Patent Application
20200256055
The present invention relates broadly to building construction and particularly to floor beams, systems comprising the floor beams and method of constructing a floor using the floor beams.
Traditional beam and block floor systems, which remains the principal flooring system of choice within a domestic setting in the UK includes concrete T beams and blocks interspersed between the T beams. Insulation is placed above the finished structural floor and a concrete screed laid above the insulation.
The concrete floor beams weigh typically around 30 to 40 KG per metre. They therefore require installation by mechanical lifting equipment (e.g., an excavator or crane).
The blocks laid between the floor beams are normally concrete blocks generally 440 mm×215 mm×100 mm, and are laid flat by hand.
Advantages of the traditional beam and block system include cost, availability of product around the UK, and the creation of an instant working floor on which finishes can be later applied. Furthermore, most builders are familiar with the design of the system.
The practical disadvantages of the beam and block system include that the beams and blocks are heavy and create a significant manual handling risk. Accordingly, they require a substantial amount of labour to lay the floor. An additional disadvantage includes the cost of the mechanical lifting equipment (including the provision of a designed safe working base for the crane to stand).
The technical disadvantages of the beam and block system include that the thermal insulation value of the floor (i.e., the U value) is provided solely by the insulation layer. In order to achieve the UK's building regulations, an insulation thickness of 150 mm is common. This adds 150 mm to the overall build height of the house. In addition, the Concrete screed is a dead weight which must be carried on the floor beams below as it does not form a structural use.
To overcome the issue of increasing thickness of insulation, an alternative system implemented within some of the more recent flooring uses the traditional concrete T beams but replaces the concrete infill block with polystyrene (e.g., expanded polystyrene “EPS”) blocks. The polystyrene wraps under the floor beam to insulate this ‘cold’ product and provides the insulation required without the addition of an insulation sheet above the floor beam. The concrete screed is then applied directly on top of the polystyrene.
An advantage of this hybrid system is that the overall thickness of the floor is reduced, whilst still providing the required U values. However, the disadvantages include that the concrete T beams are still too heavy to lift manually, the depth of insulation under the floor beams requires additional site excavation, and the screed again acts as a dead weight on the floor beams and does not contribute to the strength of the floor. The floor beams are thermally ‘cold’ and require fully insulation to avoid heat loss. The different components required mean that the floor is difficult to install and there is a lot of waste.
There is therefore a need for a flooring system which has improved manual handling characteristics and improved mechanical properties such as insulation and long-term strength.
According to a first aspect of the invention there is provided a structural beam for use in a building, the structural beam comprising;
The provision of a camber between the first end and the second end is designed so that the deflection of the beam caused by the loading of structural concrete onto the top of the beam is within building tolerances.
Optionally, the structural beam is a floor beam. In some constructions, the floor beam may have a depth of about 150 mm or about 225 mm in order to coordinate with standard build heights of floor beams within the UK. Accordingly, a conventional concrete T beam can be readily replaced with a floor beam of the present invention.
The provision of selection of floor beams having varying depths enables a beam having a greater depth to be used in order to cater for longer beam spans and/or heavier loads.
A floor system may comprise a plurality of beams each having a depth of 150 mm with the beams being spaced apart by about 400 mm. An insulation member, such as a polystyrene block, is provided between adjacent beams. Each beam has a predefined, set strength. Accordingly, when the span of the beam lengthens and/or the loading on the beam increases, the beam centres will need to be moved closer together. This provides more beams per metre width, enabling the beams to retain the load without structural failure. As a result of the narrowing of the space between adjacent beams, narrower polystyrene blocks will be required.
However, a point will be reached at which the 150 mm deep beams cannot be moved any closer together. At this point the 150 mm deep beams may be substituted with, beams having a greater depth. For example, 225 mm deep beams.
The provision of a trough within the beam enables concrete screed to be poured into the beam. Once the concrete has set the beam and the screed act as a composite structural element. The concrete will also be poured over the upper surface of the beam, and the upper surface of the insulation member.
Optionally, the structural beam is made of a polymer, for example a fibre reinforced polymer (FRP). FRP includes the class of materials known as Glass Reinforced Polymer (GRP) or Carbon Fibre Polymers.
FRP components may be manufactured by was of a pultrusion process. Pultrusion is a mechanical process that draws continuous fibres impregnated with a thermosetting resin through a heated die that polymerises the resin and forms the composite shape of the pultruded profile in a continuous process.
Despite being of a lighter weight material, pultruded FRP is similar in strength to steel and concrete in tension and compression but not as stiff.
A polymer floor beam, such as a pultruded beam is much lighter than equivalent concrete beams and is therefore easier to manually handle. This improves the health and safety issues surrounding the handling of such beams. Furthermore, as the beam of the invention can be moved around a construction/building site manually and also installed by hand, there is a reduction in the associated cost of mechanical equipment (e.g., cranes), as well as the labour costs required to install a floor.
It is envisaged that the load applied by the concrete screed upon the top surface of the beam may cause the beam to deflect. This will lead, at least temporarily, to an uneven floor. This effect might be counteracted by incorporating a camber along the length of the beam. As the concrete is applied the beam will end up level. The amount of camber provided in a given beam may be chosen in accordance with the application that is envisaged. The factors used to determine the camber may, for instance, include the strength of the beam, the length of the beam and the amount (weight) of the concrete that is to be used.
Optionally therefore, a structural beam according to the invention includes a camber provided between the first end and the second end to compensate for the weight of the concrete when the beam is in situ.
Once the concrete screed has set, with the structural beam roughly levelled out underneath, the concrete will be bonded to the beam and form a composite structural floor. The screed will not simply be carried by the beam, as in the case of a traditional concrete T beam. Instead, the floor will work compositely using the compressive strength of the concrete on top of the beam and the tensile strength at the bottom of the beam, thus creating a strong floor which is capable of carrying the uniformly distributed superimposed floor load applied in the finished structure.
In some constructions of the structural beam, the first ledge extends outwardly from a first end of the wall member and the second ledge extends outwardly from a second end of the wall member.
In some constructions of the structural beam, one or both of the first ledge and the second ledge extend outwardly from the wall member at an angle substantially perpendicular to the wall member.
In constructions of the structural beam in which the first ledge extends outwardly from a first end of the wall member and the second ledge extends outwardly from a second end of the wall member, it is advantageous that the ledges extend at an angle substantially perpendicular to the wall member as it ensures that the floor beam is able rest evenly on the foundations and also that the concrete screed is applied as a flat, even surface above the beam.
The retention of at least part of the insulation member prevents the insulation member from protruding underneath the beam. This is advantageous as it prevents the need for additional site excavation to compensate for the depth of the insulation.
According to a second aspect of the invention, there is provided a system for use in a building, the system comprising:
Optionally, an insulation member is retained within the channel formed by the cooperation of the first and second ledge of the first wall member and the second wall member. As such, the unit provided has a centrally located beam with an insulation member retained on either side.
Optionally, an insulation member is retained within the channel formed by the cooperation of the first and second ledge on a first wall member and the retaining member is also retained within the channel formed by the cooperation of the first and second ledge on a second wall member. As such, the unit provided includes a centrally located insulation member with a beam on each side.
At least part of the insulation member, for example an edge, is bonded to at least part of the channel.
Optionally, the insulation member is a polystyrene, for example an expanded polystyrene (EPS). The U value of the flooring system may be lowered by, for example, choosing a thermally enhanced polystyrene.
The U value of the flooring system may be lowered by increasing the depth of the insulation member.
According to a third aspect of the invention, there is provided a floor constructed using a plurality of structural beams as herein described.
According to a fourth aspect of the invention, there is provided a kit comprising:
According to a fifth aspect of the invention there is provided a method of installing a floor system within a building, the method comprising the steps of:
After step (b), the method may further comprise the step of installing a second structural beam adjacent to the first beam and installing at least part of the insulation member into the channel formed by the cooperation of the first ledge and the second ledge of at least the first wall member or the second wall member of the second structural beam.
After step (b), the method may further comprise the step of installing at least a part of a second insulation member into the channel formed by the cooperation of the first ledge and the second ledge of at least the first wall member or the second wall member of the structural beam.
The method of installing a floor system within a building may also comprise a step of pouring concrete into the trough formed by the cooperation of the base member and each wall member.
The invention will now be described by way of example with reference to the accompanying drawings in which:
Although particular constructions of the invention have been described, it will be appreciated that many modifications/additions and/or substitutions may be made within the scope of the claimed invention.
The first wall member 12 includes a first ledge 20a extending outwardly away from the trough 18. As shown in this construction, the first ledge 20a extends outwardly from the wall member at an angle that is substantially perpendicular to the wall member. The first ledge extends outwardly in line with the base member 16.
The first wall member 12 also includes a second ledge 22a extending outwardly away from the trough 18. As shown in this construction, the second ledge 22a extends outwardly from the wall member at an angle that is substantially perpendicular to the wall member. The second ledge extends outwardly from the top end 24 of the beam.
The first ledge 20a and the second ledge 22a on the first wall member 12 cooperate to form a channel 26 for receiving a part of an insulation member.
The second wall member 14 includes a first ledge 20b extending outwardly away from the trough 18. As shown in this construction, the first ledge 20b extends outwardly from the wall member at an angle that is substantially perpendicular to the wall member. The first ledge extends outwardly in line with the base member 16.
The second wall member 14 also includes a second ledge 22b extending outwardly away from the trough 18. As shown in this construction, the second ledge 22b extends outwardly from the wall member at an angle that is substantially perpendicular to the wall member. The second ledge extends outwardly from the top end 24 of the beam.
The first ledge 20b and the second ledge 22b on the second wall member 14 cooperate to form a channel 28 for receiving a part of an insulation member.
The structural beam of the invention may be delivered to the construction site as a standalone unit. Optionally, the structural beam may be delivered as a preassembled unit with an insulation member 200.
Although particular constructions of the invention have been described, it will be appreciated that many modifications/additions and/or substitutions may be made within the scope of the claimed invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1717087.9 | Oct 2017 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2018/052959 | 10/15/2018 | WO | 00 |
