WO2012046200A2

WO2012046200A2 - Tile and method for manufacturing a tile and rainwater drainage system provided with such a tile

Info

Publication number: WO2012046200A2
Application number: PCT/IB2011/054395
Authority: WO
Inventors: Patrick Bynens; Johan Fierlafijn
Original assignee: Eurodal Engineering Bvba
Priority date: 2010-10-05
Filing date: 2011-10-05
Publication date: 2012-04-12
Also published as: WO2012046200A3; BE1019528A5

Abstract

Tile comprising a body (2) which is provided with an upper service face (3) and a lower support face (4), in which tile (1) is integrated a water discharge device which extends at least partly through the above-mentioned body (2), characterised in that the discharge device is made in the form of a subatmospheric pressure system, whereby the tile (1) is provided with a passage (5) which comprises a recessed portion (6) in the service face (3), and whereby the discharge device comprises a cover plate (9) which extends at least partly in the space (11) of the above- mentioned recessed portion (6).

Description

Tile and method for manufacturing a tile and rainwater drainage system provided with such a tile.

The present invention concerns a tile.

By tiles are meant here, as is known, paving tiles which are usually made of concrete, and which can be used for the construction of squares, streets, sidewalks, parking places and the like. A very common type of tiles are what are called paving stones which often have a width and length of thirty centimetres; however, tiles can also have considerably larger dimensions up to a length and width of some two metres, in which case such tiles are also called mega tiles.

In practice, it was found that on roads provided with a paving, for example in the shape of tiles, a considerable rainwater drainage system must be provided to avoid flooding in times of heavy rainfall.

In the case of pavements, a conventional solution often consists in providing a gutter on one or either side of the road, whereby a street drain or what is called a rainwater cesspit is provided in this gutter, for example, connected to a sewer or pipe system which opens in a natural reservoir and/or drain and sedimentation system such as a ditch, a brook, a lake or the like. Apart from conventional street drains, also sidewalk drains are known which are built in in the kerb (also called kerbstone) , and combined drains comprising a grate in the road surface as well as in the kerb.

Conventional street drains are always fit before the adjacent paving is constructed, which may consist among others of asphalt, clinkers, concrete or the like. The construction of such street drains, which usually consist of a cast iron base or of plastic such as polyvinylchloride or polypropylene and a cast iron superstructure, is very labour-intensive.

The fitting of a street drain is often immediately followed by the construction of ditches, either or not cast on the spot, after which the pavement is connected onto the latter.

Providing street drains in combination with a pavement in the shape of big tiles consists in first providing these tiles with recesses, such that they can be properly connected onto the street drain concerned.

Also other methods are already in use which seek a solution to avoid flooding, for example by providing for the use of paving tiles or clinkers which are water-permeable.

This can be realised in different ways such as by providing drainage holes in the paving tiles concerned or by manufacturing these paving tiles from a porous material. Also the use of grass concrete tiles is known, whereby large openings are provided in these tiles, which openings are filled for example with rubble or another material which allows the water to seep through. Another known manner for making paving tiles permeable to water is by providing them with widened joints, which is done in practice by providing ridges or distance blocks on the side edges of these paving tiles maintaining a mutual distance between the tiles, such that water can seep through such tiles.

When using such water-permeable paving tiles, a buffer is often provided just below the paved road, in the subfoundation, for collecting rainwater and in order to make it possible for this water to infiltrate into the ground . A disadvantage of such water-permeable paving tiles is that, in the event of a cloudburst, when suddenly a large amount of rain falls, they are inadequate to discharge such large amounts of water in a very short time, so that flooding problems may still occur. It is also known that such an underlying buffering and/or infiltrating basin may become silted up.

It is also known that the above-mentioned clinkers, stones or tiles are not suitable for heavy transport, unless an appropriate foundation is provided.

The present invention aims to remedy one or several of the above-mentioned and/or other disadvantages of the rainwater drainage systems that are currently on the market.

To this end, the invention concerns a tile consisting of a body which is provided with an upper service face and a lower support face and whereby, according to the special feature of the invention, a water discharge device is integrated in the above-mentioned tile. A major advantage of such a tile according to the invention is that no use must be made of a separate street drain for discharging rainwater.

As the discharge device is integrated in a tile, it can be fit very easily without any labour-intensive operations being required such as providing recesses in adjacent tiles or the like.

The above-mentioned discharge device preferably at least partly extends through the above-mentioned body and comprises for example a drain pipe which connects at least partly to a passage in the tile, which passage preferably extends through the above-mentioned body as of the above- mentioned service face up to the above-mentioned support face .

According to a preferred characteristic of the invention, the above-mentioned drain pipe extends at least partly in the above-mentioned passage.

According to a preferred characteristic of the invention, the above-mentioned discharge device is made as a subatmospheric pressure system, also known as a "UV system" (Umpi Virtaus) or "closed flow system".

Subatmospheric pressure systems are known and comprise a drain which, when the water level rises up to a certain level, hermetically seals the drain pipe onto which this drain is connected, such that the water flowing away via the drain pipe produces a suction effect, as a result of which the rate of flow of the water increases.

An advantage of the use of such a subatmospheric pressure system is that it allows to process a large flow in a minimal period of time, whereas the flow section of the drain pipes can remain restricted.

The present invention also concerns a rainwater drainage system comprising a tile according to the invention, whereby this rainwater drainage system is preferably provided with a connecting pipe in which a drain pipe which is part of the above-mentioned discharge device of the tile extends at least partly.

As the above-mentioned drain pipe extends at least partly in the connecting pipe, which implies that the outer diameter of this drain pipe is smaller than the inner diameter of the connecting pipe, a fitting clearance for the tile is built in.

Preferably, there is some space between the outside of the drain pipe and the inside of the connecting pipe. As a result, a tile with a water discharge device must not be perfectly aligned with the connecting pipe, which is usually situated underground, as there is a horizontal play between the drain pipe and the connecting pipe.

Moreover, such a variant of the embodiment is particularly suitable for what are called mega tiles, which are typically used in order to save costs in terms of foundation. Indeed, the use of such big tiles makes it possible to apply elastic foundations instead of expensive, high-quality foundations, whereby these elastic foundations may either or not have a buffering and/or infiltrating action .

By using such elastic foundations, however, the mega tiles can still settle vertically, which can be absorbed by leaving the far end of the above-mentioned drain pipe which extends in the above-mentioned connecting pipe axially free, such that this far end, when the tile and the foundation settle, remains open, for example as said far end of the drain pipe is provided in a freely floating manner in the connecting pipe concerned.

The invention also concerns a method for manufacturing a tile according to the invention, whereby this method according to the invention comprises at least the following steps:

while manufacturing the body of the tile, providing a passage in this body;

at least partly providing a drain pipe in the above-mentioned passage.

With the wording "while manufacturing the body" is meant here before the tile is taken into use. This may mean for example before the body has hardened. In order to better explain the characteristics of the present invention, the following preferred embodiments of a tile according to the invention as well as of a rainwater drainage system provided with such a tile, are described by way of example only without being limitative in any way, with reference to the accompanying drawings, in which: figure 1 schematically represents a tile according to the invention, seen in perspective;

figure 2 shows a section according to line II-II in figure 1 ;

figure 3 shows a section of a tile according to the invention while it is in use;

figure 4 shows the part indicated by F4 in figure 3 to a larger scale;

figure 5 schematically shows a rainwater drainage system according to the invention;

figure 6 shows a variant of a tile according to figure

1;

figures 7 and 8 represent other embodiments of a rainwater drainage system according to the invention; figure 9 shows a variant of a tile according to the invention while it is in use, according to a view as in figure 3.

Figures 1 and 2 show a tile 1 according to the invention comprising a body 2 which is provided with an upper service face 3 and a lower support face 4.

In this example, the above-mentioned body 2 is made of either or not reinforced concrete, but the use of other materials is not excluded according to the invention. The shape of the tile may also vary from the shape represented in the figures. According to the invention, a water discharge device is integrated in the above-mentioned tile 1, which discharge device preferably extends at least partly through the above-mentioned body 2.

To this end, a passage 5 is provided in the tile which in this case, but not necessarily, extends almost centrally through the tile 1, as of the service face 3 up to the support face 4.

In this example, but not necessarily, the passage 5 has a variable flow section as this passage 5 comprises a first part with a first flow section on the side of the service face 3, and on the side of the support face 4, a second part with a second flow section which is smaller than the first flow section.

In this example, the above-mentioned first part of the passage 5 comprises a recessed portion 6 in the service face 3 of the tile 1 having a surface, in a plane parallel to the above-mentioned service face 3 and/or the support face 4, which is larger than the surface of the second part of the above-mentioned passage 5 in a plane parallel to the above-mentioned service face 3 and/or the support face 4.

In other words, the passage 5 has a stepped diameter, such that the section of the passage 5 at the recessed portion 6 on the service face 3 is larger than the section at the rest of the passage 5.

The above-mentioned discharge device preferably comprises a drain pipe 7 extending at least partly in the passage 5, more specifically in the part of said passage 5 having the smallest flow section.

The above-mentioned drain pipe 7 in this case extends as of the above-mentioned passage 5 up to a distance from the above-mentioned support face 7, but this is not strictly necessary according to the invention as the drain pipe 7 can also connect to the passage 5 only without this drain pipe 7 extending in said passage 5.

In this case, but not necessarily, there is a socket 8 between the inner wall of the passage 5 and the outside of the drain pipe 7. As the above-mentioned drain pipe 7 fits in the part of the passage 5 with the smallest inner surface, measured in a plane parallel to the service face 3 and/or the support face 4, the flow section of the above-mentioned recessed portion 6 will be larger than the flow section of the above-mentioned drain pipe 7.

According to a highly preferred characteristic of the invention, the above-mentioned discharge device is made as a subatmospheric pressure system.

To this end, the above-mentioned discharge device in this case comprises a cover plate 9 which extends at least partly opposite an inflow opening 10 of the above-mentioned passage 5 on the above-mentioned service face 3. Said inflow opening 10 is in this case situated at the bottom of the recessed portion 6 and thus at the transition between the larger flow section of this recessed portion 6 and the smaller flow section in the rest of the passage 5.

The above-mentioned cover plate 9 extends at least partly in the space 11 of the above-mentioned recessed portion 6 and is fixed to the above-mentioned body 2 by means of adjustable fasteners 12 in this case, for example in the shape of set bolts or the like which each extend through this cover plate 9 and in a respective bore hole in the bottom wall of the recessed portion 6.

Figure 3 is a section of a part of a rainwater drainage system 13 comprising a tile 1 according to the invention and, in this case, a number of adjacent tiles 14 without any discharge device which are only partly represented in the figure.

The rainwater drainage system 13 is further provided with a connecting pipe 15 which extends in a bottom in the present example, and in which the above-mentioned drain pipe 7 extends at least partly. Naturally, the flow section of the connecting pipe 15 is larger than the flow section of the drain pipe 7 to this end. In the present example, the above-mentioned connecting pipe 15 extends vertically or practically vertically in the bottom, but this is not strictly necessary according to the invention . Preferably, the difference in cross section between the connecting pipe 15 and the drain pipe 7 is such that a space is created between the outside of the drain pipe 7 and the inside of the connecting pipe 15. In other words, the exterior dimensions of the drain pipe 7 are preferably smaller than the interior dimensions of the above-mentioned connecting pipe 15.

The presence of such a space allows for a horizontal play while placing the tiles 1 on their foundation 16, in a plane parallel or practically parallel to the above- mentioned service face 3 and/or the support face 4, since the drain pipe 7 should not be situated perfectly concentrically in relation to the connecting pipe 15. Thus, the solution provides for less stringent fitting clearances, as a result of which the work efficiency when placing the tiles is increased and such placing is made relatively cheaper without compromising on quality.

Preferably, the far end of the above-mentioned drain pipe 7 extending in the above-mentioned connecting pipe 15 is axially free as well, such that this far end, as the tile 1 and foundation 16 settle after they have been provided, remains open, for example as this far end of the drain pipe 7 is provided in a freely floating manner in the connecting pipe 15 concerned. An advantage thereof is that elastic foundations can be used, as any possible vertical settlement of the tiles in a direction perpendicular or almost perpendicular to the above-mentioned service face 3 and/or support face 4 can be absorbed as well by the vertical play, in particular in the case of mega tiles having dimensions of for example one by one metre or more. According to a preferred characteristic of the invention, the above-mentioned elastic foundations also have a buffer function and/or allow water to infiltrate in the ground.

As is represented in greater detail in figure 4, the connecting pipe 15 can be provided with connecting means which, in this case, comprise a settling, resilient and/or sealing material 17 provided between the above-mentioned drain pipe 7 of the tile 1 and the connecting pipe 15.

In this example, the aforesaid sealing material 17 comprises a ring-shaped sealing element provided between the foundation 16 of the tiles 1 and 14 on the one hand, and the support face 4 of the tile 1 on the other hand.

The aforesaid ring-shaped sealing element, which is preferably made of a deformable settlement material such as foam or the like, hereby preferably has an opening whose dimensions practically correspond to or are somewhat smaller than the outer dimensions of the part of the drain pipe 7 extending through this sealing element.

However, the present invention is not limited as such, since the above-mentioned connecting means can also be made otherwise, for example as will be further described with reference to figure 9.

The working of a rainwater drainage system 13 according to the invention is simple and as follows. In case of rainfall, rainwater flows in the recessed portion 6 of the tile 1 to subsequently flow via this recessed portion 6 in the drain pipe 7, after which this water ends up in the connecting pipe 15 and is then discharged via a collecting pipe 18.

When there is suddenly a lot of precipitation, the recessed portion 6 will quickly fill up with water, until the water level in this recessed portion 6 is as high as the bottom side of the cover plate 9.

At that time, air intake in the drain pipe 7 is no longer possible, and the water which flows further downstream via the inflow opening will suck in new water as it creates a local, relative subatmospheric pressure.

This principle is known under the name "subatmospheric pressure system" or "UV system" (from Finnish ^,Umpi Virtaus' , meaning ^''closed flow' ) . This sucking action of the drain pipe 7 results in a strongly accelerated water discharge without having to enlarge the diameter of the drain pipe 7 or of the connecting pipe 15.

A major advantage of a tile 1 and a rainwater drainage system 13 according to the invention consists in that they allow to save considerably on working hours during the installation of pavements, as they comprise an integrated water discharge device, such that no adjustments to existing tiles are required such as providing recesses or the like. A simple connection of the tiles 1 to an existing pipe system is facilitated by using a drain pipe 7 with a restricted diameter which preferably allows for sufficient fitting clearances in the respective connecting pipes 15 on the one hand, and for a sufficient axial play of the drain pipe 7 on the other hand so as to set off the settlement of the tile 1 and the underlying foundation.

Figure 6 shows a variant of a tile 1 according to figure 1, which tile 1 has an almost identical structure as that in figures 1 and 2, but whereby the water discharge device is in this case not provided centrally in the tile 1 and whereby this tile 1 is provided with at least one groove- shaped recess 19 on its service face 3.

The groove-shaped recess 19 is provided at a limited distance from a side edge of the tile 1 in this case, which distance is not larger than 20% of the length of the shortest side of the tile 1.

An appropriate distance preferably amounts to less than 20 centimetres, for example 5 to 15 centimetres.

This limited distance thus provides for a pavement edge or border which is integrated with the tile, such that any additional finishing of the edge, for example by means of a kerb, is no longer necessary.

Naturally, according to the invention, it is also possible that only one of these distinctive features is found in a tile 1. According to a preferred characteristic of the invention, the groove-shaped recess 19 is connected to the aforesaid recessed portion 6. Preferably, the groove-shaped recess 19 slants in the direction of the aforesaid recessed portion 6.

Such a tile 1 can be used either or not in combination with other tiles which are also provided with groove-shaped recesses 19, but which are not necessarily provided with a water discharge device. The tiles are hereby placed such that the respective groove-shaped recesses 19 of adjacent tiles connect to one another.

In this way, rainwater is collected in the respective groove-shaped recesses 19 of the tiles and is subsequently discharged to the tiles 1 which are provided with a water discharge device.

Figure 7 shows a variant of a rainwater drainage system 13 which deviates from the embodiment in figure 5 in that in the case of figure 7, infiltration or buffering is possible as the above-mentioned connecting pipes 15 are connected to an infiltration transport pipe 20, also called "IT pipe". Such an infiltration transport pipe 20 makes sure that a direct infiltration of the discharged water in the ground is made possible and/or that this water can be stored directly in a buffer which extends either or not at least partly under the tile 1 according to the invention and which allows for a decelerated discharge of rainwater. According to another embodiment of a rainwater drainage system 13, as is schematically represented in figure 8, the above-mentioned connecting pipe 15 is connected, via the collecting pipe 18, to a processing device 21 such as a filter system or the like, which processing device 21 is also part of the rainwater drainage system 1 and whereby, preferably, this processing device 21 is connected to an underground buffer 22 for rainwater which in this example, but not necessarily, extends under the respective tiles 1 and 14, for example in a subfoundation .

Such a subfoundation can be part of the above-mentioned foundation 16 and preferably has the shape of an infiltration bed, for example a gravel bag under and next to which a geotextile 23 is preferably provided.

The working of a rainwater drainage system 13 according to figure 8 is practically analogous to that of the embodiment in figure 7, but in this case the water flowing through the connecting pipes 1 is led via the collecting pipe 18 to the processing device 21 where for example slurry is filtered from this water.

Next, the processed rainwater is carried to the buffer 22 via a return pipe 24 provided to that end, after which this water can slowly penetrate in the ground. To this end, the above-mentioned return pipe 24 may for example have the shape of an infiltration transport pipe leading the water in the buffer 22.

The pipes forming a connection with the processing device 21 and the buffer 22 preferably but not necessarily all slant in the aimed direction of flow of the water through the rainwater drainage system 13.

Figure 9 shows a section of a tile 1 according to the invention while such a tile 1 is being used, whereby this section is almost identical to the one represented in figure 3.

A distinctive feature between both embodiments, however, is that in the embodiment of figure 9 the above-mentioned connecting means comprise a pipe sleeve 25 which is connected to the above-mentioned connecting pipe 15 by means of a settlement socket 26 and in which the above- mentioned drain pipe 7 extends at least partly.

Between the pipe sleeve 25 and the settlement socket 26 is provided a seal 27 in this example.

In a special embodiment, the above-mentioned settlement socket 26 can be integrated in the above-mentioned connecting pipe 15, but it can also be made as a separate part .

The use of the pipe sleeve 25 and the settlement socket 26 allow for a flexible placing of a tile 1 according to the invention. Before the tile 1 is placed, the pipe sleeve 25 may reach a lot higher than the upper surface of the foundation 16. As the pipe sleeve 25 can freely move vertically in the settlement socket 26, the tile 1 will move the pipe sleeve 25 down while it is being placed. It is clear that, according to a variant, the tiles 1 and the rainwater drainage system according to the invention can also be applied to a roof construction. In that application, the connecting pipe 15 can be provided with a flange which may rest on the roof construction or a possible insulating layer on the latter.

A water sealing layer which is provided on the roof construction or on a possible insulating layer can be fastened in an appropriate manner to the above-mentioned flange .

On top of the water sealing layer can be provided a water- permeable layer, for example a layer of granulated material such as a porphyry 2/7 mix, and on top of that are provided the tiles 1 according to the invention and the accompanying usual tiles. The joints between the tiles may possibly be filled with a sealant .

In order to prevent the granulated material from ending up in the connecting pipe 15, a water-permeable barrier should be provided between the tile 1 and the water sealing layer.

Such a water-permeable barrier may be formed of a setting pipe which is provided in the connecting pipe 15 and is connected onto the latter, and which extends upwards up to near the support face 4 of the tile 1 according to the invention . In the zone where this setting pipe makes contact with the granulated material, the setting pipe is provided with grooves or perforations or the like, such that water which nevertheless ends up in the space between the tiles and the water sealing layer can be discharged.

The support face 4 of the tile 1 according to the invention can be provided with a local recess, such that the grooved or perforated setting pipe reaches above the granulated material.

It is clear that the setting pipe can also be replaced by a ring or the like, provided with grooves or perforations, which unlike the setting pipe does not reach into the connecting pipe 15 but has a wider diameter and rests on the above-mentioned flange or on the water seal.

It is clear that the local recess and the upwardly protruding setting pipe or ring, possibly with some adjustments, can also be applied when applying the tile according to the invention on the ground floor.

Indeed, with reference to figure 3, according to a preferred variant of the embodiment, the connecting pipe 15 can reach above the top surface of the foundation 16.

In other words, the connecting pipe 15 extends upwards above the foundation then. The support face 4 of the tile 1 in the perimeter zone of the passage 5 is preferably provided with a local recess then, such that an upwardly protruding connecting pipe 15 reaches above the top surface of the foundation, and thus reaches above the peripheral part of the local recess in the perimeter zone of the passage 5 in the support face 4 of the tile 1.

Making this local recess deeper than the height over which the connecting pipe 15 protrudes upwards offers additional flexibility, both while placing a tile according to the invention and as far as the requirements of the possibly elastic foundation are concerned, in which case the tiles may settle.

Indeed, any vertical settlement of the tiles 1 occurring in a direction perpendicular or almost perpendicular to the above-mentioned service face 3 and/or support face 4 can thus be absorbed by the vertical play between the upwardly protruding connecting pipe 15 on the one hand, and the higher part of the support face 4 at the local recess on the other hand.

As said, this feature is particularly important when using mega tiles having dimensions of for example one by one metre or more, since such tiles allow for an elastic foundation as such, but whereby providing a rainwater drainage system is usually not compatible with the less stringent foundation requirements.

Moreover, the upwardly protruding connecting pipe 15 is advantageous in that possible granulated material of the foundation is not simply carried off. Optionally, an elastic sealing can be provided between the tile 1 and the connecting pipe 15. It is clear that the last-mentioned local recess can also be applied, either combined or not, with an alternative upwardly protruding pipe section, such as for example the aforesaid pipe sleeve 25 or settlement socket 26 or the like .

As far as the adjustable fasteners 12 are concerned which connect the cover plate 9 to the body 2 of the tile 1, it is clear that they may be formed of pins worked into the body 2 having downward, widened heads when in use and an upward opening with internal thread.

The fasteners 12 can be filled up with rubber or other elastic elements provided between the above-mentioned pins and the cover plate 9. The whole is held together then for example by means of bolts which are countersunk in the cover plate 9. In the figures, the drain pipe 7 is always represented as a pipe section, as if it were obtained by cutting up a longer pipe. It is clear, however, that the drain pipe 7 can be provided with a wider collar or shoulder which is directed upwards when in use, such that the drain pipe 7 can simply rest on the bottom of the recessed portion 6 in the service face 3 of the tile 1 by means of this collar or shoulder.

Preferably, the bottom of the recessed portion 6, in the central part thereof, i.e. in the immediate perimeter zone of the passage 5, is provided with a second part situated even deeper, such that the collar or shoulder can be entirely or partly countersunk therein. Finally, it is clear that the present invention just as well concerns round, square or otherwise shaped pipes and/or passages.

The present invention is by no means restricted to the embodiments described by way of example only and represented in the accompanying drawings; on the contrary, such a tile and rainwater drainage system according to the invention can be made in all sorts of shapes and dimensions while still remaining within the scope of the invention.

Claims

Claims .

1. - Tile comprising a body (2) which is provided with an upper service face (3) and a lower support face (4), in which tile (1) is integrated a water discharge device which extends at least partly through the above-mentioned body (2), characterised in that the discharge device is made in the form of a subatmospheric pressure system, whereby the tile (1) is provided with a passage (5) which comprises a recessed portion (6) in the service face (3), and whereby the discharge device comprises a cover plate (9) which extends at least partly in the space (11) of the above- mentioned recessed portion (6) .

2. - Tile according to claim 1, characterised in that the support face (4) of the tile (1) in the perimeter zone of the passage (5) is provided with a local recess.

3.- Tile according to claim 1 or 2, characterised in that the above-mentioned discharge device comprises a drain pipe (7) which is at least partly connected to the passage (5) .

4. - Tile according to claim 3, characterised in that the above-mentioned drain pipe (7) extends at least partly in the above-mentioned passage (5) and is provided with a collar or shoulder which is directed upwards when in use.

5. - Tile according to any one of the preceding claims, characterised in that the above-mentioned passage (5) extends through the above-mentioned body (2), as of the above-mentioned service face (3) up to the above-mentioned support face (4), whereby the recessed portion (6) in the service face (3) is provided, in the immediate perimeter zone of the passage (5) , with a second part situated even deeper .

6. - Tile according to any one of claims 3 to 5, characterised in that the above-mentioned drain pipe (7) is held in a socket (8) provided in the above-mentioned passage (5) .

7. - Tile according to any one of claims 3 to 6, characterised in that the flow section of the recessed portion (6) in the service face (3) of the tile (1) is larger than the flow section of the above-mentioned drain pipe ( 7 ) .

8. - Tile according to any one of the preceding claims, characterised in that the above-mentioned cover plate (9) extends at least partly opposite an inflow opening (10) of the above-mentioned passage (5) on the above-mentioned service face (3) .

9. - Tile according to any one of the preceding claims, characterised in that the above-mentioned cover plate (9) is fixed to the above-mentioned body (2) by means of adjustable fasteners (12).

10. - Tile according to any one of the preceding claims, characterised in that, on its service face (3) , it is provided with at least one groove-shaped recess (19) provided at a distance from a side edge of the tile 1, which distance is not larger than 20% of the length of the shortest side of the tile (1) .

11. - Tile according to claim 10, characterised in that the above-mentioned groove-shaped recess (19) is connected to the above-mentioned recessed portion (6).

12. - Rainwater drainage system, characterised in that it comprises a tile (1) according to one or several of the preceding claims.

13. - Rainwater drainage system according to claim 12, characterised in that it is provided with a connecting pipe (15) in which a drain pipe (7) which is part of the above- mentioned discharge device of the tile (1) extends at least partly, whereby there is a space between the outside of the drain pipe (7) and the inside of the connecting pipe (15) in view of a horizontal play between the drain pipe (7) and the connecting pipe (15) .

14. Rainwater drainage system according to claim 12 or 13, characterised in that it is provided with a connecting pipe (15) in which a drain pipe (7) which is part of the above- mentioned discharge device of the tile (1) extends at least partly, whereby the far end of the above-mentioned drain pipe (7) which axially extends in the above-mentioned connecting pipe (15) is left free, for example provided freely floating in the connecting pipe (15) concerned, such that any vertical settling can be absorbed.

15. - Rainwater drainage system according to claim 13 or 14, characterised in that the above-mentioned connecting pipe (15) comprises connecting means, which connecting means comprise one or several of the following items:

- a settling, resilient and/or sealing material (17) which is provided between the above-mentioned drain pipe (7) of the tile (1) and the connecting pipe (15);

a pipe sleeve (25) which is connected to the above- mentioned connecting pipe (15) by means of a settlement socket (26) .

16.- Rainwater drainage system according to claim 13, 14 or 15, characterised in that the above-mentioned connecting pipe (15), pipe sleeve (25) or settlement socket (26) protrudes upwards above a foundation (16), on which foundation (16) can be provided a tile (1), which tile (1) is provided, on the support face (4) and in the perimeter zone of the passage (5) , with a local recess which is deeper than the height over which the connecting pipe (15), pipe sleeve (25) or settlement socket (26) protrudes upwards above the foundation (16) .

17. - Rainwater drainage system according to any one of claims 15 to 17, characterised in that the above-mentioned connecting pipe (15) is connected to a processing device (21) which is also part of the rainwater drainage system (13) .

18. - Rainwater drainage system according to claim 17, characterised in that the above-mentioned processing device (21) is connected to an underground buffer (22) for rainwater.

19. - Method for manufacturing a tile according to any one of claims 1 to 11, characterised in that it consists at least of the following steps:

while manufacturing the body (2) of the tile (1), providing a passage (5) in this body (2); providing a drain pipe (7) at least partly in the above-mentioned passage (5) .

20. - Method according to claim 19, characterised in that it comprises the step of providing the above-mentioned passage

(5) on the service face (3) of the tile (1) with a recessed portion (6) in this service face (3), whereby the flow section of the above-mentioned recessed portion (3) is larger than the flow section of the above-mentioned drain pipe ( 7 ) .

21. - Method according to claim 19 or 20, characterised in that it comprises the step of forming the above-mentioned water discharge device as a subatmospheric pressure system.

22. - Method according to claim 21, characterised in that it comprises the step of mounting the above-mentioned cover plate (9) axially above and at a distance from an inflow opening (10) of the above-mentioned passage (5) on the service face of the tile (1) .

23. - Method according to claim 22, characterised in that the above-mentioned cover plate (9) is mounted at least partly in the space of the above-mentioned recessed portion (6) .

24.- Method according to claim 23, characterised in that the above-mentioned cover plate (9) is fixed to the above- mentioned body (2) by means of adjustable fasteners (12) .