Patent Application
20200224415
The invention relates to end caps for preventing ingress of moisture to structural beams comprising metal, stone, concrete, reinforced concrete or a mixture thereof, and kits for installing block and beam flooring comprising said end caps, said beams, and optionally flooring blocks. Methods of making said end caps and methods of reducing corrosion comprising fitting said end caps to said structural beams before or during construction of a building are also provided.
In the construction of buildings' flooring it is common to use a “block and beam” method, typically using concrete beams such as reinforced concrete T-beams. These are generally precast by a manufacturer and then shipped to a construction site for assembly into a building. Each individual beam might typically have dimensions of anything from one to seven metres in length and between, for example, 100-170 mm wide, at the widest point. In other words each beam is a significant concrete “slab” so that holding and maneuvering these manually is difficult and dangerous, as well as being labour-intensive.
The ends of each beam in this construction system are generally supported within the inside wall of a cavity wall system (as shown in
To achieve this, the current practice within the UK building industry is to wrap the end of each beam in strips of damp-proof course material. This wrapping is done by hand, while simultaneously supporting the weight of the beam so as to elevate and access the end that must be wrapped. This is difficult and dangerous, given the weight of the beams, and is also a time-consuming process as each beam in the structure must be individually wrapped at both ends. Typically, for example, the current wrapping of beam ends involves at least three labourers and takes 10-15 minutes per beam end. Thus it is labour-intensive and inefficient as well as being a safety hazard.
As an alternative, current UK practice can also include asking for beam ends to be painted, e.g. with bitumen as a means of damp proofing. This is labour-intensive, time-consuming and difficult to carry out on-site, while pre-painting beams prior to installation does not allow for re-cutting of beams or other adjustments on site, which is frequently needed in practice.
There is also significant wastage of material in the wrapping, and the seal is imperfect and typically still allows transmission of moisture. This is a particular problem when reinforced concrete is used, due to the formation of rust in the reinforcing tie-bars within the concrete beams on exposure to moisture. This can lead to what is known as “concrete cancer”.
Concrete cancer is caused when the steel reinforcing within a concrete slab begins to rust. As the steel rusts it expands, displacing the concrete around it, causing it to become brittle and crack, thus further accelerating the process.
Signs of concrete cancer include:
Crazing and cracking concrete (concrete spalling);
Rust stains that appear to leak out from within the concrete;
Bubbling (also called “plating”) of concrete render; and
Leaks which appear in overhead concrete surfaces.
Concrete spalling, particularly on the outside of a building, is an aesthetic problem but, more than that. is indicative of a potentially growing structural weakness and a threat to the building's integrity. Over time, and with increased exposure to the elements, untreated pieces of concrete may fall from the structure. Loss of these sections not only further weakens the structure itself but the falling sections may damage property or people passing by when they fall.
One of the causes of concrete spalling is water penetration, for example if the ends of the reinforcing bars are too close to the surface, or by seep through of water during heavy rains.
Concrete cancer is presently treated with remedial waterproofing, such as by means of liquid or torch-on membranes, loose-layered sheet membranes, hypalon bandages, tanking membranes, “negative waterproofing” through injection, painted on chemical solutions, and/or polyurethane sealants. However, treatment of concrete cancer is expensive and can only have a limited effect in slowing further rusting of the reinforcing bars. The prevention of concrete cancer would be vastly preferable to its treatment.
Concrete cancer is a problem specific to a particular sector of the construction industry, namely the sector which builds with concrete and reinforced concrete. In the UK this includes, for example, the building of new domestic housing as well as industrial buildings such as carparks and even railway lines if reinforced concrete sleepers are used. The regulatory approach in the construction sector is strict. In the UK, for example, building regulations do not allow use of a product for a particular purpose until it has been tested and approved for that purpose. Other countries are likely to have similar building regulations, at least, for example, in countries such as the EU member states, the USA, Australia etc. Skilled workers in the field of construction therefore are not accustomed to developing solutions to address problems such as how to prevent concrete cancer.
There is a need to overcome these difficulties, and a safer, faster, and more reliable way of preventing moisture ingress at the ends of structural beams of this type would have widespread application in the construction industry.
In a first aspect, the invention provides an end cap for preventing ingress of moisture to the end face of a structural beam, wherein said structural beam comprises metal, stone, concrete, reinforced concrete, or a mixture thereof;
Preferably the end cap may have one or all of the following features, or a mixture thereof:
the end cap may comprise at least two end cap segments, each end cap segment comprising:
said skirt may comprise a base edge which is directly connected to at least a portion of an edge of said end plate, said skirt extending in a direction generally perpendicular to said end plate;
said transverse cross-section of said structural beam may be T-shaped, H-shaped, U-shaped, L-shaped, I-shaped, TY-shaped, TT-shaped, Y-shaped, or regular or irregular trapezoid-shaped excluding square and/or rectangular shaped; preferably T-shaped;
said material for preventing transmission of moisture may comprise or consist of a material selected from the group consisting of: plastic, polyethylene, natural rubber, synthetic rubber, thermoplastic, asphalt material, bitumen, and modified bitumen;
said material for preventing transmission of moisture may comprise or consist of a damp proof membrane;
said end plate may be planar;
said end cap may be a unitary body, or each of said end cap segments may be a unitary body;
said skirt may form a continuous side wall along substantially the totality of the edges of the end plate;
said skirt may form a continuous side wall along all except one edge of the end plate;
said structural beam may be a pre-cast concrete beam or a reinforced pre-cast concrete beam, optionally a T-beam;
said structural beam may be for use in combination with blocks to form beam and block flooring;
said end cap, when fitted to the end of said structural beam, may be locatable upon the footings of a wall such that the wall can be built upwardly thereon; said wall may preferably be an interior wall of a cavity wall;
said skirt and said end plate may be between 0.5-3.5 mm thick, preferably 1-3 mm thick, for example 1.5-2.5 mm thick;
said skirt may be at least 90 mm long and/or no more than 140 mm long, preferably 100-130 mm long.
The end cap for preventing ingress of moisture to the end face of a structural beam comprising metal, stone, concrete, reinforced concrete, or a mixture thereof, according to the invention may be defined alternatively as an end cap having
Preferably the water vapour resistance is at least 500 MNs/g, more preferably at least 600 MNs/g. Water vapour resistance may suitably be measured according to BS EN 1931 method B. Method B uses a desiccant within the test cup and 75% RH in the test chamber.
In a second aspect, applicable to all embodiments, the invention provides a kit of parts for installing block and beam flooring, comprising a structural beam and an end cap according to the invention, optionally further comprising one or more flooring blocks. Preferably, said structural beam may be a pre-cast concrete T-beam, optionally a reinforced pre-cast concrete T-beam.
In a third aspect, equally applicable to all embodiments, the invention provides a method for reducing corrosion of a structural beam comprising fitting an end cap according to the invention to a structural beam. Preferably said end cap may be fitted before or during installation of said structural beam in a building. It is preferred that said end cap may be fitted by pushing or sliding onto the end of said structural beam. Said structural beam is preferably a pre-cast concrete beam, more preferably a reinforced pre-cast concrete beam, optionally a T-beam.
In a fourth aspect, the invention provides a method of manufacturing an end cap according to the invention, comprising injection moulding or blow moulding.
All features described in connection with any aspect of the invention can be used with any other aspect of the invention.
The invention will be further described with reference to a preferred embodiment, as shown in the drawings in which:
Throughout this application terms should be interpreted according to their standard meaning in the art unless specified otherwise. The following terms should be construed according to their standard meanings, as set out below.
As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. Thus for example, a reference to “a method” includes one or more methods, and/or steps of the type described herein and/or which will become apparent to those persons skilled in the art upon reading this disclosure and so forth.
The term “approximately” or “about” in connection with a number is intended to mean “in the region of”, i.e. within normal tolerance of the stated value. In other words, a value that the skilled worker in the relevant field would round up or round down to reach the “approximate” value. For example a value in the range of 95 to 104 would be “approximately 100”, or 0.96 to 1.04 would be “approximately 1”.
The term “at least” when used in connection with a number has its standard meaning, i.e. means that number is the minimum value for the specified parameter/component. For example “at least one end plate” means there is one or more end plate and discloses the options of one end plate or more than one end plate being present.
The term “comprising” should be construed as meaning “including but not limited to”. The term “comprising” also discloses mixtures, products, processes and the like “consisting essentially of” the specified features and “consisting of” the specified features. For example, a mixture disclosed herein as comprising components (a) to (d) also discloses a mixture consisting of components (a) to (d).
The term “greater than” when used in connection with a number has its standard meaning, i.e. means that the specified parameter has a value higher than the specified number.
The term “not greater than” or “no more than” when used in connection with a number has its standard meaning, i.e. means that the specified parameter has a maximum value equal to the specified number.
The term “in the range from X to Y” has its standard meaning, i.e. the value of the parameter is a minimum of X and a maximum of Y.
The term “less than” when used in connection with a number has its standard meaning, i.e. means that the specified parameter has a value lower than the specified number.
The term “multiple” has its standard meaning, i.e. at least 2, more preferably at least 3.
The term “no less than” or “not less than” when used in connection with a number has its standard meaning, i.e. means that the specified parameter has a minimum value equal to the specified number.
The term “optionally” has its standard meaning, i.e. means that the specified feature is not essential and may or may not be present. Optional components or process steps disclose the claimed product or process including and not including the optional feature.
In this specification, unless expressly otherwise indicated, the word ‘or’ is used in the sense of an operator that returns a true value when either or both of the stated conditions is met, as opposed to the operator ‘exclusive or’ which requires that only one of the conditions is met.
The term “performed using” has its standard meaning, i.e. when the claimed method or process is carried out, the specified feature applies.
Features which are described herein with reference only to a single aspect or embodiment of the invention apply equally to all other aspects and embodiments of the invention. Hence features from one aspect or embodiment may be combined with features from another aspect or embodiment.
All prior teachings acknowledged above are hereby incorporated by reference. No acknowledgement of any prior published document herein should be taken to be an admission or representation that the teaching thereof was common general knowledge in Europe or elsewhere at the date hereof.
The invention provides an end cap for preventing ingress of moisture. Ingress of moisture is at least reduced by means of the end cap and preferably prevented. The level of ingress of moisture can be tested by methods known in the art, including measuring moisture transmission properties of the material from which the end cap is made. For example, water vapour transmission rate or moisture vapour transmission rate in g/m2/day. These may be measured by methods such as:
Preferably water vapour transmission may be measured using ASTM E96 methods or BS EN 1931 methods, most preferably by BS EN 1931 Method B providing a measurement of water vapour permeability in g/m2/day.
Preferably the end cap of the invention provides a water vapour permeability of less than 0.5 g/m2/day, more preferably less than 0.3 g/m2/day.
The end cap of the invention prevents water or moisture getting into the face of a structural beam. Water ingress here can cause corrosion, particularly where the beams are reinforced with metal rebars.
Typical structural beams are those comprising metal, stone, concrete, reinforced concrete, or a mixture thereof. Preferably the beams comprise or consist of reinforced concrete, such as those reinforced with steel rebars (reinforcing bars or ties). Such beams are often pre-cast, such as pre-cast reinforced concrete beams.
Wooden beams, e.g. joists, railings, or rafters, are not structural beams within the meaning of the invention herein. Wooden beams are not susceptible to concrete cancer or other problems caused by water permeation in the structural beams discussed herein. Wooden beams are susceptible to a different range of technical problems such as shrinkage and swelling, deterioration by decay, molds, fungi, bacteria and insects. The technical problems faced by builders using wooden beams differ significantly from those of builders using beams comprising metal, stone, concrete or reinforced concrete, or a mixture thereof. Wooden beams are typically of square or rectangular cross-section and are not suitable for the same applications as the structural beams addressed herein e.g. in block and beam flooring. In view of the strict regulation and safety aspects of the construction industry, construction workers working with structural beams comprising metal, stone, concrete, reinforced concrete, or a mixture thereof would not consider products designed for use with wood/timber as being suitable for use with structural beams comprising metal, stone, concrete, reinforced concrete, or a mixture thereof, and vice versa.
The end cap according to the invention, i.e. for preventing ingress of moisture to the end face of a structural beam comprising metal, stone, concrete, reinforced concrete, or a mixture thereof, differs from a hypothetical end cap for use with a wooden beam, e.g. a joist, rafter or railing. The type of material making up the beam can make a significant difference to the necessary shape, size and functionality of the end cap. For example, in block and beam flooring the end of the structural beam where the end cap is located may eventually form part of the interior cavity wall such that the end cap should be robust enough to maintain its integrity while bearing the load of the wall. In another example, prevention of ingress of water to a structural beam, e.g. with the aim of preventing concrete cancer, may require different water vapour transmission properties in the end cap than would be required for use in relation to a wooden beam.
The end cap for preventing ingress of moisture to the end face of a structural beam comprising metal, stone, concrete, reinforced concrete, or a mixture thereof, according to the invention may be defined alternatively as an end cap having
Preferably the water vapour resistance is at least 500 M Ns/g, more preferably at least 600 MNs/g. Water vapour resistance may suitably be measured according to BS EN 1931 method B. Method B typically uses a desiccant within the test cup and 75% RH in the test chamber.
In a preferred embodiment the structural beams are those which are suitable for use with blocks to make “beam and block flooring”.
Beam and block flooring is a type of flooring system in which structural beams are used to support blocks such as breeze-blocks. Typically, a beam having a transverse cross-section of T-shape may be used. Such a beam would be laid inverted, i.e. with the top of the “T” as the base, with blocks laid into the “lip” and supported by the lip of another inverted T-beam on the other side.
Structural beams for which the end cap of the invention is intended typically have a regular shape. In other words, they have a transverse cross-section which is consistent over the longitudinal length of the beam. Typically such beams have transverse cross-sections of a shape such as that of one of the letters T, H, U, L or I. Other typical transverse cross-sections have a shape described as “TY”, Double-T (e.g. TT), or Y cross-sections. Further typical cross-sections can be regular or irregular trapezoids, excluding square or rectangular cross-sections. Suitable structural beams typically do not have a regular quadrilateral transverse cross-section such as square or rectangular transverse cross-section.
Preferably the end caps are for use with structural beams having a transverse cross-section of a shape selected from the group consisting of: T, H, U, L or I-shaped; “TY”-shaped, double-T-shaped (e.g. TT-shaped), or Y-shaped; regular or irregular trapezoid-shaped, excluding square and rectangular cross-sections.
Especially preferred are end caps having an end plate of a shape selected from the group consisting of: T-shaped, H-shaped, U-shaped, L-shaped, I-shaped, “TY”-shaped, double-T-shaped (e.g. TT-shaped), Y-shaped, regular or irregular trapezoid-shaped, excluding square and/or rectangular shapes. Even more preferably the end plate is T-shaped, H-shaped, U-shaped, L-shaped, “TY”-shaped, double-T-shaped (e.g. TT-shaped), or Y-shaped. Most preferably the end plate is T-shaped or L-shaped. In an especially preferred embodiment applicable to all aspects of the invention the end plate is T-shaped.
Preferably the end caps are for use with beams which are pre-cast reinforced concrete beams.
In a preferred embodiment the end caps are for use with structural beams which are pre-cast reinforced concrete beams having a T-shaped transverse cross-section.
Structural beams for which the end cap of the invention is intended may be square cut to form the end face of the beam, or may be cut on an angle to fit the shape and dimensions of the building. A square cut beam, for example, typically will have an end face that is approximately perpendicular to the longitudinal axis of the beam.
An angled cut beam may have an end face which forms an acute or obtuse angle with the longitudinal axis of the beam. For example in an angled cut beam the end face may form an angle between 10-80° with the longitudinal axis, e.g. 30°, 45° or 60°.
Alternatively an angled cut beam may have an end face which forms an acute or obtuse angle with the transverse axis of the beam (z-axis). For example in an angled cut beam the end face may form an angle between 10-80° with the transverse axis (z-axis), e.g. 30°, 45° or 60°.
Angled cut beams comprising an end face which forms an acute or obtuse angle with each of the longitudinal and transverse axes of the beam are also envisaged as suitable for the end caps of the invention.
In angled cut and square cut beams the end face is typically essentially planar.
An angled cut end face may be necessary at one or both ends of a beam. For example, in constructing a room which will have a bay window, some beams may need an angled cut end face at one end of the beam.
In all types of angled cut beams, the transverse cross-section would still be consistent over the majority of the longitudinal length of the beam, for example, over 65% of the longitudinal length of the beam, such as over 75% or over 80% of the longitudinal length of the beam, preferably over 90% e.g. at least 95% of the longitudinal length of the beam.
Structural beams such as concrete or reinforced concrete beams are also used in e.g. industrial construction such as car parks. Concrete or reinforced concrete beams may further be used as railway sleepers or similar supporting beams in the laying of railway track. Such reinforced concrete railway sleepers would also be vulnerable to concrete cancer due to their ongoing exposure to the weather. In a particular embodiment, applicable to all aspects of the invention, the end cap may be suitable for use with reinforced concrete railway sleepers. Such railway sleepers typically have a transverse cross-section of a regular trapezoid shape that is not square or rectangular. Hence end caps in this embodiment would have an end plate being of a regular trapezoid shape that is not square or rectangular.
The end face of structural beams may be susceptible to corrosion caused by water, particularly when embedded within the interior wall of a cavity wall. The end caps according to the invention provide protection from such corrosion by preventing water ingress.
The end caps of the invention thus are made of material for preventing transmission of moisture. Suitable materials include damp proof materials such as materials comprising plastic, polyethylene, natural rubber, synthetic rubber, thermoplastic, asphalt material, bitumen, modified bitumen, and/or recycled materials comprising any of these e.g. recycled plastic. In a preferred embodiment the end caps may comprise or consist of recycled plastic and/or damp proof course material such as damp proof membrane. In an especially preferred embodiment applicable to all aspects of the invention the end cap comprises, consists essentially of, or consists of polyethylene, preferably recycled polyethylene.
The end cap preferably comprises or consists of a material having water vapour resistance of at least 400 MNs/g, preferably at least 500 MNs/g, more preferably at least 600 MNs/g, measured according to BS EN 1931 method B, i.e. a desiccant within the test cup and 75% RH in the test chamber. Suitable materials include, e.g. polyethylene and recycled polyethylene.
Preferably the end cap according to the invention is watertight as measured by a “pass” result in tests according to BS EN 1928 Method A at a pressure of 60 kPa for 24 hours.
More preferably the end cap according to the invention is also watertight as measured by a “pass” result BS EN 1928 Method A at a pressure of 60 kPa for 24 hours after (i) heat aging and (ii) alkali immersion according to (i) BS EN 13967 and BS EN 1296, i.e. stored at 70° C. for a period of 12 weeks prior to conditioning and testing; and (ii) BS EN 13967 and BS EN 1847 i.e. immersion in a saturated solution of calcium hydroxide for 28 days.
Suitable materials for end caps according to the invention provide water vapour transmission resistance of at least 400 MNs/g, such as 400-800 MNs/g, preferably at least 500 MNs/g, more preferably at least 600 MNs/g, measured according to BS EN 1931 method B, i.e. a desiccant within the test cup and 75% RH in the test chamber.
Typically the end cap of the invention may consist of a material composition providing resistance to static loading as measured by a “pass” result in tests according to BS EN 12730 Method B (hard support) with a 20 kg applied load.
Typically the end cap of the invention may consist of a material composition that also exhibits tensile stress of at least 7.5 N/mm2 and elongation at break of at least 20% when tested according to BS EN ISO 527-2 using Type 1A dumbbell specimens using a grip separation speed of 100 mm/minute.
Typically the end cap of the invention may consist of a material composition that exhibits impact resistance of 2000 mm as tested according to BS EN 12691: 2006 method A using the hard support. Preferably the impact test result is unaffected by storage at −20° C. for 24 hours.
Typically the end cap of the invention may consist of a material composition that exhibits resistance to tearing according to BS ISO 34-1 using a grip separation speed of 100 mm/minute where the median tear strength is at least 65 kN/m.
Suitable structural beams may be of any length appropriate for the dimensions of the flooring area or building being constructed. Typically, these beams may vary in length from 1 m to 7 m, for example, 2-5 m long.
Suitable beams are typically between 100-170 mm wide, at the widest point. In other words each beam is a significant concrete “slab” so that holding and maneuvering these manually is difficult.
Typical T-beams may be, for example, 150 mm wide at the widest point (width of the flange) and 225 mm high (perpendicular distance between the base of the web and the top of the flange), where the flange is 125 mm high and the web is 100 mm high, while the web is 90 mm wide, the flange protruding a further 30 mm beyond the web on either side to form two lips.
Another typical T-beam may be, for example, 160 mm wide at the widest point (width of the flange) and 175 mm high (height being the perpendicular distance from base of web to top of flange), where the flange is 75 mm high and the web is 100 mm high, the web being 110 mm wide, such that the flange protrudes a further 25 mm beyond the web on either side to form two lips.
Other examples of T-beams include, “deep” T-beams, being e.g. 110 mm wide at the widest point (width of the flange) and 152 mm high (height being the perpendicular distance from base of web to top of flange), and the web being 73 mm wide, such that the flange protrudes beyond the web on each side by a total of 27 mm to form two lips. Other “deep” T-beams may be e.g. 106 mm wide at the widest point (width of the flange) and 178 mm high, with a 58 mm wide web.
Other examples of T-beams include, a “deep wide” T-beam, being e.g. 168 mm wide at the widest point (width of the flange) and 152 mm high (height being the perpendicular distance from base of web to top of flange), and the web being 126 mm wide, such that the flange protrudes beyond the web on each side by a total of 42 mm to form two lips.
The end cap according to the invention may be sized to fit a T-beam of any dimensions.
Likewise the end cap according to the invention may be sized to fit any particular dimensions of an H-beam, L-beam, U-beam, I-beam, TY_beam, TT_beam, Y-beam, or trapezoid beam excluding square or rectangular beams.
The size of the end cap is such as to provide a snug fit to the structural beam, loose enough to allow the end cap to be fitted simply by pushing it on to the beam, but tight enough for the skirt or side plates to grip the beam so as to keep the end cap in place. The skilled worker will be aware when an end cap has a snug fit because, as described, the end cap will be big enough to fit onto the beam end, but small enough not to fall off and/or appreciably shift position when the beam is tilted from the horizontal to the vertical (having the end capped beam-end at the lower end of the beam). For example, a shift in position of no more than 1 cm on tilting the beam from the horizontal to the vertical.
Alternatively, a snug fit may be defined as a difference of 10 mm or less between the dimensions of the end cap and the corresponding dimensions of the beam, the dimensions of the end cap being the larger. For example, a difference of 8 mm or less, preferably 2-6 mm, for example 3-5 mm.
Typically, the skirt or side plates of end caps according to the invention will extend in the direction of the longitudinal axis of the beam sufficiently to hold the end plate in position. For example, the skirt or side plates may have a length in the region of 90-140 mm, such as 100-130 mm.
The end caps according to the invention are typically a single, unitary body. Alternatively, the end cap may consist of end cap segments which fit together to form the end cap, where each end cap segment is a unitary body.
A unitary body is a single piece, for example a single piece made by injection moulding.
In the embodiment where the end cap is made up of end cap segments, each of these segments may be a unitary body. Preferably the segments may be combined by a simple push-fit such that they combine to form an end cap according to the invention. The combined end plates in such an end cap will match the transverse cross-section of the structural beam.
The end caps according to the invention typically may have a thickness in the region of 0.5-4.0 mm, such as 0.5-3.5 mm or 0.5-3.0 mm, in a preferred embodiment applicable to all aspects of the invention, the thickness may be in the range 1.0-3.5 mm, for example preferably 1.0-2.5 mm, more preferably approximately 1.5-2.0 mm. In an equally preferred embodiment, applicable to all aspects of the invention, the thickness may preferably be in the range 2.0-3.0 mm, for example preferably 2.2-2.9 mm.
It is preferred that the thickness of the end plate and the skirt or side plates of the end caps is uniform, but this may be variable. For example, in an embodiment where it is desirable to have a thicker end plate and tapered skirt or side plate.
The end caps according to the invention are locatable upon the footings of a wall so that the wall can be built upwardly thereon. For example, so that it is possible to place the end of the structural beam, with its fitted end cap, onto the bricks or blocks of a wall and continue to place bricks or blocks on top, without adversely affecting the stability of the wall. Likewise, it is preferred that the wall can be extended outwardly from the beam as well as upwards. It is preferred that such a wall be the interior wall of a cavity wall.
The end plate of the end caps according to the invention is preferably planar. The end plate has a shape which matches the transverse cross-section of the structural beam for which the end cap is to be fitted. For example, the end plate may be in a shape selected from the group consisting of: T, H, U, L or I-shaped; “TY”-shaped, double-T-shaped (e.g. TT-shaped), or Y-shaped; regular or irregular trapezoid-shaped, excluding square and rectangular cross-sections. For example, the end plate may be in the shape of a letter T, H, L, U or I, preferably T. In a preferred embodiment applicable to all aspects of the invention the end plate may be of a shape selected from the group consisting of: T-shaped, H-shaped, U-shaped, L-shaped, TY-shaped, TT-shaped, Y-shaped, and regular or irregular trapezoid-shaped excluding square and/or rectangular shaped.
The end plate has at least one edge. The end plate may be viewed as having a single continuous edge which runs around the entirety of the end plate. This may be referred to as the peripheral edge. Alternatively the end plate may be viewed as having multiple edges where each edge is linear and connects to adjacent edges of the end plate.
The end cap may comprise a skirt for holding the end plate in position on the end face of the structural beam. The skirt may hold the end plate in position for example by gripping the longitudinal sides of the beam such as by friction-grip or by the snug-fit of the skirt.
The skirt is typically made of the same material as the end plate.
The skirt has a base edge. The base edge connects to the end plate at the edge of the end plate. The skirt connects to at least a portion of an edge of the end plate and extends in a direction which is generally perpendicular to the end plate. In other words, along the longitudinal axis of the structural beam. In embodiments suitable for angled cut beams, the skirt still extends in a direction corresponding to that of the longitudinal axis of the beam, but this may no longer be perpendicular to the end plate, depending on the angular cut of the end face of the beam which the end cap is to fit.
The skirt preferably connects along substantially the totality of the edge of the end plate. In other words all around the peripheral edge of the end plate.
In the skirt embodiment where the end cap comprises end cap segments, the skirt may connect around all except one edge of the end plate in each end cap segment, such that the end cap segments may be fitted together. This is shown, for example, in
Typically end cap segments in this embodiment may be fitted together by means of push fit. Fastening means for connecting end cap segments together are also envisaged, for example Velcro (RTM) or other suitable fastening means.
Typically the end plate of each end cap segment will include a section which overlaps with the end plate segment of an adjacent end cap segment. The overlap of end plates will generally be such that the end plate of the upper end cap segment overlays the lower end cap segment end plate. The reverse may be the case in some embodiments, however. For example, where there is concern about water transmission from pooling of water in the cavity wall, the end plate of the lower end cap segment may overlay the end plate of the upper end cap segment.
The skirt may typically be of a uniform length. Optionally the length of the skirt may be varied such as to be non-uniform. The minimum length of the skirt may typically be in the region of 90 mm, for example 100 mm. Preferably the minimum length of the skirt is equal to the width of a block for the beam and block flooring.
In an alternative embodiment, the end cap may comprise side plates which provide the same function as the skirt. In other words the side plates hold the end plate in position on the end face of the structural beam. The side plates may hold the end plate in position for example by gripping the longitudinal sides of the beam such as by friction-grip or by the snug-fit of the side plates.
The side plates are typically made of the same material as the end plate.
The end cap generally comprises more than 4 side plates, preferably at least 6 side plates. The number of side plates will generally be determined by the shape of the transverse cross-section of the structural beam. For example, a T-beam end cap will typically comprise at least 8 side plates.
Each side plate is typically planar.
Each side plate has a base edge. The base edge connects to the end plate at an edge of the end plate. The base edge of each side plate connects to at least a portion of an edge of the end plate and extends in a direction which is generally perpendicular to the end plate. In other words, along the longitudinal axis of the structural beam. In embodiments suitable for angled cut beams, the side plate still extends in a direction corresponding to that of the longitudinal axis of the structural beam, but this may no longer be perpendicular to the end plate, depending on the angular cut of the end face of the beam which the end cap is to fit.
Each side plate has at least two opposing edges. Each opposing edge is connected to at least a portion of an opposing edge of an adjacent side plate, as shown in, for example,
The side plates preferably connect along substantially the totality of the edge of the end plate. In other words all around the peripheral edge of the end plate.
The side plates may typically be of a uniform length. Optionally the length of the side plates may be varied such as to be non-uniform. The minimum length of each side plate may typically be in the region of 90 mm, for example 100 mm. Preferably the minimum length of each side plate is equal to the width of a block for the beam and block flooring.
In the side plate embodiment where the end cap is not unitary, the end cap may be viewed as including two or more end plates which combine to match the shape of the transverse cross-section of the structural beam, and a total number of side plates corresponding to at least 3 side plates per end plate. As before, each side plate has a base edge connected to at least a portion of an edge of one of said end plates and extending generally perpendicular to the end plate. Each side plate has at least two opposing edges, at least one of which is directly connected to at least a portion of an opposing edge of adjacent side plate connected to the same end plate.
Alternatively, the end caps may be viewed as including at least two end cap segments. Each end cap segment is preferably a unitary body. Each end cap segment includes an end plate, the segments combining such that the combined end plates match the shape of the transverse cross-section of the structural beam. Each end cap segment preferably includes at least three side plates. Each side plate has a base edge connected to at least a portion of an edge of one of said end plates and extending generally perpendicular to the end plate. Each side plate further has at least two opposing edges, at least one of which is directly connected to at least a portion of an opposing edge of adjacent side plate
The side plates preferably connect along all but one edge of the end plate, such that when the end cap segments are fitted together the combined end plates have side plates connected along substantially the totality of the peripheral edge of the combined end plates.
Typically end cap segments in the side plate embodiments may be fitted together by means of push fit. Fastening means for connecting end cap segments together are also envisaged, for example Velcro (RTM) or other suitable fastening means.
Typically the end plate of each end cap segment will include a section which overlaps with the end plate segment of an adjacent end cap segment. The overlap of end plates will generally be such that the end plate of the upper end cap segment overlays the lower end cap segment end plate. The reverse may be the case in some embodiments, however. For example, where there is concern about water transmission from pooling of water in the cavity wall, the end plate of the lower end cap segment may overlay the end plate of the upper end cap segment.
Structural beams for which the end caps are designed are preferably for use in combination with blocks, i.e. flooring blocks, to form beam and block flooring. The invention thus also provides a kit of parts for installing beam and block flooring, comprising at least one structural beam and an end cap according to the invention. Optionally the kit may further comprise one or more flooring blocks.
In a preferred embodiment the structural beams are pre-cast concrete T-beams, more preferably pre-cast reinforced concrete T-beams. It is equally preferred that two end caps are provided for each beam that is provided in the kit, such that one may be fitted to each end of the beam. It is further preferred that the kit provides the appropriate number of beams, end caps and flooring blocks for the desired floor space. For example, a preferred kit may provide at least two structural beams, at least four end caps, and a plurality of flooring blocks. An alternative preferred kit may provide at least two T-beams, at least two L-beams, at least four T-shaped end caps and at least four L-shaped end caps, and a plurality of flooring blocks. In all embodiments, optionally one or more of the beams may have one or more angle-cut end faces.
The end caps of the invention provide a barrier to transmission of moisture from the cavity of a cavity wall which is far more effective than the hand-wraps which are currently applied in the building industry. Thus the invention also provides a method of reducing corrosion of a structural beam, comprising fitting an end cap according to the invention.
The end caps of the invention may be fitted to the end of a beam before or during installation in a building. It may be advantageous to fit the end caps before installation when the ends of the beams are more easily accessible. It is still possible to fit end caps during the beam installation, however, and this will be quicker and less labour-intensive than the current method of hand-wrapping beam ends.
The end caps of the invention may be fitted to the structural beams manually, by pushing or sliding the end cap onto the beam end, preferably until the end plate makes contact with the end face of the beam.
The end caps and/or end cap segments of the invention may be made by conventional methods for forming plastic, rubber and/or bitumen articles which are known to the worker skilled in the art. For example, a preferred method of manufacturing may comprise one or more blow moulding processes such as extrusion blow moulding, injection blow moulding and/or injection-stretch blow moulding. Equally preferred methods may comprise injection moulding and/or rotational moulding, or a mixture of injection moulding and blow moulding processes.
Whilst the invention has been described with reference to a preferred embodiment, it will be appreciated that various modifications are possible within the scope of the invention.
Preferred embodiments of the invention include:
1. An end cap for preventing ingress of moisture to the face of a structural beam, wherein said structural beam comprises metal, stone, concrete, reinforced concrete, or a mixture thereof;
said end cap comprising:
2. An end cap comprising:
4. The end cap according to any preceding embodiment wherein said skirt comprises a base edge which is directly connected to at least a portion of an edge of said end plate, said skirt extending in a direction generally perpendicular to said end plate.
5. An end cap for a structural beam, comprising:
6. An end cap for a structural beam, comprising:
7. The end cap according to embodiment 6, comprising at least two end cap segments, each end cap segment comprising:
8. The end cap according to embodiments 5, 6 or 7 wherein said structural beam comprises metal, stone, concrete, reinforced concrete, or a mixture thereof.
9. The end cap according to any preceding embodiment wherein said transverse cross-section of said structural beam is selected from the group consisting of: T-shaped, H-shaped, U-shaped, L-shaped, I-shaped, TY-shaped, TT-shaped, Y-shaped, and regular or irregular trapezoid-shaped excluding square and rectangular cross-sections; preferably selected from T-shaped, H-shaped, U-shaped, L-shaped or I-shaped, more preferably T-shaped or L-shaped; most preferably T-shaped.
10. The end cap according to any preceding embodiment where said end plate or said combined end plate has a shape selected from the group consisting of: T-shaped, H-shaped, U-shaped, L-shaped, TY-shaped, TT-shaped, Y-shaped, and regular or irregular trapezoid-shaped excluding square and/or rectangular shaped.
11. The end cap according to any of embodiments 1-4 or 9 or 10 wherein said material for preventing transmission of moisture comprises or consists of a material selected from the group consisting of: plastic, polyethylene, natural rubber, synthetic rubber, thermoplastic, asphalt material, bitumen, and modified bitumen.
12. The end cap according to any of embodiments 1-4 or 9 or 10 wherein said material for preventing transmission of moisture comprises or consists of a damp proof membrane.
13. The end cap according to any preceding embodiment wherein said end cap comprises or consists of a material selected from the group consisting of: plastic, polyethylene, natural rubber, synthetic rubber, thermoplastic, asphalt material, bitumen, and modified bitumen.
14. The end cap according to any preceding embodiment wherein said end cap comprises or consists of a damp proof membrane.
15. The end cap according to any preceding embodiment wherein said end plate is planar.
16. The end cap according to any of embodiments 1, 2, 4, 5 or 8-15 wherein said end cap is a unitary body.
17. The end cap according to any of embodiments 3 or 6-15 wherein each of said end cap segments is a unitary body.
18. The end cap according to any of embodiments 1, 2, 4 or 9-17 wherein said skirt forms a continuous side wall along substantially the totality of the edges of the end plate.
19. The end cap according to any of embodiments 3, 4, 9-17 wherein said skirt forms a continuous side wall along all except one edge of the end plate.
20. The end cap according to any of embodiments 5, 8, 9, 10, or 13-16 wherein said side plates are connected so as to form a continuous side wall along substantially the totality of the edges of the end plate.
21. The end cap according to any of embodiments 6-9, 13-15 or 17 wherein said side plates are connected so as to form a continuous side wall along all except one edge of the end plate.
22. The end cap according to any preceding embodiment wherein said structural beam is a pre-cast concrete beam or a reinforced pre-cast concrete beam, optionally a T-beam.
23. The end cap according to any preceding embodiment wherein said structural beam is for use in combination with blocks to form beam and block flooring.
24. The end cap according to any preceding embodiment wherein said end cap, when fitted to the end of said structural beam, is locatable upon the footings of a wall such that the wall can be built upwardly thereon.
25. The end cap according to embodiment 24 wherein the wall is an interior wall of a cavity wall.
26. The end cap according to any preceding embodiment wherein said skirt and said end plate are between 0.5-3.5 mm thick, preferably 1-3 mm thick, for example 1.5-2.5 mm thick;
or
wherein said side plates and said end plate are between 0.5-3.5 mm thick, preferably 1-3 mm thick, for example 1.5-2.5 mm thick.
27. The end cap according to any preceding embodiment wherein said skirt or said side plates are at least 90 mm long and/or no more than 140 mm long, preferably 100-130 mm long.
28. A kit of parts for installing block and beam flooring, comprising a structural beam and an end cap according to any preceding embodiment, optionally further comprising one or more flooring blocks.
29. A kit according to embodiment 28 wherein said structural beam is a pre-cast concrete T-beam, optionally a reinforced pre-cast concrete T-beam.
30. A method for reducing corrosion of a structural beam comprising fitting an end cap according to any of embodiments 1-27 to a structural beam as defined in any preceding embodiment.
31. The method according to embodiment 30 wherein said end cap is fitted before or during installation of said structural beam in a building.
32. The method according to embodiment 30 or 31 wherein said end cap is fitted by pushing or sliding onto the end of said structural beam.
33. A method of manufacturing an end cap according to any of embodiments 1-27 comprising injection moulding or blow moulding.
Samples of suitable materials used in the end caps of the invention were tested to establish performance characteristics for a typical end cap. The test programme followed the methods given in BS EN 13967 (Flexible sheets for waterproofing—Plastic and rubber damp proof sheets including plastic and rubber basement tanking sheet) as the basis for the testing undertaken.
The tests were carried out on injection moulded products composed of recycled plastic suitable for use in the end caps according to the invention, specifically recycled polyethylene. The test product had a nominal thickness of 2.9 mm.
Testing was undertaken following the methodology described in BS EN 1928 using Method A at a pressure of 60 kPa for 24 hours. This method and pressure is the same as that used for testing tanking membranes as required in BS EN 13967. In addition to being undertaken on the as-received (unaged) material, this test was repeated after heat ageing and alkali immersion.
The results are presented in Tables 1-3 below.
Samples 4-6 were heat aged in accordance with the requirements given in BS EN 13967 and BS EN 1296, i.e. stored at 70° C. for a period of 12 weeks prior to conditioning and testing. Watertightness testing was carried out as for samples 1-3 described above.
Samples 7-9 were subjected to alkali immersion. Samples were immersed in a saturated solution of calcium hydroxide for 28 days as specified in BS EN 13967 and BS EN 1847. Watertightness testing was undertaken as for samples 1-3, after conditioning at ambient laboratory conditions.
Testing was undertaken following the methodology described in BS EN 12730 Method B (hard support). Three specimens were tested at the maximum loading increment of 20 kg.
The results are presented in Table 4.
Testing was undertaken following the methodology described in BS EN ISO 527-2 using Type 1A type dumbbell specimens. Five samples were tested, with elongation being determined using grip separation. Testing was carried out using a grip separation speed of 100 mm/minute.
The results are presented in Table 5.
The results of testing in Example 3 show a mean tensile stress of 8.2 N/mm2 with standard deviation 0.4 N/mm2. Mean elongation at break was 24.4%.
Testing was undertaken following the methodology described in BS EN 12691: 2006 Method A, i.e. using the hard support. A number of preliminary tests were undertaken initially to provide an indicative level of impact resistance. Subsequently, five samples (Samples 18-22) were tested at a drop height of 2000 mm which resulted in no punctures.
This result gave an impact resistance of 2000 mm for end cap test material.
Testing was undertaken following the methodology for determination of trouser tear strength (Method A) as described in BS ISO 34-1, with samples measuring 15 mm (width) by 100 mm (length). Five samples (Samples 23-27) were tested. Testing was carried out using a grip separation speed of 100 mm/minute.
The results are presented in Table 6.
The results of testing in Example 5 show a median tear strength (Trouser) Ts, of 69 kN/m with a Range of 20 kN/m.
Testing was undertaken following the methodology given in BS EN 1931 using Method B, i.e. a desiccant within the test cup and 75% RH in the test chamber. Three samples (Samples 28, 29 and 30) measuring 90 mm in diameter were tested. The nominal thickness of the samples tested was 2.9 mm. The results are presented in Table 7.
From the above table, the mean values are as follows:
Samples measuring 150 mm×150 mm were stored at a temperature of −20° C. for 24 hours before being tested for impact resistance in accordance with the method described in Example 4. The aim of this test was to investigate whether the material became embrittled after exposure to a low temperature. The results are given in Table 8.
The majority of tests cited under BS EN 13967, for CE marking purposes, require the manufacturer to declare a limiting value above which (or below for some properties) test results will not fall. The only ‘Pass’ requirements given in BS EN 13967 are as follows:
Watertightness after heat ageing
Watertightness after immersion in alkali solution (calcium hydroxide)
CE marking is a certification mark that indicates conformity with health, safety, and environmental protection standards for products sold within the European Economic Area (EEA). The CE marking is also found on products sold outside the EEA that are manufactured in, or designed to be sold in, the EEA.
The end cap product sample materials tested in Examples 1-7 passed all of the above tests at a pressure of 60 kPa, which is the maximum required for a tanking membrane according to BS EN 13967.
The impact test achieved a drop height of 2 metres, which was unaffected by exposure in the frost cabinet. Typically, tanking membranes might be expected to achieve impact drop heights up to 1 metre. Under static loading the materials showed no puncture or leakage after application of the largest (20 kg) load. The value for water vapour resistance (526 MNs/g) compares favourably with a value for 1000 gauge polyethylene given in Table E2 of BS 5250, which suggests a range of 400 to 600 MNs/g. 1000 gauge polyethylene is often considered to be a ‘typical’ damp proofing membrane.
The tensile stress and tearing strength exemplified are more than sufficient to provide a robust product for use with structural beams.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1714182.1 | Sep 2017 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2018/052483 | 9/3/2018 | WO | 00 |
