fixedly arrange the pins on the plates of the connecting elements. For example, the plates may alternatively be provided with. holes which can be brought into alignment with the through holes in the edge profile members, in which case a separate pin can be fitted simultaneously through both holes.

However the preferred use of connecting elements with fixed pins tends to be more cost effective and easier to handle.

Alternatively the connecting element can be welded at one end to an edge profile member so that it is permanently connected to a roadway portion and only the connection to the second roadway portion is releasable. In this case also preferably the releasable connection is implemented by means of a securing pin which at the same time defines the pivot axis for the pivotal movement of the mutually adjoining roadway portions.

In order to produce a curve in the construction road, it is preferred to use connect- ing elements whose ends are pivotable relative to each other about a vertical axis.

Preferably those connecting elements have a divided bar or plate, the portions of which are connected together pivotably by means of a hinge pin. The plate of the connecting element is disposed in the plane of a longitudinally extending edge profile member of a roadway portion. Thus the two roadway portions which are connected together by that pivotable connecting element can involve longitudinal directions which extend inclinedly relative to each other. That pivotable connecting element forms the inner region of a bend in the roadway. By virtue of the pivotal movement, the edge profiles of the roadway, which are in the outer region of the bend, move away from each other. For that reason, an extension member should additionally be provided, which can be fixed to at least one pivotable connecting element. The second end of the extension member can be fixed either directly or by way of a second pivotable connecting element to the edge profile of the second roadway portion. In that way, using means which are very simple and easy to handle, it is possible to achieve a bend in the longitudinal direction of plate-shaped roadway portions which are pivotably connected together. The extension members can be for example telescopically displaceable or they may have a plurality of fixing holes which are arranged in mutually juxtaposed relationship in the longitudinal direction so that they are adjustable in length. It is possible in that way to set any angles in a given range of angles, between each two successive roadway portions.

The invention further concerns a method of producing a roadway on unconsolidated ground. Preferably the kit in accordance with the foregoing configurations is used in carrying out that method.

The method includes the following steps: a) transporting a plurality of plate-shaped roadway portions on a transport vehicle to the location at which the construction road is to be laid; b) lifting a roadway portion with an excavator or other crane jib; c) lowering the lower transverse edge of the roadway portion into the proximity of the ground; d) laying down the lifted roadway portion; e) moving the transport vehicle and the excavator or other crane jib in the laying direction; and f) repeating steps b) through e).

In a preferred embodiment of the method a lifted roadway portion is pivotably connected to a roadway portion which has already been laid. In an alternative embodiment the roadway portion may be laid without connection to the adjacent roadway portions. In that case the roadway portion is preferably charged with a weight in order to sink projections on the bottom side of the roadway portion into the unconsolidated ground.

As mentioned the individual plate-shaped roadway portions can be transported to the building site with any transport vehicles. Special vehicles are not required. In general an excavator is used as the first working apparatus on building sites. The excavator can individually lift the roadway portions off the transport vehicle and lower them into the proximity of the ground. A worker can readily pivotably connect the lower transverse edge of the lowered roadway portion to the adjoining transverse edge of a roadway portion which has already been laid, if this is necessary. In that operation, aligning the roadway portions relative to each other can be implemented without any problem as the weight of the lifted roadway portion is being carried by the excavator.

0 The lifted roadway portion has to be roughly aligned by the excavator driver with the roadway portion which has already been laid. The worker can precisely align the lifted roadway portion by hand and fit the connecting element or elements to produce the pivotable connection. The connected roadway portion is then set down by the excavator. The transport vehicle then moves on the roadway which has just now been laid by the length of a roadway portion in the laying direction, that is to say towards

the front end of the laid roadway. The excavator also travels in the laying direction approximately by a distance corresponding to the length of a roadway portion. Steps b) through e) are then repeated until all roadway portions have been lifted down from the transport vehicle and laid. After the laying procedure the transport vehicle preferably moves away from the laying location. If the roadway has not yet attained the desired length, another transport vehicle or the same re-loaded transport vehicle advances on the previously laid roadway to the end thereof, that is to say to the laying location.

In principle the excavator or a crane jib which is similar to the jib arm of an excavator can also be a fixed component part of the transport vehicle. The operation of lifting the roadway portion only requires a motor-actuated and in particular hydraulically actuated lift arm which, like the jib arm of an excavator, is suitable for lifting, moving and setting down the load of the roadway portion. If a transport vehicle comprising a lift arm of that kind is used for transporting the roadway portions, it will be appreciated that this lift arm can be used for unloading the roadway portions.

The described laying method can be implemented at very low labour costs and at a very high laying speed. Only the driver of the transport vehicle, if necessary the driver of the excavator and a worker who guides the lifted roadway portions into place by hand are required. If necessary the worker may also produce the pivotable connections. The excavator can be provided with an automatic gripping tongs unit which grips the roadway portions carried on the transport vehicle, without human intervention. The excavator driver then lifts the roadway portions off the transport vehicle and moves the excavator in such a way that the lower transverse edge of the roadway portion to be laid is moved into the proximity of the free transverse edge of a roadway portion which has already been laid. The worker can manually align the two roadway portions relative to each other and fit the connecting elements.

After the roadway portion to be laid has been lowered and after the gripping tongs unit has been released, the vehicles can be displaced by the length of a roadway portion. The laying procedure is repeated with the next roadway portion.

The operation of pivotably connecting two mutually adjoining roadway portions is preferably effected by manually inserting pins which are mounted on connecting elements into through holes which are provided in the end region of the roadway portion, preferably in an edge profile member. Alternatively, separate pins can be

fitted through holes in the plate-shaped connecting elements and through the through holes in the edge profile member.

In addition, the pivotal connecting operation preferably includes fitting securing elements which prevent a pin which has been fitted through a through hole from dropping out or being pulled out. The securing elements are preferably of the kind described hereinbefore. As mentioned above, it is sufficient to have one securing element for each connecting element in order securely to lock the connecting element in both through holes in the mutually adjoining roadway portions. If the connecting element is fixedly arranged on a roadway portion, it is possible to entirely omit a securing element as the laid roadway portions cannot move relative to each other.

As already mentioned, the roadway portions are preferably transported to the laying location in a condition of bearing flat against each other, either on edge or lying flat on the load surface of the transport vehicle.

For the purposes of producing curves, the worker preferably inserts a connecting element between two mutually adjoining roadway portions, the ends of the connect- ing element being pivotable relative to each other about a vertical axis. Disposed in the region of the inside radius of a curve or a change in direction is a short connect- ing element. A long connecting element is disposed in the region of the outside radius. The long connecting element is preferably formed from two short pivotal connecting elements. Alternatively, a short pivotal connecting element can be joined to a rigid extension member to form a long connecting element. Particularly preferably, the long outer connecting element is formed by two pivotal connecting elements, between which is arranged a rigid extension member.

As mentioned above, the roadway portions may also be laid without any intercon- nection if the condition of the subsoil is appropriate for holding the roadway portion in their position. The bottom side of roadway portions described above mainly consists of thin edges of the profile members extending in the longitudinal and in the transverse direction. These edges form projections on the bottom side of the roadway portions which may be pushed into the soft ground. To some extent the edges are already pushed into the ground by the proper weight of the roadway portions. During the installation procedure and use of the roadway the roadway portions are charged with the weight of the vehicles travelling across the roadway.

This weight will push the edges further into the soft ground. These sunk in projec-

tions on the bottom side of the roadway portions localize them in place and avoid any undesirable displacement of the laid roadway portions.

Finally, the invention concerns the use of a roadway portion for producing a roadway on unmade-up ground comprising the following features: two edge profile members of metal; a plurality of mutually juxtaposed profile members of metal which extend transverse with respect to the edge profile members and which form the support surface for the wheels of vehicles; 'connecting means for fixedly connecting the two ends of each of the transverse profile members to a respective edge profile member.

The terms'horizontal'and'vertical'used in this description relate to the orientation of a roadway portion laid on a horizontal surface. Therefore'horizontal'essentially denotes a direction parallel to the surface of the ground on which the roadway portion is laid. In that respect'vertical'essentially denotes a direction which is perpendicular to the horizontal plane. It is clear to the man skilled in the art that, in the transport condition of the roadway portions, the actual orientation of the direction identified by'horizontal'and'vertical'can change. Further, especially the vertical portions of the transverse profile members can deviate through a certain angle from a direction extending precisely at a right angle to the horizontal plane.

Embodiments of the invention are described hereinafter with reference to the accompanying drawings in which: Figure 1 shows a side view of a transport vehicle and an excavator when laying a roadway in accordance with the method according to the invention using a kit according to the invention, Figure 2 shows a rear view of the transport vehicle of Figure 1, Figure 3 shows a perspective view of two roadway portions which are to be connected together, Figure 4 shows a side view of the roadway portions of Figure 3, Figure 5 shows a plan view of the roadway portions of Figure 3, Figures 6-8 show three embodiments of connecting elements for connecting two roadway portions,

Figure 9 shows a plan view of the interconnected edge profile members of two roadway portions with an alternative embodiment of a con- necting element, Figure 10 shows a side view of the two roadway portions of Figure 9, Figure 11 shows a view in section of a first embodiment of a transverse profile member which is fixed to an edge profile member of a roadway portion, Figure 12 shows an alternative embodiment of the fixing of the transverse profile member of Figure 11 to the edge profile member, Figure 13 shows an alternative embodiment of the transverse profile mem- bers, Figure 14 shows a plan view of mutually adjoining roadway portions as shown in Figure 13, which form a change in direction, Figure 15 shows a perspective view of a pivotable connecting element, Figure 16 shows a perspective view of an extension member, Figure 17 shows a view corresponding to Figure 1 of a transport vehicle with an integrated crane jib when laying a roadway in accordance with the method according to the invention using a kit according to the invention, and Figure 18 shows a plan view of an alternative embodiment of a roadway produced using a kit according to the invention.

Figures 1 and 2 show the principle of the method according to the invention for laying a construction road. The construction road comprises a plurality of roadway portions 1 which are connected together pivotably about a pivot axis by means of connecting elements 2. The pivot axis extends substantially parallel to the transverse edge of the roadway portions. A plurality of the plate-shaped roadway portions 1 are arranged in succession on the load surface of a transport vehicle 3. The transport vehicle 3 transports the roadway portions 1 to the laying location at which the construction road is to be built. An excavator 4 is used for lifting a respective roadway portion 1 carried on the load surface and for lowering that roadway portion 1 into the proximity of the ground. An excavator 4 is in principle to be found on any building site as the first item of construction machinery, in order to begin with the excavation operations.

A cable 6 with a tongs unit 7 which grips the upper edge of the roadway portion 1 for lifting and lowering the roadway portion 1 is fixed to the excavator bucket 5.

The roadway portion 1 is moved by the excavator driver into the direct proximity of the free transverse edge of the roadway portion 1 which has already been laid. In that position, a worker can fit on each of the two sides of the roadway portion 1 a respective connecting element 2 which forms a pivotable connection between the lifted roadway portion 1 and the roadway portion 1 which has already been laid.

The excavator 4 then lowers the lifted roadway portion 1 and the worker can release the tongs unit 7 from the free transverse edge of that roadway portion 1. The transport vehicle 3 and the excavator 4 travel by a distance which approximately corresponds to the length of a roadway portion 1 in the laying direction which is illustrated by the arrow 8. The tongs unit 7 of the excavator 4 then grips a fresh roadway portion 1, lifts it off the load surface of the transport vehicle 3 and lowers it until its lower transverse edge is in the proximity of the ground.

That laying procedure is repeated until all roadway portions 1 have been lifted down from the load surface of the transport vehicle 3. If then the length of the construc- tion road produced is not sufficient, a further transport vehicle which is loaded with roadway portions 1 can travel over the construction road to the laying location.

Figures 3 through 5 show a first embodiment of the kit with which the construction road is produced. The kit includes a plurality of roadway portions 1 according to the invention which are connected together by way of connecting elements 2 which function in a similar manner to a chain connecting link for bicycle or motorcycle chains. The connecting element 2 substantially comprises a flat steel plate on which two mutually parallel pins are formed.

Each roadway portion 1 comprises two edge profile members 10 extending in the longitudinal direction and six transverse profile members 11. The transverse profile members 11 extend in mutually parallel relationship and at a small spacing side-by- side. The edge profile members 10 include a horizontal limb 12 and a vertical limb 13. Through holes 14 are provided in the vertical limb 13, near the two ends of the edge profile member 10. As can be seen from Figure 3, the pins 9 of a connecting element 2 can be fitted into the through holes 14 which are arranged in the adjacent ends of the edge profile members 10 of two mutually adjoining roadway portions 1.

As can be seen from Figures 4 and 5 the two roadway portions 1 are securely connected together by the pins 9, wherein each roadway portion 1 is pivotable about the pin 9 fitted into the through hole 14 of its edge profile member 10.

In order to prevent the connection of adjacent roadway portions 1 from coming undone, the pins 9 of the connecting elements 2 are preferably secured to prevent them from falling out. Any suitable securing elements can be used for that purpose.

Figures 6,7 and 8 show by way of example resilient securing split pins 15, securing nuts 16 which can be screwed on to threaded portions of the pins 9, or securing springs 17 or a resilient ball element 18 which secures the pins 9 to prevent them from dropping out. The split pins 15 (Figure 6) and the securing nuts 16 (Figure 7) have the advantage that they prevent the pins 9 from slipping out of the through holes 14 by positively locking engagement and thus in an absolutely reliable fashion. In regard to the resilient securing elements 17 and 18 in Figure 8 a sufficiently high holding force must be produced by the securing elements 17,18 in order to prevent the pins 9 from unintentionally slipping out of the through holes 14.

Figures 9 and 10 show an alternative embodiment of a connecting element 2'. Here, the plate-shaped connecting element 2'is fixed at one end to the vertical limb 13 of the edge profile member 10, by means of a weld seam 19. Only the second end of the connecting element 2'has a pin 9'. That pin 9'forms a separate component and projects through a hole in the free end of the plate-shaped connecting element 2'and the through hole in the vertical limb 13 of the edge profile member 10 of the second roadway portion 1. On the outward side the pin 9'has a plate-like head 32 which prevents it from falling through. On the inward side, i. e. within the vertical limb 13 of the edge profile member 10, the pin 9'is secured by a securing split pin 15.

Figures 11 through 13 show some details of the structure of the roadway portions 1.

Figure 12 shows the structure of the roadway portions 1, which is to be seen in the preceding Figures. Each roadway portion 1 comprises two edge profile members 10 which are in the shape of an inverted'L'. Fixed to the edge profile member 10 are six transverse profile members 11 which are in the shape of a'U', with two adjoining, substantially horizontal limbs 22,23. The two horizontal limbs 22,23 form the support surface for supporting the wheels of the vehicles which travel on the construction road. The limbs 20,21 which extend substantially in a vertical direction provide for the necessary flexural rigidity of the transverse profile members 10. The particular profile shape shown in Figures 11 and 12 was adopted because it is produced in the form of a rolled steel profile member in very large amounts for the production of crash barriers on motorways or expressways. In that manner, a roadway portion can be extremely cheaply produced using a plurality of inexpensive transverse profile members 11. As shown in Figure 12 the transverse

profile member 11 can be welded to the longitudinal profile member 10. Alterna- tively and as shown in Figure 11 connecting screws 24 can be fitted through screw holes in the horizontal limbs 12 of the edge profile members 10 and through screw holes in the horizontal limbs 22,23 of the transverse profile members 11 to make the connection. A cap nut 25 is screwed on to the screwthreaded bolt of the connecting screw 24 at the underside.

The screw construction shown in Figure 11 is somewhat more costly than the welded construction shown in Figure 12. It does however afford the advantage that defective transverse profile members 11 can be replaced by simply releasing four connecting screws 24. For export purposes it is also useful to transport the trans- verse profile members 11 separately from the longitudinal profile members 10.

During transportation, the transverse profile members 11 can be stacked one upon the other to save a very great amount of space. Assembly of the transverse profile members 11 to the edge profile members 10 is effected only near the location of use of the roadway portions 1.

Figure 13 shows an alternative embodiment of a transverse profile member 11'which is in the shape of an inverted'U'. Such a simple profile member can be produced in any gauge sizes and can be used for carrying very high weights. In that respect, the upwardly directed surface of the inverted'U'forms the support surface of the roadway portion 1. The two lateral limbs of the U-shaped transverse profile member 11'extend substantially vertically, that is to say in practice they are inclined slightly relative to the vertical direction. It can be seen from Figure 13 that, unlike Figure 4, the edges of the vertical limbs of two adjacent transverse profile members 11'lie closely against each other. That improves the load-bearing capability of the roadway portion 1. If a transverse profile member of the roadway portion is subjected to a short-term overloading due to a particularly heavy construction vehicle, the horizontal portion threatens to buckle downwardly, in which case the edges of its two substan- tially vertical limbs bulge out, that is to say they curve outwardly. That bulging is avoided by the edge of a first transverse profile member 11'coming to bear against the edge of an adjacent transverse profile member.

The bottom side of the roadway portion 1 of Fig. 13 consists mainly of the lower edges of each edge profile member 10 and the lower edges of each transverse profile member 11'. The single edges of the edge profile members 10 and the outer transverse profile members 11'are very thin and measure approximately 6 mm

Even the twin edges of two adjacent transverse profile members 11'which are welded together are relatively thin (approx. 12 mm). The edges of the profile members 10,11'form projections on the bottom side of each roadway portion 1 which sink into the ground if the each roadway portion 1 is laid on soft soil due to the loads applied to said roadway portion 1.

In addition, Figure 13 shows a short bar or strap 34 of steel which is welded near the edge profile member 10 between the two outer mutually juxtaposed transverse profile members 11'. As can be seen from Figure 14, a strap 34 is provided in the region of each corner of a roadway portion 1. Between two respective outermost transverse profile members 11'of the roadway portion 1, a strap is welded in position in the two outer regions, near the two edge profile members of the roadway portion 1. It is possible to fix to the strap 34 a loop or a hook which is connected to the jib arm or crane jib for lifting the roadway portion 1. Such a strap 34 consists of a rod steel which is at least 10 mm thick and which is welded between the transverse profile members 11'. It is therefore readily suited to bear the weight of the roadway portion 1. It is also possible to weld between the transverse profile members a slightly curved strap, that is to say a hoop member. That gives more space for passing the hook or the loop therethrough. However, the hoop member must not project excessively far out of the support surface of the roadway portion 1 so that the tyres of the vehicles travelling on the roadway portion cannot suffer damage.

Figures 14 through 16 show the elements of the kit according to the invention, which permit the production of curves or changes in direction in the longitudinal direction of the roadway portions 1. The roadway portion 1 at the extreme right involves a longitudinal direction which is angled through about 20° with respect to the adjoining roadway portions 1. That angular diversion or curve is achieved by using a connect- ing element 26 whose ends are pivotably connected together by a hinge pin 27 which forms a vertical axis. As can be seen from Figure 15, the connecting element 26 comprises two steel elements which have the plate-shaped end regions 28,29 and bearing bushes 33 for receiving the hinge pin 27. A long hinged connecting element is used in the region of the outside radius of the curve. For that purpose, inserted between the two ends 28,29, which are pivotable relative to each other, of the connecting element 26, is an extension member 30 which has bearing bushes 33 arranged in complementary relationship with the bearing bushes 33 of the respective ends 28,29. The length of that extension member 30 can be so selected as to afford the desired angle between the longitudinal directions of two successive roadway

portions 1. Ballast can be filled into the triangular portion 31 which is formed between two roadway portions 1 which are joined at an angle, in order to prevent the wheels of a transport vehicle moving on the roadway from sinking in.

Figure 17 clearly shows that an excavator is not required and the lift arm for lifting the roadway portion 1 can also be a crane jib 35 which is integrated in the transport vehicle 3'or other lifting arm. It will be apparent that it can perform the same function as the jib of the excavator in the laying method according to the invention.

Fig. 18 shows an alternative embodiment of a roadway produced with a kit accord- ing to the invention. In this embodiment the edge profile members 10 of each roadway portion 1 extend transverse to the longitudinal direction of the roadway.

The transverse profile members 11'extend transverse to the edge profile members 10 and thus parallel to the longitudinal direction of the roadway. In this case the connecting element 36 is arranged between the front and back edge of two adjacent roadway portions 1. The connecting element 36 resembles a cylindrical hinge such as used for doors and windows. The dimensional stability of the roadway is not noticeably influenced by the orientation of the profile elements. The driving comfort for the vehicles using the roadway may be enhanced in this alternative since the wheels remain on the transverse profile members 11'for a longer time compared to the previous embodiment where the wheels cross the transverse profile members 11' widthwise. The different options for arranging the roadway portions 1 enable the worker to install roadways with different widths if the surface of the roadway portions is not a square but rather a rectangle with different dimensions lengthwise and widthwise.

It is also possible to install the roadway portions 1 without installing the connecting elements 36 (Fig. 18) or 2 (Fig. 3). Especially for short temporary use the roadway portions 1 may simply be placed on the ground as single slabs independently from any adjacent roadway portion 1. The roadway portions 1 measure more than 2 m in length and in width. Their considerable weight ascertains that they do not move, even without connection elements. They rather tend to sink in to the soft ground and thus be additionally fixed in their location.

List of references: 1 roadway portion 2,2'connecting element 3,3'transport vehicle 4 excavator 5 excavator bucket 6 cable 7 tongs unit 8 laying direction 9 pin 10 edge profile member 11,11'transverse profile member 12 horizontal limb 13 vertical limb 14 through hole 15 securing element, securing split pin 16 securing element, securing nut 17 securing element, securing spring 18 securing element, resilient ball element 19 weld seam 20 vertical limb 21 vertical limb 22 horizontal limb 23 horizontal limb 24 connecting screw 25 cap nut 26 connecting element 27 hinge pin 28 first end 29 second end 30 extension member 31 triangular portion 32 plate-like head 33 bearing bush 34 strap 35 crane jib, jib arm 36 connecting element