The subject matter of the invention is a system of pavement panels made of laminated composite plastic material having noise and vibration reduction properties consisting of coupled elements which can be applied for railway bridges of steel structure.

The plastic plate system according to invention can be applied to cover the area between rails, or between a rail and the edge of bridge structure on railway bridges to enable safe pedestrian traffic.

Covering of the same level with the rails is also applied on railway tracks.

The Hungarian published patent application of No. P0002071 describes a solution wherein the tracks are covered with panels preferably with reinforced concrete panels.

There are certain sections of railway lines, where the track goes along railway bridges of steel structure. It is necessary to cover spaces between the rails and between the rail and the edge of bridge structure with panels, which resist the load of pedestrian traffic. The panels should enable fastening equally to the wooden beams of bridge or sleepers and to the steel structure of the bridge.

Up to now striped steel sheet material was applied for covering.

The disadvantages of this solution are as follows: * The weight of applied striped steel panels loads considerably the bridge structure.

* The covering requires a considerable quantity of steel sheet material, the panels should be cut to required dimensions, drilled and welded on the building site.

The time of installation is long i. e. the track is closed and security guard with motorboat is required for long time during the installation on large bridges over a river by this reason. The waste of steel sheet material is relatively high.

* The steel panels resonate when railway vehicles pass they are therefore noisy.

* The materials and chemicals dropping from railway vehicles corrode the panels.

* The covering requires a considerable amount of maintenance because the panels should be regularly re-painted to avoid corrosion. The covering panels should be dismounted each time to paint them.

* The service life of the steel panels is short in comparison with that of the bridge because they are destroyed or corroded in 10 to 15 years even under regular maintenance.

* The panels corroding continuously on the hidden lower surface cause danger of accident because they become thin and they can suddenly break under the weight of a pedestrian.

* The disadvantage of the known solutions is furthermore that they do not provide vibration reduction of panels and do not include noise-reducing layer.

Our target is to develop a system of pavement panels, which comply with the following requirements.

* The vibration and the noise should be reduced for environment protection purposes.

* The dead weight of the bridge should be reduced to enhance its load-bearing capacity.

* The system should require small amount of maintenance.

* The material consumption for maintenance should be low.

* The installation time should be short.

* The weight of pavement panels should be small with high load-bearing capacity.

* The pavement panels should be weather resistant, their service life should be long.

* The surface of pavement panels should be proof against skid for the safety of pedestrian traffic.

The subject matter of the invention is a pavement panel design, which eliminates the disadvantages of known solutions using striped steel panels. The panels can be pre-fabricated easily and with high accuracy, they can be assembled easily and quickly on the building site and they fulfil the rest of the above mentioned requirements, as well.

The design of the system of pavement panels is based on the recognition that the surfaces for traffic should be covered by a system of joined elements, which were not used formerly for this purpose.

The outside shell layers of the elements should be made of reinforced plastic, advantageously of glass-fibre reinforced one to obtain a light but load bearing structure resistant against weather and chemicals.

The surface of the system of pavement panels is provided with special spikes and the elements have a shape, which enables them to build in either between the rails or into the space between the rail and edge of bridge structure.

The length of each element should suit to the spacing between the wooden beams of railway bridge and to the distances between steel elements of the bridge structure, as well. The elements should have adequate structure and thickness to provide the required load bearing capacity and resistance against footsteps. The mass of elements should enable to move and transport them by hand.

The above mentioned targets are reached by a system of pavement panels, which have advantageously green surfaces made of coloured material, and the going surface is covered with micro-spikes.

Consequently, the subject matter of the invention is a system of pavement panels consisting of joined layered plastic elements, applicable for railway bridges of steel structure.

The characteristic features of the system of pavement panels are as follows. The layered elements comprise a reinforced plastic upper shell layer having outer surface covered with micro-spikes, a lower reinforced plastic layer and a plywood core layer with a noise and vibration reducing layer bound onto its upper surface.

The lower shell layer is provided with a bent-up section for overlap slip joint on one edge serving for overlap slip joint and the same lower shell layer is provided with another bent-up section for butt joint on the edge of element serving for butt joint.

The upper shell layer is provided with a bent-down section on the edge serving for overlap slip joint. The elements are joined longitudinally with overlap slip joint, and

transversally with butt joint. Each element is provided with holes for the purpose of fastening to beams respectively to the elements of steel structure of the railway bridge.

The upper shell layer and the lower shell layer are made advantageously of glass fibre reinforced plastic, the core layer is made of plywood or of plywood layered with glass fibre fabric and impregnated with artificial resin, the noise and vibration reducing layer is made of a polymer filled with filling material, advantageously with barium sulphate.

It is advantageous to apply the plastic material of trade name PEMsBELL (produced by PEM9 Ltd. , HU) for the noise and vibration reducing layer.

The core layer and the noise and vibration reducing one are bound together advantageously by gluing.

Both the shell layers and the core layer can be, of course, made of other materials, too.

The structure according to invention is shown in the Figures 1 to 5.

The Figure 1 shows the system of pavement panels assembled from the elements.

The Figure 2 shows the underside view of an element The Figure 3 shows the topside view of an element The Figure 4 shows the section by"A-A"of an element The Figure 5 shows the section by"B-B"of an element.

The Figure 1 shows the system of pavement panels built up of the layered panels 1.

Each element comprises an upper shell layer 2, a lower shell layer 3, a core layer 4 with a noise and vibration reducing layer 5 bound advantageously by gluing to it.

One of the edges of the upper shell layer shaped for the overlap slip joint is provided with a bent-down section 7.

The lower shell layer is provided with a bent-up section 6 shaped for the overlap slip joint on one of its edges.

The upper shell layer 2 and the lower shell layer 3 of the element 1 are made advantageously of glass fibre reinforced plastic, advantageously glass fibre reinforced thermosetting material and the core layer is made advantageously of plywood.

The noise and vibration reducing layer is made of a polymer, advantageously a mixture of ethylene-vinyl acetate and polystyrene with a high percentage of filling material.

The mixture contains advantageously barium sulphate as filling material.

The noise and vibrationrreducing layer 5 can be made, of course of other material, too.

The upper shell layer 2 of the element 1 is provided with a bent-down section 7 on the edge shaped for the overlap slip joint.

The upper shell layer 2 is provided with a surface covered by micro-spikes 10 to provide a surface free of skid.

The Figure 2 shows the underside view of the layered element 1. The Figure shows the lower shell layer 3 provided with the bent-up section 6 on the one of edges shaped for the overlap slip joint. The Figure shows furthermore the bent-down section 7 of the upper shell layer 2 and the holes 9 made for fastening elements.

The Figure 3 shows the topside view of the layered element 1. The Figure shows the upper shell layer 2 with the bent-down section 7 on the one of edges shaped for overlap slip joint, of the element 1 furthermore the bent-up section 6 of lower shell layer 3 and the holes made for fastening elements in the element 1.

The upper shell layer is provided with a surface covered by micro-spikes 10.

The surface with micro-spikes 10 provides the element 1 with skid free properties.

The Figure 4 shows the section"A-A"of the layered element 1.

The parts of the element 1, the upper shell layer 2 made of glass-fibre reinforced artificial resin, the lower shell layer 3 and the core layer 4 made of plywood with the bound noise and vibration reducing layer 5 between them are shown in the Figure.

The two last mentioned layers are bound together by gluing.

The lower shell layer 3. is provided with a bent-up section 6 on the one of edges shaped for overlap slip joint of the elements 1.

The one of edges of the upper shell layer 2 shaped for overlap slip joint of elements 1 is provided with a bent-down section 7. Its surface is provided with micro-spikes 10.

The Figure 5 shows the section"B-B"of the layered element 1.

The parts of the element 1 the upper shell layer 2 made of glass fibre reinforced plastic, the lower shell layer 3, the core layer 4 made of plywood with the noise and the bound vibration reducing layer 5 between them are shown in the Figure.

The lower shell layer 3 is provided with a bent-up section 8 at the butt joint edge of the element 1.

The upper shell layer has a surface with micro-spikes 10.

The element 1 is provided with holes 9 for fastening elements.

According to an advantageous embodiment of the invention the lower shell layer 3 has plain surface, but a variant with surface covered by micro-spikes 10 of the lower shell layer 3 can be produced, as well.

The system of pavement panels is described by the Example 1.

Example 1 Layered panels 1 are manufactured having an upper shell layer 2 made of green glass-fibre reinforced plastic sheet material, resisting to weather and chemicals, wherein the plastic material is coloured and the surface of layer is provided with micro-spikes 10.

The one of edges of the upper shell layer 2 shaped for overlap slip joint is provided with a bent-down section 7.

The lower shell layer is also made of glass fibre reinforced plastic sheet material, resisting to weather and chemicals and the one of its edges shaped for overlap slip joint is provided with a bent-up section 6.

The core layer 4 made of plywood is between the shell layers. The noise and vibration reducing layer 5 is fastened by gluing to said layer.

The laminated element 1 provided with noise and vibration-reducing layer 5 reduces the noise level by at least 4 to 5 decibels.

The layered elements 1 are provided with holes 9 for fastening elements.

The layered elements 1 are self-supported.

The pavement panels are fastened advantageously with wood-screws to the wooden beams or sleepers and with coach screws of the company HILTI to the steel elements of bridge structure. The layered elements 1 are joined together transversally by butt joint, longitudinally by overlap slip joint. The overlap slip joint enables the elements to follow the dilatation movement of the bridge without tension in the pavement elements. This is supported by that holes of diameters greater than those of fastening wood screws or HILTI coach screws are made in the panels la for said screws.

The system of pavement panels according to invention can be applied for tracks of standard gauge and for those of narrow gauge, because the elements are manufactured by accuracy of millimetre and the dimensions can be adapted to any bridge.

The advantages of the system of pavement panel according to invention are as follows: * The building work on the site can be completed in short time.

* The elements can be moved and built in even by hand because of their small weight.

* It does not require painting.

* It can be applied to any system of tracks on any railway bridge.

* The fastening either to the wooden beams or to steel bridge elements is simple.

* It can be joined also the formerly built steel pavement sheets.

* It is resistant to physical or chemical loads, as well as to UV rays.

* It is applicable to cover any traffic zone according to requirement.

* It has long service life, its material does not age.

* Its walking surface is free of skid.

* It does not require maintenance.

* No waste material is produced at the mounting on the site.

* It has small weight, the load capacity of the bridge structure is higher and its service life is longer.

* The vibration caused by the trains is much smaller so their noise is much smaller, as well.

LIST OF THE NOTATIONS 1 Element 2 Upper shell layer 3 Lower shell layer 4 Core layer 5 Noise reduction layer 6 Bent-up section 7 Bent-down section 8 Bent-up section for butt joint 9 Hole 10 Surface with micro-spikes