The present invention relates to a kerb drainage system. In one embodiment the invention comprises a kerb system that includes an integral drain, and in another embodiment the invention comprises a drainage system that is configured to be located alongside a kerb. In particular but not exclusively, the invention relates to a composite lightweight combined kerb drainage system formed of a containment shell with a concrete infill. The present invention also relates to a method of installing a kerb drainage system.

In one embodiment (referred to herein as the "LT-kerb"), the kerb drainage system is composed of a lightweight outer kerb-shaped thin shell unit, housing a drainage conduit with drainage openings on the kerb face connected to the drainage conduit inside the shell to form a kerb drainage system. In another embodiment (referred to herein as the "LT- Drain"), the kerb drainage system is composed of a lightweight outer thin drain shell unit, housing a drainage conduit with drainage openings connected to the drainage conduit inside the shell to form a kerb drainage system. In both embodiments the shell unit is designed to be filled with concrete on site to form a combined kerb drainage system. This can also be configured in a similar way to form a road drainage channel.

Current drainage kerbs consist of a solid kerb-shaped structure with an internal void and holes on the carriageway face of the kerb connecting onto the internal void to convey drainage runoff from the carriageway. They are either precast or factory made, and are designed to be installed on site as manufactured by butting each unit against the other on a bed of concrete. They are mainly manufactured from concrete, polymer concrete or polymers as short units (1.2m long) designed to be butted against each other to form a continuous void within the kerb to convey drainage runoff to outfall units. The outfall units collect runoff from the kerb units to the highway drainage system.

Concrete and concrete polymer units are heavy, requiring mechanical lifting aids for safe installation on site. LT- Kerb units are light to install as only the drainage kerb shell is initially installed on a concrete bed and filled with concrete after installation. Polymer drainage kerb units although light have raised concerns regarding their performance in high impact environments. There have also been concerns of extensive damage to polymer kerb units in accidental high temperature fires say after flammable liquid spills on carriageways. The LT- kerb is lightweight and easy to install, and due to its concrete component can withstand high impacts and temperatures with only cosmetic damage, the same as conventional concrete kerbs.

Road drainage systems are designed to be watertight to convey highway drainage effluent without leakage. The drainage effluent contains contaminants such as oils, brake dust and road dusts, which have the potential to cause ground and water pollution making any leakage in a drainage system undesirable. The current concrete, polymer concrete and polymer kerbs are designed to be butted against each other to form a continuous void from one drainage outfall point to another. The butt joints sometimes receive sealants but it is difficult to make them fully watertight. Sometimes, water ingress in the joints leads to freezing and thawing in the colder months causing the joints to slightly open up, resulting in some undesirable leakage.

The LT-Kerb addresses this problem by providing a continuous conduit inside the kerb shell that extends from one outfall point to another. The conduit units can be joined together like normal drainage pipes before placement into the kerb shell and then infilling with concrete. They can undergo an air-test to ensure no leakages before concrete infill. The conduit unit is flexible and can be lifted off the kerb shell for assembly and testing. The conduit can also be removed altogether to create a solid kerb without a drainage function. This is not possible with current kerb drainage systems. Drainage kerbs have drainage holes set at a fixed height from the top of the kerb and are installed with a constant kerb face (the distance from top of road surface to top of kerb). There are some instances where it is desirable to have a variable kerb face due to obstacles or existing road and footway levels. Drainage kerbs are not suitable for this application. In such instances, the kerbs are supplemented by concrete channels and gullies. A road channel with a drainage function (referred to herein as an LT-Drain) can also be used and removes need for gullies.

The LT-Drain channel is similar to the LT-Kerb and is composed of a lightweight outer channel-shaped thin shell unit, housing a drainage conduit with inlets at the top of channel connected to the drainage conduit inside the shell to form a drainage channel. The unit is designed to be filled with concrete on site to form a drainage channel to be installed alongside highway kerbs. The light shell is installed first and then filled with concrete once installed. The LT-Drain channel can also complement the LT-Kerb where the areas to be drained are large. There is currently no lightweight highway drainage channel in the market.

According to one aspect of the invention there is provided a kerb drainage system comprising:

an elongate shell structure having a length, and

an infill material,

wherein the elongate shell structure includes:

an outer shell having a top wall, a side wall and at least one infill opening, an internal conduit shell located within the outer shell, said internal conduit shell providing a drainage conduit that extends longitudinally along the length of the elongate shell structure, and

at least one drainage pipe having an inner end that is connected to an opening in the internal conduit shell and an outer end that opens through a drainage opening in an outer surface of the kerb drainage system to provide a fluid flow passageway that enables fluid to flow from the drainage opening into the drainage conduit, wherein the elongate shell structure has an internal volume defined between an inner surface of the outer shell, an outer surface of the internal conduit shell, and an outer surface of the drainage pipe,

and the infill material substantially fills the internal volume of the elongate shell structure,

and wherein the kerb drainage system is embedded adjacent an edge of a carriageway, with the drainage opening substantially level with the carriageway.

Optionally, the outer shell includes a support structure that supports the internal conduit shell within the void. Optionally, the internal conduit shell includes a conduit connection socket, which is configured to allow the conduit shell to be joined end-to-end with another conduit shell to form a continuous drainage channel.

Optionally, the at least one infill opening is provided in the top wall.

Optionally, the elongate shell structure comprises plastic moulding kerb drainage system. Optionally, the infill material is a cement-based material.

Optionally, the kerb drainage system comprises a lower portion that is embedded in a foundation material below a carriageway surface, and an upper portion that extends above carriageway surface to provide a kerb.

Optionally, the upper portion includes a drainage opening in a side portion thereof, which is connected by said at least one drainage pipe to the internal conduit shell, to provide a fluid flow passageway that enables fluid to flow from an exterior region into the internal drainage conduit.

Optionally, the kerb drainage system comprises a lower portion that is embedded in a foundation material below a carriageway surface, and an upper surface that is located substantially level with a carriageway surface. Optionally, the upper surface includes a drainage opening connected by said at least one drainage pipe to the internal conduit shell, to provide a fluid flow passageway that enables fluid to flow from an exterior region into the internal drainage conduit.

According to another aspect of the invention there is provided a method of installing a kerb drainage system, the method comprising:

providing a kerb drainage system unit that includes an elongate shell structure having a length and an infill material,

wherein the elongate shell structure includes outer shell having a top wall, a side wall and at least one infill opening, an internal conduit shell located within the outer shell, said internal conduit shell providing an internal drainage conduit that extends

longitudinally along the length of the elongate shell structure, and at least one drainage pipe having an inner end that is connected to an opening in the internal conduit shell and an outer end that opens through a drainage opening in an outer surface of the kerb drainage system to provide a fluid flow passageway that enables fluid to flow from the drainage opening into the drainage conduit, wherein the elongate shell structure has an internal volume defined between an inner surface of the outer shell, an outer surface of the internal conduit shell, and an outer surface of the drainage pipe,

embedding the elongate shell structure unit alongside a carriageway with the drainage opening substantially level with the carriageway, and

introducing an infill material into the internal volume of the elongate shell structure, to substantially fill the internal volume.

According to another aspect of the invention there is provided a kerb drainage system comprising:

an elongate outer shell having a length, said outer shell having an outer surface and an inner surface defining a void that extends longitudinally along the length of the outer shell,

an internal conduit shell located within the void, said internal conduit shell providing an internal drainage conduit that extends longitudinally along the length of the outer shell, at least one drainage pipe that extends substantially transversely between the outer shell and the internal conduit shell, to provide a fluid flow passageway that enables fluid to flow from an exterior region into the internal drainage conduit, and

at least one infill opening in the outer shell, which allows a filler material to be introduced into the void between the outer shell and the internal conduit shell.

Optionally, the method further comprises:

providing a plurality of kerb drainage system units; and

positioning the kerb drainage system units end-to-end alongside a carriageway, so that the internal conduit shells provide an internal drainage conduit that extends substantially continuously along the length of the kerb drainage system units,

and subsequently introducing a filler material into the void between the outer shell and the internal conduit shell, to substantially fill the void.

Optionally, the method further comprises:

embedding a lower portion of the or each kerb drainage system unit in a foundation material, before introducing a filler material into the void.

Optionally, the method further comprises removing the internal conduit shell from the void before introducing a filler material into the void to substantially fill the void without forming a drainage conduit.

According to another aspect of the invention there is provided a method of installing a kerb drainage system, the method comprising:

providing a kerb drainage system unit that includes an elongate outer shell having a length, said outer shell having an outer surface and an inner surface defining a void that extends longitudinally along the length of the outer shell, an internal conduit shell located within the void, said internal conduit shell providing an internal drainage conduit that extends longitudinally along the length of the outer shell, at least one drainage pipe that extends substantially transversely between the outer shell and the internal conduit shell, to provide a fluid flow passageway that enables fluid to flow from an exterior region into the internal drainage conduit, and at least one infill opening in the outer shell, positioning the kerb drainage system unit alongside a carriageway, and

introducing a filler material into the void between the outer shell and the internal conduit shell, to substantially fill the void.

Summary of problems addressed by invention:

1. Provides a composite drainage kerb with a continuously joined internal conduit similar to traditional drainage pipes, which can receive air test to ascertain no leaks before filling with concrete to form the finished composite drain kerb. This ensures no leakage of potentially contaminated road drainage effluent with potential to pollute ground and water.

2. Provides a light to install composite drainage kerb which when infilled with concrete forms a sturdy composite kerb suitable for high impact environments.

3. Conduit can be removed completely from the drain kerb to form a solid kerb with no drainage function.

4. LT-Kerb drainage kerb and LT-Drain drainage channel can be installed together to provide effective drainage for large areas.

5. Provides a light drainage kerb system that can be manufactured and installed in long lengths unlike traditional sections that are shorter due to weight and manufacturing method.

Drawings that accompany invention

The drawings that follow help explain the invention further.

Certain embodiments of the invention will now be described by way of example with reference to the accompanying drawings, wherein:

Fig. 1 is a perspective view of a first embodiment of the LT-Kerb kerb drainage kerb; Figs. 2a and 2b are additional perspective views of the first embodiment of the LT-Kerb kerb drainage system, showing the kerb at slightly different viewing angles;

Fig. 3 is a partially sectional perspective view of an installed LT-Kerb kerb drainage system, before concrete in-fill; Fig. 4 is a perspective view showing the drainage conduit of an installed LT-Kerb kerb drainage system;

Fig. 5 is a partially sectional perspective view of an installed LT-Kerb kerb drainage system, after concrete in-fill;

Fig. 6 is a cross-sectional view of an installed LT-Kerb kerb drainage system, after concrete in-fill;

Fig. 7 is a partially sectional perspective view of an installed LT-Kerb kerb system omitting the drainage conduit, after concrete in-fill;

Fig. 8 is a perspective view of the LT-Drain kerb drainage system, before concrete in-fill;

Fig. 9 is a perspective view of the LT-Drain kerb drainage system, after concrete in-fill; Fig. 10 is a partially sectional perspective view of a combined LT-Kerb and LT-Drain kerb drainage system, after concrete in-fill, in which the LT-Kerb system omits the drainage conduit; and

Fig. 11 is a perspective view of another combined LT-Kerb and LT-Drain kerb drainage system, before concrete in-fill. Figures 1, 2a and 2b show the general arrangement of an LT-Kerb kerb drainage system comprising a drain kerb 2, which includes a kerb-shaped shell structure 4 made for example of a moulded plastics material. The kerb shell structure 4 includes an outer shell 5 that has inner and outer side walls 6a 6b, a base 8 and a top wall 10, which contain an internal void 12. Openings 14 are provided in the top wall 10, allowing a filler material such as concrete to be poured into the void 12. Optionally, the side walls 6a 6b may include anchoring formations 16, for example in the form of raised elongate ribs, to anchor the finished kerb into the ground. Optionally, the outer shell 5 can be pigmented, texturized or printed to suit the application environment. The outer shell 5 includes an internal support structure 18 for supporting an internal conduit shell 20 within the void 12. The conduit shell 20 is made for example of a moulded plastics material, and consists essentially of a pipe-like structure, which may be round, oval or any other suitable shape in cross-section.

Drainage openings 22 are provided in the inner sidewall 6a, which faces the carriageway when the LT-Kerb has been installed. The drainage openings 22 are connected by drainage pipes 24 to drainage sockets 26 provided in the conduit shell 20, allowing water to flow from the carriageway, through the drainage pipes and into the conduit shell 20, which provides a drainage conduit 34.

As shown most clearly in Fig. 3, the conduit shell 20 is provided at its end with a conduit connection socket 28, which allows a number of conduit shells to be joined together end- to-end to form a continuous drainage conduit 34.

To install the LT-Kerb 2, the shell structures 4, comprising the outer kerb shells 5 together with the internally supported conduit shells 20, are typically placed end-to-end with the lower part of each kerb shell 5 partially embedded in a foundation bed 30, for example of concrete, as shown in Fig. 3. After the conduit shells 20 have been connected together, concrete is poured through the openings 14 in the top wall 10 of the kerb shell 5 to fill the void 12 and form a concrete infill 32 that surrounds the conduit shell 20 and the drainage pipes 24. The finished LT-Kerb kerb drainage system is shown in Figs. 5 and 6. The drainage openings 22 are ideally arranged approximately at the carriageway level 38, so that water can flow freely from the carriageway into the drainage conduit 34 via the drainage pipes 24. Optionally, the conduit shell 20 may be omitted as shown in Fig. 7, to provide a solid kerb without an internal drainage conduit.

Referring again to Fig. 1, this drawing shows the outer shell 5, internal conduit 20 and inlet pipes 24 that provide a connection to the internal conduit 20. The drainage conduit 20 is contained within the kerb shell 6. An opening 14 is provided in the top of the kerb shell 5 to enable filling with concrete 32. This has a provision for an optional cover (not shown), or the void 12 can be filled to the top with concrete 32, which is then finished with a brush finish. The drainage apertures 22 on the face of the kerb provides inlets that are connected to the internal conduit 20. The kerb-shaped shell 5 contains an internal conduit 20 and drainage inlets 22. The conduit support structure 18 also reinforces the drain kerb shell 6.

Figs. 2a and 2b show perspective and 3D views of the LT-Kerb drain kerbs 2. Some of the parts are explained above. The inlet pipes 24 extend from the kerb drain outer shell 5 to the conduit pipe 20. The drainage pipes 24 are installed onto openings in the conduit and installed air tight with sealing rings (not shown), similar to those used to connect plastic drainage pipes.

Fig. 3 shows the bedding of the LT-Kerb drain kerb. Most of the parts are as explained in figs 1 and 2a, 2b above. A socket 28 within the drain kerb conduit 20 enables connection to the adjacent unit. These are connected to each other using sealing rings in a similar way to drain pipes. This should form a continuous drainage conduit from one outfall point to the other that can be air tested for leakage in compliance with drainage standards. The concrete bedding 30 holds the kerb drain in place before the kerb shell 5 is filled with concrete.

Fig. 4 shows the internal conduit shell 20 contained within the LT-Kerb drain kerb 2. Most of the parts are as explained in Figs 1, 2a, 2b and 3 above. The drainage inlets 22 are connected to the drainage conduit 20 via sockets 26 on the drainage conduit. The conduit shell 20 is housed within the LT Kerb shell 2. When the drain kerb shell 5 is filled in concrete, the drain kerb and inlets are cased in concrete to provide an airtight drainage kerb. Fig. 5 shows the LT-Kerb drain kerb 2 after installation. Most of the parts are as explained in Figs 1, 2a, 2b, 3 and 4 above. The apertures 14 in the top wall 10 are used for concrete infill. They can be either be fitted with a cover to match the rest of the drain kerb or receive brush finish for improved aesthetics. Fig. 6 shows a section view of the LT-Kerb drain kerb 2. Most of the parts are as explained in Figs 1, 2a, 2b, 3, 4 and 5 above. A concrete backfill 36 may be installed after the concrete infill to support the kerb. Fig. 6 shows the finished level of a carriageway 38 and the finished level of a footway 40.

Fig. 7 shows the LT-Kerb drain kerb with the conduit omitted to form solid kerb with no drainage function. The parts are described in the figures above.

Figures 8 and 9 show the general arrangement of an LT-Drain drainage system 42, which includes a drain shell 44 made for example of a moulded plastics material. The drain shell 44 has side walls 46, a base 48 and a top wall 50, which contain an internal void 52. An opening 54 is provided in the top wall 50, allowing a filler material such as concrete to be poured into the void 52. Optionally, the side walls 46 may include anchoring formations (not shown) for anchoring the finished drainage system into the ground.

The drain shell 44 may include an internal support structure (not shown) for supporting a conduit shell 60 within the void 52. The conduit shell 60 is made for example of a moulded plastics material, and consists essentially of a pipe-like structure, which may be round, oval or any other suitable shape in cross-section.

Drainage pipes 64 extend from the top surface of the LT-Drain 42 to the conduit shell 60, allowing water to flow from the carriageway, through the drainage pipes and into the conduit shell 60, which provides a drainage conduit 74.

The conduit shell 60 may optionally be provided at its end with a conduit connection socket (not shown), which allows a number of conduit shells to be joined together end-to-end to form a continuous drainage conduit 74. To install the LT-Drain 42, the drain shells 44 together with the internally supported conduit shells 60, are typically placed end-to-end with the lower part of each drain shell 44 partially embedded in a foundation block, for example of concrete. After the conduit shells 60 have been connected together, concrete is poured through the openings 54 in the top wall 50 of the drain shell 44 to fill the void 52 and form a concrete infill 72 that surrounds the conduit shell 60 and the drainage pipes 64. The drainage openings 62 are ideally arranged approximately at the carriageway level 38, so that water can flow freely from the carriageway into the drainage conduit 34 via the drainage pipes 24. Optionally, the LT- Drain system may be installed next to and alongside a kerb 2, as shown in Fig. 10. The kerb 2 may be a conventional kerb or an LT-Kerb kerb system as described herein (either with or without a drainage conduit).

For example, Fig. 10 shows a general arrangement of a LT-Kerb drain kerb 2 without drainage function installed together with LT-Drain drain system 42 with concrete infill. The LT-Drain drainage system 42 can also be installed with an LT-Kerb drain kerb 2 with drainage capacity to increase hydraulic capacity.

Fig. 11 shows an alternative arrangement in which the LT-Kerb drain kerb 2 has inlets connected to drainage pipes 24 located within LT-Drain drainage system, to provide drainage where a constant kerb face is not possible.