Patent Application
20180016759
The invention relates to a bridge deck comprising a composite panel with a top plastic skin, a bottom plastic skin and a core between and attached to the plastic skins, and an edge beam on at least one edge of the composite panel.
Such a bridge deck is known. The composite panel thereof is often provided with steel edge beams at the edges. These steel edge beams may extend transversely to the longitudinal direction of the bridge deck, and conduct the forces which result from the weight of the bridge deck and the weight of the road traffic travelling over the bridge deck. The concentrated imposition forces which occur at the site of the support of the edge beam on the bridge support can therefore be distributed regularly over the composite panel. Also, such edge beams may be provided at the longitudinal edges of the composite panel.
Although a bridge deck produced in this way is ideal for heavy traffic, it is found however in practice that, in the long term, problems can occur at the site of the transition from the steel edge beam to the composite material of the bridge deck. These problems are partly caused by the fact that the steel edge beam has a greater stiffness than the composite material. The forces exerted on the bridge construction from the wheel loads of the road traffic therefore lead to uneven deformations occurring at the transition between the steel edge beam and the composite material. The steel edge beam deforms to a lesser extent than the composite material, such that the adhesion between the components is continuously subjected to alternating loads. In the end, the adhesion can fail.
The resulting crack formation in the surface of the bridge deck allows moisture to seep in, such that corrosion and further cracking can occur in frost.
It is therefore desirable to create an improved bridge deck. Furthermore, it may be desirable to create a bridge deck which is less susceptible to differences in deformation which occur between the steel parts and the composite parts thereof. It may also be desirable to create a bridge deck in which cracking under the influence of alternating loads is countered.
According to a first aspect of the invention, a bridge deck is provided comprising a composite panel with a top plastic skin, a bottom plastic skin and a core between and attached to the plastic skins, and an edge beam on at least one edge of the composite panel. The edge beam overlaps the core of the composite panel in the height direction, the top plastic skin has a protruding part which protrudes relative to the core, and the protruding part of the top plastic skin extends over and is attached to the edge beam.
In the bridge deck according to this aspect, the top layer of the composite panel is configured such that this layer extends relative to the core of the composite panel. The top layer, in contrast to the core, does not butt up against the steel edge beam but extends over this. The steel edge beam thus forms a component of the bridge deck which is fully concealed below the top layer of the composite panel. The top layer of the composite panel, in other words the protruding part of the top plastic skin, completely covers the edge beam. As a result, wheel contact only occurs on the surface of the top layer, resulting in a more uniform load development from the bridge deck to the adjacent abutment and vice versa.
In contrast to the known bridge decks, there are no significant differences in deformation, which helps to safeguard the integrity of the bridge deck. As a result, there is no or virtually no cause for crack formation, and seepage of moisture and local freezing are avoided.
The core may butt up against the edge beam or against a filling layer, such as an adhesive layer, with which the edge beam is coated or covered at least partially. In particular, the composite panel may comprise a bulkhead that delimits the core and where applicable the plastic skins, which bulkhead then lies against the edge beam or against a filling layer, such as an adhesive layer, with which the edge beam is coated or covered at least partially. Such a bulkhead is, however, not necessary. In the absence of a bulkhead, the bottom plastic skin and the core butt up against the edge beam or against the filling layer directly.
By means of the adhesive layer, the composite panel may be attached reliably and in a sealing manner to the steel edge beam. In addition, mutually aligned openings may be present in the protruding part of the top plastic skin and the edge beam. A peg or bolt may extend through each pair of an opening in the top plastic skin and an opening in the edge beam which are aligned to each other. If the edge beam has a top support surface on which the top plastic skin is supported, the openings may be located therein. The edge beam may comprise a top flange, and the support surface may be at least partially defined by this top flange. The openings may then be defined in this top flange.
Furthermore, the edge beam may have a bottom flange on which the bottom skin is supported. This bottom plastic skin and the bottom flange may also have mutually aligned openings; a peg may extend through each pair of an opening in the bottom plastic skin and an opening in the bottom flange.
In this way, a positive mechanical connection is ensured between the edge beam and the composite panel. In a preferred embodiment, the openings may form a row of pairs of openings. This row extends in the longitudinal direction of the edge beam. Of this row, at least one pair of openings and the associated peg cooperate closely so as to ensure a fixed position of the edge beam and the composite panel relative to each other. The other pairs of openings however have the form of a slot, the largest dimension of which is directed in the longitudinal direction of the edge beam, to compensate for the expansion differences between the edge beam and the composite panel.
At the free edge of the protruding part of the top plastic skin and the edge beam, an angle profile may be provided, one leg of which covers the top surface of the protruding part or a cover layer located on the protruding part, and the other leg of which extends along the border of the protruding part of the top plastic skin, the edge beam and any cover layer present on the protruding part. Such an angle profile offers further protection of the laminate of cover layer, top plastic skin and flange of the edge beam.
The edge beam may be configured with various cross sections. An example is an edge beam with a box section, relative to which the top flange and the bottom flange protrude. The openings for the bolt or peg may be located in the top flange but may also open into the box section. Other forms without box section, such as a Z-shaped edge beam, are however also possible.
According to another aspect, the invention concerns an edge beam for the bridge construction described above, comprising a top side and a bottom side, a front side for facing the composite panel and a back side opposite this, wherein the top side has a row of openings extending in the longitudinal direction, in each of which a peg can be received, wherein the front side is provided with a bottom flange which faces away from the back side, in which bottom flange a row of openings is located, in each of which a peg can be received.
The bottom flange is preferably at a non-zero distance from the top side and from the bottom side of the edge beam viewed in the height direction thereof. Furthermore, the top side of the edge beam may comprise a top flange which protrudes relative to the rear side of the edge beam and which faces away from the front side of the edge beam, in which top flange the row of openings is located. Preferably, the edge beam is box shaped, relative to which the top and bottom flanges protrude.
According to yet another aspect of the invention, there is provided a composite panel for the bridge construction as described above. The composite panel comprises a top plastic skin, a bottom plastic skin, and a core between and attached to the plastic skins. The top plastic skin has a protruding part which protrudes relative to the core.
A row of openings, in which a peg may be received, may be located in the protruding part of the top plastic skin. Also, the bottom plastic skin may contain a row of openings which runs parallel to the row of openings in the protruding part of the top plastic skin, wherein the distance between the row of openings and the edge of the core adjacent to the protruding part of the top plastic skin is of the same order of magnitude as the width of the protruding part.
Embodiments will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts.
The figures are meant for illustrative purposes only, and do not serve as restriction of the scope or the protection as laid down by the claims.
The following is a description of exemplary embodiments of the invention, given by way of example only and with reference to the figures.
The edge beam 9 has a bottom flange 24 on its front side 10. On the opposing back side 12 of the edge beam 9 is a top flange 14 which connects to the top side 11 of the edge beam 9. The bottom side 13 of the edge beam 9 has support ridges 15 with which the bridge deck 1 is supported on an abutment 2. Said top side 11, bottom side 13, front side 10, and back side 12 in the example shown define the box section, indicated as a whole as 26, with rectangular cross section. Other cross sections are, however, possible for this box section. Furthermore, cross sections are possible without box section, such as a Z-shaped edge beam.
The top flange 14 has a row of holes 16, as shown in the top view of
The top plastic skin 6 and the road surface 22 thus extend from the core 7 of the composite panel 5 continuously to the transition to the road surface 3 on the abutment 2. There will therefore be no wheel contact with the edge beam 9 so that a uniform transition for the wheel loads from the composite panel 5 to the abutment 2 is obtained. Differential deformation between the edge beam 9, which normally consists of steel, and the composite panel 5 consisting of plastic is thus reduced or even avoided, yielding a bridge construction with an improved resistance to fatigue.
An adhesive layer 25 may also be provided between the composite panel 5 thus formed and the adjacent surfaces of the edge beam 9. Although, in the exemplary embodiment shown, the edge beam 9 is located at the edge of the composite panel which faces the abutment, such edge beams may alternatively or additionally also be placed at the other edges of the composite panel.
It should be clear that the embodiments described above are described merely by way of example and are not in any way restrictive, and that various modifications and adaptations are possible without leaving the scope of the invention, and that the scope is determined only by the attached claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014337 | Feb 2015 | NL | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/NL2016/050126 | 2/22/2016 | WO | 00 |
