CA1279771C - Steel stud and precast panel therefor - Google Patents

Abstract

ABSTRACT
A steel member for a pre-cast panel having two parallel angle members parallel to one another, a plurality of struts extending from one angle member to the other; openings between the struts; junction strips extending from one of the angle members, and; anchor formations formed on the junction strips.
Also disclosed is a precast panel having a slab of cast material and a plurality of such steel members on one side, with their anchor formation embedded in the slab.

Description

'l'he invent;ion relates to a ste~el stud adclp-ted ~or ~ISe in assoc:i.atiorl wiL;h preccl.s-t panels, arLcl-tc) a p~etast panel i.ncorpora-ting such st1lds.
OUN~ OF 'l'tlE~lNVLi;N'l'ION
Precast panels, typically being cinished on one side, ot`ter numerous advanta~es in construction. In the majority o~` cases -the cost o~ the building will be ~ -reduced, where precast panels are used~ In addition~ i-t is possible to design an ex-terior formation on the panel , , "
having a7l attractive apyearance~ In ïnany cases -the panel ma-terial~is concrete, incorpora-tin~ reinforee1nen-t.
'I'ypic:a:l.ly the thickness of the concrete pane:Llin~ will be be-tween abou-t an inch. and two or -three inches ~:
Panels o~ this ~thickness require some ~orm of - struc-tural reinforcemerlt -to provide rigidi-ty. In addition, where such panels are used for ex-terlor load bearing walls, then -they mllst incorporate some ~orm o~
load bearing struc-tural mem'bers.
Typically', such panels will 'be erec-ted in place -to provide a fin:Lshed exterior, and the interior of the ~ '~
panels will -then be covered in arld finished at a later stage.
Qther applications t'or such precast panels are in providing èxterior wall systems -~or commercial and industrial buildings and hig~l rise otfice buildings and ':' :
apartments ancl-the like.
In this case such parlelling sys-tems are supported on the building structure, and do not normally provide any load bearing capaci-ty.
However, in these ccases the panels must, be --1-- . . .

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sec~lL~el~ atl;aclled on their lnteriors to l;he ~'a'brlc o:t' L~lildina~ arld are prefe.ra~:Ly bracecl interrla.lly, f'or add.itloIIal ~-treng-t~l and rigidi-ty.
'I'he desigll o:t SUCil p.recast panels must 'however be such t.hat it ~eets all oi`-the l'oregolng objec-tives in a sa-tis-factory and e:Eficient manner, and also at a reasorla'ble cost. In most cons-truction projec-ts the actual weight of -the materia:l used in corlstruction is of great impor-tance. l'he weight of the mat;erials affects 'bo-th the cos-t of the materials and also the cost of shipping, and impose limi-ts on -the manner in which the matsrials can be handled at the cons-tructioll site.
In addi-tion -to all of these limitations however especially in t'he cons-truc-tioll of high ri.se buildin~Ss, the .-weig~-t of -the construction ma-terials i5 a crit,ical fac-t-or in the desi~n of the elltire buildin~
Where a significant reduction in material weight can be achie~ed, -then i-t becomes possible -to optimize the design of the entire building cmd reduce construction cos-ts. For all these reasons therefore it is desirable that -the thickness of -the precast panel shall be reduced - to a minimum compatible with achieving these objec-tives.
Accordingly, developments in the design Or suc'h precast panelling have been along -the lines of reducing the thickness of -the panelling, and incorporating me-tal struc-tural studs or channels on the one side of -the panel.
In this way, the exterior of the panel presents a finished appearance, and the interior of the panel has a plurali-ty of metal studs or channels partially embedded in .~0 its surface .~. . ."

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U-i:ing -tllese techlr)i~lles, it has beerl:ec~urld po<is:Lble to constrllo~t precast pcLnels of very consider~ble Si.:;e?, and oi` a thicknG-ss of between one arld two inches.
:Rein:eorcing s-teel is inGorporclted in -the panels, a~ld t~le struc-tural ste~l studs have por-tions which are embedded in the concrete on one side of rein-forcing steel web.
In t'he past, the steel stud used for this - : -purpose has of-ten been of a simple C-shaped chan.nel, with one edge of the channel simply resting against the reinl`orcing s-teel mesh.
'I'his however! is no-t alwa~s a sufficieIlt method .
of attachmen-t. Dlrect a-t-tachment betweHn -the studs and steel mesh l~ay be more desirable irl some cases.
In addition -the use of a simple C-shaped channel creates obstructions in -the wall. ..
If any elec-trical services are to be run through the wall) then the openings must be made -through -the .~ .

chanrlels. One of the most significant problems has been -the heat transfer through the studs. The metal causes ::
patches of cold on -the in-terior of the wal'ls, resulting in condensation in and on the wall. The heating load in -the ~' building is also increased.
The weight of the mstal s-tuds -them.selves is also a significan-t factor in the o-verall weight of -the panels. . ' Any reduc-tion in weight -that can be achieved, without loss in rigidity, will produce significant benefits. ~ -For all of these reasons -therefore it is desirable to employ a steel s-tud ~hich is designed particularly for use in precast panels~ in which the .,"~ , .
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~ei~Silt ot` the steel stud .is reduced to a m:inimuml and i.n wh:ich it may have i-ts own i.lltegral securing means ~or securing -the stud -to the rei.nlorci:ng steel mesh in -the panel and which inco:rporates open:irlgs along i-ts length to reduce hea-t trans~er -throug'h the stud.
E.~RIE:F _UMMARY__F'rL'HE INV.E.NTION.
With a view to achieving the various objec-tives se-t out above, the invention provi.des a struc-tural steel : member comprising -two parallel spaced~-apar-t generally L-shaped angle members e~-terlding parallel to one another, a pluraIity of spaced-apart stru-t members ex-tending integrall~ from one said angle membex -to the o-ther and defining openi.ngs -therebetween said an~le mem'bers and said stru-t members being formed ou-t of a single integral piece o~ sheet me-tal, ed~.re ~lange forma-tions :Eormed on the stru~t members, defining a generally three-sided channel shape in cross section or greater stren~th, each of said angla members defi.ning rnounting surfaces, lying in parallel spaced-apart planes, a jullction s-trip extending from one of said angle mem`bers normal to said mounting surface, a locking strip formed on said junction strip, and anchor formations formed on said locking strip.
More particularly, -the invention seeks -to provide a s-tud member having -the foxegoing advan-tages, including struck out -tab members located a-t spaced intervals along said locking strip, said tab mernbers being dimensioned and adapted -to fit around and engage portions of reinforcirlg s-teel. :.

More par-ticularly, it is an o`bjecti-ve of the '.
inven-tion to provide such a s-tud member including loop ~. --'1--.~

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~L279771 formations t`o.rmed in said locking strip, said loop forllla-tions beirlg designed to be embeddecl in a panel material.
It is ~ further and relate(l o~jective of -the invention to provide a precast panel incorporating a plurality of stud members according t.o -the inven-tion loca-ted in predetermined parallel s~aced-ap~trt rela-tionship, ex-tending from orle edge -to the other of said :-pancl, arld including upper and lower frame ~lembers e~-tending between -the upper and lower ends o~ said stud ~ .
members, and pa~lel ma-terial cas-t around said lockin~
s-tr;ps.
The various featuxes o novelty which ~`.
charac-terize -the invention a:re :pointed out with particularity in the clain~s annexed -to and ~Pormin~ a part of this disclosure. For a be.tt.er understanding o~ -the inventio~l~ i-ts operating advantaFSes and specific ob~jects a-ttained by i-ts use, reference should be had to -the accompanying dra~7ings and descriptive matter in which there are illus-trated and described preferred embodimen-ts of the invention.
- IN THE DR WINGS
Figure 1 is a perspective of a typical p.recast panel according -to th~ invention;
Figure 2 is a perspective illustration o~ a s-tud mernber accordlng -to the invention;
Figure 3 is a sec-tion through a typical panel incorpora-ting s-tud members according -to -the invention;

E'igure 4 is a perspective of another embodiment;
Figure 5 is a perspective o-f a further . . ~ 5 ....
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E'igure 6 is a sectional illus-tration o~ a :t`ul.~ttler embodlMen-t;
Ii'igure 7 is a perspec-tive of'-the xtud of:
Figure 6;
Figure 8 is a partial sectioIlal stration of a further embodimen-t;
Fi~ure 9 is a partial sectional view o-f a further alt`ernate embodimen-t; and, Figure 10 is a partial sec-tional view of a ~urther~alterna~te embodimen-t.
Precast panel 10 has a slab 12, -typically formed of concrete, with steel reirl~orcing embedcled therein. A
plurality o~ s-teel stud mem~ers 14 are at-tached O~l one side of ~the slab por-tion 12 and in a manner -to be described below.
As best shown in Figure 2, -the stud member 14, according to the invention, comprises inner and outer :.
generally L-shaped anglc- portions 20 and 22. :Each o~ ;-`
angle portions 20 and 22 comprises respective moulltirlg flanges 24 and 26, and bracing flangec; 23 and 30.
- Respective mounting flanges and bracing flanges form a right angle, so that the -two moun-ting ~langes are loca-ted in paralle:l spaced-apart planes.
:[n order to join -the two angle portion.s 20 arid 22 toge-ther, angled struts 32 extend integrally between them. Struts 32 are formed into a generally three-sided channel shape by means of turning down the edge flallge por-tion 34 on either side.

Angle portions 20 and 22 and s-truts 32 are all :
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fc.rnled integrally out of a single piece of sheet metal.
Typically -tlley will. ~e ~ormed by roll formiIIg -tec~-mi~ues, wil;h o,pening being blanked out be-tween -the struts 32.
Such openings are shown generally as 36. ~tuds ~.
of this type are considerably lighter than equivalent - -~
.s-tuds o the conven-tional C-shape cross section. In addition, -the forlning of openings in the studs between the struts both reduces the heat transfer throu~h the stud, and at the same time provides ade~ua-te openings for passing services through the studs. , ., -~ In order to sacure -the studs in a precast parle].
a .iul:lction flarlge 40 extends from mounting flange 26, at ri~ht angles thereto, and a lockiIIg strip 42 ex-tends rom '~-~;unction ,strip 40 also a-t right angles. :' Lockin~ strip 42 is thus located in a plane parallel to but spaced apart from the plane of mollnl,illg flange 26.' Fastenin~ tabs 44 are s-truck out of lockin~
stri.p ~2 a-t i.ntervaIs, for attachment to reinforci~1g s~eel ~ `
rods such as 46. Rods 46 are not shown in detail being ~'.
~eLl known in -the art and requiring no fur'ther ~ ' description.
In t.he manufacture of the composite precast panel, the studs are assembled ~together and fastened ill-tO
a framework~ similar to the ~ramework used w~len erecting studding for a wall. That is to saY, a plurality of the studs are arran~ed in parallel spaced-apart locations ~.
typically on 16 or 24-inch centres for example, and top and bottom pla-tes 13 may be:attached at either end.

~ mesh or grid of reinorcing steel 46 i.s -then , ~ .
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laCe~1 ~n ~I1e I OC ki71g StriPS 4~ of eclc'h of th~ s-tuc1s.
Some of -the ta~s 44 will extend a.ro~lnd ad;jlcent por-tions o:t' the relnforcing rods 46. T:llese -ta'bs can then si1llp.ly be bent around witl1 a hammer or a sui-table tool.
. In this way the reinforcing rods will be attachecl to the .rectangular framework Oe studs at spaced-apar-t points.
The manufacture of the composite panel -then ~ -proceeds by''pouring A suf-ficien-t dep-th of -the precast ma-terial -typically conc.re-te, in-to a horizon-tal mou:Ld. In a -tyRica`l example it will be pour~d -to a depth of abou-t -one and a half inches, the thickn~ss depending upon Yarious factors and design considerations.
The entire rectan~ular ~ramework o~ studs togetller with the reinforcing mesh a-ttached -to -the one side is -then ralsed a'hove the mould, and lowered down into -the mould, so -that the reinforcing mesh descends part way in-to the concrete.
When the~desired dep-th has 'been reached, the locking strip 42, and junction strip 40, will in -fact'be im1nersed in the concre-te, and the mounting flange 26 will -typically be resting on the surface of -the concre-te.
The rectangular framework of studs is then secured so that it canno-t sink any fur-ther, and it is held .
until the panel is se-t and cured~
The en-tire panel is -then freed from the mould.
Panels made in -this way are found to e~hibit great streng-th, and durability. The studs are securely fastened -to the sla'b, enabling the panels to be moved, installed and fastened.

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'l'he low t~lertnal conduc-tivlty of -the studs su~stantially elimina-tes cold spots ancl condensa-tion c~used by conven-tioIlal stud5.
'rhe slab may ~e C.lst o~ some ma-terial other -than concre-te. Various proplietary 'brands of casting materials are available on -the market havin~ a grea-ter streng-t}l than concrete. When using these materials it may become possi~le to reduce the thickness o~ the slab.
I~ -this case -the plate portion ma~ no-t be as suffiGiently thick to permit embedmerlt of any subs-tantial por-tion of the studs 14.
Accordingly in this situation a modified s-tud 14A as shown in Fi~ure 4 may be provided. It has -tha same ~asic componen-ts namely angles ~0 and 2~ s-truts 32 ancl openings 36.
However in this case the moun-ting :elan~e 26 is provided wi-th stxuck ou-t -tabs 50 and spacer abu-tment 52 may also be ~oxmed adiacen-t -to tabs 50.

Embeclment locks 54 may also be struck out in -the orm simply of loops o-f sheet metal.
In Fi~ure 4 these axe illus-trated as 'being separate from the -ta'bs. However, it will be apprecia-ted ~ ~;
-that a variety of diffexeIlt arrangements of tabs and loops and abutmen-ts could be employed withou-t departine~ from the .. . _ .. .... ~ . .. . .
inven-tion.
In this form of the inven-tion the reinforcing steel or mesh i.s laid directly on the spacer abutments 5 Tabs 50 are therl turned over so as to secure -the reinforcing mesh in position.

The reinforcing mesh is -then lowered in-to the ,.,, , ~_ .., .
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Ccl~till~ material whi:l.st 5till ln a p:Las-t:ia sl;ate. 'l'lle emhedment portio~ls 5~l will become embedded in the ~lab.
Using t'tlis Xorm oX a stud a s'hallower degr~e oX
pe~netra-tion and 0mbedment is achieved permittin~ the use of thinner slab~. -' -A fu,rt'her embodiment oP stud member is shown in -Figure 5. -~' .
In this embodiment, the s-tud member 14C has the san~e angle forma-tions 20 and 22, facing flanges Z4 and 26, bracing flanges 28 and 30, struts 32, and opening 36.
This em'bodiment also has the same junc~ion ~' -t'langes 40 as the embodimen-t o~f '~i~ure 2.
In this embodiment however, loc'king tongues 60 ~' are Pormed alon~ the upper free edge oP junc-tion flange ~0. Tong~ues 60 are ben-t or formed a-t right an~les to flan~e 40, and are turned in opposi-te directions in an alternate Xashion. In this way some of -the ~tongues overlie the mounting ~lange 26, and other~tongues in the opposi-te direc-tion. All oX the tongues 60 are located in a common plane, in this particular embodiment.
ln this form of the invention -the locking '' tongues will be embedded in the casting material, and will securely look the stud member in -the slab. ' ~. , In this Porm of the i.nven-tion it may not be found necessary to provide any attachmen-t be-tween the stud mem'bers and the rein~orcin~ steel in the concrete.
However, for the sake of convenience if some form of .
at-tachment is desired, Por example to assist ln the ac-tual assembly and casting of -the panels, then the reinforcing mesh can be at-tached 'by simply looping wires -throu~h the &
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reirlfoxcing mes~l alld througll the opening 36, and -tying tllem ot`f a-t various intervclls.
If it i5 desired to mclrl-lfac-tllre panels ~i-thout such t,ying between tha reinforcirlg mesh and -t;he s-tuds, howe~er, it is simply a mat-ter of fixs-t of all placing the reinforcin~ mesh on the poured concrete in -the mould, and thell lowering the framework consisting of s-tuds down on to -the reinforcing mesh, and continulrlg lowering the ~ `

framework unt.il it has entered the concre-te to -the desired ' ' depth.

This will also ha~e the effect of forcin~ the reinforcing mesh into the concrete -to the desired dep-th.
In prac-tice it is found tha-t -the reinforcing mesh will no-t sin~ an~ further, bu-t wil:l remain in position~
' S~UPJ_ E~ENTARY IS~LOSUk~'S
In -the E'i.gure 2 and S embodiments the jurlction f:lange 40 is continuous arld unin-terxupted. Typically, in a slab o~ a -thickness of 1 1/2 inches~ -the junc-tion flange 40 will form a con-tinuous barrier or line of weakness in the s].ab, to a depth of 3/4 of an inch. This may not be desirable in some circumstances.
Accordin~ly, in a further embodimen-t shown in Fi~ures 5, 6, and 7, a par-tial solu-tion to the problem is provided.
In th~ Figure 6 embodiment, the s-tud is formed with an angle por-tion 70, de~'ining a facing flange 7? and a bracing strip 74. ~iagonal struts 76 extend from strip 74 -to flange 78. Angled edge por-tions 80 are formed along strip '74 J stru-ts 76 and flange 78.
A series o~ discontinuous junction members 82 ~ ~ .
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are formecl a:lorlg the free edge of f'larlge 78 being o~' recL.c)rl~ular shape o~ predetermined len~-th ancl height. l'he spaces betwec~n ~embers 82 -typically would have a leng-t'h e~u~l -to the length o:~ mem~ers 82.
Junctlon n~embers ~2 are -i'ormed into an L,-shape, in section, so as to provide a secure e~bedment in -the slab.
A locking strip 84 is formed alon~ the ends of members 82 and further secures the members 82 in the slab.
A serles of depth spacer tabs 86 are also formed on -the free edge oi' flange 78. Tabs ~6 are formed by the metal portions struck out be-tween mem'bers S2. Ta'bs 86 are formed at an angle to flange 78. They may be turned in ei-ther direction, or alternativelY in both direc-tions.
In use the junc-tion strip 84 and members 82 are embedded in the slab, as before. The~ n~ay or may not be attached to the reinforcirlg stee:l. The materi.al of thq slab will ~low around strip 84 and 'be-tween membesr 82. In this way the slab will be somewha-t stxon~er, and i-t may be .
possible to use a -thinner slab.
ln some cases, it is desirable to use panels ~-~
according to -the invention, as flooring, or roofing.
~ epending upon the load to be carried, it may be desirable -to increase -the load-bearing capacity of the studs .
In accordance with a fur-ther embodiment shown in Figure 8, any of the studs may be modified by a triangular rein~orcemen-t tube 90.
Tube 90 is located in place of an~le por-tion 70 of Figure 6, for example, and similarly in Figures . -12-- - . , , ~27~

2 and 5~ -'I'ube 90 com:pri5es slcle walls 92A-B and bottom wall 9~ formed integrally in-to a tr:iangular shape in section Reinforcing ribs 96 may be formed a-t spacetl inter~-als and side walls 92 for greater strength~
Side wall 92B is formed integrally with ed~e strip 9~ and diagonal struts '76~ Side wall 92A has a fasterling strip 100, overlying edge s-trip 98. These two - ' strips maY be fastened together bY any suitable means such as spotweldin~ riveting, or inte~ral swagin~ 102.
The tubular construction of rein-Porcemen-t 90 adds increased stress resistance to -the strut. By its :
location in a plane spaced below the slab, it is placed in tension and resis-ts flexing o-f the slab.
The triangular shape o~ reinforcement 90 can be replaced by a generally closed T-shaped formation 110 as shown in Figure 9. .:

This is o~ essentially the same construction as reinforcemen-t 90, bu-t wi-th the fold lines formed in differen-t loca-tions It is believed -that i.-ts construction is self-evident and requires no fur-ther descrip-tion.
In use oP the embodiment of Figure 6, -the clepth spacer tabs 86 define -the depth to which the junction ~:
members and lockin~ strip are to be inserted into -the ma-terial, such as concre-te, oP the slab.
The junction members 82, arld the continuous locking strip 84, provide a secure embedment in the slab, bu-t ~o a considerable way to overcomin~ the problem caused ,~ .

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l~y ~ e cc ntinuous ~jurlct.ion .stripr. ol'-' the earl.it-~.r em~odi.mcrl ts .
,.~f~- ~;ince th~ material of th~ cilab ls ~.ree -to flow tl~rough the o:pen~ gs be-tweeIl tlle junc-tion members~ t:he slabs resulting from th~ .se of'-this em~odln~nt wlll be considerably st*on~er, and carry considerably heavier loads, than is possible using the embodiment.s o~' F'igures 2 and 5.
In addi-tion to these advarltages however -the provision of spaces be-tweèn -the junctlon member 82 also assists ~iIl reducing problems created by differences in the rate of thermal ex:pansion as between the mate'rial of -the ~' ` .
s-tuds themselves, and the slab.
. In Figu.re 10 a further minor modifica-tion of the stud of Fi.gure 6 is shown. In this embodiment, the strip ~4 is tur-ned at a rlinety tlegree angle to flanges 82, but is o-therwise unchanged.
The foregoing is a description of a preferred embodiment of the inven-tion which is given here 'by way of example onlY. The inven-tion is not to be taken as limited .
to any of the specific features as described, but comprehends all such variations -thereof as come within the scope of the appended claims. ~' :

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Claims (5)

1. A precast thin walled construction panel having a low thermal conductivity and comprising a slab of cast concrete material, and a plurality of parallel spaced-apart steel stud members partially embedded in, and extending from one side of said slab, each said stud member comprising:
two parallel spaced-apart structural members extending parallel to one another;
a plurality of spaced-apart strut members extending integrally from one said structural member to the other, said strut members defining openings therebetween;
a junction flange extending at an angle from one of said structural members and embedded in said cast material;
a locking strip formed along said junction flanges at an angle thereto remote from said structural member and embedded in said cast material, and, a plurality of openings formed in said locking strip, said cast concrete material extending therethrough, and integrally bonding said cast concrete material on opposite sides of said locking strip, and wherein said structural members and said strut members, said junction flange and said locking strip all being formed out of a single integral piece of sheet metal.

2. A precast thin-walled construction panel as claimed in Claim 1 wherein said openings in said locking strip extend partially into said junction flange.

3. A precast thin-walled construction panel as claimed in Claim 1, including reinforcing tubes formed on the other of said structural members.

4. A precast thin-walled construction panel as claimed in Claim 1 wherein said strut members lie on axes diagonal to the axes of said structural members whereby to define generally trapezoidal openings.

5. A steel stud member for partial embedment in a concrete panel for reinforcement thereof and comprising:
two parallel spaced apart generally L shaped angle members extending parallel to one another;
said angle members defining mounting flanges, lying in parallel spaced apart planes, and bracing flanges normal thereto;
a plurality of spaced apart strut members extending integrally from one said angle member to the other;
openings between said strut members;
said angle members and said strut members being formed out of a single integral piece of sheet metal;
edge flange formations formed on the strut members defining a generally three sided channel shape in cross section for greater strength;
a junction strip extending from said mounting flange of one of said angle members normal to said mounting flange and defining two sides, and, locking tongue formations formed on the edge of said junction strip, said tongue formations being bent over at angles to said junction strip alternately in opposite directions and being in a common plane spaced from said mounting flange of said one of said angle members for embedment in said panel, there being spaces between adjacent tongue formations on each side of said junction strip.

8. A steel stud member for partial embedment in a concrete panel for reinforcement thereof and comprising;
two parallel spaced apart generally L-shaped angle members extending parallel to one another;
said angle members defining mounting flanges, lying in parallel spaced apart planes bracing flanges normal thereto;
a plurality of spaced apart strut members extending integrally from one said angle member to the other;
openings between said strut members;
said angle members and said strut members being formed out of a single integral piece of sheet metal;
edge flange formations formed on the strut members defining a gnerally three-sided channel shape in cross section for greater strength;
integral tab formations struck out of said mounting flange of one of said angle members for embedment in said concrete panel;
said tab formations being of a predetermined shape and extending from said mounting flange substantially normal thereto, whereby said tab formations may be entirely immersed in said concrete material with said mounting flange abutting the surface of said concrete material to maximize the reinforcement of said concrete panel.