AU2008200970B2 - A pad element for use in forming a building foundation - Google Patents

Abstract

Abstract: A pad element for use in forming a building foundation, the pad element comprising: a body, a first channel for receiving concrete formed in the body and a second channel for receiving concrete formed in the body intersecting the first channel o277 to~

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Standard Patent Applicant: Charles Cameron Invention Title: A PAD ELEMENT FOR USE IN FORMING A BUILDING FOUNDATION The following statement is a full description of this invention, including the best method for performing it known to me/us: - 2 A PAD ELEMENT FOR USE IN FORMING A BUILDING FOUNDATION Field of the Invention 5 The present invention relates to a pad element for use in forming a building foundation, and to a method of forming a building foundation using a plurality of the pad elements. 10 Background of the Invention Building foundations are generally formed by pouring concrete into a defined volume to form a concrete slab on the ground. Steel reinforcement bars are often provided throughout the formed concrete slab to give added 15 strength. Systems have been proposed to reduce the volume of concrete required in which square pads of polystyrene are laid on the ground prior to pouring the concrete, thereby filling up some of the foundation space. These 20 polystyrene pads, which are referred to also as boxes, waffle pods or rafts, are light and much cheaper to manufacture than the equivalent volume of concrete. Furthermore, as polystyrene is strong in compression, its use in the foundation does not adversely effect the 25 strength of the foundation. In these systems, the pads are regularly spaced out by plastic spacers which are shaped to snugly engage the corners or sides of the pads. The spacers may also have webs to receive the steel reinforcing bars. The 30 spaces between the pads enable a matrix of concrete ribs to be formed throughout the foundation which contact and engage the ground underneath the foundation and provide the load bearing strength of the foundation. N:\Brisbane\Cases\Patent\7S000-75999\P75663.AU.1\Specis\P7S663.AU.l.doc 29/02/08 20 FEB 2014 RECEIVED IPL Summary of the Invention According to a first aspect of the present invention, there is provided a pad element for use in forming a building foundation, the pad element comprising: 5 a body; a first channel for receiving concrete formed in the body; and a second channel for receiving concrete formed in the body, intersecting the first channel wherein the first and second channels divide the body of the pad element into at least four quadrants; 10 wherein the pad element comprises a number of webs which connect each quadrant to its adjacent quadrants, across either first or second channels; and wherein each of the webs comprises arms which extend into opposing quadrants of the body. 15 According to a second aspect of the present invention, there is provided a pad element for use in forming a building foundation, the pad element comprising: a body; a first channel for receiving concrete formed in the body; and a second channel for receiving concrete 20 formed in the body, intersecting the first channel, wherein the first and second channels divide the body of the pad element into at least four quadrants; wherein the pad element comprises a number of ribs for receiving reinforcing bars 25 The first and second channels may also receive reinforcing bars. The body may have a top surface, a bottom surface and at least three sides. The sides of the body may be rectilinear. 30 The body may have four side walls. The body may be a rectangular prism in shape. The first channel may extend between opposing first and third sides of the body, and the second channel may extend between opposing second and fourth sides of the 35 body. 5134442_1 (GHMatters) P75663.AU.1 20/02/14 - 3A The first channel may extend between the centre of the first side and the centre of the third side. Similarly, the second channel may extend between the centre of the second side and the centre of the fourth 5 side. The channels may intersect one another at the centre of the body. The channels may intersect one another orthogonally. 10 The first channel may extend between opposing first and third vertices of the body and the second channel may extend between opposing second and fourth vertices of the body. The body may be a triangular prism in shape 15 (three sides) or a hexagonal prism in shape (six sides) or an octahedral prism in shape (eight sides) or any other suitable shape. The body may be of any shape that will allow the body to tessellate and also the first and second channels 5134442_1 (GHMatters) P75663.AU.1 20/02/14 -4 to tessellate. Were the body has more than four side walls and thus is a shape other than a rectangular prism, the pad element may comprise additional channels to the first and 5 second channels. The first and second channels divide the body of the pad element into four quadrants. Each quadrant may be spaced apart from the other quadrants by a portion of the first channel and a portion 10 of the second channel. The quadrants may be all of equal size. The pad element may comprise apertures from the top surface to the bottom surface of the body for enabling concrete, when poured over the pad element in forming a 15 building foundation, to flow through the pad element. A number of portions of the first channel and a number of portions of the second channel may have a depth which is equal to the depth of the body. These portions may define apertures located in 20 the first channel, and apertures located in the second channel. The pad element may also comprise a number of webs which connect each quadrant to its adjacent quadrants, across either first or second channels. 25 The webs may be located towards the bottom surface of the body. However, they need not be. The webs may be straight edged or they may be arched. The pad element may comprise a number of ribs for 30 receiving reinforcing bars. The ribs may extend between adjacent quadrants, across either first or second channels. The ribs may also provide added strength to the connections between the quadrants. 35 Each of the ribs may have a notch in its top surface for a portion of the reinforcing bars to be located in. N:\Brisbane\Cases\Patent\75000-75999\P75663.AU.1\Specis\P75663.AU.l.doc 29/02/08 - 5 The notches may be arcuate in shape. However, in other embodiments, they are of different shapes. For example they may be V-shaped. The ribs may be located at the top surface of 5 the body. However, the ribs need not be located at this exact position. The ribs may be readily knocked out. When this occurs the reinforcing bars may drop down onto the webs. The webs may therefore provide a surface upon 10 which the reinforcing bars can reside at a sufficient distance about the ground. The first channel and the second channel may be substantially identical. The number, position, size and shape of the 15 apertures, ribs and webs in the first channel may be the same as those in the second channel. The pad element may also comprise a number of hollows, formed in the bottom surface of the body for reducing the volume of the pad element. 20 The pad element may comprise four hollows per quadrant. The body of the pad element may be manufactured from polystyrene foam. However, in other embodiments, the body is 25 manufactured of any other suitable material such as cardboard or other suitable polymers, for example polyurethane. The body of the pad element may have a colouring agent distributed throughout. 30 The colour of the colouring agent may be light green. The body of the pad element may have a fire retardant distributed throughout. The webs may be formed from a different material 35 to the body of the pad element. The webs may be formed from the same material to the body of the pad element. N:\Brisbane\Case9\Patent\75000-75999\P75663.AU.1\SpeciB\P75663.AU.l.doC 29/02/08 - 6 The webs may be integrally formed with the body of the pad element. The webs may be formed from a harder and more rigid material than the material from which the body is 5 formed. Where the body is formed from polystyrene foam, the webs may be formed from a hard plastic material such as polyurethane, PVC or high density polyethylene for example. 10 Each of the webs may comprise arms which extend into opposing quadrants of the body. The webs may be fixed to the quadrants by their arms. The pad element may be formed by moulding the 15 quadrants around the arms of the webs. The webs may be joined by cross members to form a unitary lattice. The pad element may be formed by moulding the body around portions of the lattice. 20 The webs may comprise foot portions for enabling the webs to stand upright in a mould used in forming the body of the pad element. The webs may comprise notches for receiving reinforcing bars. 25 According to a second aspect of the present invention, there is provided a method of forming a building foundation, the method comprising the steps of: (a) positioning a plurality of the pad elements according to an embodiment of the present invention on the 30 ground abutting one another; and (b) pouring concrete over the pad elements. The method may also comprise the step prior to step (b) of placing reinforcing bars in the first and/or second channels of the pad elements. 35 The step of placing the reinforcing bars in the first and/or second channels may comprise locating the reinforcing bars in the notches of the ribs located in the 5134442_1 (GHMatters) P75663.AU.1 20/02/14 -7 channels. The method may also comprise the step of fixing the reinforcing bars in the first channels to the reinforcing bars in the second channels to form a grid of 5 reinforcing bars. The method may also comprise the step prior to step (b) of knocking out the ribs. This step may result in the reinforcing bars dropping onto the webs of the pad elements below. 10 The step of positioning the pad elements on the ground may include aligning the first and second channels. Where the first and second channels are different, the step of positioning the pad elements on the ground may include aligning the first channel of each pad 15 element with the first channels of the other pad elements and aligning the second channel of each pad element with the second channels of the other pad elements. However, where the first and second channels are substantially identical, then the first channel of one pad 20 element may be aligned with the second channel of another pad element. According to a third aspect of the present invention, there is provided a building foundation comprising at least one pad element according to an 25 embodiment of the present invention. The building foundation may be formed by the method according to an embodiment of the present invention. 30 Brief Description of the Drawings Embodiments of the present invention will now be described, by example only, with reference to the accompanying drawings, in which: Figure 1 is an isometric view of a pad element 35 for use in forming a building foundation according to an embodiment of the present invention; Figure 2 is a top view of the pad element of 5134442_1 (GHMatters) P75663.AU.1 20/02/14 -8 Figure 1; Figure 3 is a bottom view of the pad element of Figure 1; Figure 4 is a side view of the pad element of 5 Figure 1; Figure 5 is a top perspective view of a pad element according to another embodiment of the present invention; Figure 6 is a top plan view of the pad element of 10 Figure 5; Figure 7 is a bottom view of the pad element of Figure 5; Figure 8 is a cut-away perspective view of the pad element of Figure 5; and 15 Figure 9 is a photograph from the side of the pad element of Figure 5. Detailed Description of Embodiments Referring to Figures 1 to 4, a pad element 10 for 20 use in forming a building foundation according to an embodiment of the present invention is shown. The pad element 10 comprises a body 11, a first channel 18 for receiving concrete formed in the body 11 and a second channel 19 for receiving concrete formed in the body 11, 25 intersecting the first channel 18. The first and second channels 18, 19 are preferably also for receiving reinforcing bars. A significant advantage of the pad element 10 according to embodiments of the present invention is that 30 the first and second channels 18, 19 provide the space in which concrete can be poured to form the matrix of concrete ribs for the building foundation. This means that there is no need to use spacers to position multiple pad elements relative to one another. Rather, the pad elements 35 10 can be placed abutting one another in a side-by-side arrangement with the channels 18, 19 in alignment. This provides a substantial reduction in cost, both in terms of N:\Brisbane\Casea\Patent\75000-75999\P75663.AU.1\Specis\P75663.AU.l.doc 29/02/08 - 9 time and money, in using the pad elements 10 when forming a building foundation, particularly as correctly positioning the spacers (in previously employed systems) can be a time consuming process. 5 The body 11 has a top surface 12, a bottom surface 13 and at least three sides. In the embodiment shown in the Figures, the body has four sides 14, 15, 16 and 17 respectively. The four sides 14, 15, 16, 17 of the body 11 are rectilinear and thus, the body 11 is a 10 rectangular prism in shape. However, the body may have more than four side walls and thus be of any other suitable shape which enables the body to tessellate and also the first and second channels to tessellate. For example the body may be a triangular prism in shape (three 15 sides) or a hexagonal prism in shape (six sides) or an octahedral prism in shape (eight sides). It is noted that in these embodiments, where the body has more than four side walls and thus is a shape other than a rectangular prism, that the pad element may comprise additional 20 channels to the first and second channels. The first channel 18 extends between opposing first and third sides 14, 16 of the body 11, and the second channel 19 extends between opposing second and fourth sides 15, 17 of the body 11. However, in a 25 variation, the first channel extends between opposing first and third vertices of the body and the second channel extends between opposing second and fourth vertices of the body. The first channel 18 extends between the centre 30 of the first side 14 and the centre of the third side 16. Likewise, the second channel 19 extends between the centre of the second side 15 and the centre of the fourth side 17. The channels 18, 19 thus intersect one another at the centre of the body 11. As the body 11 of the pad element 35 10 as shown in the Figures is a rectangular prism in shape, the channels 18, 19 intersect one another orthogonally. N:\Brisbane\Caoea\Patent\75000-75999\P7S663.AU.1\SpeCiG\P75663.AU.I.doc 29/02/08 - 10 The first and second channels 18, 19 divide the body 11 of the pad element 10 into four equally sized quadrants 25. Each quadrant is spaced apart from the other quadrants by a portion of the first channel 18 and a 5 portion of the second channel 19. The pad element 10 comprises apertures 26 from the top surface 12 to the bottom surface 13 of the body 11. The apertures 26 are for enabling concrete, when poured over the pad element 10 in forming a building 10 foundation, to flow through the pad element. A number of portions of the first channel 18 and a number of portions of the second channel 19 have a depth which is equal to the depth of the body 11. These portions thus define apertures 26a, located in the first channel 15 18, and other apertures 26b, located in the second channel 19. The pad element 10 also comprises a number of webs 27 which connect each quadrant 25 to its adjacent quadrants, across either first or second channels 18, 19. 20 The webs 27 are located towards the bottom surface 13 of the body 11. However, they need not be. The webs 27 may be straight edged or they may be arched as shown, in particular in Figures 1 and 4. Also, in the embodiment shown in Figures 1 to 4, the webs 27 are formed from the 25 same material as and are integrally formed with the body 11 of the pad element 10. Thus, the pad element 10 may be produced as a unitary moulding. The pad element 10 also comprises a number of ribs 28 for receiving reinforcing bars. The ribs 28 extend 30 between adjacent quadrants 25, across either first or second channels 18, 19 so as to allow for the provision of a grid of reinforcing bars. The ribs 28 are also for providing added strength to the connections between the quadrants 25, particularly for during handling of the pad 35 element 10. Each of the ribs 28 has a notch 29 in its top surface for a portion of the reinforcing bars to be located in. In the Figures, the notches 29 are shown as N:\Brisbane\Cases\Patent\75000-75999\P75663.AU.1\Speci5\P75663.AU.1.doc 29/02/0a - 11 being arcuate in shape. However, they may be of different shape in other embodiments, for example they may be V shaped. In Figures 1 to 4, the ribs 28 are shown located 5 at the top surface 12 of the body 11. Although the ribs 28 need not be located at this exact position. The ribs 28 are readily knocked out, which enables the reinforcing bars to drop down onto the webs 27. The webs 27 are therefore arranged to provide a 10 surface upon which the reinforcing bars can reside at a sufficient distance about the ground. This sufficient distance allows the reinforcing bars to be sufficiently enclosed by concrete once the building foundation has been formed. 15 In one embodiment of the invention, the number, position, size and shape of the apertures 26, webs 27 and ribs 28 in the first channel 18 are the same as those in the second channel 19, so that the first channel 18 and the second channel 19 are substantially identical. An 20 advantage of this embodiment is that when pad elements 10 are being laid on the ground to form part of a building foundation, there is no need to orientate the pad elements 10 so that the first channels 18 and second channels 19 of the pad elements 10 align. 25 The pad element 10 also comprises a number of hollows 30, formed in the bottom surface 13 of the body 11 (see Figure 3) for reducing the volume of the pad element 10. In Figure 3 the pad element 10 is shown comprising four hollows 30 per quadrant 25. However, each quadrant 25 30 may have more less hollows, and need not each have the same number of hollows. The body 11 of the pad element 10 is typically manufactured from polystyrene as it is an inexpensive, light-weight and easily mouldable material. However, the 35 body 11 could be manufactured of another suitable material such as cardboard or other suitable polymers, for example polyurethane. N:\Brisbane\Cases\Patent\75000-75999\P75663.AU.1\SpeCis\P7S663.AU.l.doc 29/02/06 - 12 The body 11 of the pad element 10 may also have a colouring agent distributed throughout so as to reduce the glare reflected off the pad element 10 when it is exposed to sunlight (as compared to if it was white). A 5 particularly preferred colour in this regard is light green. The body 11 of the pad element 10 may also have a fire retardant distributed throughout so as to reduce the flammability of the pad element 10. A method of forming a building foundation using a 10 plurality of the pad elements 10 described above, involves positioning the pad elements 10 on the ground abutting one another and pouring concrete over the pad elements 10. Prior to this, reinforcing bars may be placed in the first and/or second channels 18, 19, specifically in the notches 15 29 of the ribs 28 located in the channels 18, 19. This provides a further advantage for the pad elements 10 according to embodiments of the present invention. By placing the reinforcing bars on the pad elements 10, this weighs the pad elements 10 down and holds them in 20 position. Previously used systems, where the reinforcing bars are placed on the spacers, have suffered significant problems with wind as the light-weight polystyrene pads, which have nothing to hold them down, are susceptible to being blown around. 25 The reinforcing bars in the first channels 18 and the reinforcing bars in the second channels 19 are then preferably fixed together (where they intersect) to form a grid of reinforcing bars. Once this has been done, the ribs 28 are knocked out to enable the grid of reinforcing 30 bars to drop onto the webs 27 of the pad elements 10 below. When placing the pad elements 10 on the ground, the first and second channels 18, 19 need to be aligned. Where the first and second channels 18, 19 are different, 35 then the first channel 18 of a pad element 10 needs to be aligned with the first channels of other pad elements and similarly the second channel 18 of the pad element 10 N:\Brisbane\Cases\Patent\75000-75999\P7S663.AU.1\SpeCis\P75663.AU.1.doc 29/02/08 - 13 needs to be aligned with the second channels of other pad elements. However, in the embodiment where the first and second channels 18, 19 are substantially identical, then the first channel of one pad element may be aligned with 5 the second channel of another pad element. Referring now to Figures 5 to 9, a pad element 110 for use in forming a building foundation according to another embodiment of the present invention is shown. Similar features of the pad element 110 to those of the 10 pad element 10 shown in Figures 1 to 4 have been given the same reference numbers but have been prefixed with the numeral 1. The pad element 110 comprises a body 111 and first and second channels 118, 119 formed in the body 111 15 for receiving concrete. The body 111 comprises four equally sized quadrants 125, each quadrant being spaced apart from other quadrants by a portion of the first channel 118 and a portion of the second channel 119. The pad element 110 also comprises a number of 20 webs 127 which connect each quadrant 125 to its adjacent quadrants, across either of first or second channels 118, 119. The webs 127 are formed from a different material to the body 111 of the pad element 110. More specifically, the webs 127 are formed from a harder and more rigid 25 material than the material from which the body 111 is formed. For example, the body 111 is in one embodiment formed from polystyrene foam and the webs 127 are formed from a hard plastic material such as polyurethane, PVC or high density polyethylene. The harder and more rigid webs 30 127 provide greater structural rigidity and strength to the pad element 110, in particular for the connections between the quadrants 125 of the body 111. Because the webs 127 are stronger, less of them need to be provided between the quadrants 125, allowing for more space in the 35 channels 118, 119 for concrete to be poured. Each of the webs 127 comprise arms 140 which extend into opposing quadrants 125 of the body 111. The N:\Brisbane\Cases\Patent\75000-75999\P75663.AU.1\SpeCis\P75663.AU.l.doc 29/02/08 - 14 arms 140 thus fix the webs 127 to the quadrants 125. In forming the pad element 110, the quadrants 125 are moulded around the arms 140 of the webs 127. That is, the webs 127 may be placed in the mould for forming the pad element 5 110 after being separately moulded and/or extruded, and the quadrants 125 of the body 111 are moulded around the arms 140 of the webs 127 accordingly. For example, where the body 111 is formed from polystyrene, the quadrants 125 are blow moulded around the arms 140 of the webs 127. 10 Advantageously, this removes the need to assemble the pad elements 110 at the building site where the building foundation is to be formed. In a variation not shown in the Figures, the webs may be joined by cross members to form a unitary lattice. 15 In this variation, the pad element 110 is formed by moulding the body 111 around portions of the lattice. The webs 127 comprise foot portions 141 which enable the webs 127 to stand upright in the mould used in forming the body 111 of the pad element 110. The webs 127 20 also comprise notches 129 for receiving reinforcing bars. In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as 25 "comprises" or "comprising" is used in an inclusive sense, ie. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. N:\Brisbane\Cases\Patent\75000-75999\P75663.AU.1\Specio\P75663.AU.l.doc 29/02/08

Claims (20)

1. A pad element for use in forming a building foundation, the pad element comprising: a body; a first 5 channel for receiving concrete formed in the body; and a second channel for receiving concrete formed in the body, intersecting the first channel, wherein the first and second channels divide the body of the pad element into at least four quadrants; 10 wherein the pad element comprises a number of webs which connect each quadrant to its adjacent quadrants, across either first or second channels; and wherein each of the webs comprises arms which extend into opposing quadrants of the body. 15

2.A pad element as claimed in claim 1, wherein the channels intersect one another at the centre of the body.

3. A pad element as claimed in claim 1 or 2, wherein the 20 channels intersect one another orthogonally.

4. A pad element as claimed in any one of the previous claims, wherein the pad element comprises apertures from a top surface to a bottom surface of the body for enabling 25 concrete, when poured over the pad element in forming a building foundation, to flow through the pad element.

5. A pad element as claimed in any one of the previous claims, wherein the pad element also comprises a 30 number of hollows, formed in a bottom surface of the body for reducing the volume of the pad element.

6. A pad element as claimed in any one of the previous claims, wherein the body of the pad element is 35 manufactured from polystyrene foam.

7. A pad element as claimed in any one of the previous 5134442_1 (GHMatters) P75663.AU.1 20/02/14 - 16 claims, wherein the body of the pad element has a colouring agent distributed throughout.

8. A pad element as claimed in any one of the previous 5 claims, wherein the body of the pad element has a fire retardant distributed throughout.

9. A pad element as claimed any one of the precious claims, wherein the webs are formed from a different 10 material to the body of the pad element.

10.A pad element as claimed in claim 9, wherein the webs are formed from a harder and more rigid material than the material from which the body is formed. 15

11. A pad element as claimed in any one of the previous claims, wherein the webs are joined by cross members to form a unitary lattice. 20

12. A pad element as claimed in any one of the previous claims, wherein the webs comprise foot portions for enabling the webs to stand upright in a mould used in forming the body of the pad element. 25 12. A pad element as claimed in any one of the previous claims, wherein the webs comprise notches for receiving reinforcing bars.

13. A pad element for use in forming a building 30 foundation, the pad element comprising: a body; a first channel for receiving concrete formed in the body; and a second channel for receiving concrete formed in the body, intersecting the first channel, wherein the first and second channels divide the body of the pad element into at 35 least four quadrants; wherein the pad element comprises a number of ribs for receiving reinforcing bars and each rib extends 5134442_1 (GHMatters) P75663.AU.1 20/02/14 - 17 between adjacent quadrants, across either first or second channels. wherein the ribs are arranged to be readily knocked out during use of the pad element. 5

14. A pad element as claimed in claim 13, wherein each of the ribs has a notch in its top surface for a portion of the reinforcing bars to be located in. 10

15. A pad element as substantially described herein with reference to the accompanying drawings.

16. A method of forming a building foundation, the method comprising the steps of: 15 (a) positioning a plurality of the pad elements as claimed in any of claims 1 to 15 on the ground abutting one another; and (b) pouring concrete over the pad elements. 20

17. A method as claimed in claim 16, wherein the method also comprises the step prior to step (b) of placing reinforcing bars in the first and/or second channels of the pad elements. 25

18. A method as claimed in either claim 16 or 17, wherein the step of placing the reinforcing bars in the first and/or second channels comprises locating the reinforcing bars in the notches of the ribs located in the channels. 30

19. A method as claimed in claim 18, wherein the method also comprises the step prior to step (b) of knocking out the ribs. 35

20. A building foundation comprising at least one pad element as claimed in any one of claims 1 to 15. 5134442_1 (GHMatters) P75663.AU.1 20/02/14