EP3699397A1

EP3699397A1 - A waterproof covering system for covering a surface, civil structure and corresponding method for forming a waterproof covering system

Info

Publication number: EP3699397A1
Application number: EP19382130.3A
Authority: EP
Inventors: Hugo Herault Vila; Paul Terente Herrero
Original assignee: Aplinor Xpraytech Systems SL; Krypton Chemical SL
Current assignee: Aplinor Xpraytech Systems SL; Krypton Chemical SL
Priority date: 2019-02-22
Filing date: 2019-02-22
Publication date: 2020-08-26
Anticipated expiration: 2039-02-22
Also published as: EP3699397B1; ES2901408T3

Abstract

A waterproof covering system (1) for covering a surface comprising a geotextile (2), a geogrid (8) arranged on the geotextile (2). The system further comprises anchoring means (10), comprising a nailing member (12) and a retaining plate (14) operatively associated thereto. The retaining plate (14) comprises a plurality of through holes and is arranged such that in the operation position of the anchoring means (10), the retaining plate (14) overlaps the geogrid (8). Finally, a first coating layer (18) of synthetic polymer forms a continuous coating is applied by in situ projection. The first coating layer (18) covers the geotextile (2), the geogrid (8) and the anchoring means (10), and cures to a solid state to provide a positive fit connection between the first coating layer (18) and the anchoring means (10). The invention further relates to a civil structure and a method for forming a waterproof covering system.

Description

Field of the invention

The invention relates to the area of the waterproof covering of structures in civil works.
More particularly, the invention relates to a waterproof covering system for covering a surface comprising: a geotextile, with a first face intended to be applied on said surface and a second face opposite to said first face, a geogrid, comprising a plurality of fibres intertwined with each other, said plurality of fibres being connected at their intersection zones, and said geogrid being arranged on said second face of said geotextile.
The invention further relates to a civil structure covered with the waterproof covering system of the invention.
Finally, the invention further relates to a method for forming a waterproof covering system for covering a surface that comprises the steps of: providing a geotextile, with a first face and a second face opposite to said first face, and applying said geotextile on said surface, providing a geogrid, comprising a plurality of fibres intertwined with each other, said plurality of fibres being connected at their intersection zones, and arranging said geogrid on said second face of said geotextile.

State of the art

In the field of civil construction, the correct handling of water filtration is of utmost importance. Especially in subterranean, but also in surface constructions, water has several negative side effects. These side effects are among others an increased number of incidences in the structure, a shorter service life of the construction, damages in the installations such as pipes, cables and the like, as well as a reduced security of use.
As an example, the current technical requirement for tunnels in terms of service life is of 100 years. Therefore, a good isolation of the surfaces of the walls of civil constructions, preventing water from dripping or pouring down the walls in an uncontrolled manner is very important. A correct drainage and foreseeable circulation of water provides for a longer service life of the construction, a better preservation, as well as for an increased security of usage.
As an example, conventional tunnels are waterproofed by way of projecting a first coating layer of shotcrete, i. e. a layer of concrete projected at a high velocity against the surface to be covered. This layer already provides a good waterproof covering due to the low porosity reached on the material once it has cured.
Afterwards, a covering layer is made from a plurality of crosslinked polyethylene panels attached to the shotcrete layer. This kind of panels is easy to adapt to the irregularities of the tunnel wall.
However, this method has some disadvantages. In particular, the application of the panels is time consuming. Furthermore, the joints between panels are difficult to seal. Therefore, even though the system works quite well, it is very difficult to completely avoid the water from dripping off at the joints between panels.

Summary of the invention

It is an object of the invention to provide a waterproof covering system for a surface which has an improved waterproofing performance but that is easier to install and that is thus less expensive. This purpose is achieved by a waterproof covering system for covering a surface of the type indicated at the beginning, characterized in that it further comprises a plurality of anchoring means, each anchoring means of said plurality of anchoring means comprising: a nailing member for nailing said anchoring means on said surface through said geotextile and a retaining plate operatively associated with said nailing member, said retaining plate comprising a plurality of through holes and said retaining plate being arranged such that in the operation position of said anchoring means, when said anchoring means are nailed on said surface, said retaining plate overlaps said geogrid , and said waterproof covering system further comprising a first coating layer of synthetic polymer continuous coating that from a liquid state in which said synthetic polymer is applied by in situ projection to cover said second face of said geotextile, said geogrid and said anchoring means, said first coating layer is cured to a solid state to provide a positive fit connection between said first coating layer and said retaining plate of each of said anchoring means.
In a preferred embodiment, when the system comprises only the first coating layer, said layer has a mean thickness comprised between 0.7 and 3.2 mm and especially preferably between 0.8 and 2.5 mm.
Several advantages are achieved by the waterproof covering system of the invention. First of all, thanks to the retaining plate of the anchoring system provided with holes on its main surface, the first coating layer of synthetic polymer can penetrate in the holes and provide retention for the first coating layer of polymer. Once the first coating layer is cured, a positive fit connection between the first coating layer and the anchoring means is achieved. Therefore, even if this first coating layer of coating is applied by projection, the layer holds its position forming a solid unit with the geogrid and the geotextile.
On the other hand, another great advantage of this system is that the waterproof covering system is continuous, i.e. it has no joints. In the waterproof covering system with panels, it is difficult to avoid the creation of openings at the overlapping areas between panels. Water can easily exit through these overlapping areas with the disadvantages already explained. Instead, in the system according to the invention, the coating is continuous. This prevents water from dripping down the outer face of the system, i.e. the face opposite to the covered surface. The water can then be prevented from dripping out the coating and therefore it can be drained towards the most convenient place of the surface that has been covered. Normally, below the ground level a drainage pipe or canal system can be installed in functional cooperation with the coating. The water is collected at the lowest point of the system and thus evacuated through the drainage system.
Finally, another great advantage obtained through the system of the invention is that the covering layer is much easier to apply than the panels. This layer is simply projected over the geotextile and the geogrid in a very fast manner.
In an embodiment of the invention, seeking for a more mechanical behaviour which is more constant in all directions, preferably said plurality of fibres of said geogrid are connected at their intersection zones in order to achieve a higher stiffness of the geogrid.
The invention further includes a number of preferred features that are object of the dependent claims and the utility of which will be highlighted hereinafter in the detailed description of an embodiment of the invention.
In order to improve the adhesion of the first coating layer in the areas of the covering system in which not anchoring means are provided, preferably said geotextile is a nonwoven fabric, punched having a first face which is raw and a second face smoothed by hot melt, and the geotextile has a grammage greater than 150 g/m² and preferably greater than 200 g/m². The smoothed surface in combination with the indicated grammages provides for a better adhesion of the first coating layer on to the geotextile.
Preferably, the geogrid 8 and the geotextile 2 are bonded together building a single unit for better mechanical resistance.
In another embodiment conceived for covering surfaces with higher mechanical loads due to external conditions, such as for example train tunnels, said plurality of fibres has a tensile strength greater than 30 kN. When the train moves inside a tunnel the covering system is subject to suction forces created by the same train, which tend to separate the covering
In another embodiment of the invention, directed to improve the mechanical strength of the covering system said plurality of fibres comprises a plurality of polymer bars interlaced by extrusion. This allows the geogrid to work as a unit or block.
Preferably, in order to have a more foreseeable behaviour, the fibres of the geogrid are oriented in a first and a second directions, said first and second directions being perpendicular to one another.
Preferably, in order to gain application velocity and thus reducing the installation costs, said first covering synthetic polymer is a polyurea or polyurethane applicable by projection.
Also in order to improve the stiffness of the anchoring means and to simplify the production, said retaining plate is a circular disc, and said plurality of holes are evenly distributed on the surface of said disc and with their axes of symmetry perpendicular to the surface of the disc. Alternatively the retaining plate can have other shapes such as a cross, a square a triangle or the like.
In another embodiment, the retaining plate comprises a peripheral rim that in the operation position of said anchoring means, said rim creates a hollow space between said retaining plate and said geotextile. This improves the entrance of liquid polymer under the retaining plate and creates a better positive fit connection, i.e. the coating adopts the shape of the plate thus avoiding the first coating layer to be easily separated from the system.
In order to obtain an optimum adhesion and stiffness of the first coating layer, in a preferred embodiment of the system said first coating layer of synthetic polymer is a mixture of a first and a second components, said first component being one or more of the group formed by a polyol and a polyamine and said second component being an isocyanate, and said first and second components have a ratio of 1:1 v/v. This combination of materials and mixing ratio has shown to provide a good continuity and resistance of this layer. In some applications, for example when the system must be hold against its own weight or when it is subject to tensile loads, a bad connection between this first layer, and the geotextile and the anchoring means could cause a notably shortening of the service life of the coating system.
The invention further relates to the problem of providing a good fireproof in a simple manner. To this end, in an alternative embodiment the mixture of first coating layer further comprises a flame retardant filler. Also preferably said flame retardant filler is one or more of the group formed by expandable graphite, aluminium hydroxide, magnesium hydroxide, ammonium polyphosphate, trialkyl-phosphate, triaryl-phosphate, chlorinated paraffin, melamine cyanurate (MC), tris(chloropropyl)phosphate (TCPP), triethyl phosphate (TEP), tetrabromobisphenol .
Another object of the invention is to provide a covering system with fireproof properties that can be applied fast without causing discontinuities in the covering and providing a good resistance to external loads. To this end, preferably the system further comprises a second coating layer of synthetic polymer forming a continuous coating that from a liquid state in which said synthetic polymer is applied by in situ projection to cover said first coating layer, said second coating layer is cured to a solid state, said second coating layer of synthetic polymer coating is a mixture of a third and a fourth components, said third component being one or more of the group formed by a polyol and a polyamine and said fourth component being an isocyanate, said third and fourth components of said second coating layer are mixed in a ratio of 2.5 to 4 : 1 v/v and said second coating layer further comprising a flame retardant filler, said flame retardant filler being one or more of the group formed by expandable graphite, aluminium hydroxide, magnesium hydroxide, ammonium polyphosphate, trialkyl-phosphate, triaryl-phosphate, chlorinated paraffin, melamine cyanurate (MC), tris(chloropropyl)phosphate (TCPP), triethyl phosphate (TEP), tetrabromobisphenol A (TBPP-A), resorcinol bis (diphenyl phosphate) (RDP) or bis-phenol A-bis(diphenyl phosphate). The indicated volume ratio allows obtaining a mixture which, although containing a flame retardant component, is fluid enough and it can still be properly projected without causing discontinuities in the coating.
Especially preferably the third and fourth components of said second coating layer are mixed in a ratio of 2.9 to 3.1 : 1 v/v.
In a preferred embodiment, when the system comprises a first and a second coating layers, the mean thickness of the first and the second coating layers together is comprised between 0.7 and 3.2 mm and especially preferably between 0.8 and 2.5 mm. Preferably, the first coating layer is between 40% and 60% of the thickness of the ranges given above. The invention further relates to a civil structure which wall is covered with a waterproof covering system according to the invention.
Finally, the invention also relates to method for forming a waterproof covering system for covering a surface as described above. The method of the invention solves the problem of providing a continuous covering of the surface leading to improved waterproof properties to the surface which is to be covered. Furthermore, the covering is easy to install and is reliable. To this end, the method further comprises the steps of: providing a plurality of anchoring means, each anchoring means of said plurality of anchoring means comprising: a nailing member for nailing said anchoring means on said surface through said geotextile and a retaining plate operatively associated with said nailing member, said retaining plate comprising a plurality of through holes, nailing each nailing member with its corresponding retaining plate of said plurality of anchoring means such that in the operation position of said anchoring means said retaining plate overlaps said geogrid and said method further comprising the steps of forming a first coating layer of synthetic polymer continuous coating that, from a liquid state in which said synthetic polymer is applied by in situ projection to cover said second face of said geotextile said geogrid and said anchoring means, said first coating layer is cured to a solid state to provide a positive fit connection between said first coating layer and said plurality of through holes of each of said anchoring means.
In order to have improved mechanical properties of the first coating layer, preferably said first coating layer of synthetic polymer is a mixture of a first and a second components, said first component being one or more of the group formed by a polyol and a polyamine and said second component being an isocyanate, and said first and second components are mixed in a ratio of 1:1 v/v.
Also preferably, in the method of the invention, said mixture of first coating layer further comprises a flame retardant filler, said flame retardant filler is one or more of the group formed by expandable graphite, aluminium hydroxide, magnesium hydroxide, ammonium polyphosphate, trialkyl-phosphate, triaryl-phosphate, chlorinated paraffin, melamine cyanurate (MC), tris(chloropropyl)phosphate (TCPP), triethyl phosphate (TEP), tetrabromobisphenol .
Finally, in order to have a covering layer with fireproof properties preferably, the method further comprises the steps of mixing a second coating layer of synthetic polymer from of a third and a fourth components, said third component being one or more of the group formed by a polyol and a polyamine and said fourth component being an isocyanate, said third and fourth components of said second coating layer are mixed in a ratio of 2.5 to 4 : 1 v/v, adding a flame retardant filler to said second coating layer, said flame retardant filler being one or more of the group formed by expandable graphite, aluminium hydroxide, magnesium hydroxide, ammonium polyphosphate, trialkyl-phosphate, triaryl-phosphate, chlorinated paraffin, melamine cyanurate (MC), tris(chloropropyl)phosphate (TCPP), triethyl phosphate (TEP), tetrabromobisphenol A (TBPP-A), resorcinol bis (diphenyl phosphate) (RDP) or bis-phenol A-bis(diphenyl phosphate) and forming said second coating layer of synthetic polymer as a continuous coating that from a liquid state in which said synthetic polymer is applied by in situ projection to cover said first coating layer, and said second coating layer is cured to a solid state.
Likewise, the invention also includes other features of detail illustrated in the detailed description of an embodiment of the invention and in the accompanying figures.

Brief description of the drawings

Further advantages and features of the invention will become apparent from the following description, in which, without any limiting character, preferred embodiments of the invention are disclosed, with reference to the accompanying drawings in which:

Figure 1, an isometric view of a first embodiment of the waterproof covering system of the invention before the application of the first coating layer.
Figure 2, an isometric view of the system of Figure 1, after the application of the first coating layer.
Figure 3, a longitudinal section view of the system of Figure 1, after the application of the first coating layer.
Figure 4, an isometric view of a second embodiment, based in the system of Figure 1, after the application of the second coating layer.
Figure 5, an isometric view of the system of Figure 4, after the application of the second coating layer.
Figure 6, a cross section view of a civil structure, in particular a tunnel with the tunnel wall covered with the waterproof covering system of the invention before the application of the first coating layer.
Figure 7, a cross section view of the tunnel of Figure 6, with the covering system after the application of the first coating layer.
Figure 8, a cross section view of a tunnel similar to the one of Figure 6, with the covering system after the application of a second coating layer.
Figure 9, a cross section view of the tunnel of Figure 8, with the effect of the own weight and the normal loads applied to the system.
Figure 10, a bottom isometric view of a first embodiment of the retaining plate of the anchoring means used in the system of the invention.
Figure 11, a bottom isometric view of a second embodiment of the retaining plate of the anchoring means used in the system of the invention.
Figure 12, a bottom isometric view of the anchoring means of Figure 11 when mounted on the geogrid of the system of the invention.
Figure 13, an isometric view of a third embodiment of the system of the invention, after the application of the second coating layer.

Detailed description of embodiments of the invention

Figures 1 to 3 show an embodiment of the waterproof covering system 1 according to the invention. This kind of covering system can be used in on several types of surfaces. However, it is especially interesting for applications in which water must be drained in a controlled manner, such as for example tunnels, road slopes or the like.
Figures 1 to 3 show the most relevant elements of the covering system in its most general form. These are a geotextile 2, a geogrid 8, anchoring means 10 and a first coating layer 18 covering all the previous elements and the covered surface.
The geotextile 2 has a first face 4 which is intended to be applied on the surface which must be covered and a second face 6 opposite to the first face 4. Preferably the geotextile 2 is a nonwoven fabric which is punched. The first face 4 is raw, in other words it is not smoothed, while de second face 6 is smoothed by hot melt. Preferably the geotextile 2 has a grammage greater than 150 g/m². In this case, the geotextile shown has a grammage greater than 200 g/m².
The next layer of the system is a geogrid 8. As it is apparent from Figure 1, the geogrid 8 has a plurality of fibres intertwined with each other. The geogrid 8 is arranged on the second face 6 of the geotextile 2. Preferably, the geogrid 8 and the geotextile 2 are bonded together building a single unit. The distance between fibres of the geogrid shown is of 32x32 mm, that is the separation between longitudinal and crosswise fibers.
It is preferred that the plurality of fibres comprises a plurality of polymer bars interlaced by extrusion. The fibres have a preferred tensile strength greater than 30 kN in any of the linear direction of the fibres. Also preferably the geogrid 8 is made of polypropilene. However other embodiments and materials are also possible.
Furthermore, the fibres of the geogrid 8 are oriented in first and second directions L, P. Figure 1, shows that the fibres are arranged in a first direction L which is longitudinal, and a second direction P which is perpendicular to the longitudinal direction. However, other orientations are also possible. For example, the fibres of the first and second directions can be arranged crosswise forming angles different to 90º relative to each other.
Alternatively, the geogrid 8 can be formed from a plurality of plastic fibres in the shape of first and second bands or strips. These strips are thus arranged in at least two different non parallel directions. This plurality of first and second bands can be connected to each other, e.g. by hot melt, in their intersection zones. An example of this embodiment can be seen in Figure 12 or else in Figure 13.
The system further has a plurality of anchoring means 10. Each of the anchoring means 10 comprises a nailing member 12 and a retaining plate 14.
As it is apparent from Figure 1, the nailing member 12 is an elongated metal spike, preferably made of steel or stainless steel. Optionally, the nailing member 12 can also have a screw section in order for the nailing member 12 to be screwed into the surface. The nailing member 12 is nailed or screwed through the geotextile 2 in order to provide a better holding of the system to the surface to cover.
On the other hand, the retaining plate 14 is also a steel or stainless steel plate. In the preferred embodiment of Figure 10, the retaining plate 14 is a disc shaped cylindrical plate with a central protrusion 32. On the flat surface 30, the retaining plate 14 has eight circular through holes 16. These holes 16 are evenly distributed on the surface 30 of the disc. However, if desired they must not be at the same angle or radial distance. Further, as it is apparent from Figure 10, the axes of symmetry of the holes 16 are perpendicular to the surface 30. The retaining plate 14 is preferably produced by stamping. Alternatively, it could also be produced by moulding or eventually machining.
Furthermore, the retaining plate 14 has a central hole 22 provided in the centre of the protrusion 32. This central hole 22 allows to operatively associate the retaining plate 14 with the nailing member 12.
The retaining plate 14 has also a peripheral rim 24. In operation position of the anchoring means 10, the rim 24 together with the protrusion 32, create a hollow space 28 between the retaining plate 14 and the geotextile 2. As it will be explained below, this hollow space 28 below the retaining plate 24, allows the first covering layer to penetrate the retaining plate 14 for improving the holding of the surface layers of the system.
The retaining plate 24 of this embodiment has 52 mm of diameter with 8 through holes of 8 mm of diameter each. On the other hand, it has 2 mm thickness and a rim of 4 mm thickness. In a preferred embodiment, the rim can also have several recesses for better penetration of the first covering layer 18.
Figure 1 shows how, when the nailing member 12 is inserted in the central hole 22 of the retaining plate 14, the anchoring means 10 can be arranged such that in its operation position, the retaining plate 14 overlaps the fibres of the geogrid 8, thus providing much better hold for the geotextile 2 and the geogrid 8 to the covered surface.
Finally, in order to solve the main problem of the invention, the covering system 1 has the first coating layer 18 of synthetic polymer forming a continuous coating. In particular, this first coating layer 18 is projected in situ in a liquid state in which the synthetic polymer covers the second face 6 of the geotextile 2, the geogrid 8 and the anchoring means 10. The first coating layer 18 is made of synthetic polymer such as a polyurea or polyurethane. The first covering layer 18 is thus continuous and without joints or noticeable irregularities. In this embodiment the first coating layer is 2 mm thick. From this liquid state, the first coating layer 18 is cured to a solid state. This to provide a positive fit connection between the first coating layer 18 and the retaining plate 14 of each of the anchoring means 10. This provides an especially reliable waterproof barrier with an excellent mechanical resistance.
In order to have a good adhesion of the first coating layer 18 of synthetic polymer, the first covering layer 18 is made of a mixture of a first and a second components. The first component is one or more of the group formed by a polyol and a polyamine. The second component is an isocyanate. Finally, the first and second components are mixed in a ratio of 1:1 v/v.
Sometimes, it is required that the surface covered is fireproofed. In particular, and only as an exemplary case, the covering systems of tunnels need to fulfil several functions in relation to fire. In particular in Spain, it is requested that the covering of tunnels fulfils the so called UNE norm no. UNE-EN 13501-2:2009+A1:2010. Tunnels have to fulfil level B s2 - d0 of this norm. According to this designation the coating layer must be self-extinguishing (B), producing a certain maximum amount of smoke (s2) and not causing drops of burning coating to drip down the tunnel walls.
In order to fulfil these requirements, the mixture of first coating layer 18 further comprises a flame retardant filler. This flame retardant filler is one or more of the group formed by expandable graphite, aluminium hydroxide, magnesium hydroxide, ammonium polyphosphate, trialkyl-phosphate, triaryl-phosphate, chlorinated paraffin, melamine cyanurate (MC), tris(chloropropyl)phosphate (TCPP), triethyl phosphate (TEP), tetrabromobisphenol .
This has the advantage that a very fast coating the tunnel is achieved, because the operator must create one single layer of polymer coating.
Figure 4, shows an alternative embodiment of the invention, also having fireproof properties. This solution maintains the advantages of the invention regarding the load capacity of the first coating layer 18. However, in this case, the first coating layer 18 is free of frame retardant filler. This first coating layer 18 in now only 1 mm thick.
Depending on the environmental conditions the in situ projection of a fireproof polymer coating can be difficult if the polymer does not flow properly. On the other hand, a coating layer which is too fluid does not guarantee a good mechanical resistance. In order to obtain fireproof properties by maintaining the good mechanical resistance, special additives need to be added, making the coating much stickier. Therefore, an optimum balance between fluidity and mechanical resistance needs to be found.
To this end, for providing the fireproof properties, the waterproof covering system 1 further comprises a second coating layer 20 of synthetic polymer forming a continuous coating of 1 mm of thickness. Again, as it was the case of the first coating layer 18, the second coating layer 20 is applied on the surface in a liquid state by in situ projection to cover the first coating layer 18. The first coating layer 18 is already cured, before the second coating layer 20 is applied. After the projection the said second coating layer 20 is cured to a solid state.
Also, in order to have a good balance between projection application and resistance, the second coating layer 20 of synthetic polymer coating is a mixture of a third and a fourth components. The third component is one or more of the group formed by a polyol and a polyamine. The fourth component is an isocyanate.
For providing the fireproof properties, which in this case are not provided by the first coating layer 18, the second coating layer 20 further comprises a flame retardant filler. Again, this flame retardant filler is, e.g. expandable graphite, aluminium hydroxide, magnesium hydroxide, or other components already cited above.
Since the addition of the filler causes difficulties for in situ projection the third and fourth components of said second coating layer 20 are mixed in a ratio of 3:1 v/v. These exemplary proportions have shown to provide a good balance between projectability, adhesion and mechanical performance when the environmental conditions make the application of a single first coating layer with fireproof properties.
This second coating layer 20, even if having the flame retardant filler has a viscosity of 6500 ± 500 Mpas and a density of about 1.44 kg/litre.
Figures 6 to 7 show an first example of civil structure 100 according to the invention. In particular, the civil structure 100 is a tunnel with a tunnel wall 102.
The tunnel wall 102 shown in the Figures is pure rock. Therefore, the covering system 1 can be applied directly. However, in some applications, a prior shotcrete layer can be applied in order to stabilize the wall of the civil structure.
Below, the method of the invention is explained basing on the tunnel shown in the Figures.
In a first step, the geotextile 2, with a first face 4 and a second face 6 opposite to the first face 4 is applied on the tunnel wall 102.
Afterwards, the geogrid 8, having a plurality of fibres intertwined with each other, said plurality of fibres being connected at their intersection zones, is arranged on the second face 6 of said geotextile 2. It is important to say that it is preferable that the geotextile 2 and the geogrid 8 form a single unit. This simplifies dramatically the application of these two layers. However, this is not compulsory and could also be separate parts being applied the one after the other.
These two layers are fixed to the tunnel wall 102 by providing a plurality of anchoring means 10 comprising: a nailing member 12 for nailing the anchoring means 10 on the tunnel wall by perforating the geotextile 2 and the retaining plate 14 operatively associated with the nailing member 12. As already explained, the retaining plates 14 comprise a plurality of through holes 16.
In order to correctly mount the anchoring means each nailing member 12 with its corresponding retaining plate 14 is nailed to the tunnel wall 102 such that in the operation position of the anchoring means 10 the retaining plate 14 overlaps at least one of the plurality of fibres of the geogrid.
This overlapping has already been appreciated in Figure 1. In order to guarantee a good holding of the system to the surface It is advisable to arrange an anchoring means each 0.25 m².
Once all the anchoring means are duly nailed to the wall and the geogrid 8 and the geotextile 2 are fixed, the first coating layer 18 of synthetic polymer continuous if formed as shown in Figure 7.
From a liquid state the synthetic polymer is applied by in situ projection to cover the second face 6 of the geotextile 2, said geogrid 8 and the anchoring means 10. In this case, reference is made to Figure 3, showing the relevance that the first coating layer penetrates each of the retaining plates 14 of each anchoring means 10. Thanks to the through holes 16 and the peripheral rim 24, the first coating layer 18 in liquid state flows below each retaining plate such that the anchoring means 10 are embedded within this first coating layer 18. Once applied, the first coating layer 18 is cured to a solid state to provide a positive fit connection between said first coating layer 18 and the retaining plate 14 of each of the anchoring means 10. This notably impacts on the right holding of the system 1 to the wall 102. This step is shown in Figure 7.
The d first coating layer 18 of synthetic polymer is a mixture of a first and a second components, the first component being one or more of the group formed by a polyol and a polyamine and the second component being an isocyanate. The first and second components are mixed in a ratio of 1:1 v/v. In this particular case it is preferable that the mixture of first coating layer 18 further comprises a flame retardant filler of the type described before.
Figures 8 and 9 show an alternative embodiment to the tunnel of Figures 6 and 7. In this case, the first coating layer 18 is free of flame retardant fillers.
In order to provide these fireproof properties to the system, the method has the step of mixing a second coating layer 20 of synthetic polymer from of a third and a fourth components. The third component is one or more of the group formed by a polyol and a polyamine. The fourth component is an isocyanate. In order to have a good flowability and mechanical resistance, the third and fourth components of said second coating layer 20 are mixed in a ratio of 3:1 v/v. Additionally, a flame retardant filler is added to the second coating layer 20. Once the mixture is available, the second coating layer 20 of synthetic polymer is formed as a continuous coating from a liquid state. The synthetic polymer is applied by in situ projection to cover said first coating layer 18. Finally, this second layer 20 is cured to a solid state. This is shown in Figure 8. This embodiment is especially adapted to the environments in which the polymer has more difficulties to flow due to the addition of the flame retardant filler.
Finally, Figure 9, shows the effect of the suction when a vehicle such as a train drives through the tunnel 100. As it is apparent, the covering system 1 can deform. However, thanks to the anchoring means 10, the covering system 1 remains in the position. In case the covering system moves by the action of the external loads, such as suction forces of the vehicle passing through the tunnel, the system moves as a unit.
Figures 11 and 12 show another alternative embodiment of the retaining plate 14 of the anchoring means 10.
In this case, the retaining plate 24 is cross shaped. The retaining plate 24 is made of steel sheet of 2 mm thickness, for example by mould pressing. The width of the cross is 102 mm and comprises 24 through holes of 8 mm of diameter. Also the ends of the cross arms are provided with a peripheral rim 24 to allow the first coating layer to easily embed the anchoring systems within itself.
Figure 12 shows how the arms of the cross shaped retaining plate 14 overlap the fibres of the geogrid 8.
Finally, Figure 13 shows a third embodiment of the system according to the invention based on the embodiment of Figures 4 and 5. In this case, the geogrid 8 is be formed from a plurality of plastic fibres in the shape of first and second bands or strips. The first coating layer 18 is free of flame retardant. Finally, the second coating layer 20, which is fireproof. This second coating layer 20 does not solve the main problem of the invention, which is to provide a waterproof covering system for a surface with an improved waterproofing performance but that is easier to install and that is thus less expensive. For the rest of the elements, reference is made to the description of the previous embodiments.

Claims

A waterproof covering system (1) for covering a surface comprising:
[a] a geotextile (2), with a first face (4) intended to be applied on said surface and a second face (6) opposite to said first face (4),

[b] a geogrid (8), comprising a plurality of fibres intertwined with each other and said geogrid (8) being arranged on said second face (6) of said geotextile (2), characterized in that it further comprises

[c] a plurality of anchoring means (10), each anchoring means (10) of said plurality of anchoring means (10) comprising:
[i] a nailing member (12) for nailing said anchoring means (10) on said surface through said geotextile (2) and

[ii] a retaining plate (14) operatively associated with said nailing member (12), said retaining plate (14) comprising a plurality of through holes and said retaining plate (14) being arranged such that in the operation position of said anchoring means (10), when said anchoring means (10) are nailed on said surface, said retaining plate (14) overlaps said geogrid (8), and
said waterproof covering system (1) further comprising

[d] a first coating layer (18) of synthetic polymer forming a continuous coating that
[i] from a liquid state in which said synthetic polymer is applied by in situ projection to cover said second face (6) of said geotextile (2), said geogrid (8) and said anchoring means (10),

[ii] said first coating layer (18) is cured to a solid state to provide a positive fit connection between said first coating layer (18) and said retaining plate (14) of each of said anchoring means (10).
The waterproof covering system (1) according to claim 1, characterized in that said geotextile (2) is a nonwoven fabric, punched having a first face (4) which is raw and a second face (6) smoothed by hot melt, and in that it has a grammage greater than 150 g/m² and preferably greater than 200 g/m².
The waterproof covering system (1) according to claim 1 or 2, characterized in that said plurality of fibres has a tensile strength greater than 30 kN.
The waterproof covering system (1) according to claim 3, characterized in that said plurality of fibres comprises a plurality of polymer bars interlaced by extrusion.
The waterproof covering system (1) according to any of claims 1 to 4, characterized in that said first coating layer (18) of synthetic polymer is a polyurea or polyurethane applicable by projection.
The waterproof covering system (1) according to any of claims 1 to 5, characterized in that said retaining plate (14) is a circular disc, and said plurality of holes are evenly distributed on the surface of said disc and with their axes of symmetry perpendicular to the surface of the disc.
The waterproof covering system (1) according to any of claims 1 to 6, characterized in that if comprises a peripheral rim (24) that in the operation position of said anchoring means (10), said rim (24) creates a hollow space (28) between said retaining plate (14) and said geotextile (2).
The waterproof covering system (1) according to any of claims 1 to 7, characterized in that said first coating layer (18) of synthetic polymer is a mixture of a first and a second components,
[a] said first component being one or more of the group formed by a polyol and a polyamine and

[b] said second component being an isocyanate, and in that

[c] said first and second components are mixed in a ratio of 1:1 v/v.
The waterproof covering system (1) according to claim 8, characterized in that said mixture of first coating layer (18) further comprises a flame retardant filler, said flame retardant filler being one or more of the group formed by expandable graphite, aluminium hydroxide, magnesium hydroxide, ammonium polyphosphate, trialkyl-phosphate, triaryl-phosphate, chlorinated paraffin, melamine cyanurate (MC), tris(chloropropyl)phosphate (TCPP), triethyl phosphate (TEP), tetrabromobisphenol .
The waterproof covering system (1) according to any of claims 1 to 8, characterized in that it further comprises a second coating layer (20) of synthetic polymer forming a continuous coating that
[i] from a liquid state in which said synthetic polymer is applied by in situ projection to cover said first coating layer (18),

[ii] said second coating layer (20) is cured to a solid state, in that
[a] said second coating layer (20) of synthetic polymer coating is a mixture of a third and a fourth components,

[b] said third component being one or more of the group formed by a polyol and a polyamine and

[c] said fourth component being an isocyanate, in that

[d] said third and fourth components of said second coating layer (20) are mixed in a ratio of 2.5 to 4 : 1 v/v and in that

[e] said mixture of said second coating layer (20) further comprises a flame retardant filler, said flame retardant filler being one or more of the group formed by expandable graphite, aluminium hydroxide, magnesium hydroxide, ammonium polyphosphate, trialkyl-phosphate, triaryl-phosphate, chlorinated paraffin, melamine cyanurate (MC), tris(chloropropyl)phosphate (TCPP), triethyl phosphate (TEP), tetrabromobisphenol A (TBPP-A), resorcinol bis (diphenyl phosphate) (RDP) or bis-phenol A-bis(diphenyl phosphate).
A civil structure (100) having a wall (102), said wall (102) being covered with a waterproof covering system (1) according to any of claims 1 to 11.
A method for forming a waterproof covering system for covering a surface that comprises the steps of:
[a] providing a geotextile (2), with a first face (4) and a second face (6) opposite to said first face (4), and applying said geotextile on said surface,

[b] providing a geogrid (8), comprising a plurality of fibres intertwined with each other, said plurality of fibres being connected at their intersection zones, and arranging said geogrid (8) on said second face (6) of said geotextile (2),
characterized in that it further comprises the steps of:
[c] providing a plurality of anchoring means (10), each anchoring means (10) of said plurality of anchoring means (10) comprising:
[i] a nailing member (12) for nailing said anchoring means (10) on said surface through said geotextile (2) and

[ii] a retaining plate (14) operatively associated with said nailing member (12), said retaining plate (14) comprising a plurality of through holes,

[d] nailing each nailing member (12) with its corresponding retaining plate (14) of said plurality of anchoring means (10) such that in the operation position of said anchoring means (10) said retaining plate (14) overlaps said geogrid (8) and
said method further comprising the steps of

[e] forming a first coating layer (18) of synthetic polymer continuous coating that,
[i] from a liquid state in which said synthetic polymer is applied by in situ projection to cover said second face (6) of said geotextile (2), said geogrid (8) and said anchoring means (10),

[ii] said first coating layer (18) is cured to a solid state to provide a positive fit connection between said first coating layer (18) and said retaining plate (14) of each of said anchoring means (10).
The method of claim 12, characterized in that said first coating layer (18) of synthetic polymer is a mixture of a first and a second components,
[a] said first component being one or more of the group formed by a polyol and a polyamine and

[b] said second component being an isocyanate, and in that

[c] said first and second components are mixed in a ratio of 1:1 v/v.
The method of claim 13, characterized in that said mixture of first coating layer (18) further comprises a flame retardant filler, said flame retardant filler being one or more of the group formed by expandable graphite, aluminium hydroxide, magnesium hydroxide, ammonium polyphosphate, trialkyl-phosphate, triaryl-phosphate, chlorinated paraffin, melamine cyanurate (MC), tris(chloropropyl)phosphate (TCPP), triethyl phosphate (TEP), tetrabromobisphenol A (TBPP-A), resorcinol bis (diphenyl phosphate) (RDP) or bis-phenol A-bis(diphenyl phosphate).
The method of any of claims 12 to 13, characterized in that it further comprises the steps of:
[a] mixing a second coating layer (20) of synthetic polymer from of a third and a fourth components,

[b] said third component being one or more of the group formed by a polyol and a polyamine and

[c] said fourth component being an isocyanate, in that

[d] said third and fourth components of said second coating layer (20) are mixed in a ratio of 2.5 to 4 : 1 v/v,

[e] adding a flame retardant filler to said second coating layer (20), said flame retardant filler being one or more of the group formed by expandable graphite, aluminium hydroxide, magnesium hydroxide, ammonium polyphosphate, trialkyl-phosphate, triaryl-phosphate, chlorinated paraffin, melamine cyanurate (MC), tris(chloropropyl)phosphate (TCPP), triethyl phosphate (TEP), tetrabromobisphenol A (TBPP-A), resorcinol bis (diphenyl phosphate) (RDP) or bis-phenol A-bis(diphenyl phosphate) and

[f] forming said second coating layer (20) of synthetic polymer as a continuous coating that
[i] from a liquid state in which said synthetic polymer is applied by in situ projection to cover said first coating layer (18), and

[ii] said second coating layer (20) is cured to a solid state.