GB2617894A

GB2617894A - A foundation beam

Info

Publication number: GB2617894A
Application number: GB2302176.9A
Authority: GB
Inventors: David Barnett Jonathon
Original assignee: Sustainable Resources Ltd
Current assignee: Sustainable Resources Ltd
Priority date: 2022-02-15
Filing date: 2023-02-15
Publication date: 2023-10-25
Also published as: GB202201984D0; GB202302176D0

Abstract

The fibre reinforced foundation beam M is made from a synthetic plastic composite material and includes holes for receiving a reinforcement bar. The beam may be an I, box beam or bar. The beam may include a number of holes O which allow a reinforcement bar to pass through. The beam’s end may be cast into a ring beam or a foundation slab. Also claimed is a is a method of installing an insulated foundation comprising a foundation slab and a fibre reinforced foundation beam and inserting a reinforcement bar, rebar, through the aperture. Also claimed is a method of resisting differential settlement by deploying the foundation beam.

Description

A FOUNDATION BEAM

FIELD

The present invention relates to a foundation beam or support for brick walls using insulated foundations. In particular, the present invention relates to a fibre reinforced foundation beam and to a method for installing an insulated foundation.

More particularly, but not exclusively, the foundation beam is employed as part of a system for preventing differential settlement in foundations which may have been damaged by movement, such as movement caused by thermal stress.

BACKGROUND OF THE INVENTION

Insulated foundations describe a method of building foundations for structures where the insulation is placed under and around the perimeter of foundation slabs. Insulated foundations are designed to carry the weight of the building and to thermally insulate the foundations from the ground.

PRIOR ART

International patent application number WO 2013/000470 (THOMAS) discloses an edge insulation structure which comprises an elongate edge insulation rail and an elongate edge rail.

The edge insulation rail comprises a first abutment face for abutting a foundation, a second abutment face for partially abutting an underlying insulation layer and an adjacent cast floor plate. The edge insulation rail extends from a level below the floor plate to the surface of the floor plate.

The edge rail comprises a first flange that is adapted to cover the upper face of the edge insulation rail, a second flange for abutting the upper surface of the floor plate and a third flange for abutting a side face of the edge insulation rail.

The floor and the foundation are structurally separate elements. The insulation is not continuous between the wall and the floor. The role of the edge rail is to span the vertical edge of the insulation layer at the perimeter of a room. The edge rail performs no structural role as it is not attached to any part of the foundation of the building.

Chinese patent application number CN 106836639 (Technical University of Nanjing) discloses a bidirectional shear key box-shaped section concrete composite beam. The composite beam comprises a pair of box-shaped beam external panels, a box-shaped beam lower flange and a box-shaped beam upper flange. A pair of internal panels which are parallel to the box-shaped beam external panels, are arranged in a chamber.

A U-shaped slot is formed by the box-shaped beam upper flange and the box-shaped beam external panels on the upper part of the composite beam and a bidirectional shear key is arranged in the U-shaped slot which receives poured concrete.

The box shaped beam provides adequate sheer bonding between parts of the structure formed from FRP and those parts made formed from concrete.

Chinese utility model number CN 216276463 (Dongguan Ginglong Shaped Plastic Product Company Limited) discloses a cooling injection mould which comprises an upper mould plate, an upper mould core, a lower mould core and a lower mould plate which are sequentially arranged from top to bottom.

An inner cup surface profiling block corresponding to an outer cup surface profiling groove is arranged on the lower mould core and a glue feeding mechanism is arranged on the upper mould plate. A glue feeding mechanism penetrates downwards to the outer cup surface profiling groove, so that the product forming time is shortened.

A concrete beam which is formed using the mould and method is thereby reinforced (using steel and FRP) in such a way as to limit corrosion caused by the use of sand dredged from seawater.

Australian patent application number AU2016201900 (Euretech Int Pty Ltd) describes a method of constructing a building using fibre reinforced polymer (FRP) members.

The building has a foundation having FRP posts, a frame having a base portion of FRP beams located on top of the foundation, and flooring and walls affixed to the base portion. The walls can be fixed to the base portion using reinforcement members such as cyclone rods.

The method of constructing a building foundation using piles (or stilts) and beams made from FRP requires vertical structural posts to be sunk into the ground until the ground is sufficiently stable to resist the weight of the building.

Referring briefly to Figure 1, (PRIOR ART), there is shown an example of a perimeter of insulation around the foundation slab that is designed to align with the insulation in the wall which is built on the foundation; that is where the insulation is primarily outside the superstructure. This arrangement works well if the weight of the external cladding of the building can be caned back to the internal wall and into the foundation slab.

Using this method of building foundations with brick, stone or other heavy external skin can however be problematic. The weight of the external skin needs to be carried or supported without: a) allowing external bricks, masonry blocks or stone, and the internal load bearing structure to move independently; b) creating a thermal break i.e. an easy route for heat to escape; and c) creating a detail that is complex and costly to build on site.

Other examples of conventional methods of providing a brick/stone skin on the outside of an insulated foundation are shown in Figures 2 to 4.

Each of these methods has disadvantages which are briefly described below.

The method illustrated in Figure 2 (PRIOR ART) requires the use of a separate footing (A) to carry the weight of the brick/stone skin (H).

The use of a separate footings can allow the brick/stone wall to move or settle at a different rate to the internal load bearing structure which can result in damage to the building.

Figure 3 (PRIOR ART) illustrates another method which required the use of an insulated ring beam (J) to carry the weight of the bricks (H). The ring beam however is not wide enough to spread the load adequately which can result in excessive load on the insulation. Furthermore, there may be differential settlement between the external brick (H) and the foundation slab (E) resulting in damage to the building.

Attempts have been made to link the ring beam (J) to the foundation slab (E) using stainless steel wire or reinforcement bars. The wires or bars have however been found to fail. Failure is caused as a result of the bars being only large enough to prevent rotation of the ring beam (J) but not large enough to prevent settling.

Furthermore, the number of bars required causes an excessive amount of heat loss.

Figure 4 (PRIOR ART) illustrates a yet further existing method in which a foundation is formed using a foundation slab (E) which is cast to create a toe detail (K). The toe detail is linked to the foundation slab by reinforcement bars cast in to the concrete at the time of pouring.

The weight of the external brick (H) is carried by the toe detail. Building the toe detail (K) without a piece of high compressive strength insulation (L) under the brick (H) would result in excess heat bypassing the wall insulation (G) and escaping.

Even with the use of high compressive strength insulation (L), as shown in Figure 4, the toe detail (K) suffers from additional heat loss due to the significant extra amount of concrete surface area provided. This method is complex and requires concrete to be poured in at least two stages which is time consuming.

In view of the aforementioned existing systems, there is therefore a need for a method of building insulated foundations which addresses the problems associated with the conventional methods.

In particular, there is a need for a method of building insulated foundations which is simple, cost effective, energy efficient and reliable with reduced risk of damage to the building.

SUMMARY OF INVENTION

According to a first aspect of the present invention, there is provided a fibre reinforced foundation beam formed from a synthetic plastics composite material, the beam has at least one hole formed therein to allow one or more reinforcing bar(s) to pass therethrough.

The beam may link together parts or regions of a foundation of a building.

Preferably the aforementioned beam may be used in a method of constructing a 'thermally broken' raft (slab, semi-rigid, shallow concrete foundation) that allows for the support of an external masonry (stone/brick etc) cladding while maintaining a continuous layer of insulation between the wall and foundation/floor slab.

According to a second aspect of the present invention, there is provided a method of installing an insulated foundation comprising: providing a foundation slab; obtaining at least one fibre reinforced foundation beam with at least one hole formed therein for receiving one or more reinforcing bar(s) therethrough; and positioning the at least one fibre reinforced foundation beam to connect a perimeter of a building to the foundation slab.

The method allows the construction of a footing for the external wall and a separate footing for the internal wall that is structurally linked and robust enough to prevent differential settlement between the two footings, while at the same time maintaining the continuous thermal barrier between inside and outside.

The fibre reinforced foundation beams are preferably arranged around a perimeter of a building, such that the longitudinal axis of each beam extends from the perimeter (for example from a concrete ring beam) towards, and such that each beam is in communication with, a foundation slab According to a third aspect there is provided a method for resisting differential settlement in thermally broken foundation slabs.

The FRP beam acts as a foundation linking beam rather than a foundation beam, per se.

In one embodiment, at least one end of the beam is cast into, or fixed toa concrete ring beam.

In one embodiment, at least one end of the beam is cast into, or fixed to a foundation slab.

The fibre reinforced foundation beam is preferably configured to connect a ring beam to a foundation slab. The fibre reinforced foundation beam is preferably configured to transfer load from the ring beam or lintel to the foundation slab during use. By transferring the load exerted on the ring beam or lintel (for example by the external skin of brick, stone or other heavy external material) to the foundation slab, the fibre reinforced foundation beam of the present invention reduces, and preferably prevents, differential settlement between the external and internal walls of the building.

As such, the use of the fibre reinforced foundation beam of the present invention reduces damage to the building compared to conventional methods.

The, or each, fibre reinforced foundation beam is preferably configured to receive and support a load, for example brick, stone or other heavy external skin, supported thereon.

The, or each, fibre reinforced foundation beam is preferably configured in use to transfer a load supported thereon to the foundation slab.

The, or each, fibre reinforced foundation beam preferably has sufficient strength to transfer the load supported thereon (for example from the brick, stone or other heavy external skin) to the foundation slab The fibre reinforced foundation beam may be in the form of a box section; an I-section; or a bar section.

The fibre reinforced foundation beam is preferably an l-section.

An l-section fibre reinforced foundation beam has an optimal shape for achieving maximum strength with minimal cross-sectional area.

The fibre reinforced foundation beam may comprise at least one hole formed therein to allow one or more reinforcing bar (also referred to herein as "reban to pass therethrough. In one embodiment, the beam comprises a plurality of spaced apart holes.

The holes may be provided at any suitable location, in any suitable arrangement, with any suitable spacing therebetween, dependent on the particular requirements for the beam. In one embodiment, the holes are spaced apart from each other along the length of the beam.

Holes may be provided in a vertical section (web) of an I-beam and/or holes may be provided in a horizontal section (flange or leg) of an I-beam.

The holes enable the reinforced bar(s) or bolts or reinforcement meshes to pass through the beam to provide additional structural security thereby reducing and preferably preventing rotation of the beam under load.

In one embodiment, one or more reinforced bar(s) are inserted through one or more corresponding holes of the beam.

The holes may be spaced to receive ends of a reinforcement mesh. The spacing of the holes may be selected to algin with the spacing of industry standard fabric mesh reinforcement.

The thermal properties of the fibre reinforced foundation beam are preferably such that the use of the beam does not give rise to any additional heat loss or only causes a negligible increase in additional heat loss of the foundations such that it can be ignored for the purposes of determining Building regulation compliance.

Embodiments of the present invention will now be described in more detail in relation to Figures, with specific reference to Figures 5 to 10.

BRIEF DESCRIPTION OF FIGURES

Figure 1 is a schematic illustration of a conventional perimeter insulation; Figure 2 is a schematic illustration of a conventional method for assembling an exterior skin on the outside of an insulated foundation; Figure 3 is a schematic illustration of a further conventional method for assembling an exterior skin on the outside of an insulated foundation; Figure 4 is a schematic illustration of a further conventional method for assembling an exterior skin on the outside of an insulated foundation; Figure 5 is a schematic illustration of a method of installing an insulated foundation using a fibre reinforced foundation beam according to one embodiment of the present invention; Figures 6A to 60 are schematic illustrations of fibre reinforced foundation beams according to one embodiment of the present invention; and Figure 7 is a schematic illustration of a further method of installing an insulated foundation using a fibre reinforced foundation beam according to one embodiment of the present invention; Figure 8 is a schematic diagram showing a method of supporting an exterior skin between individual fibre reinforced foundation beams; Figure 9 is a schematic sectional diagram through a building and shows foundation slab, wall and position of a fibre reinforced plastics I-beam in accordance with one embodiment of the present invention; and Figure 10 is an image of fibre reinforced plastics I-beam embedded in a concrete slab fabricated according to one embodiment of the present invention

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

With reference to Figures 6A to 60, a fibre reinforced foundation beam is formed from a synthetic plastics composite material. As shown in Figures 6A to 60, the fibre reinforced foundation beam (M) may be in the form of: an l-section (Figure 6A); a box section (Figure 6B); or a bar section (Figure 60). It is however to be understood that the fibre reinforced foundation beam may have any cross-sectional shape and dimensions.

The fibre reinforced foundation beam (M) shown in Figure 6A is an l-section which has an optimal shape for achieving maximum strength with minimal cross-sectional area.

Each of the beams (M) of Figures 6A to 6C has eight holes formed therein. The holes (0) are formed perpendicular to the longitudinal axis of the beam. The holes (0) are provided in two sets of four holes. Each set of holes being provided adjacent an end of the beam. Each set of holes (0) is provided in a square arrangement. It is to be understood that each beam (M) may provide any suitable number of holes (0), in any suitable arrangement, at any suitable location along the beam (M).

The holes (0) are dimensioned to allow one or more reinforcing bar (R) (also referred to herein as "rebar") to pass therethrough.

Alternatively the holes (0) are spaced to receive ends of a reinforcement mesh. The spacing of the holes (0) is selected to algin with the spacing of industry standard fabric mesh reinforcement.

As shown in Figures 5 and 7, an insulated foundation is installed by providing a foundation slab (E). The, or each, fibre reinforced foundation beam (M) is positioned to connect a concrete ring beam (J) to the foundation slab (E).

The fibre reinforced foundation beams (M) are arranged around a perimeter of a building, such that the longitudinal axis of each beam (M) extends from the concrete ring beam (J) towards, and such that each beam is in communication with, the foundation slab (E). A first end (M-1) of the beam (M) is cast into the concrete ring beam (J) and the second end (M2) of the beam (M) is cast into a foundation slab (E).

Reinforcing bars (R) are inserted through holes (0) in the beam (M). Each bar (R) is inserted through a hole (0) in a first set of holes and a hole (0) in a second set of holes of the beam (M). Each bar (R) provides additional structural security thereby reducing and preferably preventing rotation of the beam under load. The hole (0) may be circular or oval so as to allow a degree of tolerance between bars (R). In this sense therefore holes may be oval to receive oval shaped bars or square or triangular, thereby preventing rotation of the beams when bars are inserted therethrough.

The fibre reinforced foundation beam is configured to transfer load from the ring beam (J) to the foundation slab (E) during use. By transferring the load exerted on the ring beam (J) (for example by the external skin of brick, stone or other heavy external material) to the foundation slab (E), the fibre reinforced foundation beam (M) of the present invention reduces, and preferably prevents, differential settlement between the external and internal walls of the building. As such, the use of the fibre reinforced foundation beam of the present invention reduces damage to the building compared to conventional methods.

The beams of the present invention can be used to provide a more thermally efficient insulation foundation. Furthermore, the beams of the present invention can be used, with or without additional reinforcing bars, to effectively transfer load from the external material to the foundation slab, with reduced risk of rotation, thereby reducing damage to the building.

Figure 9 shows how the insulation is continuous between the wall 3 and the foundation/floor of a building. Heat cannot readily escape from inside a building to outside the building without passing through a layer of insulation. The weight of the bricks 2 is supported on the small footing 6, which in turn is supported on the insulation layer 8 beneath the footing 6. The weight of the remaining part of the superstructure is carried on foundation slab 5, which is supported by the insulation layer 8 underneath.

The load on the insulation under brick footing (6) may be significantly different to the load on the insulation under the foundation slab (5). This is because the loads applied are different and the area over which the loads are spread is different.

An advantage of the FRP I-beam 7 is that it transfers loads from one footing to the other (in either direction) and thereby evens out the loads applied. Without the I-beam 7 there is a risk of differential settlement between the two footings.

Figure 10 shows how the I-beam 7 has holes in its upper flanges or legs to allow reinforcement bars to be used within the concrete footings and to pass vertically through the I-beam and thereby improve and enhance the connection between the I-beam 7 and the footings 6 and 8.

Variation may be made to the invention for example by forming the beam by casting or extrusion.

Claims

CLAIMS1. A fibre reinforced foundation beam formed from a synthetic plastics composite material, the beam has at least one hole formed therein to allow one or more reinforcing bar(s) to pass therethrough.
2. A fibre reinforced foundation beam according to claim 1, in the form of a box section.
3. A fibre reinforced foundation beam according to claim 1, in the form of an l-section.
4. A fibre reinforced foundation beam according to claim 1, in the form of a bar section.
5. A fibre reinforced foundation beam as claimed in any preceding claim, in which the holes are spaced to receive ends of a reinforcement mesh.
6. A fibre reinforced foundation beam according to any preceding claim, wherein at least one end of the beam is cast into a concrete ring beam.
7. A fibre reinforced foundation beam according to any of claims 1 to 5, wherein at least one end of the beam is cast into a foundation slab
8. A fibre reinforced foundation beam according to any of claims 3 to 7, wherein the holes are provided in a vertical section (web) of the I-beam.
9. A fibre reinforced foundation beam according to any of claims 3 to 8, wherein the holes are provided in a horizontal section (flange or leg) of an I-beam.
10. A method of installing an insulated foundation comprising: providing a foundation slab; obtaining at least one fibre reinforced foundation beam as claimed in any one of claims 1 to 9; positioning the at least one fibre reinforced foundation beam to connect a perimeter of a building to the foundation slab; and inserting one or more reinforcing bar(s) through one or more holes.
11. A method for resisting differential settlement in broken foundation slabs, such as thermally broken foundation slabs includes deploying a fibre reinforced foundation beam according to any of claims 1 to 9 as a foundation linking beam.