AU686223B2 - Method of reinforcing brick walls - Google Patents

Description

_I 1 METHOD OF REINFORCING BRICK WALLS This invention relates to a method of reinforcing brick walls.

This invention has particular but not exclusive application to methods useful in construction of buildings in brick veneer, and for illustrative purposes reference will be made to such application. However, it is to be understood that this invention could be used in other applications, such as super reinforcing the skins of cavity brick walls.

Cavity brick construction is the traditional brick construction wherein the load bearing walls of a building are formed of spaced brick skins interconnected by ties. The structure is very strong but is expensive in both time and materials. Brick veneer construction involves the provision of an internal structural frame capable of withstanding dead and live loads, clad in a skin of fired clay or other bricks attached with brick ties to the internal frame. The advantage of brick veneer construction over cavity brick or cavity block construction lies in its relatively low cost and speed of construction, whilst delivering the outward solid 20 appearance of a cavi t y brick construction.

A disadvarl ge of brick veneer construction lies principally in the strength limitations of the brick veneer skin. The internal frame must be adapted to support the entire structure of the building to an extent that if ithe external brick skin failed the frame would be strong enough to withstand the forces. Whilst there have been other methods designed to substitute for cavity brick construction, 0=9 2 such as the integration of brick piers in single skin constructions, these at least in part retain the disadvantages thereof and do not incorporate the full strength advantages of cavity brick construction.

Concrete block construction utilizes hollow concrete blocks of half block and full block size having one and two vertical passages therethrough respectively. By virtue of larger block footprint, single skin load bearing construction can proceed higher than for clay or other small-brick construction. Additionally, the cores can be used as conduits for steel reinforcing, which may render the wall acceptable for load bearing, particularly with stressing.

Generally, such reinforced walls are formed by casting starter bars into a footing and laying the blocks over the bars, whereafter the bars are grouted by filling the cavities with concrete slurry. If necessary, further reinforcing is then tied to the starter bars and wall construction proceeds, the reinforcing being grouted in as before. This

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construction is made possible by the size of the cavities 20 relative to the reinforcing being such that reasonable variation in positioning of the reinforcing may occur.

This method of construction is unsuited to use in single *e skin reinforced wall construction using clay or other small bricks. In the case of conventional clay bricks comprising a substantially solid prismatic form having a frog in the upper surface, the absence of a core or cavity physically precludes the construction method. In the case of the now common extruded clay bricks having, in lieu of a frog, a series of 3 vertical holes or cores, the method is precluded due to the small cores requiring an accuracy of placement of the starter bars which cannot in practice be achieved and which cannot easily accommodate continuance of the reinforcing above the starter bars.

The present invention aims to substantially alleviate the above disadvantages and to provide construction methods which will be reliable and efficient in use. Other objects and advantages of this invention will hereinafter become apparent.

As used hereinafter, the term "clay brick" refers to bricks of the "core" type whatever its material of construction, generally of 110 mm dimension or less, although it is envisaged that methods in accordance with the present invention will find utility in respect of other types of 3: common building bricks or blocks.

With the foregoing and other objects in view, this invention in one aspect resides broadly in a method of reinforcing brick walls of standard extruded clay core bricks 20 including the steps of:forming a footing for the wall; determining the corresponding positions on said footing of selected cores of a first course of said core bricks, said selected cores to receive reinforcing; providing attachment means for said reinforcing at said positions; laying subsequent courses of bricks with said selected cores in register with said positions; engaging reinforcing with said attachment means, and grouting said selected cores.

The footing may take any suitable form. For example, the footing may take the form of a conventional footing of poured reinforced concrete, a pier and beam footing, or an integrated footing and preferably stepped slab. Preferably, for ease of damp coursing and to conform with commonly accepted practice the footing comprises a reinforced footing portion formed integrally with a stepped slab portion, such that the wall may be formed on a damp proof course on the lower step, the damp proof course extending up to the slab surface under the floor plate or other lower portion of the inner skin of the structure.

The means of determining the positions on the footing of 15 brick cores to receive reinforcing may be by means selected from measuring or templating the positions out on the footing, or by permanent or temporary laying of one or more courses of bricks over the footing. Since the cores of bricks may vary from brickworks to brickworks, between brick 20 sizes and styles, or even between batches of bricks, it is preferred that the positioning be determined with the bricks on site. By this means, the spacing can be accurately determined from a sample drawn therefrom.

The attachment means may comprise holes drilled or otherwise formed in the footing, sockets, spigots or other

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engagement means complementary to the reinforcing. The engagement means may comprise starter bars positioned in the footing either with or without connection to footing reinforcing. Engagement means may be cast into the footing or post formed, and be either attached or unattached to the reinforcing of the footing. Preferably, the attachment means comprises a series of holes accurately positioned as described above in the support. The holes may comprise a series of drillings into the cured footing of a wall, may comprise a plurality of holes formed by a concrete-displacing template when the footing is cast, or may comprise a similar template bearing separable inserts adapted to be accurately placed in situ when casting the footing.

The attachment means may secure the reinforcing members to the footing by any suitable securing means generally determined by the selection of attachment means. For example, sockets, spigots or holes may be amenable to adhesive or grouted securement, intermetallic connection may be by threaded, welded or other conventional intermetallic 20 connection. Where the mounting means comprises the preferred o o accurately positioned holes in the footing, the reinforcing members are preferably secured thereto by adhesive, grout or other like means. Preferably, where adhesive is used, this is high strength adhesive such as epoxy resin compositions.

25 The laying of courses of bricks with selected cores in register with the selected reinforcing positions may be done in a conventional manner, unhindered by starter bars or the u 6 like. Preferably, the first course is provided with cleanouts at the selected positions whereby access to the attachment means may be provided and whereby wash water or roding spoil may be cleared. The clean-outs also provide for illumination of the bottom of the lined up cores, whereby the courses may be maintained with cores in register by eye.

Hole roding means may also help maintain alignment.

Preferably, the attachment means is provided with removable cover means whereby the attachment means is protected from damage by spoil. For example, where the attachment means comprises holes or sockets provided in the footing, the removable cover means may comprise plugs or discs temporarily installed in or over the holes.

The reinforcing members are preferably conventional reinforcing bar, although it is envisaged that other S. reinforcing means may be appropriate, particularly if modification to suit a particular attachment means is S. contemplated. For example, the reinforcing means may include a rod or wire member adapted for post tensioning, or may be tube where threaded engagement or extension is contemplated.

The reinforcing members are preferably grouted into the cores with a high slump slurry including sand and portland cement.

Where the wall is to be relatively high it may be advantageous to utilize successive lengths of reinforcing 25 member and add these progressively as the wall goes up. The successive lengths may be installed in a common core through the wall and be lapped to provided continuity of reinforcing.

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7 Where lapped reinforcing members are required, it is advantageous to provide a core brick having larger that normal core sizes to accommodate the specified reinforcing doubled in the lapped region whilst providing sufficient space for passage and setting of grout.

However, in general the cores of core bricks will be too small to accommodate lapped reinforcing. Additionally, the requirement for lapping will dictate that the wall be concluded by threading the bricks over the lapped members, which is inconvenient and awkward. Alternatively, the reinforcing may include complementary joining means permitting the attachment of reinforcing in end to end relation whilst permitting grouting of the core.

It has been surprisingly determined that it is also effective to extend the reinforced height of the wall by providing reinforcing in a core other than the core reinforced from the footing, which provides for the use of conventional reinforcing bar without the need for specialized interconnection means.

20 Accordingly, in a further aspect this invention resides broadly in a method of reinforcing brick walls as described above and including the steps of:laying said subsequent courses to form a wall portion of height less than the length of said reinforcing me ibers; blocking the remaining unselected cores of said wall portion; laying further courses to a height substantially the length of said reinforcing members; I _L M ~R~BB 8 performing said grouting of said reinforcing members; laying upper courses to a selected wall height, and grouting upper reinforcing into said further and upper courses in cores aligned with said blocked cores.

Preferably, the blocked cores are selected to be adjacent to the cores having the lower reinforcing members grouted therein. The respective reinforcing members preferably overlap be an amount sufficient to prevent separation of the upper and lower wall portions under expected ultimate design loadings. In order to facilitate installation of the upper reinforcing members it is preferred that the course bearing the upper reinforcing attachment means be provided with clean-outs, with it being particularly preferred to provide these on the interior of the wall to avoid external patching.

15 The upper extremity of the wall may be finished by any suitable means. For example, the grouted reinforcing members may protrude above the upper course of the wall and be adapted to engage a top plate, lintel or the like. Plain

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reinforcing bar may be bent over and/or clinched to retain 20 the top plate or lintel. Alternatively, the upper 4 reinforcing portion may be threaded such that the top plate ".or lintel may be retained by nuts. If desired, the e* reinforcing means may be post tensioned with or without retention of the top plate or lintel thereby. For example, reinforcing bar, wire rope or tension rod reinforcing means i

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may be post tensioned through tension collets or other conventional tensioning means.

Accordingly, in a yet further aspect, this invention resides broadly in a method of construction of stressed brick walls including the steps of:forming a footing for the wall; determining the positions on said footing of brick cores to receive stressing members; providing attachment means for said stressing members at said positions; forming a wall of core bricks with selected cores in register with said positions; engaging stressing members with said attachment means; providing load distribution means on an upper portion of the wall, and tensioning said tension member between said support ea means and said load distribution means.

The tension member may also take any suitable form with ego it being envisaged that metal or synthetic fibre ropes, metal rod or the like will generally be utilized. Preferably, for oeeS low cost and ease of integration with the preferred concrete footing, it is preferred to utilize steel rod of threaded or *8*C unthreaded section as the tension member.

Preferably, the tension members are grouted in their 25 respective cores with mortar, the post tensioning of the tension members being preferably performed while the grout is still wet. Mortar grouting of the tension members prevents I' L I movement or knocking within the wall as well as providing corrosion resistance by virtue of the alkalinity of the mortar.

The bricks are preferably laid in bond courses in the conventional way with adhesive laid between the bricks and between the courses. Preferably, the adhesive used is common mortar, although it is envisaged that certain block or brick materials may be bonded with other adhesive materials.

For walls beyond a selected height, the tension member.s may be provided in selected lengths shorter than the wall height and joinable as the wall progresses by joining means.

Alternatively, stressing members may be positioned in .eoe alternate cores, preferably vertically overlapping the first eeo S.set, such that the wall may be stressed progressively. In °•go this embodiment, the first courses of the wall at the commencement of the alternate cores are preferably provided e e with in-wall anchor means for the upper stressing members.

The load distribution means may take any form consistent with the function of providing means against which the tension members may be tensioned to load the wall in compression. For example, the load distribution means may comprise, in the case of the tension members passing through the cores, a spreader of dimension larger than the core. If desired the spreader may comprise a washer like member adapted to transfer the tensile load on the tension member to the uppermost brick having the core. Alternatively, the load distributing member may take the form of an upper wall plate I I or lint'l substantially extending along the top of the wall and engageable by a plurality of tension members.

Tension may be applied to the tension members before or after curing of the mortar by any suitable means. The preferred choice of tensioning means will of course be determined by the nature of the tension members. For example, threaded rod tension members may be tensioned by means of a nut or threaded collet. Plain ended or cable type members may be tensioned by post tensioning apparatus and retained in the tensioned state by a suitable swaged or otherwise affixed collet.

Preferably, the wall is frameless, the dead and live ~loadings of the wall in construction and use being borne by the veneer skin constructed in accordance with the present methods. Of course, if desired for some ancillary reason such as support for internal loads, the structure may include a free standing or tied internal frame. Where the wall assembly is to constitute an outer load bearing wall or the S. like, the load distribution means preferably takes the form 20 of a timber or metal section adapted to receive or have formed therewith attachments for rafters, joists or the like.

In general, buildings manufactured using walls in accordance with the present method will be lined to provide raking protection, suitable appearance and insulative properties. Such lining is preferably of conventional lining materials such that a conventional internal appearance may be presented. Preferably, the lining is spaced apart from the o brick veneer skin to provide a moisture, h( and sound reducing space. For example, a wallboard lining mty be supported on battens and/or spacers to provide an air gap.

It is a significant advantage of the present invention that the internal skin need only provide sufficient strength to support itself and to withstand impact loads which may occur during use. The outer surface of the wall may be waterproofed in a conventional manner.

In order that this invention may be more easily understood and put into practical effect, reference will now be made to the following examples and accompanying drawings which illustrate preferred embodiments of the invention, wherein:- FIG. 1 is a section view of a wall constructed in accurdance with the present method, and FIG. 2 is a section view of a wall constructed in accordance with an alternate embodiment to that of FIG. 1.

EXAMPLE 1 20 In FIG. 1, there is provided a wall assembly 10 built above ground level 11 and including a poured concrete footing portion 12 having cast therein reinforcing bars 13. Tied to the reinforcing bars 13 and extending upwardly from the footing portion 12 are starter bars 14. Laid over the starter bars by threading thereover are two lower courses of bricks having cores, the starter bars 14 being bent inwardly into the slab space above and after laying of the 13 lower courses 15. A slab base material 16 is laid up to the lower courses Attachment members 17 are provided with a slab insertion portion 20 bent at right angles to the upstanding portion of the attachment members 17 and are tied to a corresponding portion of the starter bars 14, the position of upstanding portions of the attachment members 17 being determined by a template spacing the members 17 according to the selected core positions of the bricks. The concrete slab 21 is then poured and allowed to cure after insertion of a damp proofing course 22 on top of the lower courses 15 and extending into a vapour barrier 23 provided between the slab base material 16 and the slab 21.

The brick veneer wall courses 24 are then laid in conventional bond by threading the cores over the top of the attachment members 17 with mortar between the courses and between the bricks in the course and extending the wall to the desired height. At appropriate ones of the wall courses S. 24, there are provided channel brick courses 25 having 20 grouted therein lintel reinforcing bars 26.

The uppermost course 27 is laid and the selected cores cleaned out by roding and/or washing, the spoil being cleared through a clean-out portion 28 provided in the lower course.

The reinforcing members 18 are then passed into the cleaned cores and attached to the attachment members by tying, welding or any other suitable means, whereupon the reinforcing members 18 are grouted into the cores and the

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14 cleanout face grouted in position. When the wall is cured, a timber top plate 30 is installed over the ends of the reinforcing members 18. Plate washers 31 are installed over the ends of the reinforcing members 18 and nuts 32 threaded thereon whereupon the tension members are tensioned with a spanner to place the wall in compression.

A roof truss assembly comprising a ceiling joist 33 and a rafter 34 is supported on the top plate 30, the sealing joist 33 bearing down on the top plate and the rafter 34 being secured to the top plate by means of a truss anchor Ceiling battens 36 support a diaphragm ceiling 37 and roof battens 40 support a roofing material 41. An eaves assembly 42 is supported between the wall assembly 10 and a facia 43 provided at the outer ends of the rafters 34. The facia 15 supports guttering 44 in a conventional manner. A none e structural interior veneer 45 is supported in spaced relation to the wall assembly EXAMPLE 2 [.In the embodiment of FIG. 2, bricks are provided on site prior to set-out of the wall, and a random sample from the ***brick stockpile is used to determine the horizontal gauge e e that will be required to ensure alignment of the cores vertically. If necessary, overall dimensions of the slab are adjusted to accommodate the sizing of the bricks in the stockpile.

In the embodiment, an integra slab 50 and footing 51 is allowing a suitable step-down 52 as per standard brick veneer construction. After completion of the slab, the set-out of the brickwork is done in accordance with the horizontal gauge determined above. The first two courses 53 are laid around the perimeter using cleanouts 54 during the first course wherever vertical reinforcement is required. The cleanouts 54 are be positioned facing outward to provide access for cleaning and steel fixing.

Following the set-out and laying of the first two courses, holes 55 are drilled at core placement positions to a suitable diameter to receive the reinforcing and a settable adhesive and to a depth to provide sufficient bonding length u: ing, in the present embodiment, epoxy resin. The holes are thoroughly cleaned and sealed off using a metal disc siliconed down to prevent entry of moisture or material while bricklaying is continued.

The wall 56 is continued with the bricklaying done ensuring alignment of vertical coring where reinforcing is

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required occurs and ensure that the same remain clear of mortar by washing and roding as necessary.

20 At a selected course 57, further cleanouts 60 are provided in cores adjacent to the first cores for .reinforcing, so as to allow cleaning of cores in the upper sections of the wall. These cleanouts 60 are facing inward ensuring minimum patching to the face of the brickwork.

Bricklaying is continued to a height approximately the length of the lower reinforcing, typically 1800 mm. At this point the metal discs protecting the holes 55 are removed and the lower reinforcing bars 61 are epoxied in to the holes using the clean-outs 54 provided for access. The faces to the clean-outs 54 are replaced and the cores grouted using a high slump mix of sharp sand and 33% cement.

The wall is then continued ensuring that the adjacent cores for the upper reinforcing remain clean and aligned, up to finished wall height. The upper reinforcing 62 comprising reinforcing bar having a threaded upper portion, is then installed in the adjacent cores and grouted in as before provided for the first lower cores. The upper reinforcing 62 is provided with sufficient thread to allow a top plate 63 to be fixed down thereby by means of a nut 64. If desired, ~additional short all-thread top plate studs 65 may be grouted into additional cores where the top plate requires more fixing points that the wall requires reinforcing.

The brickwork is sealed with a proprietary sealant to form a first barrier against moisture penetration, with the cavity formed between the brick and the internal stud wall providing a backup.

e o A conventional roof assembly 66 may now be installed 05. bearing on the wall assembly and internal framing 67 can be installed within the structure as a substantially non load bearing structure.

In the above embodiments, conventional, cored, 110 millimetre external brick is envisaged for use. However, it is envisaged that methods of construction and walls in accordance with the present invention may comprise other

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17 bricks or blocks. Whilst, in general, conventional cored bricks have typically three cores and it is prefeired that the outer cores be utilized, it is envisaged that the courses may be laid such that in alternative, either central or one of the outer cores are reinforced, to accommodate nonstandard bonds in the method The foregoing methods provide walls of sufficient strength to resist both the dead and live loads associated with the construction and use of load bearing walls and the like and the methods in accordance with the above embodiment are suitable for most terrain categories.

It will of course be realised that while the above has S.been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as defined in the claims appended hereto.

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Claims (16)

1. A method of reinforcing brick walls of standard extruded clay core bricks including the steps of:- forming a footing for the wall; determining the corresponding positions on said footing of selected cores of a first course of said core bricks, said selected cores to receive reinforcing; providing attachment means for said reinforcing at said positions; laying subsequent courses of bricks with said selected cores in register with said positions; engaging reinforcing with said attachment means, and grouting said selected cores.

2. A method of reinforcing brick walls according to Claim i, *wherein said determination of the positions on the footing of brick cores to receive reinforcing is by permanent or temporary laying of one or more courses of bricks over the footing.

3. A method of reinforcing brick walls according to Claim i, wherein said determination of the positions on the footing of brick cores to receive reinforcing is provided by measuring or templating the positions out on the footing, and wherein the measure or template is determined from a sample drawn from the bricks to be laid.

4. A method of reinforcing brick walls according to any one A R~II~II 19 of the preceding Claims, wherein said attachment means is selected from holes formed in the footing, sockets, spigots, or starter bars positioned in the footing. A method of reinforcing brick walls according to Claim 4, wherein said attachment means comprises a series holes drilled into the cured footing and adapted to receive said reinforcing and retain said reinforcing by means of a settable adhesive macerial.

6. A method of reinforcing brick walls according to Claim wherein said settable adhe' ive material comprises epoxy resin.

7. A method of reinforcing brick walls according to any one of the preceding Claims, wherein the first course of said wall is provided with clean-outs at said selected positions. 555 S

8. A method of reinforcing brick walls according to any one S S of the preceding Claims, wherein said reinforcing is grouted into said cores with a high slump slurry including sand and S. S portland cement.

9. A method of reinforcing brick walls according to any one of the preceding Claims, wherein further reinforcing is Iovided in an upper portion of the wall. 0. A method of reinforcing brick walls according to Claim 9, 9i oftepeedn lisweenfute enfrigi I _sll~ wherein said further reinforcing is provided in a core other than the core reinforced from the footing.

11. A method of reinforcing brick walls according to claim 1, including the steps of:- laying said subsequent courses to form a wall portion of height less than the length of said reinforcing members; blocking the remaining unselected cores of said wall portion; laying further courses to a height substantially the length of said reinforcing members; performing said grouting of said reinforcing members; laying upper courses to a selected wall height, and grouting upper reinforcing into said further and upper courses in cores aligned with said blocked cores. a

12. A method of reinforcing brick walls according to Claim "11, wherein said blocked cores are selected to be adjacent to the cores having the lower reinforcing members grouted a therein. Sa a

13. A method of reinforcing brick walls according to Claim a 12, wherein the course bearing the blocked cores is provided with clean-outs disposed towards the interior surface of said wall.

14. A method of reinforcing brick walls according to any one of the preceding Claims, wherein a portion of the grouted l~ I 1 III 21 reinforcings protrude above the upper course of the w:tll and are adapted to engage a top plate, lintel or the like. A method of reinforcing brick walls according to Claim 14, wherein the protruding reinforcing portion is threaded such that the top plate or lintel may be retained by nuts.

16. A method c2 reinforcing brick walls according to Claim 14, wherein the reinforcing is post tensioned.

17. A method of construction of stressed brick walls including the steps of:- ;forming a footing for the wall; determining the positions on said footing of brick cores to receive stressing members; providing attachment means for said stressing members at a.. said positions; forming a wall of core bricks with selected cores in register with said positions; engaging stressing members with said attachment means; providing load distribution means on an upper portion of the wall, and tensioning said tension member between said attachment means and said load distribution means.

18. A reinforced core brick wall constructed substantially in accordance with the method of Claims 1 to 17. 1 ~Z~ 22

19. A method of reinforcing brick walls substantially as hereinbefore defined, with reference to the examples 1 or 2 and the accompanying drawings. A reinforced core brick wall substantially as hereinbefore defined, with reference to the accompanying drawings. DATED THIS TWENTIETH DAY OF OCTOBER 1997. RAYMOND NIEL HORN BY PIZZEY COMPANY PATENT ATTORNEY oa a o a o• 4 a a a..a a..t a. a. a a oQ a a a 0a a 1 4 c C I