[0001] The present invention relates to a structure for draining surface water, a method
for draining surface water, use of a structure for draining surface water and a method
of installing a structure for draining surface water.
[0002] Precipitation such as rain, snow, sleet, hail and the like results in surface water
which can cause the ground to become waterlogged. It is important to drain surface
water to prevent damage to the ground caused by excess water. This is a particular
issue for recreation grounds, including children's playgrounds and sports grounds
where there is a high level of wear on the ground. If the ground becomes waterlogged,
the surface can become damaged by the high level of wear, and then needs repair or
replacement. It is therefore important that the ground is provided with an efficient
drainage system.
[0003] NL1013987 discloses a subsurface comprising stone wool granulate for a sports field which is
at least partly covered in natural grass. The purpose of the stone wool granulate
is to stabilise the ground and improve the flatness of the sports field even when
the grass is played on excessively. It is necessary to provide drainage lines in addition
to the stone wool granulate in order to provide adequate drainage.
[0004] FR2877956 discloses a layered structure for a children's play area which has improved properties
for cushioning falls. The structure comprises a layer or mat of grass, a layer of
earth and a layer of mineral fibres bound by a binding agent and comprising a wetting
agent. The wetting agent is present to allow the mineral fibre panels to absorb water
to help the grass to grow. The wetting agent is designed to wash out over time so
that the mineral fibre panels gradually lose their water retention capacity. There
is no consideration of the importance of draining water from the children's play area.
[0005] It is known to provide drainage lines under recreation grounds such as football pitches
in order to drain surface water to a water disposal point. It is also known to use
a drainpipe that is provided with apertures, surrounded by gravel, beneath the surface
as a drainage line. The main purpose of the gravel is to create an area around the
drainpipe where water can run relatively freely towards the drainpipe, since the capacity
of the gravel to hold water is limited by the available space between the particles
of gravel. Often a geo-textile is wrapped around the drainpipe in order to prevent
soil from entering the drainpipe through its apertures. This drainage system is often
insufficient and requires secondary drainage systems in order to manage the volume
of surface water. Secondary drainage systems include slitting of the ground to install
trenches of sand. This system requires regular maintenance with frequent sand dressing
to maintain the safety and quality of the surface. This system is costly to install
and maintain as excavations are expensive and involve the removal of a large area
of ground and replacing the area with the required materials.
[0006] US4019,326 discloses a horizontal soil drainage system consisting of a nonwoven three-dimensional
mat of a plurality of looped, intersecting and substantially amorphous filaments of
melt-spun synthetic polymers bonded together at their intersections, at least one
of the outer surfaces of said mat having a lower cross-sectional porosity than the
center zone of said mat. This mat can be rolled up and therefore does not have a high
compressive strength and may be compacted by force impacting from the ground surface.
This will reduce the porosity of the mat, and thus the ability of the mat to drain
water.
[0007] There is a need for a structure for draining water that can be easily installed.
There is a need for a structure that is easy to maintain. There is a need for a structure
which prolongs the usability of the surface and a structure which can convey water
to a disposal means. There is a need for a drain that can absorb water from the ground
and store the water until it can be dissipated back to the ground. Further there is
a need for a structure that does not become contaminated with earth from the ground
and which can be installed without being wrapped in a geo-textile material. Further
there is a need for a structure which has a buffering capacity to hold water as well
as a capacity to convey water. There is a need to produce such a structure which is
environmentally acceptable and economical in terms of production, installation and
use. The present invention solves these problems.
Summary of Invention
[0008] In a first aspect of the invention, there is provided a structure for draining surface
water, comprising a coherent force distribution layer and a drain layer, wherein the
drain layer is formed of an array of coherent man-made vitreous fiber (MMVF) drain
elements, wherein each of the drain elements comprises man-made vitreous fibres bonded
with a cured binder composition, wherein the drain layer is below the force distribution
layer.
[0009] In a second aspect of the invention, there is provided a use of a structure for draining
surface water, the structure comprising a coherent force distribution layer and a
drain layer, wherein the drain layer is formed of an array of coherent man-made vitreous
fiber (MMVF) drain elements, wherein each of the drain elements comprises man-made
vitreous fibres bonded with a cured binder composition, wherein the drain layer is
below the force distribution layer, whereby water in fluid communication with the
drain elements is: (i) absorbed by the MMVF substrate, and/or (ii) conveyed along
the drain elements.
[0010] In a third aspect of the invention, there is provided a method of installing a structure
for draining surface water, the method comprising positioning a drain layer in the
ground, wherein the drain layer is formed of an array of coherent man-made vitreous
fiber (MMVF) drain elements, wherein each of the drain elements comprises man-made
vitreous fibres bonded with a cured binder composition, and positioning a coherent
force distribution layer above the drain layer.
[0011] In a fourth aspect of the invention, there is provided a method of draining surface
water, the method comprising providing a coherent force distribution layer and a drain
layer, wherein the drain layer is formed of an array of coherent man-made vitreous
fiber (MMVF) drain elements, wherein each of the drain elements comprises man-made
vitreous fibres bonded with a cured binder composition, wherein the drain layer is
below the force distribution layer, whereby water in fluid communication with the
drain elements is: (i) absorbed by the MMVF substrate, and/or (ii) conveyed along
the drain elements.
Detailed description of the invention
[0012] The invention relates to draining surface water, preferably draining surface water
from recreation grounds such as children's playgrounds and sports grounds, preferably
sports grounds. Sports grounds include football pitches, rugby pitches, cricket pitches,
lawn bowling greens, lawn tennis courts, golf greens, playing fields, athletic grounds
and equestrian centres. This invention is particularly useful for draining surface
water from football pitches.
[0013] MMVF substrates are known for numerous purposes, including for sound and thermal
insulation, fire protection and in the field of growing plants. When used for growing
plants, the MMVF substrate absorbs water to allow plants to grow. When used for growing
plants, it is important that the MMVF substrate does not dry out. In the field of
growing plants, an MMVF substrate is normally used instead of soil to grow plants.
The relative capillarity of soil and an MMVF substrate is not important in the field
of growing plants.
WO01/23681 discloses the use of MMVF substrate as a sewage filter.
[0014] The man-made vitreous fibres (MMVF) can be glass fibres, ceramic fibres, basalt fibres,
slag wool, stone wool and others, but are usually stone wool fibres. Stone wool generally
has a content of iron oxide at least 3% and content of alkaline earth metals (calcium
oxide and magnesium oxide) from 10 to 40 %, along with the other usual oxide constituents
of MMVF. These are silica; alumina; alkali metals (sodium oxide and potassium oxide)
which are usually present in low amounts; and can also include titania and other minor
oxides.
[0015] Fibre diameter is often in the range of 3 to 20 µm, preferably 3 to 5 µm.
[0016] The MMVF substrate is in the form of a coherent mass. That is, the MMVF substrate
is generally a coherent matrix of MMVF fibres, which has been produced as such, but
can also be formed by granulating a slab of MMVF and consolidating the granulated
material. The binder may be any of the binders known for use as binders for coherent
MMVF products. The MMVF substrate may comprise a wetting agent.
[0017] The MMVF substrate is hydrophilic, that is it attracts water. The MMVF substrate
is hydrophilic due to the binder system used. In the binder system, the binder itself
may be hydrophilic and/or a wetting agent used.
[0018] The hydrophilicity of a sample of MMVF substrate can be measured by determining the
sinking time of a sample. A sample of MMVF substrate having dimensions of 100x100x65
mm is required for determining the sinking time. A container with a minimum size of
200x200x200 mm is filled with water. The sinking time is the time from when the sample
first contacts the water surface to the time when the test specimen is completely
submerged. The sample is placed in contact with the water in such a way that a cross-section
of 100x100 mm first touches the water. The sample will then need to sink a distance
of just over 65mm in order to be completely submerged. The faster the sample sinks,
the more hydrophilic the sample is. The MMVF substrate is considered hydrophilic if
the sinking time is less than 120 s. Preferably the sinking time is less than 60 s.
In practice, the MMVF substrate may have a sinking time of a few seconds, such as
less than 10 seconds.
[0019] When the binder is hydrophobic, in order to ensure that the substrate is hydrophilic,
a wetting agent is additionally included in the MMVF substrate. A wetting agent will
increase the amount of water that the MMVF substrate can absorb. The use of a wetting
agent in combination with a hydrophobic binder results in a hydrophilic MMVF substrate.
The wetting agent may be any of the wetting agents known for use in MMVF substrates
that are used as growth substrates. For instance it may be a non-ionic wetting agent
such as Triton X-100 or Rewopal. Some non-ionic wetting agents may be washed out of
the MMVF substrate over time. It is therefore preferable to use an ionic wetting agent,
especially an anionic wetting agent, such as linear alkyl benzene sulphonate. These
do not wash out of the MMVF substrate to the same extent.
[0020] EP1961291 discloses a method for producing water-absorbing fibre products by interconnecting
fibres using a self-curing phenolic resin and under the action of a wetting agent,
characterised in that a binder solution containing a self-curing phenolic resin and
polyalcohol is used. This type of binder can be used in the present invention. Preferably,
in use the wetting agent does not become washed out of the MMVF substrate and therefore
does not contaminate the surrounding ground.
[0021] The binder of the MMVF substrate can be hydrophilic. A hydrophilic binder does not
require the use of a wetting agent. A wetting agent can nevertheless be used to increase
the hydrophilicity of a hydrophilic binder in a similar manner to its action in combination
with a hydrophobic binder. This means that the MMVF substrate will absorb a higher
volume of water than if the wetting agent is not present. Any hydrophilic binder can
be used.
[0022] The binder may be a formaldehyde-free aqueous binder composition comprising: a binder
component (A) obtainable by reacting at least one alkanolamine with at least one carboxylic
anhydride and, optionally, treating the reaction product with a base; and a binder
component (B) which comprises at least one carbohydrate, as disclosed in
WO2004/007615. Binders of this type are hydrophilic.
[0023] WO97/07664 discloses a hydrophilic substrate that obtains its hydrophilic properties from the
use of a furan resin as a binder. The use of a furan resin allows the abandonment
of the use of a wetting agent. Binders of this type may be used in the present invention.
[0024] WO07129202 discloses a hydrophilic curable aqueous composition wherein said curable aqueous
composition is formed in a process comprising combining the following components:
- (a) a hydroxy-containing polymer,
- (b) a multi-functional crosslinking agent which is at least one selected from the
group consisting of a polyacid, salt(s) thereof and an anhydride, and
- (c) a hydrophilic modifier;
wherein the ratio of (a):(b) is from 95:5 to about 35:65.
[0025] The hydrophilic modifier can be a sugar alcohol, monosaccharide, disaccharide or
oligosaccharide. Examples given include glycerol, sorbitol, glucose, fructose, sucrose,
maltose, lactose, glucose syrup and fructose syrup. Binders of this type can be used
in the present invention.
[0026] Further, a binder composition comprising:
- a) a sugar component, and
- b) a reaction product of a polycarboxylic acid component and an alkanolamine component,
wherein the binder composition prior to curing contains at least 42% by weight of
the sugar component based on the total weight (dry matter) of the binder components
may be used in the present invention, preferably in combination with a wetting agent.
[0027] Binder levels are preferably in the range 0.5 to 5 wt%, preferably 2 to 4 wt%, based
on the weight of the MMVF substrate.
[0028] Levels of wetting agent are preferably in the range 0 to 1 wt%, based on the weight
of the MMVF substrate, in particular in the range 0.2 to 0.8 wt%, especially in the
range 0.4 to 0.6 wt%.
[0029] The MMVF product may be made by any of the methods known to those skilled in the
art for production of MMVF growth substrate products. In general, a mineral charge
is provided, which is melted in a furnace to form a mineral melt. The melt is then
formed into fibres by means of centrifugal fiberisation e.g. using a spinning cup
or a cascade spinner, to form a cloud of fibres. These fibres are then collected and
consolidated. Binder and optionally wetting agent are usually added at the fiberisation
stage by spraying into the cloud of forming fibres. These methods are well known in
the art.
[0030] The present invention provides a structure for draining surface water, comprising
a coherent force distribution layer and a drain layer, wherein the drain layer is
formed of an array of coherent man-made vitreous fiber (MMVF) drain elements, wherein
each of the drain elements comprises man-made vitreous fibres bonded with a cured
binder composition, wherein the drain layer is below the force distribution layer.
[0031] Preferably, each of the drain elements has opposed first and second ends and a passage
within the drain element which extends from a first opening in the first end to a
second opening in the second end. The advantage of a passage is that this gives a
defined path for the water to flow through.
[0032] Preferably the openings of the passages of two drain elements are aligned to allow
water to pass through the two drain elements. This means that two of the openings
are lined up with each other so as to allow water to pass from the passage of one
drain element into the passage of the other drain element and vice versa.
[0033] The passage in at least one drain element may be at an angle of 0.5 to 5° from horizontal,
preferably 1- 4° from horizontal, preferably 1-3° from horizontal. Preferably the
second opening is higher than the first opening. The advantage of a sloping passage
is that water can flow towards the first opening of the passage. The water can then
be disposed of. Preferably the water flows via the first opening to a water disposal
point, preferably a tank mains drainage, or a water drain reservoir.
[0034] Alternatively, the passage within at least one drain element may be horizontal.
[0035] Preferably the passages within two drain elements are connected and form an inverted
V shape with respect to the horizontal. This allows water to be directed in two directions
for disposal away from the mid point of the inverted V, rather than requiring all
the water to flow in one direction. This particularly useful when the drained area
is large, such as a football pitch. In order to provide a passage at an angle from
the horizontal, the passage can be formed at an angle with respect to the top of the
MMVF substrate, or the MMVF substrate can be installed so that its top surface at
an angle with the horizontal. The passage may be at an angle with respect to the top
surface of the MMVF substrate. It is highly desirable that the top of the MMVF substrate
is substantially level so that the force distribution layer can be arranged directly
on top of the MMVF substrate. This gives a level surface on which the force distribution
layer can be positioned.
[0036] Preferably, the passage is enclosed within the MMVF of the drain element, except
at the first and second openings. This prevents any debris from entering the passage
along the length of the passage. Alternatively, the passage may be exposed at the
top surface of the drain element such that the passage is enclosed by the layer above
the drain element, for example, the force distribution layer.
[0037] The MMVF substrate that is used as drain element in the present invention preferably
has a density in the range of 60 to 280 kg/m
3, preferably in the range of 70 to 150 kg/m
3, more preferably 100 to 130 kg/m
3, such as around 110 kg/m
3. The density of the MMVF substrate is the density of the MMVF substrate as such,
that is the density of the MMVF substrate excluding a passage, if present. The optional
passage is not taken into account when calculating the density of the MMVF substrate.
[0038] The advantage of density in this range is that the MMVF substrate has a relatively
high compression strength. This is important because the MMVF substrate will be installed
in a position where people need to travel over the ground in which the MMVF substrate
is positioned.
[0039] Some of the drains may not have passages. The advantage of having some drains without
passages is that there are less passages to connect to a water disposal point.
[0040] The advantage of more of the drains have a passage is that water can flow more easily
through the passages to a water disposal point than through the drains without passages.
[0041] Preferably at least 20 % of the drains comprise a passage, more preferably at least
40 %, more preferably at least 50 %, more preferably at least 80 %, most preferably
all of the drains comprise a passage.
[0042] Preferably the drain layer covers the whole area which is to be drained with the
drain elements arranged in parallel rows. Preferably the drain elements are arranged
in at least one row, preferably a plurality of parallel rows. In the case of a pitch
such as a football pitch, the drain layer will cover the whole area under the pitch.
[0043] The cross-sectional width and height of each drain element are preferably each independently
in the range 10 to 80 cm, more preferably 15 to 60 cm. The advantage of using a drain
element with these widths and heights is that it is large enough to be able to store
water within the pores of the MMVF substrate and thus buffer an amount of water. The
widths and heights are small enough for it to be straightforward to install the drain
underground. The drain elements may optionally have a greater height and/or width,
but this will increase the time and effort required to install the drain.
[0044] The length of each drain element may be any length, but will normally be in the range
of 50 cm to 200 cm, such as around 100 cm. In use the drain will normally be combined
with other drain elements as required to cover the area to be drained.
[0045] It is envisaged that several drain elements could be in fluid communication with
each other by lining up their ends and passages, where present, in order to create
a longer drain.
[0046] The volume of each of the drain elements is preferably in the range 5000 to 700,000
cm
3, more preferably 20,000 to 200,000 cm
3. The precise volume is chosen according to the volume of water which is expected
to be managed.
[0047] Preferably the drain elements have a rectangular or square cross-section which makes
it easy to manufacture and reduces production wastage of the MMVF substrate. Drain
elements with rectangular or square cross-section can be installed in close connection
with each other as they can abut each other. Alternatively the cross-section may be
circular, triangular or any convenient shape.
[0048] Preferably the cross-sectional area of the drain element is substantially uniform
along the length. Substantially uniform means that the cross-sectional area at all
points along the length remains within 10 % of the average cross-sectional area, preferably
within 5 %, most preferably within 1 %.
[0049] Preferably, the cross-sectional area of the first and second openings are in the
range 2 to 200 cm
2, preferably 5 to 100 cm
2.
[0050] Preferably the cross-sectional area of the first opening is in the range 0.5 % to
15 % of the cross-sectional area of the first end MMVF substrate, more preferably
1 % to 10 %.
[0051] Preferably the cross-sectional area of the second opening is in the range 0.5 % to
15 % of the cross-sectional area of the second end MMVF substrate, more preferably
1 % to 10 %.
[0052] The openings are such a small percentage of the cross-sectional area of the ends
of the drain since the vast majority of the MMVF substrate is used to buffer the amount
of water that is to be conveyed. The larger the proportion of the MMVF substrate,
the greater the volume of water that can be buffered by a drain of a given cross-sectional
area.
[0053] The cross-sectional area of the passage is preferably substantially uniform along
the length of the MMVF substrate. Substantially uniform means that the cross-sectional
area is within 10 % of the average cross-sectional area, preferably within 5 %, most
preferably within 1 %. If necessary however, the cross-sectional area can be varied
according to the requirements of the passage to be smaller or larger.
[0054] The passage is preferably configured so that each passage takes the most direct route
through the MMVF substrate to allow water to take the most direct route along the
passage to the second opening. This is for ease of manufacture.
[0055] The passage may have a triangular cross-sectional area. When installed, the base
of the triangle is preferably parallel with the base of the drain. Alternatively the
passage can have a semi-circular cross-sectional area. Again, the base of the drain
is preferably parallel with the base of the semicircle. Alternatively, the passage
can have a circular or a rectangular cross-sectional area.
[0056] The passage is preferably positioned substantially centrally in the width of the
cross-section of the drain element. The reason for this is so that the flow of water
which is then along a line in the centre of the drain element. This has the advantage
that the strength of the drain is maintained at the sides of the drain. If however
the passage were arranged close to one side of the drain element, this may reduce
the strength of the structure.
[0057] Preferably the passage is offset towards a first direction. The advantage of this
is that the drain may be installed with the passage at the bottom of the drain element,
and it is easier to drain the water from the drain element since there is a smaller
volume of MMVF substrate below the passage. This means that when the drain element
takes on water, there is a smaller volume to saturate with water below the passage
before the excess water goes into the passage and can be removed. If the drain element
were to be installed with the passage at the top there would be a larger volume of
MMVF substrate which would need to be saturated with water before the excess water
goes into the passage and can be removed.
[0058] The drain element may comprise a first part in contact with a second part, wherein
the passage is disposed between the first part and the second part. This can be achieved
by providing a first part which is preformed so that it has a groove along the length
of the MMVF substrate, and when the first part and second parts are placed together,
the passage is formed by the groove and the second part. Alternatively the second
part may have the groove. Alternatively, both the first and second part may have a
groove and the grooves may be lined up to form the passage when the first and second
parts are joined together. The groove or grooves may be of any shape, as required
to form the passage. The groove or grooves may therefore have a cross-section which
is semi-circular, triangular, rectangular or the like.
[0059] The first and second parts of the MMVF substrate may simply be placed in contact,
or they may be connected, e.g. using an adhesive.
[0060] Preferably the passage is formed of a pipe, preferably a perforated plastic pipe,
such as a PVC pipe. The pipe gives strength to the drain and prevents the passage
from becoming closed. The pipe is perforated in order to allow the water to drain
into the passage.
[0061] Preferably the water holding capacity of the MMVF substrate is at least 80 % of the
volume of the substrate, preferably 80-99 %, most preferably 85-95 %. The greater
the water holding capacity, the more water can be stored for a given substrate volume.
The water holding capacity of the MMVF substrate is high due to the open pore structure
and the MMVF substrate preferably being hydrophilic.
[0062] Preferably the amount of water that is retained by the MMVF substrate when it emits
water is less than 20 %vol, preferably less than 10 %vol, most preferably less than
5 %vol based on the volume of the substrate. The water retained may be 2 to 20 %vol,
such as 5 to 10 %vol. The lower the amount of water retained by the MMVF substrate,
the greater the capacity of the MMVF substrate to take on more water. Water may leave
the MMVF substrate by water being conveyed by the passage to a disposal means and/or
by dissipating into the ground when the surrounding ground is dry and the capillary
balance is such that the water dissipates into the ground.
[0063] Preferably the buffering capacity of the MMVF substrate, that is the difference between
the maximum amount of water that can be held, and the amount of water that is retained
when the MMVF substrate gives off water is at least 60 %vol, preferably at least 70
%vol, preferably at least 80 %vol. The buffering capacity may be 60 to 90 %vol, such
as 60 to 85 %vol based on the volume of the substrate. The advantage of such a high
buffering capacity is that the MMVF substrate can buffer more water for a given substrate
volume, that is the MMVF substrate can store a high volume of water when required,
and release a high volume of water into the surrounding ground once the has ground
dried out. The buffering capacity is so high because MMVF substrate requires a low
suction pressure to remove water from the MMVF substrate. This is demonstrated in
the Example.
[0064] The water holding capacity, the amount of water retained and the buffering capacity
of the MMVF substrate can each be measured in accordance with EN 13041 - 1999.
[0065] The coherent force distribution layer is present in order to ensure that a drain
elements are not destroyed and/or does not move out of position when pressure is applied
to it, for example by a person running or jumping on it. The force distribution layer
ensures that force impacting from the ground surface is not concentrated on a single
point of a drain element, but is instead distributed over a larger area. The force
distribution layer may be made of a plurality of plates in order to cover the whole
area to be drained. Each plate may have a width and length in the range of 0.5 to
5 m, preferably 1 to 3 m, more preferably 1 to 2 m. The force distribution layer is
preferably a plastic layer, a rubber layer or an MMVF layer. The force distribution
layer must allow water to pass through it to the drain elements. Where the force distribution
layer is made of plastic or rubber, the layer may be perforated to allow water to
pass through it to the drain elements. The thickness of the force distribution layer
is preferably up to 10cm, preferably 1-5 cm depend on material it is made from. The
force distribution layer needs to be thick enough to distribute force across more
than one drain element, and shallow enough to allow easy installation and water permeation.
Preferably the force distribution layer covers the whole of the drain layer present.
[0066] When the force distribution layer is a coherent MMVF layer, it preferably has a compressive
strength of at least 20 kPa, such as 30 kPa to 100 kPa, preferably 30 to 60 kPa, and
the compressive strength may be up to 20 MPa. The compressive strength is measured
according to European Standard EN 826:1996. Force distribution layers with such a
compressive strength are particularly suitable for use in the present invention as
they ensure that force impacting from the ground surface is not concentrated on a
single point of a drain element, but is instead distributed over a larger area.
[0067] When the force distribution layer is a coherent MMVF layer, it preferably has a density
of at least 100 kg/m
3, such as 100 to 280 kg/m
3, preferably 150 to 200 kg/m
3, and the density may be up to 600 kg/m
3. Force distribution layers with such a density are particularly suitable for use
in the present invention as they ensure that force impacting from the ground surface
is not concentrated on a single point of a drain element, but is instead distributed
over a larger area.
[0068] When the force distribution layer is a coherent MMVF layer, it is preferably hydrophilic,
that is it attracts water. The MMVF layer is in the form of a coherent mass. That
is, the MMVF layer is generally a coherent matrix of MMVF fibres, which has been produced
as such, but can also be formed by granulating a slab of MMVF and consolidating the
granulated material. The binder may be any of the binders known for use as binders
for coherent MMVF products. The MMVF layer may comprise a wetting agent. The binder
and optional wetting agent of the MMVF layer may be as described for the MMVF substrate.
[0069] The structure can further comprise an upper layer above the force distribution layer.
The upper layer is preferably grass, earth, artificial grass, sand, gravel, clay or
combinations thereof.
[0070] The structure can further comprise a heating layer between the force distribution
layer and the drain layer. A heating layer is particularly useful to defrost pitches,
such as football pitches in cold weather. Where the structure comprises an upper layer,
a heating layer, a force distribution layer and a drain layer, the heating layer can
be positioned between the upper layer and the force distribution layer.
[0071] The present invention relates to a structure for draining surface water, comprising
a coherent force distribution layer and a second layer, wherein the second layer is
formed of an array of coherent man-made vitreous fiber (MMVF) elements, wherein each
of the elements comprises man-made vitreous fibres bonded with a cured binder composition,
wherein the second layer is below the force distribution layer. The second layer is
a drain layer and the coherent MMVF elements are coherent MMVF drain elements.
[0072] The present invention relates to the use of a structure for draining surface water,
the structure comprising a coherent force distribution layer and a drain layer, wherein
the drain layer is formed of an array of coherent man-made vitreous fiber (MMVF) drain
elements, wherein each of the drain elements comprises man-made vitreous fibres bonded
with a cured binder composition, wherein the drain layer is below the force distribution
layer, whereby water in fluid communication with the drain elements is: (i) absorbed
by the MMVF substrate, and/or (ii) conveyed along the drain elements.
[0073] Preferably each of the drain elements has opposed first and second ends and a passage
which extends from a first opening in the first end to a second opening in the second
end, whereby water in fluid communication with the first drain is: (i) absorbed by
the MMVF substrate, and/or (ii) conveyed along the passage.
[0074] An advantage of using the structure according to the invention is that the drain
elements can absorb water and store it within its open pore structure and the drain
elements can convey water along the passage towards the first opening. This means
that the drain elements can store water when required, and also convey water to a
water disposal point when required. An advantage of storing the water is that when
the surrounding ground is dry enough, the water stored in the MMVF substrate can dissipate
from the substrate into the ground. This means that it is not always necessary to
remove the water and arrange to dispose of it. The drain elements can store the water
and then gradually dissipate it to the ground when the capillary balance between the
MMVF substrate and the ground allows the water to dissipate into the ground.
[0075] The water can be conveyed by gravity along the passage, for example, by installing
the passage with a slope such that the second end of the MMVF substrate is higher
than the first end of the MMVF substrate as discussed above. An advantage of installing
the drain with a slope is that it is not necessary to pump the water from the drain
element.
[0076] Alternatively, a pump can be provided which is in fluid communication with the first
opening of the passage, wherein the pump conveys water towards the first opening of
the passage. The pump may be in fluid communication with the first opening by means
of a conduit, such as a pipe. The water can be pumped along the passage to a water
disposal point such as a tank, mains drainage or a water drain reservoir. An advantage
of using a pump is that the drain element can be installed in such a way that the
passage is not at an angle with the horizontal and therefore on installation it is
not necessary to ensure that the passage has the required angle.
[0077] It is possible to have both install the MMVF substrate passage on a slope and use
a pump system.
[0078] In use, the passage is preferably offset and positioned in the lower half of the
MMVF substrate. It is advantageous for the passage to be at the bottom of the MMVF
substrate as this means that there is a smaller volume of MMVF substrate to saturate
with water before the water goes into the passage.
[0079] It is not necessary to wrap the drain of the present invention in any geo-textile
material on installation because the MMVF substrate acts like a filter itself in order
to prevent any contaminate such as earth entering the drain element and blocking the
passage.
[0080] There is provided a method of installing a structure for draining surface water,
comprising positioning a drain layer in the ground, wherein the drain layer is formed
of an array of coherent man-made vitreous fiber (MMVF) drain elements, wherein each
of the drain elements comprises man-made vitreous fibres bonded with a cured binder
composition, and positioning a coherent force distribution layer above the drain layer.
[0081] Preferably each of the drain elements has opposed first and second ends and a passage
which extends from a first opening in the first end to a second opening in the second
end, wherein the first opening of the drain is arranged in fluid communication with
a water disposal point.
[0082] Preferably the drainage system is installed by digging out an area which is to be
drained, positioning the drain elements in the area in fluid communication with each
other area so that a layer of drain elements covers the entire area to be drained,
positioning a coherent force distribution layer on top of the drain layer and optionally
positioning an upper layer on top of the force distribution layer. In this way, a
level surface is created through which surface water can drain.
[0083] In this method, the MMVF substrates may be installed so that the passages are on
a slope, and/or connected to a pump.
[0084] There is provided a method of draining surface water, the method comprising providing
a coherent force distribution layer and a drain layer, wherein the drain layer is
formed of an array of coherent man-made vitreous fiber (MMVF) drain elements, wherein
each of the drain elements comprises man-made vitreous fibres bonded with a cured
binder composition, wherein the drain layer is below the force distribution layer,
whereby water in fluid communication with the drain elements is: (i) absorbed by the
MMVF substrate, and/or (ii) conveyed along the drain elements.
[0085] Preferably each of the drain elements has opposed first and second ends and a passage
which extends from a first opening in the first end to a second opening in the second
end, whereby water in fluid communication with the first drain is: (i) absorbed by
the MMVF substrate, and/or (ii) conveyed along the passage.
Brief description of figures
[0086]
Figure 1 shows a cross-sectional view of a structure with a drain element
Figure 2 shows a cross-sectional view of a structure with a drain element with a passage
Figure 3 shows a cross-sectional view of a structure with a two drain elements, each
with a passage
Figure 4 shows a cross-sectional view of a structure with a drain element and a heating
layer
Figure 5 shows a cross-sectional view of a structure with a drain element and an upper
layer
Figure 6 shows a section view of a structure with an array of drain elements
Figure 7 shows the water holding capacity of an MMVF substrate according to the invention
as discussed in the Example
Detailed description of figures
[0087] Figure 1 shows a force distribution layer 1 above a drain element 2.
[0088] Figure 2 shows a force distribution layer 1a above a drain element 2a. The drain
element 2a has a passage 3a running from the first end of the drain element to the
second end of the drain element. The passage 3a is sloped to allow water to flow along
the passage towards the lowest point. The water then flows from the passage to a water
disposal point 4a.
[0089] Figure 3 shows a force distribution layer 1b above a first drain element 2b and a
second drain element 5b. The first drain element 2b and second drain element 5b each
have a passage 3b and 6b respectively. The passages 3b and 6b are each at an angle
and the passages are aligned at the highest point. In this way the water can flow
through either passage, depending which drain element the water enters. The water
flows to two water disposal points, 4b and 7b respectively. The water disposal points
4b and 7b could be the same water disposal point.
[0090] Figure 4 shows a force distribution layer 1c above a heating layer 8c. The drain
elements 2c, 9c and 10c are each directly below the heating layer. Drain element 9c
is disposed between drain elements 2c and 10c. A horizontal passage 3c runs through
each of the drain elements 2c, 9c and 10c. This shows how multiple drain elements
can be in fluid communication which each other to form the structure.
[0091] Figure 5 shows an upper layer 11d above a force distribution layer 1d. A drain element
2d is below the force distribution layer.
[0092] Figure 6 shows a force distribution layer 1e, above a drain layer. The drain layer
comprises an array of drain elements 2e and spacing elements 12e. Each drain element
has a passage 3e extending from one end of the drain element to the other end of the
drain element. Some of the drain elements 2e are aligned to the next drain element
2e by aligning the passages 3e to create a row of drain elements 2e. The spacing elements
12e are aligned in rows between the rows of drain elements 2e. The force distribution
layer 1e is shown partially covering the drain layer, but in practice will completely
cover the drain layer. The spacing elements may be drain elements without a passage.
Alternatively, the spacing elements may comprise an MMVF substrate which is hydrophobic.
The drain layer as a whole is still able to drain surface water, whether the spacing
elements are hydrophilic or hydrophobic as the drain elements 2e are sufficient to
drain the surface water.
[0093] The invention will now be described in the following example which does not limit
the scope of the invention.
Example
[0094] The water holding capacity of a MMVF substrate and silt loam were tested in accordance
with EN 13041 - 1999. The MMVF substrate was a stone wool fibre product with a phenol-urea
formaldehyde (PUF) binder and a non-ionic surfactant wetting agent. The results are
shown in Figure 7.
[0095] The MMVF substrate has a maximum water content of 90 %vol based on the substrate
volume. When the MMVF substrate gives off water, it retains about 2-5 %vol of water.
This means that the MMVF substrate has a buffering capacity of 85-87 %vol. This shows
that the MMVF substrate has a high maximum water content, as well as a lower water
retention level.
[0096] The maximum water content of the silt loam is lower than the MMVF substrate. The
capillarity of the silt loam is much higher than that of the MMVF substrate, which
means a suction pressure of several meters is required in order to withdraw water
from the silt loam. This means that the soil will easily drain water from the MMVF
substrate as soon as the soil is not saturated.
[0097] It will be appreciated by the skilled person that any of the preferred features of
the invention may be combined in order to produce a preferred method, product or use
of the invention.
Numbered Embodiments
[0098]
Numbered Embodiment 1. A structure for draining surface water, comprising a coherent
force distribution layer and a drain layer, wherein the drain layer is formed of an
array of coherent man-made vitreous fiber (MMVF) drain elements, wherein each of the
drain elements comprises man-made vitreous fibres bonded with a cured binder composition,
wherein the drain layer is below the force distribution layer.
Numbered Embodiment 2. A structure according to Numbered Embodiment 1, wherein each
of the drain elements has opposed first and second ends and a passage which extends
from a first opening in the first end to a second opening in the second end.
Numbered Embodiment 3. A structure according to Numbered Embodiment 2, wherein the
openings of the passages of two drain elements are aligned.
Numbered Embodiment 4. A structure according to any preceding Numbered Embodiment,
wherein the drain elements are arranged in at least one row, preferably a plurality
of parallel rows.
Numbered Embodiment 5. A structure according to any of Numbered Embodiments 2 to 4,
wherein the passage in at least one of the drain elements is at an angle of 0.5 to
5° from horizontal, preferably 1- 4° from horizontal, preferably 1-3° from horizontal
and the second opening is higher than the first opening.
Numbered Embodiment 6. A structure according to any of Numbered Embodiments 2 to 5,
wherein the passage is in the bottom half of the MMVF drain element.
Numbered Embodiment 7. A structure according to any preceding Numbered Embodiment,
wherein at least 20 % of the drain elements comprise a passage.
Numbered Embodiment 8. A structure according to any preceding Numbered Embodiment,
wherein the MMVF drain elements comprises a wetting agent.
Numbered Embodiment 9. A structure according to any preceding Numbered Embodiment
for draining recreation grounds, preferably sports grounds.
Numbered Embodiment 10. A structure according to any preceding Numbered Embodiment,
wherein the force distribution layer comprises a continuous plastic layer, a continuous
rubber layer, or a coherent MMVF layer.
Numbered Embodiment 11. A structure according to any preceding Numbered Embodiment,
further comprising an upper layer above the force distribution layer, wherein the
upper layer is preferably grass, earth, artificial grass, sand, gravel, clay, or a
combination thereof.
Numbered Embodiment 12. A structure according to any preceding Numbered Embodiment,
wherein the system further comprises a heating layer between the force distribution
layer and the drain layer.
Numbered Embodiment 13. A structure according to any preceding Numbered Embodiment,
wherein the array of drain elements is in fluid communication with a water disposal
point, preferably a tank, mains drainage or water drain reservoir.
Numbered Embodiment 14. Use of a structure for draining surface water, the structure
comprising a coherent force distribution layer and a drain layer, wherein the drain
layer is formed of an array of coherent man-made vitreous fiber (MMVF) drain elements,
wherein each of the drain elements comprises man-made vitreous fibres bonded with
a cured binder composition, wherein the drain layer is below the force distribution
layer, whereby water in fluid communication with the drain elements is: (i) absorbed
by the MMVF substrate, and/or (ii) conveyed along the drain elements.
Numbered Embodiment 15. A use according to Numbered Embodiment 14, wherein each of
the drain elements has opposed first and second ends and a passage which extends from
a first opening in the first end to a second opening in the second end, whereby water
in fluid communication with the first drain is: (i) absorbed by the MMVF substrate,
and/or (ii) conveyed along the passage.
Numbered Embodiment 16. A use according to Numbered Embodiment 14 or 15, further comprising
the features of any of Numbered Embodiments 3 to 13.
Numbered Embodiment 17. A method of installing a structure for draining surface water,
the method comprising positioning a drain layer in the ground, wherein the drain layer
is formed of an array of coherent man-made vitreous fiber (MMVF) drain elements, wherein
each of the drain elements comprises man-made vitreous fibres bonded with a cured
binder composition, and positioning a coherent force distribution layer above the
drain layer.
Numbered Embodiment 18. A method according to Numbered Embodiment 17, wherein each
of the drain elements has opposed first and second ends and a passage which extends
from a first opening in the first end to a second opening in the second end, wherein
the first opening of the drain is arranged in fluid communication with a water disposal
point.
Numbered Embodiment 19. A method of draining surface water, the method comprising
providing a coherent force distribution layer and a drain layer, wherein the drain
layer is formed of an array of coherent man-made vitreous fiber (MMVF) drain elements,
wherein each of the drain elements comprises man-made vitreous fibres bonded with
a cured binder composition, wherein the drain layer is below the force distribution
layer, whereby water in fluid communication with the drain elements is: (i) absorbed
by the MMVF substrate, and/or (ii) conveyed along the drain elements.
Numbered Embodiment 20. A method according to Numbered Embodiment 19 wherein each
of the drain elements has opposed first and second ends and a passage which extends
from a first opening in the first end to a second opening in the second end, whereby
water in fluid communication with the first drain is: (i) absorbed by the MMVF substrate,
and/or (ii) conveyed along the passage.
Numbered Embodiment 21. A method according to Numbered Embodiment 19 or 20, further
comprising the features of any of Numbered Embodiments 3 to 13.
1. A structure for draining surface water, comprising a coherent force distribution layer
and a drain layer, wherein the drain layer is formed of an array of coherent man-made
vitreous fiber (MMVF) drain elements, wherein each of the drain elements comprises
man-made vitreous fibres bonded with a cured binder composition, wherein the drain
layer is below the force distribution layer.
2. A structure according to claim 1, wherein at least one drain element comprises a passage.
3. A structure according to claim 1, wherein at least one drain element comprises a horizontal
passage
4. A structure according to claim 1, wherein at least 20 % of the drain elements have
opposed first and second ends and a passage which extends from a first opening in
the first end to a second opening in the second end.
5. A structure according to claim 1 wherein each of the drain elements has opposed first
and second ends and a passage which extends from a first opening in the first end
to a second opening in the second end.
6. A structure according to claim 4 or 5 wherein the openings of the passages of two
drain elements are aligned.
7. A structure according to any preceding claim, wherein the drain elements are arranged
in at least one row, preferably a plurality of parallel rows.
8. A structure according to any of claims 2 to 7, wherein the passage in at least one
of the drain elements is at an angle of 0.5 to 5° from horizontal, preferably 1- 4°
from horizontal, preferably 1-3° from horizontal and the second opening is higher
than the first opening.
9. A structure according to any of claims 2 to 8, wherein the passage is in the bottom
half of the MMVF drain element.
10. A structure according to any preceding claim, wherein the MMVF drain elements comprises
a wetting agent.
11. A structure according to any preceding claim for draining recreation grounds, preferably
sports grounds.
12. A structure according to any preceding claim, wherein the force distribution layer
comprises a continuous plastic layer, a continuous rubber layer, or a coherent MMVF
layer.
13. A structure according to any preceding claim, further comprising an upper layer above
the force distribution layer, wherein the upper layer is preferably grass, earth,
artificial grass, sand, gravel, clay, or a combination thereof.
14. A structure according to any preceding claim wherein the system further comprises
a heating layer between the force distribution layer and the drain layer.
15. A structure according to any preceding claim, wherein the array of drain elements
is in fluid communication with a water disposal point, preferably a tank, mains drainage
or water drain reservoir.
16. Use of a structure for draining surface water, the structure comprising a coherent
force distribution layer and a drain layer, wherein the drain layer is formed of an
array of coherent man-made vitreous fiber (MMVF) drain elements, wherein each of the
drain elements comprises man-made vitreous fibres bonded with a cured binder composition,
wherein the drain layer is below the force distribution layer, whereby water in fluid
communication with the drain elements is: (i) absorbed by the MMVF substrate, and/or
(ii) conveyed along the drain elements.
17. A method of installing a structure for draining surface water, the method comprising
positioning a drain layer in the ground, wherein the drain layer is formed of an array
of coherent man-made vitreous fiber (MMVF) drain elements, wherein each of the drain
elements comprises man-made vitreous fibres bonded with a cured binder composition,
and positioning a coherent force distribution layer above the drain layer.
18. A method of draining surface water, the method comprising providing a coherent force
distribution layer and a drain layer, wherein the drain layer is formed of an array
of coherent man-made vitreous fiber (MMVF) drain elements, wherein each of the drain
elements comprises man-made vitreous fibres bonded with a cured binder composition,
wherein the drain layer is below the force distribution layer, whereby water in fluid
communication with the drain elements is: (i) absorbed by the MMVF substrate, and/or
(ii) conveyed along the drain elements.
19. A use according to claim 16 or a method according to claim 17 or 18, further comprising
the features of any of claims 2 to 15.