PLATE-SHAPED CONSTRUCTION ELEMENT
The invention relates to a plate-shaped construction element comprising a frame that extends over a large part of said construction element, which frame includes recesses, so that the frame allows water to pass through. The term recesses is understood to mean openings in the frame, which openings extend between the two surfaces of the construction element.
A floor which is sufficiently strong to walk on and/or sufficiently strong to carry a vehicle, and which must also allow water to pass through to prevent pools of water forming thereon, can be made up of a grid. Such a grid may be built up of metal strips, which have their width in vertical direction and which enclose square recesses. Such grids are known, and they are sufficiently strong to walk on, whilst their are supported along their edges.
Such grids are especially used outdoors, where they form the treads of a stairway or a platform, for example, on which rain water must not remain. Such construction elements can also be used inside a building, for example to form a floor which people can see through, at least locally.
One drawback of such a construction element may be the fact that it is difficult to walk thereon with stiletto heels and that pets do not find sufficient support for their legs thereon. Also the fact that the construction element is transparent, at least in those places where people walk, may be a drawback, especially for persons who suffer from a fear of heights. Also the hard and sometimes slippery surface can be considered to constitute a drawback under certain circumstances.
The object of the invention is to provide a construction element which allows water to pass through and which does not exhibit one or more of the aforesaid drawbacks . Another object of the invention is to provide an aesthetically attractive construction element, which can readily be produced in various colours and which may or may not be locally non-transparent .
In order to accomplish that objective, a porous material has been bonded to the frame, which makes the frame non- transparent, at least locally, because the porous material obstructs the view through recesses . Furthermore the porous material forms an additional support for persons and objects that are present on the construction element. In addition it makes the surface of the construction element non-slip, which is important especially in wet weather conditions.
The frame may be a metal plate provided with recesses (openings) . Preferably, the frame consists at least partially of a metal grid, which is entirely or partially filled with said porous material . The grid may comprise metal strips, whose width direction extends perpendicularly to the plane of the plate-shaped construction element, which adds to the stiffness and the strength of the construction element.
The frame may comprise parts, such as the aforesaid strips, which measure more than 15 mm, preferably more than 25, more preferably more than 35 mm, in a direction perpendicularly to the plane of the construction element. The frame, which can give the porous material additional strength, can thus obtain the stiffness that is required for the construction element in question.
Furthermore, the aforesaid parts may at least locally have a dimension of less than 5 mm, preferably less than 4 mm,
more preferably less than 3 mm, in the plane of the construction element. Metal strips of this dimension exhibit adequate resistance to bending in vertical direction whilst they enable a relatively light construction of the frame.
The grid may also comprise plate-shaped metal parts that extend at an angle relative to the plane of the construction element. Said parts may be present under the porous material, so that said porous material is supported by said parts .
The frame may comprise plate-shaped metal parts, or strips, for supporting the porous material, which strips are provided with embossments, that is, material moved outside the plane of the plate-shaped part. An embossment may consist of material that has been moved outside its original plane by means of a stamping operation.
Preferably, the porous material is substantially a plastic material, and said porous material is a flexible and/or elastic material, such as rubber. In one preferred embodiment the porous material is a granular material, which consists of bonded-together grains, for example of a rubber or of a plastic similar thereto.
In one preferred embodiment the porous material is at least partially from used car tyres, which have been shredded into grains . The grains may be bonded together and to the frame by means of a polyurethane resin or a similar substance, which appears to provide a sufficiently strong bond.
Preferably, the porous material fills a number of the recess of the frame entirely, so that at least part of the construction element will look non-transparent .
In one preferred embodiment the construction element has a substantially flat surface, which is formed both by parts of the frame and by parts of the porous material . Said surface can be formed by placing a grid upside down on a flat supporting surface, and subsequently deposit the granular material, and a bonding agent, in the recesses of the grid. After curing, the construction element can be turned and the upper side will have a smooth surface, in which parts of the frame are locally visible.
In another preferred embodiment the construction element has a substantially smooth surface in those places where the frame is spaced from said surface. In that case a surface is obtained which only consists of said porous material.
The invention furthermore relates to a method for forming a plate-shaped construction element, wherein a metal frame comprising recesses is at least locally provided with a porous material which is bonded to the metal frame. Preferably, a grid is place upside down on a flat supporting surface, after which a granular material mixed with a bonding agent is introduced into recesses of the grid.
The invention furthermore relates to a method for forming a structure on which people can tread, wherein a floor is formed by positioning plate-shaped construction elements side by side in a horizontal plane, which construction elements comprise a frame extending at least over a large part of the construction element, which frame includes recesses, so that the frame allows water to pass through, and a porous material that has been bonded to the frame, wherein parts of different frames provided with the porous material are positioned adjacently to each other.
In order to explain the invention more fully, an embodiment
of a plate-shaped construction element will now be described with reference to the drawing.
Figure 1 is a top plan view of a construction element; Figures 2 and 3 are sectional views along lines II- II and III-III, respectively, of Figure 1 ; Figure 4 is an exploded view; and Figure 5 is a sectional view of a preferred embodiment.
The figures are merely schematic representations of the embodiment .
The illustrated embodiment comprises a metal grid 1 which is known per se, which grid consists of eleven metal strips 2 having a width equal to the thickness (height) of the grid 1, for example 30 mm. Disposed perpendicularly to the strips 2 are eleven metal strips 3, which strips extend in a vertical plane, just like strips 2, but which have a smaller width, for example 12 mm. Strips 3 extend through recesses in strips 2, and strips 2, 3 are interconnected by means of welded joints, so that a strong and rigid grid 1 is obtained.
The term strip as used herein is understood to mean a material of elongate shape, whose thickness is much smaller than its width. A strip is a length of a band-like material, therefore.
Grid 1 comprises square recesses, seen in top plan view, whose sides measure 30 mm, for example. The thickness of metal strips 2, 3 is 2 mm, for example.
A porous material 4 is present in the recesses in grid 1, which material consists of grains of a rubbery material, which have an average size of 3 - 5 mm. The grains have been obtained by shredding used car tyres . The grains have been mixed with a polyurethane resin and have subsequently
been introduced into the metal grid 1. The grains are bonded together and to the metal of the grid 1 upon curing of the polyurethane resin, with openings remaining between the grains, so that the material 4 is porous.
Figure 4 shows the grid 1 disposed above the porous material 4, which material 4 fills all the spaces within the grid 1 in this embodiment .
It has become apparent that the porous material can be bonded to the grid 1 so strongly that it is possible to walk on grid 1 with stiletto heels.
Figure 5 shows the metal strips 2 of Figure 2 is a sectional view, from which the porous material 4 has been left out, however. According to Figure 5 the strips 2 are provided with embossments 5, that is, parts of material of strip 2 that have been bent outside the plane of strip 2. Such embossments 5 provide an enhanced adherence of the porous material 4 to the metal grid 1.
The plate-shaped construction element that is shown in Figures 1 - 3 is not transparent, but it allows water to pass through. Furthermore it is sufficiently strong to serve as a floor on which persons can walk. Since the porous material is resilient, the construction element is pleasant to walk on.
The construction element according to the embodiment can be formed by placing grid 1 upside down on a flat supporting surface that does not adhere to the porous material 4, and subsequently introduce the porous material therein until said material extends as high as the surface of grid 1.
When grid 1 is kept slightly spaced from the supporting surface thereby, the entire upper surface of the construction element will consist of the porous material 4,
which may be desirable.
Another possibility is not to fill all the recesses of grid 1 with the porous material, but for example only parts that people actually will walk on. This may be desirable especially if large construction elements are concerned.
Possibly a primer is applied to the metal grid 1 prior to introducing the porous material 4, so as to enhance the adherence.