WO1992002701A1

WO1992002701A1 - A method of wall construction

Info

Publication number: WO1992002701A1
Application number: PCT/AU1991/000334
Authority: WO
Inventors: David Allan Burke
Original assignee: James Hardie and Coy Pty Ltd
Current assignee: James Hardie and Coy Pty Ltd
Priority date: 1990-08-01
Filing date: 1991-07-31
Publication date: 1992-02-20
Anticipated expiration: 1993-02-01
Also published as: NZ239193A; CN1059771A

Abstract

The invention provides a method of wall construction. Temporary open sided upright channel shaped formwork members (10, 16, 20) are placed on footing stools (46, 67), the open sides of the formwork members (10, 16, 20) are closed off with wall panels (84) to define spaces which are filled with liquid concrete. The formwork members (10, 16, 20) are removed when the concrete is set. Block out inserts (32) are used to form door (40) and window (41) studs.

Description

TITLE A METHOD OF WALL CONSTRUCTION FIELD OF THE INVENTION The present invention relates to a method of wall construction and to buildings and other structures incorporating such walls.

SUMMARY OF THE INVENTION There is an ever increasing demand for low cost housing. In particular, developing countries require housing that can be erected rapidly with the minimum of skilled labour and raw materials. Further, such housing frequently needs to be able to withstand adverse climatic conditions such as cyclones and other strong winds. Similarly, in remote areas, the cost of transportation of raw materials and labour to the building site can contribute significantly to the final cost of the building, and in many commercial buildings the time required for completion of the building may be a determining factor when considering the overall cost of the building. The present invention seeks to provide a building system which allows for the rapid construction of buildings using mainly unskilled labour and a minimum of raw materials by using a temporary formwork system that is reusable. In accordance with one aspect of the present invention there is provided a method of wall construction characterised by locating a plurality of temporary open sided upright channel shaped formwork members in spaced apart manner on a footing, closing off the open sides of the formwork members to define spaces, filling the spaces with liquid concrete, allowing the concrete in the spaces to set and subsequently removing the temporary formwork members to leave a plurality of upright free standing concrete studs mounted on the footing. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:- Figure la is a perspective view of a standard formwork member in accordance with one aspect of the present invention;

Figure lb is a perspective view of a corner formwork member in accordance with one aspect of the present invention; Figure lc is a perspective view of a window/door formwork member in accordance with one aspect of the present inventio ;

Figure Id is a perspective view of a block out formwork re be used with the window/door stud of Figure lc; Figure le is a cross-sectional view of the blockout insert taken through the line e-e shown on Figure Id;

Figure If is a cross-sectional; view of the blockout insert taken through the line f-f shown on Figure 12; Figure lg is a perspective view of a pressing to be used with the window/door stud of Figure lc and the block out of Figure Id;

Figure lh is a view of a middle window stud formwork in accordance with one aspect of the present invention; Figure 2 is a view of a standard pre-cast footing in accordance with one aspect of the present invention; Figure 3a is a view of a standard stud in accordance with one aspect of the present invention;

Figure 3b is a view of a corner stud in accordance with one aspect of the present invention; Figure 3c is a door jamb stud in accordance with one aspect of the present invention;

Figure 3d is a view of a window stud in accordance with one aspect of the present invention;

Figure 4 is a section of toe formwork in accordance with one aspect of the present invention;

Figure 5 shows a top plan view of a building pad with an excavated trench showing the footing stool of Figure 2 in position;

Figure 6a illustrates a corner of the building of Figure 5 with the toe formwork in position;

Figure 6b is a cross-sectional side view of a footing stool and tow formwork assembly;

Figure 7a is a view of the building of Figure 5 with the toe formwork and footings in position; Figure 7b is a cross-sectional side view of the footing stool and toe formwork assembly of Figure 7a;

Figure 8 is a view of the standard stud of Figure la being connected via top and bottom connecting bars;

Figure 9 illustrates a corner of the building of Figure 5 showing the arrangement of formwork studs connected by connecting angles;

Figure 10a illustrates an arrangement of a window/door stud formwork, a pressing and a block out stud to form the window stud of Figure 3d; Figure 10b is a cross-sectional view of the arrangement of Figure 10a taken along the line b-b on Figure 10a. Figure 10c is cross-sectional view of the arrangement of Figure 10a taken along the line c-c; Figure lOd is a cross-sectional view of the arrangement of Figure 10a taken along the line d-d

Figure 11a illustrates an arrangement of formwork used to form a middle window recess. Figure lib is a cross sectional view of the arrangement of Figure 11a taken across the line b-b on Figure 11a,

Figure lie, is a cross sectional view of the arrangement of Figure 11a taken across the line c-c on Figure 11a, Figure lid is a cross sectional view of the arrangement of Figure 11a taken across the line d-d on Figure 11a, Figure 12 is a side elevation of a lower end of a wall construction in accordance with one aspect of the present invention; and

Figure 13 is a perspective view of an upper end of the wall of Figure 12. DESCRIPTION OF THE INVENTION

In the drawings, the items depicted in Figures 1 to 4 represent the components of the method of construction of the present invention. Figures 5 to 13 represent various stages in the construction of a building according to one embodiment of the present invention using the components identified in Figures 1 to 4.

The formwork members shown in Figures la to lh are used to form upright studs in a building. The standard formwork member 10 is shown in Figure la. The formwork member 10 is a three sided channel which is shaped with one open end and sides 11 which taper inwardly towards a rear face 12. The stud formwork member 10, when filled with building material such as concrete gives rise to a standard stud 14 as shown in Figure 3a.

A corner formwork member 16 is shown in Figure lb. The corner formwork member 16 may be regarded as a composite of two formwork members 10 arranged with their respective rear faces 12 at right angles to one another. A horizontal apertured plate 17 is located between the rear faces 12 of the corner formwork member 16 adjacent the upper end of the formwork member 16. In position, the corner formwork member 16 results in a corner stud 18 depicted in Figure 3b which is L shaped in cross section. A door/window formwork member 20 illustrated in Figure lc is formed by truncating one of the sides 11 of a standard formwork member 10 to form a narrow connecting strip 22. The connecting strip 22 has a plurality of aligned, spaced apertures 23 extending along its length. A door/window pressing 2_.4 (Figure Ig) is adapted to be connected to the door/window formwork member 20. The pressing 24 is dimensioned such that it rests in the door/window formwork member 20 with an overlap section 26 resting on the rear face 12 and a side section 28 overlying the connecting strip 22. There are a series of aligned, spaced apertures 30 in the side section 28 which correspond with respective apertures 23 in the connecting strip 22. A block out insert 32 shown in Figures Id, le and If forms the final element of the door/window formwork set. The block out insert 32 is designed to be located within the door/window formwork member 20, in use, as shown in Figures

10 a,b,c and d.

The block out insert 32 comprises a three sided channel with sides 33,34 and 35.

A first side 33 is truncated and corresponds to the connecting strip 22 of the door/window formwork member 20. There are a series of aligned, spaced holes 36 in the side 33 which correspond to respective holes 23 on the connecting strip 22.

The side 33 tapers inwardly towards a second, rear, side 34. The rear side 34 extends partially along the length of the rear face 12 of the door/window formwork member 20. A third side 35 extends at right angles from the rear side 34.

At an upper end of the insert 32 there is a horizontal plate 37. The horizontal plate 37 is defined by the sides 33, 34 and 35 and an extension 38 of the side 33, and an edge 39 which extends between the sides 38 and 35. The door window formwork member 20, the pressing 24 and the insert 32 are used to form door jamb studs 40 and window studs 41 shown in Figures 3d and 3c respectively. (The embodiments shown in Figures lc-g is used for forming a left hand cut out in a window or door stud as shown in Figures 3d and 3c. To form a right hand cut out in the studs a correspondingly modified version of a blockout insert 32 would be used.

Figure Ih illustrates a middle window section 43. The middle window section 43 is a three sided channel with a rear face 42 and sides 44. Each side 44 of the section 43 is truncated such that the section 43 forms a shallow channel. There are two vertical rows of spaced aligned apertures 45 on the rear face 42. In use, the section 43 is located intermediate two sections of standard formwork member 10 such that an extended window may be placed across a stud 14 and the stud 1,4 may continue above the window as described hereinafter. The section 43 is dimensioned so as to be fitted around a formwork member 10 . Figure 2 illustrates a pre-cast standard footing stool 46. The stool 46 is formed of a substantially horizontal base 50 and respective substantially vertical studs 52. A metal reinforcing rod 48 projects upwardly from the upper surface of the vertical stud 52. Similarly, a corner footing stool 67 (see Figure 5) has a base 67b and a vertical stud 67a which is L-shaped in cross-section.

The vertical stud of the corner footing stool 67 has two reinforcing rods projecting one from each limb of the stud 67a. Figure 4 illustrates a section of raft toe formwork 56 to be used with the footing stools 46 and 67. The raft toe formwork 56 comprises an upper vertical section 58 which is shaped to overlie a vertical stud 52 and a lower vertical section 60 which is shaped to lie adjacent the outer edge of the base 50 of the footing stool 46. The upper and lower vertical sections 58 and 60 are connected by an intermediate substantially horizontal section 62 with an angled outer edge. The formwork system of the present invention is used to construct a generally hollow formwork which may be subsequently filled with liquid concrete which sets to form a solid stud free standing for a building. The stud is mounted directly on the footing as described hereinafter. The framework is dismantled and removed before the building is completed and may be- removed for re-use in later projects.

The following description describes a method of construction of a building according to the present invention.

In Figure 5 there is shown a plan view of a building pad 64 and surrounding excavated trench 66. A corner footing 67 has been placed in each corner. The corner footings 67 may conveniently be used to provide anchoring points for a string line extending around the pad 64 from corner to corner. The string line provides a levelling site for the placement of standard footing stools 46 between each corner. Sections of toe formwork 56 are placed externally around the footing stools 46 and corner footings 67 as shown in Figures 6a and 6b. The toe formwork 56 is secured in position by an angled cleat 68 which has an aperture engaged with the reinforcing rod 48 and a downwardly depending flange engaged with the toe formwork 56. A cross-sectional view of the arrangement of toe formwork 56 and stool 46 can be seen in Figure 6b.

The assembly of the stools 46 and toe formwork 56 can thus be achieved without the need for skilled labour. Further, because the components fit together without requiring any screws, bolts or nails, the components may be assembled quickly. The metal reinforcing rods 48 act as starter bars for the placement of formwork members 10,16,20,43. A formwork member being located about each reinforcing rod 48.

When the footing stools 46 and toe formwork 56 are in place, the building and footing concrete 69 can be poured. During the pouring of the concrete 69, the footing stools 46,67 need supporting. As shown in Figure 7a apertured support beams 70 have apertures engaged with the reinforcing rods 48 and secured to the ground by means of pins 71. The support beams 70 support the footing stools 46, 67 by virtue of their engagement with the reinforcing rods 48. The liquid concrete is then poured into the trench 66 to the level of the upper end of the studs 52 and 67a. This can be seen in cross section in Figure 7b. As shown in Figure 7b, the concrete also extends across the top of the pad 64 to form a unitary upper surface. Once the concrete in the trench 66 has set, the support beams 70, angle cleats 68 and the toe formwork 56 may be removed for future re-use.

The next stage in the construction is the assembly of the upright formwork structure. Figure 8 depicts schematically the components of the upright formwork structure. A standard formwork member 10 is secured at an upper end to an upper connecting angle 72 and at a lower end to a lower connecting angle 74 by upper and lower brackets 76. The upper and lower connecting angles 72, 74 are formed of lengths of right angled metal. Each bracket 76 has an offset portion 78 forming a slot 77 between the bracket 76 and the formwork member 10. The slots 77 are arranged to receive the connecting bars 72, 74. The offset portions 78 contain threaded apertures in which are located bolts 79. The bolts 79 are screwed in securing the bars 72, 74 in position. Further, the corner formwork members 16, and door/window formwork members both have brackets 76 attached to the rear faces thereof. In practice the formwork structure is assembled as follows. The.lower connecting bar 74 is placed on the internal side of the building and secured to the concrete by means of masonary nails. The lower connecting bars 74 are positioned side by side until a complete circuit is made over the footing stools 46 and 67. The corner studs 16 are then placed in position about the reinforcing bars 48. The positions of the corner studs 16 are made plumb and_. brakes (not shown) are used to maintain the positions of the corner studs 16 temporarily.

Standard formwork members 10 are placed between the corner studs 16 and secured to the lower connecting bar 74 by means of the brackets 76. The upper connecting bar 72 can then be secured between the corner formwork 16 and standard formwork member 10 by engaging the upper connecting bar 72 with the bracket 78 in the corner formwork 16 and a bracket 76 on the formwork member 10. If it is desired a further, intermediate connecting bar can be used between upper and lower connecting bars 72, 74, to provide further rigidity to the structure. Intermediate connecting bars can be secured to additional brackets 76 (not shown) located on the face 12 intermediate the upper and lower brackets 76 on the formwork members 16. The assembled framework is illustrated in Figure 9. Where studs for windows or doors are required the window/door formwork member 20, pressing 24 and blockout insert 32 are used.

Figure 10a illustrates an arrangement of the door/window formwork member 20, pressings 24 and insert 32 which would be used to produce a window stud 41 of the type shown in Figure 3d. The components would be assembled as follows. A first section of pressing 24 is located with the apertured side 28 overlying the connecting strip 22 of the formwork member 20. The apertures 23 and 30 are aligned. Bolts passed through the aligned apertures 23, 30 secure the formwork member 20 and pressing 24 in position. The pressing 24 and formwork member 20 in position form the equivalent of a standard formwork member 10. A cross-sectional view of the pressing 24 and formwork member 20 is shown in Figure 10b. The pressing 24 extends only partially down the length of the formwork member 20.

Below the pressing 24 a blockout insert 32 is connected to the connecting strip 22 by aligning the apertures 36 on the side 33 with the apertures 23 on the connecting strip 22. The insert 32 is connected with the horizontal plate 37 upper most.

Figure 10c shows in cross-section the arrangement of the formwork member 20 and insert 32 through the horizontal plate 37. In use, the horizontal plate 37 produces an upper horizontal ledge 81, window stud 41, as shown in Figure 3c Further, the inner side 35 of the insert 32 extends downwardly from the horizontal plate 37 and produces a narrowed section 83 of the stud member 41 as shown in Figure 3c. Below the insert 32 a second section of pressing 24 is connected to the formwork member 20 as described above. The second section of pressing 24 forms the lower portion of the window stud 41. Where it is desired to form the door jamb stud 40 a sectio of insert 32 which is of sufficient length to extend to th base of the stud 40 is used, thus producing an elongated door recess 85.

Thus, a door/window formwork member 20 would have a first upper section of pressing 24 below which an insert 32 woul be connected. The insert 32 would extend downwardly to th base of the formwork member 20 forming an elongated recess in use.

Figure 11a illustrates a window recess 75 across a stud member 14. Figures llb,c and d are cross sectional views of the formwork arrangements required to produce the recess 75 at lines b-b, c-c and d-d on Figure 11a respectively. The window studs 41 on either side of the window recess 75 are formed from the formwork member 20, pressing 24 and insert 32 as previously described.

To form the lower part of the central stud 14 a short section of formwork member 10 is attached to a length of middle window insert 43. The middle window insert 43 is secured by bolts engaged through holes 45. This is shown _ _

in cross section in Figure lib.

The formwork member 10 extends to the height of the lower horizontal ledge on the window stud 41.

Figure lie shows a cross sectional view of the formwork across the window recess 75. The middle window section 43 extends vertically behind the window recess 75, Figure lid shows detail of the top of upper surface of the window recess 75. A section of formwork member 10 is attached to the middle window section 43. The formwork 10 has a floor plate 79 attached to the lower end thereof. In use, the concrete poured into the upper formwork 10 forms stud with a lower end defined by the plate 79. It is also possible to reinforce the area above the window recess 75 by attaching horizontal angled formwork members (not shown) to enable a concrete lintel to be poured. The lintel can be further reinforced by the addition of a horizontal reinforcing bar inserted through notches cut into the formwork members 10 and 20. A reinforcing bar 80 is inserted vertically into each upright stud formwork member 10, and window/doer formwork member 20. Two reinforcing bars 80 are added to each corner formwork member 16. Each reinforcing bar 80 projects through apertures in the upper connecting bar 74 and may be used for subsequent connection to roof members. As shown in Figure 9, horizontal pins 82 are inserted through aligned holes in the formwork members 10,16 and 20. Further, the position of the reinforcing bar 80 may be maintained by ties (not shown) securing the bars 80 to the horizontal pins 82.

Wall panels 84 are mounted to the formwork members by engaging downwardly extending ties 86 located on the rear of the panels 84 to the pins 82 in a known manner. The wall panels 84 and ties 86 can be seen in Figure 12. When the panels 84 have been fitted into position, the spaces defined by the upright formwork members 10,16,20 an the wall panels 84 are filled with liquid concrete. Any windows can be fitted into window recesses formed by the window/door formwork member 20 pressing 24 and block out 32. Further, horizontal reinforcement bars may be added above the window to reinforce the lintels. The reinforcement bars are positioned so as to pass through th formwork members 20 over the window recess. The formwork components are dismantled once the outer panels 84 have been placed and the concrete in the spaces defined by the formwork members 10, 16, 20 and the wall panels 84 has set. The procedure for dismantling the formwork is as follows. Firstly, the horizontal pins 82 are removed from the formwork members 10, 16 20. The bolts connecting the formwork members 10, 16 20 to the upper and lower connecting bars 72, 74 can now be released and upper connecting bars 72 removed. The masonary nails fixing lower connecting bars 74 are removed and the bars 74 are released. Any intermediate connecting angles may also be removed at this stage. The support beams 70 for the corner formworks can also be removed at this stage. The formwork members 10, 16 20 will now lift away easily leaving an arrangement of freestanding stud members mounted directly on the footing and panels 84.

It is convenient to lubricate all the formwork components at this stage to facilitate further use and prolong the component life.

The studs 14,18,40 and 41 may be connected to roof members 90 as shown in Figure 13.

The reinforcing bar 80 is threaded through a top plate 92. The top plate 92 is supported on the stud member 14,18,40 or 41. The top plate 92 would typically extend along the full length of each side of the building. To secure the stud member 14 an L shaped bracket means 94 is provided. The bracket means 94 has apertures 96,98 on both horizontal and vertical limbs. The apertures 96, 98 are situated so that the reinforcing bar 80 is inserted through the aperture 96 in the horizontal limb of the bracket means 94 whilst the vertical limb of the bracket means 94 is secured to a roof member 90 through the aperture 98. As an alternative to the top plate 92, a concrete ring beam may be formed around the perimeter of the building. The reinforcing bars 80 in such a situation are arranged so as to project beyond the upper face of the ring beam for further connection to roof members. Interior walls may be formed in the building either by means of fibre cement or the lining panels being fixed directly to the stud members 14,18,40 and 41 or alternatively, panels may be attached by means of furring channels and associated fixing clips. In a second embodiment, the present invention may also be used for the formation of retaining walls. In the case of a retaining wall the footing stools 46 are placed entirely below ground and additional concrete reinforcing is added in situ around the footing 46. Formwork members 10, 16 are used to create the desired wall shape. The reinforcing bar 80 may be secured at the upper end of the wall by known fixing means. It would also be possible to replace the outer wall panels 84 by other known wall panels attached directly to the stud members 14,18,40 and 41. In such a case, the formwork members 10,16 and 20 would be used without apertures for the horizontal pins 82. Further , the open sides of the formwork members would be closed off by means of elongated strips to form a space defined by the formwork members and the strips. These spaces would then be filled with liquid concrete as described above. After the concrete sets the strips and the formwork members would be removed and panels attached to the stud members. For example, timber grounds could be attached to the stud members 14,18,40 and 41 and wall panels connected thereto in a known manner. Using the formwork system of the present invention as described above it is possible to design and construct buildings which may be built with only a minimum of skilled labour and which may be constructed in the minimum of time. Further, the formwork components are all re-useable and adaptable to the individual requirements of each building.

Modifications and variations such as would be apparent to a skilled addressee are deemed within the scope of the present invention.

Claims

1. A method of wall construction characterised by locating a plurality of temporary open sided upright channel shaped formwork members in spaced apart manner on a footing, closing off the open sides of the formwork members to define spaces, filling the spaces with liquid concrete, allowing the concrete in the spaces to set and subsequently removing the temporary formwork members to leave a plurality of upright free standing concrete studs mounted on the footing.

2. A method according to claim 1, characterised in that the concrete studs are mounted directly on the footing.

3. A method of wall construction according to claim 1 or 2, characterised in that the footing contains a plurality of footing stools.

4. A method of wall construction according to claim 3, in which the footing stools are immersed in concrete.

5. A method according to claims 3 or 4, in which each footing stool comprises a base and an upright stud extending from the base.

6. A method of wall construction according to any one of claims 3 to 5, characterised in that a respective reinforcing bar extends upwardly from the footing and extends into each space.

7. A method of wall construction according to any one of claims 3 to 6, characterised in that the footing is formed by mounting a toe formwork adjacent to the footing stools located in a trench adjacent to a concrete pad, the toe formwork serving to define a volume externally of the footing stools, filling said volume with concrete and the outer edge of the footing, allowing the concrete to set and then removing the toe formwork.

8. A method of wall construction according to any one of the preceding claims, characterised in that an upright reinforcing bar extends throughout the length of each space from a point adjacent a lower end thereof to a point adjacent an upper end thereof.

9. A method of wall construction according to any one of the preceding claims, characterised in that the channel shaped formwork members are located in a spaced apart manner and connected by first upper and second lower connecting means attached to upper and lower ends of the channel shaped formwork members, the first and second connecting means extending between the formwork members along the length of the wall.

10. A method of wall construction according to any one of the preceding claims, wherein transverse pins are inserted across each stud formwork member, wall panels are mounted on the transverse pins, each wall panel comprising a rear face having outwardly projecting tie members extending therefrom, the tie members extending into the channel shaped formwork members and engaging the transverse pins.

11. A method of wall construction according to any one of the preceding claims, characterised in that at least some of the channel shaped formwork members include block out inserts which reduce the effective width of the spaces so as to produce studs with portions of reduced width.

12. A wall constructed by the method of any one of the preceding claims.