CA2282676C - Structural core of the three-dimensional concrete reinforcing mat and method of its fabrication - Google Patents
Structural core of the three-dimensional concrete reinforcing mat and method of its fabrication Download PDFInfo
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- CA2282676C CA2282676C CA002282676A CA2282676A CA2282676C CA 2282676 C CA2282676 C CA 2282676C CA 002282676 A CA002282676 A CA 002282676A CA 2282676 A CA2282676 A CA 2282676A CA 2282676 C CA2282676 C CA 2282676C
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
- E04C5/01—Reinforcing elements of metal, e.g. with non-structural coatings
- E04C5/06—Reinforcing elements of metal, e.g. with non-structural coatings of high bending resistance, i.e. of essentially three-dimensional extent, e.g. lattice girders
- E04C5/0604—Prismatic or cylindrical reinforcement cages composed of longitudinal bars and open or closed stirrup rods
- E04C5/0613—Closed cages made of one single bent reinforcement mat
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
- E04C5/01—Reinforcing elements of metal, e.g. with non-structural coatings
- E04C5/06—Reinforcing elements of metal, e.g. with non-structural coatings of high bending resistance, i.e. of essentially three-dimensional extent, e.g. lattice girders
- E04C5/0627—Three-dimensional reinforcements composed of a prefabricated reinforcing mat combined with reinforcing elements protruding out of the plane of the mat
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- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Rod-Shaped Construction Members (AREA)
- Reinforcement Elements For Buildings (AREA)
- Manufacturing Of Tubular Articles Or Embedded Moulded Articles (AREA)
- Laminated Bodies (AREA)
Abstract
The invention applies to the structural core of the three-dimensional concrete reinforcing mat consisting of distribution bars and load-bearing bars, where the distribution bars (1) of folded length equal to the width (W) of the mat, are throughout their length bent forming a meander consisting of a continuous row of incomplete equilateral trapezoids with slanted sides (h w), shorter bases (b) and imaginary longer bases (c). The equilateral trapezoids of the distribution bar (1) are laying in the same plane oriented alternately mutually opposite each other so, that slanted sides (h w) of each two opposing each other trapezoid s are of the same length and are identical. The straight load-bearing bars (2) of the structural core's length, are attached to meandrically bent distribution bars (1) into each corner-bend on inner side of their trapezoids. The distribution bars (1) and load-bearing bars (2 ) form together structural mat-core's longitudinal ribs (R) of regularly by 180.degree. alternating trapezoidal cross-sectional form. The m at based on this structural core is designated for its usage primarily as reinforcement of concrete structures and of miscellaneous precast concret e products used in construction of highrises, bridges and/or in underground structures of civil engineering, as well as for military purpose s, security installations and/or temporary structures, where this structural mat's core due to its formed longitudinal load-bearing ribs (R) would serve mainly without its combination with concrete as a steel structure, that is as a finished product.
Description
1 Structural core of the three-dimensional concrete reinforcing mat and method of its fabrication.
Technical field The invention concerns the structural core of the three-dimensional concrete reinforcing matand itsfabrication with longitudinal ribs of tra-pezoidal cross-section, formed by mat-core's longitudinalload-bearing bars together with a certain number ofits distribution barssuitably bentinto a particular meandrical shape. The structural mat-core is designated for usage not only asconcrete reinforcing material or as aload-bearing steel structure in construction industry, butalso without mat-core's combination with concrete for other purposes in other application fields. This inventi-on concerns also the method of fabrication of this mat-core and of its comple-tion into athree-dimensional concrete reinforcing mat, making it suitable for typification.
Background of the invention The reinforcing steel during past one hundred years wasfabricated for and used by construction industry only, and there only in its form as indivi-dual straight bars or wires which maybe alsocoiled, this bars andwires cut and bend as needed at place of their use, or in a form of flat - i .e. from struc-tural point of view two-dimensional only - two-way load-bearing welded steel reinforcing fabric/mesh, fabricated from twolayers ofmutually cros-sed reinforcing bars or wires, in their mesh-form shipped by their fabrica-for either in bundles of flat sheets or in rolls.
Those two forms ofreinforcing steel were complemented roughly fifty years ago by a specific third type, i .e. by cables for pre stressed concrete, which of course are designated to serve an entirely different structural purpose and therefore this type features anappropriate set of properties assimilar to two other conventional types of common reinforcing steel.
An additional -at present generally used form ofconcrete structures' reinforcement are by structural analysis individually case by case designed three-dimensional mats, assembled fully on site usually d rectly on the formwork through anlabour-intensive manual assembly of individually cat and bent bars and wires by tying them or manually welding them together, which excludes use of reinforcing wires of smaler profiles, asthose can be welded through anautomated electrical welding process in factory conditi-ons only. Individually designed reinforcing mats sometimes do contain individual barsand/or wires plusflat welded steel wire fabric/mesh combi-SUBSTITUTE SHEET (RULE 26~
_2.
1 ned together. However, both thistwo types of reinforcing material lack en-tirely any resistance to bending moments perpendicularly to their profiles/
sections, and therefore to maintain the needed designed distance between layers of load-bearing reinforcement inindividual three-dimensional mats it isnecessary toinsert and to tie-in, or manually to weld-in between those layers the required layers-distancing "chairs", which have to be al-so fabricated individually asneeded from individual reinforcing bars di-rectly on the same site.
Should theindividual reinforcing bars or wires ofany individually de-signed three-dimensional mat be welded together on site manually by a pro-cess of electrical-resistance welding, the varying intensity of fusion at cross-points' welds of so connected bars and/or wires may cause spot-weake-ning of their tension-resistance which can't be tested onsites, as they aren't usually equipped with any device for testing even of an incompletely assembled three-dimensional mat. Such testing would require modification of saddle-vise jawsof existing testing devices, while for completely assem-bled three-dimensional mats -to verify their true load-bearing capacity -- a testing device doesn't exist yet at all.
In a few individual states some attempts were made to simplify and thus to make more economical all work onreinforcement preparation and on itsas-sembly bystandardization of some individual systems of three-dimensional mat's construction -for example see DIN 488, Teil 4, 2.i Lagermatten and/
or 2.3 Zeichnungsmatten, however, such matsaren't suitable for a true ty-pification, and thus they don't satisfy ~.t~e requirements of the mass-pro-duction, which severely limits opportunities for their use.
The list of obstacles so far preventing anysystematical standardizati-on and thus wider use of structurally and physically complete three-dimen-sional mats based on their selfsupporting, however-incomplete cores/semi-products, reads as follows:
a) a verified, generally valid, uniform and practical calculation method for designing of suitable types of structurally complete three-dimen-sional mats based on their cores/semiproducts until now didn't exist;
b) the absence of such structuralcalculation method made itimpossible to calculate the exact negative impact of buckling forces on vertical-, and particularly onslanted stems of distancing "chairs", used between cour ses/layers ofload-bearing bars inindividual atypical physically com-plete three-dimensional mats, i.e.forces which determine the possibi-1 ity and the way of such mats' use, and also the possibility of their use without concrete asfree-standing, selfsupporting structures or their SUBSTITUTE SHEET (RULE 26) 1 such parts;;
c) the impossibility of economically feasible mass-production of physical-ly complete three-dimensional concrete reinforcing mats, or economical-ly feasible fabrication of individual ones with their load-Uearing ca-pacity being guaranteed;
d) due to their overall size theindividually designed physically comple-te three-dimensional reinforcing mats bar any possibility of their economically-feasible transport in bulk from their fabricator to the place of their use;
e) yet another obstacle to more common usage of structurally complete three-dimensional reinforcing mats istheir cumbersome weight when physically completed. Such weight requires mobile mechanical lifting devices for manipulating withand transfer ofsuch completed and thus hea-vy three-dimensional mats until theyare in their place ofuse, which does exclude them from use onsmaller sites and/or from"do-it-yourselves" ty-pes of sites even inindustrialized countries, not mentioning sites in underdeveloped countries, where suitable mobile mechanical lifting de-vices aren't always available;
f) the present way of three-dimensional reinforcing mats' fabrication and assembly being donestrictly entirely onsites, without any lessstrong and lessclimatically resistant way of mats' individual bars' and/or wires' cross-joining in other way than by tying them together, or by the manual process of electrical resistance welding.
The above listed shortcomings prevented sofar all attempts to typify or to mass-produce either the three-dimensional mats, or to typify atleast their semiproducts/cores suitable for their mass-production -thus those above listed shortcomings being the main obstacles to the general acceptance and use of prefabricated three-dimensional mat.
_Summary of the invention The above listed shortcomings are eliminated by the structural core of a three-dimensional concrete reinforcing mat constructed according to this invention, t:he iclc~a of which is based on that each of distribution bars of this basic and fast-fixed together by welding or glueing mat-co-re, i.e. the semiproduct is longitudinally throughout its length bent, forming a meander consisting of a continuous row of incomplete equila-teral trapezoids consisting of slanted sides plus shorter bases, but with imaginary longer basis/transomes only, those equilateral trapezoids laying in the same plane alternatively mutually opposite, so that slan-ted sides of two adjacent hut opposing each other trapezoids are of the SUBSTITUTE SHEET (RULE 26) 1 same length and are identical, and also consisting of straight load-bearing bars of mat's length attached to the meandrically bent distribu-tion bars into each corner-bend of their trapezoids, in that way the distribution bars forming together with welded-in load-bearing bars mat's longitudinal ribs of in place by an angle of 180° alternately oriented trapezoidal cross-sectional form.
The advantage of into such configuration constructed structural core of the three-dimensional mat's semiproduct factory-made from standardi-zed concrete reinforcing steel by an automated process of electrical resistance welding or chemical glueing together -both methods guarantee-ing the required resulting quality of the finished product, due to the meandrically bent form of its distribution bars and exactly because of mat-core's state of incompleteness as a semiproduct, it is well suited for easy transportation in bulk to mat's place of use, where its mat-core is appropriately completed by adding and affixing of more bars according to the requirements of the structural design into a physically complete three-dimensional mat of required load-bearing capacity.
Yet another advantage of this mat's structural solution is, that its core, that is its semiproduct, until its completion at the place of mat's use, is weight-vise suitable for manual handling on small and on "do-it-yourselves" sites without any need. for use of mobile mechanical lifting devices, which would be necessary for handling of the relatively heavy physically complete three-dimensional mats, should they be used on those sites.
The advantageous structural solution of the three-dimensional pre-fabricated mat by completion of its core, that is of its semiproduct at place of its use requires, that in-between meandrically bentdistribution bars -usually only to the side of the mat which will be subjected to tension, but sometimes also to the compressed side of the mat -perpendi-cularly across the straight Load-bearing bars -are attached additional straight distribution bars, the purpose of which is to limit the negati-ve impact of a vertical load, particularly where the mats are used with-out their combination with concrete. Arresting of those horizontal for-ces prevents flattening, that is "opening" of slanted sides of trape zoids, and thus preventing losses of three-dimensional mats' load bearing capacity.
Yet another advantage of the solution of the three-dimensional mat through its completion at its place of use is, that intoits structurally SUBSTITUTE SHEET (RULE 26) *rB
WO 99/27210 PCTlCZ98/00004 1 determined tensioned zone, between the load-bearing bars of the mat-core, i.e. of the mat's semiproduct, there is inserted and affixed at least one additional straight load-bearing bar, by adding of which the mat-core, i.e. mat's semiproduct reaches the required full load-bearing capacity of a particular physically fully completed three-dimensional mat, and if this semiproduct constitues the reinforcement of a continu-ous concrete slab then it is complemented above its supports by an inserted strip of an identical mat-core.
In certain cases of the intended use of the structural core of a three-dimensional mat, it is advantageous to fabricate all slanted sides of trapezoids in at least one of their rows, in plane of those trapezoids with-into their slanted sides cold-formed bent hib-forming seats for affixing of additional stiffening bars _S -longitudinally along those rows of trapezoids. Through this arrangement it is achieved the overall beter structural and economical efficiency and performance of three-dimensio-nal reinforcing mats with high ribs.
It is an advantage, if the meandrically bent distribution bar of.a mat-core has such shape, that all trapezoids are uniform. The advantage of a three-dimensional concrete reinforcing mat with in such way formed meandrically bent distribution bars of its mat-core is the univesality and widest possible applicability.and use of such mat and maximal simplicity of its mat-core's fabrication.
With an advantage the geometrical parameters of equilateral trape zoids of the meandrical form of mat-core's distribution bar are set in such way, that the angle of trapezoid's imaginary longer base and its slanted side is from 45° up to 85°, and the length relation of slanted sides of the equilateral trapezoid to the length of its shorter base is within the brackets of 1,5:1 or up to 5:1.
Even more advantageous is, if the geometrical parameters, that is the shape of the equilateral trapezoid of the meandrically bent distribution bar of the structural core, i.e. the semiproduct mat-core of a three-dimensional mat is set in such way, that the angle of trapezoid's imaginary longer base and its slanted sides is of an angle 60° or up to 78° and the length's relation of slanted sides of the equilateral trapezoid to the length of its shorter base is within the brackets of 2:1 or up to 5:1. At any particular slant of trapezoid's sides and their length in relation to the length of trapezoid's shorter base being within the brackets shown above, it is easy by a simple structural calcnlatinq method to establish precisely the load-bearing SUBSTITUTE SHEET (RULE 26) proportion expressed by percentage of the proportion of the structual core's i.e. of the mat-core's trapezoidally bent distribution bars subjected to tensile forces, and thus to establish the portion by which the distribution bars participate in the overall load-bearing capacity of a certain structural mat-core's type, allowing for the selection of the most suitable one for a particular structural application.
The structural core i.e. mat-core, that is the semiproduct of the three-dimensional concrete reinforcing mat, containing only its meandri-cally bent distribution bars welded over its longitudinal load-bearing bars which form longitudinal edges of mat-core's ribs, may be also used - bent paralelly to and along of its load-bearing.bars into an opened or closed curve, or into a triangle, a quadrangle or a polygon containing therequired number of ribs with their load-bearing bars in vertical position, as reinforcing in vertical supports such as columns.
In order to achieve the bi-directional load-bearing capacity in a three-dimensional concrete reinforcing mat based on its structural core, it is feasible to attach to its structurally designated tensioned side instead of straight distribution bars the required additional load-bearing reinforcement, or an additional -on a structural core based three-dimensional mat perpendicularly laid and attached onto the previous one.
The structural core of the three-dimensional concrete reinforcing mat according to this invention is fabricated from. standardized reinfor-cing steel gradually - in the first stage the structural core and in the second stage the rest of the three-dimensional concrete reinforcing mat, the two stages being quantitatively and qualitatively different:
During the first fabrication stage done in conditions of factory mass-production, by a method of automated electrical resistance welding or chemical glueing into a configuration according to this invention, are affixed together meandrically bent distribution bars with straight load-bearing bars into a structural mat-core, that is into a semiproduct of a three-dimensional concrete reinforcing mat. 1n such way fabricated semiproduct, i.e. the structural mat-core, shaped into its longitudinal ribs formed by rows of equilateral trapezoids of its meandrically bent distribution bars, has guaranteed consistent geometrical parameters of its trapezoids and also the guaranteed required quality of all cross-welds and thus guaranteed its required load-bearing capacity.
During the second fabrication stage, carried out at the place of the three-dimensional concrete reinforcing mat's use, its structural core, SUBSTITUTE SHEET (RULE 26) 1 that is its semiproduct, on its structurally determined tensioned side, is only manually complemented into a physically complete three-dimensio-nal mat of required capacity, by tying on of straight distribution bars and of additional straight load-bearing bars, or instead of straight distribution bars by attaching of additional load-bearing reinforcement perpendicularly to the structural mat-core, thus making it load-bearing bi-directionally. If the structural mat-core serves as the reinforcement of a multispan concrete slab, then during the second stage it is supple-mented above slab's supports by inserting of a strip of ~ structural mat-core identical with the previous one.
It is the advantage of two-staged way of this three-dimensional con-crete reinforcing mat's fabrication, that at the end of the first fabri-cation stage the structural mat-core, that is the semiproduct iseconomi-cally transportable in bundles "on flat", and that relatively low weight of the structural core prior to its completion into a structurally and physically complete three-dimensional mat is suitable for use on sites without any available mobile mechanical lifting device. The completion of any structural mat-core's into a complete three-dimensional mat accor-ding to the requirements of its structural design, doesn't require specially qualified workforce, as all necessary straight distribution bars and additional load-bearing bars required for completion of structu-ral mat-cores into structurally and physically complete three-dimensio-nal mats, or any other required type of additional reinforcing material are delivered to the place of mat's use in required thicknesses and lengths, tied together into appropriately marked bundles, this arrange-ment saving production time on sites, and reducing losses of reinforcing material incured through its cut-offs, and it is also beneficial to the universality of the three-dimensional concrete reinforcing mats based on their structural cores, and it supports their general use.
Brief description of the drawings The invention will be illustrated on drawings, on which the unit of length used, doesn't have any specified definitive real value, except to express the relative relation between lengths of slanted sides and bases of trapezoids of meandrically bent distribution bars 1 of the structural core of a three-dimensional concrete reinforcing mat. All illustrations on drawings are shown in the logical sequence of the two-stage fabrication.
The illustrations 1 to 7 reflect the first fabrication stage, i.e.
the factory mass-rrnclnci.inn <,f the ~tr~~ctnral cnrP of the three-dimen-SUBSTITUTE SHEET (RULE 26) _ g_ 1 sionai concrete reinforcing mats.
The illustration Fig.1-shows schematically and also_l~n detail geo-metrically and structurally the.most advantageous meandrical form of distribution bars _1 in four basic types A, B, C and D of the semiproduct, that is of the structural core of the three-dimensional concrete rein-forcing mat assembled into the configuration according to this invention, and it also shows schematically an equilateral trapezoid within the width of one rib R of the structural mat-core, marked by symbols of its vari-ables.
On the illustration Fig.2 -in a cross-section of a rib R, is shown the configuration of distribution bars 1 and load-bearing bars 2, to-gether with the trigonometry of equilateral trapezoids of distribution bars _1 in all six structural types A, B, C, D, E, F of the semiproduct, i.e. of the structural core of the three-dimensional reinforcing mat constructed according to this invention, and the Fip.2 also shows the points for attaching of non-load-bearing stiffening bars S1 on slanted sides ~ of trapezoids in the type E, as well as points for attaching of stiffening bars S2 and S3 in the type F.
The illustration Fig.3 -in connection with Fig.1 and Fig.2 schemati-cally shows the structurally and constructionally important increase of "density" of ribs _R in the semiproduct, i.e. in the structural core of the three-dimensional concrete reinforcing mat made in accordance with this invention. The "density" increases from type A towards types D, E
and _F with maintained uniform bight _v in trapezoids of distribution bar _1 in alI six types of the structural core, while changing only the ratio of the length of the slanted side h~,~ to the length of the trapezoid's shorter base _b, which then for the type A is h~~2b,for the type H is h~H~3b, for the type C i s h~,~4b and for types D, E and F i s h ,~ 5b.
The illustration Fig.4 -in an alternative to the Fig.3 maintaining both -the uniform bight _v of equilateral trapezoids of the distribution bar _1, and the uniform ratio between the length of slanted sides/arms hw of trapezoids, and the length of their shorter bases b as h,~,:b=2:1 in all six types of the structural mat-core.
The illustration Fig.5 shows the configuration of distribution bars _1 and load-bearing bars _2 of the structural core of the three-dimensio nal concrete reinforcing mat, which is crucial to this invention.
The illustration Fig.6 shows the configuration of distribution bars _1 and load-bearing bars _2 in a cross-section of the same structural mat-core, with all symbols of its variables marked accordingly.
SUBSTITUTE SHEET (RULE 26) _g_ 1 The illustration Fig.7 shows the economically advantageous way of stacking and transporting in bulk of structural cores of three-dimensio-nal concrete reinforcing mats.
The illustrations Fig.B to Fig. l5 reflect the second fabrication stage, i.e. the manual physical completion of structural cores into com-plete three-dimensional concrete reinforcing mats, which is to be done strictly at their place of use.
The illustration Fig.B shows in a cross-section of a structural core the sequence of the core's completion into a structurally and physically complete three-dimensional mat by inserting and affixing of straight distribution bars _3, and of additional load-bearing bars 4 into their respective correct structural positions in the configuration of the structural core of the three-dimensional concrete reinforcing mat.
In the illustration Fig.9 the axonometrical view shoes a semiproduct, i.e. a structural core of a three-dimensional concrete reinforcing mat when it has been already completed the way shown in the Fig. B.
In the illustration Fig.lO -in a cross-section through the side-edge section of the three-dimensional mat completed as shown in Fig.9, there is shown that the straight distribution bars _3, as well as the additio-nal load-bearing bars _~1 are to be.attached only to the side of thestructu-ral mat-core of the three-dimensional mat, which has been structurally designated as the side subjected to tension.
In illustrations Fig. l1 and Fig. l2 is shown the correct way of longi-tudinal and transverse splicing of three-dimensional concrete reinforcing mats, which has to be carried out in compliance with Standards' require-ments for splicing of other existing types of reinforcing material.
The illustration Fig.l3 shows the possibility and the way how to change the typical one-directional load-bearing capability of the semi-product, i.e. of the structural core of a three-dimensional concrete reinforcing mat, into a bi-directional one, by attaching of perpendicu-larly across mat's load-bearing bars the required load-bearing cross-bars -usually to the mat's structurally designated tensioned side, hut sometimes even to the opposite side -the compressed one.
The illustrations Fig. l4 and Fig. l5 of cross-sections of concrete columns show yet another possible use of structural mat-cores - without straight distribution bars _3 and without the additional load-bearing bars _4 -by rolling of three or four ribs R of a mat-core -along its load-bearing hays 2 into the required polygonal shape.
SUBSTITUTE SHEET (RULE 26) WO 99127210 PCT/CZ9$/00004 1 Detailed description of the prefered structural core's formation.
The structural core of the three-dimensional concrete reinforcing mat as shown on illustration Fig.t to Fig.l5, vizually distinctive by its longitudinal ribs R, its fabrication width limited by the Interna-tional Transportation highway Code to max. 2400mm, and with the vari-able fabrication length of up to 6000mm -corresponding with the max.
web-span module of construction design, this structural core of the three-dimensional mat to be fabricated in configuration of its compo-nents according to this invention, from a certain number of smooth or deformed bars of standardized reinforcing steel as a mixed construction, i.e. in two qualitatively and quantitatively distinct fabricated stages.
In mat's first fabrication stage -as shown on illustrations Fig.1 to Fig.7, this structural core of the three-dimensional mat, fabricated in bulk, i.e. mass-produced as a semiproduct, i.e. as a mat-core, con-sisting of two components, that is distribution bars 1 and of straight, mutually parallel load-bearing bars _2 of the length equal to the requi-red length of a particular mat, those distribution bars 1 and load-bearing bars _2 mutually fast-fixed together by cross-joint welds through an automated process of electric-resistance welding, which allows for cross-welding even of thin steel bars or wires, or by an automated glueing process using chemical adhesiv:.~s - use of which prevents fabrica-tion, transport and/or use of structural mat-cores at atmospheric tempe-ratures below 0°C scale.
The distribution bars _1 of the structural mat-core, made in accordan-ce with this invention, are throughout their length, which is equal to the width IJ of the particular mat-core, cold-formed into a trapezoidal meander, with in its plane bent and formed equilateral trapezoids iden-tical in size and shape throughout the particular structural mat-core, and each two adjacent trapezoids of the meandrically bent distribution bar _1 will be mutually turned by an angle of 180° thus making them alternately opposing each other so, that their two adjacent slanted sides h;,l are throughout their length common and identical. The angle 9 (=theta) between slanted sides hw and the imaginary longer base c of the trapezoid plus the ratio of the length of slanted side h~ to the shorter base _b of the particular trapezoid do designate the structural and fabrication type of the semiproduct, that is of the type of the particular structural mat-core.
The four basic types of the structural core of the three-dimensio-nal concrete reinforcinc7 mat, i.e. semiprocdct made accnrdiry to this SUBSTITUTE SHEET (RULE 26) 1 invention, this types marked with capital letters A, B, C, D and two modified types by letters E and F as shown on Fig. l, Fig.2 and Fig.3 are fabricated as a semiproduct, i.e. as a structural core of three-dimensional mats of the above types, in. the length proportion of vari-ables of their distribution bars 1, asshown in following Tables1 and 2 Table 1 . Types _A, B, _C, _D, _E and _F, designated sizes of their angle 8 (=theta),~and the length-relations between their main variables v, hue, b, c.
Type ~ 8 v b h« c A 60° 1,73 1,0 2,0 3,0 +longitudinal load-bearing bars 2 -in twos -see:Fig.2A
g 70° 2,83 1,0 3,0 3,0 + ditto above - see Fig.28 C 75° 3,88 1,0 4,0 3,0 * ditto above - see Fig.2C
D 78° 4,90 1,0 5,0 3,0 + ditto above - see Fig.2D
E 78° 4,90 1 ,0 5,0 3,0 +ditto above -see Fig.2E +2 stiffening bars +3~$1 _S~ attached alongside of ribs R at the hlght of hyr:2 F 78° 4,90 1 ,0 5,0 3,0 +ditto above - see Fig.2F ~~ 2 stiffening +3~S2 bars ~ attached alongside of ribs R
at the hight of hy~:3 + 2 stiffening +3~S3 bars S3 attached algngside of ribs _R
at the hight of h~,,r. /3 PJote: The figure ~3~S1S2S3 means such length's addition to the imaginary _longer base c.
Symbols of variables - as shown in Tab.t and on the following Tab.2 and in Fig.1 throughout the Fig.lS:
~ ~ - angle theta between the slanted side h~,~ of the trapezoid and the imaginary longer base c,i.e.the slant of trapezoid's side and thus of the rib R
v - height of trapezoids, i.e. of the rib R
hw - lenght of the slanted side of the trapezoid, i.e.of the rib R
b - lenght of the shorter base of the trapezoid c - length of the imaginary longer base of the trapezoid r=~~-complementary angle to the angle ~ 0 , their sum being always equal to 180°
e=R - axial distance of two adjacent trapezoids of the same axial orien tation, i.e. the axial distance being the width of one rib R
t - thickness ~ of the distribution bar 1 of the structural mat-core m - spacing of meandrically bent distribution bars 1 along the entire length of the structural mat-core '/.
SUBSTITUTE SHEET (RULE 26~
1 I~J - fabrication width of the structural mat-core, that is the length of distribution bars 1 in their folded form, also the actual tenth of straight distribution bars 3 L - fabrication length of the structural mat-core, also the length of load-bearing bars 2 and of additional load-bearing bars 4 S1 S2 S3 - non-load-bearing bars longitudinally stiffening the slanted sides h~ of ribs _R of the structural mat-core of type _E or F, of the length identical to the length _L of the structural mat-core and their thickness t being equal to or thinner than ~
of the distribution bar 1 Longitudinal stiffening bars _S1 ~ S3 of the type _E and the type F of the semiproduct, i.e. of the structural core of the three-dimensional mat shown on Fig.2E and on Fig.2F are at the factory during the first product-ion stage of the structural mat-core's fabrication welded or glued onto 1,5~S protruding humps/steps cold-formed into each slanted side I~ of trapezoids within the meander-plane of folded meandrical form of distri-bution bars _1 with high trapezoids, i.e. with high ribs R only, at their appropriate heights as shown in the Fig.2E and in Fig.2F.
The increase of load-bearing capacity, or shear- and torsion-resistan-ce and of the overall stiffness -all those jointly reducing the deflec-tion of the structural core of a three-dimensional mat, foremostly depend upon the increase of density -that is upon the increase of the number of load-bearing ribs _R per one length's unit of the width of the structural core of the three-dimensional mat, this increase depending upon the type of the structural mat's core, i.e. on the size/value of its angle ~ as shown in the Table 2, developed from the Table 1 by maintaining of a uniform height _v=1,0 of trapezoids for all six types A, B, C, D, E and _F of the structural core of a three-dimensional mat. The Table 2 also contains the fabrication information on the length-relation, that is on the ratio of slanted sides h~ of trapezoids to the length of their shor-ter base _b, i.e. of the trapezoidal cross-section of the rib R of the structural mat-core, according to which for all types of structural cores it is expressed by the common formula: 1R=2(hy~~+b).
Table 2:
1 '1 Type~ v hw b R 1R=2(hw+b)R R
A 60 1,0 1,15610,578 4bA=2,312143,4682 1R5 0,75 B 70 1,0 1,06010,3534 4b8=1,413432,82692 2,0 1,0 C 75 1,0 1,03090,2577 4bC=1,030922,5773 2,5 1,25 D 78 1,0 1,02040,2041 4bD=0,81632,44896 3,0 1,5 (continues-'/.) SUBSTITUTE SHEET (RULE 26) _13_ 1 Type ~ ~ v hw b R 1R=2(hw+b) 1R 1R
E 78° 1,0 1,0204 0,2041 4bE=0,8163 2,44896 3,0 1,5 +3~S1 F 78° 1,0 1,0204 0,2041 4bF=0,8163 2,44896 3,0 1,5 ' +3PSS2 +3~S3 where: 1R - unfolded, that is straightened into a straight line-length of the distribution bars _1 of the structural core of the three-dimensional mat, which were bent as directed by this invention. This straightened length increases gradually from the minimum for the type A of the structural mat-core - to the maximum common for types D, E and F;
- the coefficient stating the length-relation, that is the ratio of straightened length of one trapezoid of the rib R
to the width R=4b, which is needed in order to establish the overall weight per 1mz of the fabricated structural mat-core, that weight dependant from the particular type 1 of the structural mat-core;
R - the multiplier-coefficient varying according to the type of the structural mat-core, serving for establishing of the value of the portion of length of the meandrically hent distribution bar _1, which is located in the structurally designated tensioned zone of the structural core of a par-ticular three-dimensional mat, the part which complements - that is adds to the overall capacity of all load-bearing bars of that particular mat.
This three informations, i.e. the length 1~ and the relation of varia-bles 1~:R, necessary for the selection of an economically andstructural-ly most advantageous structural mat-core's design and fabrication concer-ping all mentioned types A,B,C,D,E,F, and even all other -nontypified three-dimensional concrete reinforcing mats constructed in accordance with this invention - those three information data at the same time showing the impact of structural mat-core's fabrication weight, that is the importance of completion of each structural mat-core by adding of all required additional reinforcing steel bars -both distributing and load-bearing ones only at the place of the structural core's use, i.e.
during the second stage of fabrication, where the activity of "comple-ting" of the structural core of the mat as a mixed steel construction is the quantitative change, and the manner/way of completing by tying only of bars together - from tt~e strn ctiiral calculation's point of view is SUBSTITUTE SHEET (RULE 26) WO 99/27210 PCT/CZ9$/00004 1 a qualitative change.
The second fabrication stage -the manual one -of structural cores of three-dimensional concrete reinforcing mats -according to th a Claim 10 -is shown in Fig.8 to the Fig. l5 inclusive:
During the second fabrication stage -i.e. during the completion of the structural core into a structurally and physically complete three-dimensional concrete reinforcing mat at the place of its use, to the side/
face of the structural mat-core structurally designated as the tensioned one, are tied on regularly spaced straight distribution bars 3 of the length equal to the width of that structural mat-core, and usually of the same number and of the same thickness as distribution bars 1, and the total cross-sectional area Fa of straight distribution bars 3 and distribution bars _1 should equal 10% or up to 15% of the total cross-sectional area of load-bearing reinforcing bars of the concrete construc-tion part being executed.
Then follows tying on of additional straight load-bearing bars 4 of the structural mat-core's length, which are inserted and attached only into bottom corners of structurally designated tensioned part of trape-zoids, while the thickness t of additional straight load-bearing bars 4, by Standards allowed to be only 2mm thicker than the load-bearing bars2, must maintain the standardized spacing between load-bearing bars 2 and the additional straight load-bearing bars 4, which might require modifi-cation of the fabrication length of all shorter bases b of trapezoids of bars 1 of a particular structural mat-core.
To ensure that the designated load-bearing capacity of the executed reinforced concrete structure is being maintained -the fabricator of the structural mat-cores used in that structure; together with structural mat-cares will supply bundles of required straight distribution bars 3 and also bundles of additional straight load-bearing bars 4 of the appropriate thickness and length.
All fabricated structural cores of three-dimensional concrete rein-forcing mats made in accordance with this invention must be marked by their fabricator on attached to structural cores durable tags with the internationally recognizable distinguishing name mark "3D-mat" to be used in structural calculations, on drawings and on other documents, and with a capital letter-symbol of the structural mat-core's type, plus with the fabricator's structural cores' production catalog-number -this in-formations being the product's, that is the structural mat-cores' manda-tory guarantee of quality and of itsload-bearing capacity.
SUBSTITUTE SHEET (RULE 26) 1 All bars 1,2,3,4 as well as S1 ~ and ~ and also any other additio-nal load-bearing or distribution reinforcement used -for example as the reinforcement changing the typical one-directionally load-bearing struc-tural core of the three-dimensional mat into a bi-directionally load-s bearing mat, that reinforcement must be of the same identical Standards' quality as that of the three-dimensional mat's basic structural mat-core's bars 1,2, and also bars S1 -or ~ and S3 in case of a structural mat-core with high ribs R.
All tie-wire connections of a three-dimensional concrete reinforcing mat constructed according to this invention must be done with the stan-dardized black soft cold drawn tie-wire.
Testing of structural mat-cores' cross-welds for weld-shear strength and adhesion under a bending stress, has to be done in laboratory condi tions by Authorities concerned, or under their supervision by the struc tural mat-cores' fabricator.
The structural calculation of structural mat-cores, or on such structural cores based structurally and physically complete three-dimen-sional concrete reinforcing mats used without concrete as a load-bearing steel construction, can be done using the modified currently used formu-las for designing of use of load-bearing folded sheet-metal panels used in composite floors'~construction.
Industrial application The typifiable structural core of a three-dimensional concrete rein-forcing mat, fabricated in accordance with this invention, foremostly is to be used as the reinforcing material for concrete structures, con-crete panels and other concrete products not only for civil engineering structures, bridges and underground constructions for civilian use, but also for military purposes, and as part of security- and temporary structures, where this ctructural core of the three-dimensional mat due to its longitudinally formed ribs will serve mainly without its combina-nation with concrete, i.e. as selfsupporting load-bearing steel structu-re - that means as a finished product.
SUBSTITUTE SHEET (RULE 26)
Technical field The invention concerns the structural core of the three-dimensional concrete reinforcing matand itsfabrication with longitudinal ribs of tra-pezoidal cross-section, formed by mat-core's longitudinalload-bearing bars together with a certain number ofits distribution barssuitably bentinto a particular meandrical shape. The structural mat-core is designated for usage not only asconcrete reinforcing material or as aload-bearing steel structure in construction industry, butalso without mat-core's combination with concrete for other purposes in other application fields. This inventi-on concerns also the method of fabrication of this mat-core and of its comple-tion into athree-dimensional concrete reinforcing mat, making it suitable for typification.
Background of the invention The reinforcing steel during past one hundred years wasfabricated for and used by construction industry only, and there only in its form as indivi-dual straight bars or wires which maybe alsocoiled, this bars andwires cut and bend as needed at place of their use, or in a form of flat - i .e. from struc-tural point of view two-dimensional only - two-way load-bearing welded steel reinforcing fabric/mesh, fabricated from twolayers ofmutually cros-sed reinforcing bars or wires, in their mesh-form shipped by their fabrica-for either in bundles of flat sheets or in rolls.
Those two forms ofreinforcing steel were complemented roughly fifty years ago by a specific third type, i .e. by cables for pre stressed concrete, which of course are designated to serve an entirely different structural purpose and therefore this type features anappropriate set of properties assimilar to two other conventional types of common reinforcing steel.
An additional -at present generally used form ofconcrete structures' reinforcement are by structural analysis individually case by case designed three-dimensional mats, assembled fully on site usually d rectly on the formwork through anlabour-intensive manual assembly of individually cat and bent bars and wires by tying them or manually welding them together, which excludes use of reinforcing wires of smaler profiles, asthose can be welded through anautomated electrical welding process in factory conditi-ons only. Individually designed reinforcing mats sometimes do contain individual barsand/or wires plusflat welded steel wire fabric/mesh combi-SUBSTITUTE SHEET (RULE 26~
_2.
1 ned together. However, both thistwo types of reinforcing material lack en-tirely any resistance to bending moments perpendicularly to their profiles/
sections, and therefore to maintain the needed designed distance between layers of load-bearing reinforcement inindividual three-dimensional mats it isnecessary toinsert and to tie-in, or manually to weld-in between those layers the required layers-distancing "chairs", which have to be al-so fabricated individually asneeded from individual reinforcing bars di-rectly on the same site.
Should theindividual reinforcing bars or wires ofany individually de-signed three-dimensional mat be welded together on site manually by a pro-cess of electrical-resistance welding, the varying intensity of fusion at cross-points' welds of so connected bars and/or wires may cause spot-weake-ning of their tension-resistance which can't be tested onsites, as they aren't usually equipped with any device for testing even of an incompletely assembled three-dimensional mat. Such testing would require modification of saddle-vise jawsof existing testing devices, while for completely assem-bled three-dimensional mats -to verify their true load-bearing capacity -- a testing device doesn't exist yet at all.
In a few individual states some attempts were made to simplify and thus to make more economical all work onreinforcement preparation and on itsas-sembly bystandardization of some individual systems of three-dimensional mat's construction -for example see DIN 488, Teil 4, 2.i Lagermatten and/
or 2.3 Zeichnungsmatten, however, such matsaren't suitable for a true ty-pification, and thus they don't satisfy ~.t~e requirements of the mass-pro-duction, which severely limits opportunities for their use.
The list of obstacles so far preventing anysystematical standardizati-on and thus wider use of structurally and physically complete three-dimen-sional mats based on their selfsupporting, however-incomplete cores/semi-products, reads as follows:
a) a verified, generally valid, uniform and practical calculation method for designing of suitable types of structurally complete three-dimen-sional mats based on their cores/semiproducts until now didn't exist;
b) the absence of such structuralcalculation method made itimpossible to calculate the exact negative impact of buckling forces on vertical-, and particularly onslanted stems of distancing "chairs", used between cour ses/layers ofload-bearing bars inindividual atypical physically com-plete three-dimensional mats, i.e.forces which determine the possibi-1 ity and the way of such mats' use, and also the possibility of their use without concrete asfree-standing, selfsupporting structures or their SUBSTITUTE SHEET (RULE 26) 1 such parts;;
c) the impossibility of economically feasible mass-production of physical-ly complete three-dimensional concrete reinforcing mats, or economical-ly feasible fabrication of individual ones with their load-Uearing ca-pacity being guaranteed;
d) due to their overall size theindividually designed physically comple-te three-dimensional reinforcing mats bar any possibility of their economically-feasible transport in bulk from their fabricator to the place of their use;
e) yet another obstacle to more common usage of structurally complete three-dimensional reinforcing mats istheir cumbersome weight when physically completed. Such weight requires mobile mechanical lifting devices for manipulating withand transfer ofsuch completed and thus hea-vy three-dimensional mats until theyare in their place ofuse, which does exclude them from use onsmaller sites and/or from"do-it-yourselves" ty-pes of sites even inindustrialized countries, not mentioning sites in underdeveloped countries, where suitable mobile mechanical lifting de-vices aren't always available;
f) the present way of three-dimensional reinforcing mats' fabrication and assembly being donestrictly entirely onsites, without any lessstrong and lessclimatically resistant way of mats' individual bars' and/or wires' cross-joining in other way than by tying them together, or by the manual process of electrical resistance welding.
The above listed shortcomings prevented sofar all attempts to typify or to mass-produce either the three-dimensional mats, or to typify atleast their semiproducts/cores suitable for their mass-production -thus those above listed shortcomings being the main obstacles to the general acceptance and use of prefabricated three-dimensional mat.
_Summary of the invention The above listed shortcomings are eliminated by the structural core of a three-dimensional concrete reinforcing mat constructed according to this invention, t:he iclc~a of which is based on that each of distribution bars of this basic and fast-fixed together by welding or glueing mat-co-re, i.e. the semiproduct is longitudinally throughout its length bent, forming a meander consisting of a continuous row of incomplete equila-teral trapezoids consisting of slanted sides plus shorter bases, but with imaginary longer basis/transomes only, those equilateral trapezoids laying in the same plane alternatively mutually opposite, so that slan-ted sides of two adjacent hut opposing each other trapezoids are of the SUBSTITUTE SHEET (RULE 26) 1 same length and are identical, and also consisting of straight load-bearing bars of mat's length attached to the meandrically bent distribu-tion bars into each corner-bend of their trapezoids, in that way the distribution bars forming together with welded-in load-bearing bars mat's longitudinal ribs of in place by an angle of 180° alternately oriented trapezoidal cross-sectional form.
The advantage of into such configuration constructed structural core of the three-dimensional mat's semiproduct factory-made from standardi-zed concrete reinforcing steel by an automated process of electrical resistance welding or chemical glueing together -both methods guarantee-ing the required resulting quality of the finished product, due to the meandrically bent form of its distribution bars and exactly because of mat-core's state of incompleteness as a semiproduct, it is well suited for easy transportation in bulk to mat's place of use, where its mat-core is appropriately completed by adding and affixing of more bars according to the requirements of the structural design into a physically complete three-dimensional mat of required load-bearing capacity.
Yet another advantage of this mat's structural solution is, that its core, that is its semiproduct, until its completion at the place of mat's use, is weight-vise suitable for manual handling on small and on "do-it-yourselves" sites without any need. for use of mobile mechanical lifting devices, which would be necessary for handling of the relatively heavy physically complete three-dimensional mats, should they be used on those sites.
The advantageous structural solution of the three-dimensional pre-fabricated mat by completion of its core, that is of its semiproduct at place of its use requires, that in-between meandrically bentdistribution bars -usually only to the side of the mat which will be subjected to tension, but sometimes also to the compressed side of the mat -perpendi-cularly across the straight Load-bearing bars -are attached additional straight distribution bars, the purpose of which is to limit the negati-ve impact of a vertical load, particularly where the mats are used with-out their combination with concrete. Arresting of those horizontal for-ces prevents flattening, that is "opening" of slanted sides of trape zoids, and thus preventing losses of three-dimensional mats' load bearing capacity.
Yet another advantage of the solution of the three-dimensional mat through its completion at its place of use is, that intoits structurally SUBSTITUTE SHEET (RULE 26) *rB
WO 99/27210 PCTlCZ98/00004 1 determined tensioned zone, between the load-bearing bars of the mat-core, i.e. of the mat's semiproduct, there is inserted and affixed at least one additional straight load-bearing bar, by adding of which the mat-core, i.e. mat's semiproduct reaches the required full load-bearing capacity of a particular physically fully completed three-dimensional mat, and if this semiproduct constitues the reinforcement of a continu-ous concrete slab then it is complemented above its supports by an inserted strip of an identical mat-core.
In certain cases of the intended use of the structural core of a three-dimensional mat, it is advantageous to fabricate all slanted sides of trapezoids in at least one of their rows, in plane of those trapezoids with-into their slanted sides cold-formed bent hib-forming seats for affixing of additional stiffening bars _S -longitudinally along those rows of trapezoids. Through this arrangement it is achieved the overall beter structural and economical efficiency and performance of three-dimensio-nal reinforcing mats with high ribs.
It is an advantage, if the meandrically bent distribution bar of.a mat-core has such shape, that all trapezoids are uniform. The advantage of a three-dimensional concrete reinforcing mat with in such way formed meandrically bent distribution bars of its mat-core is the univesality and widest possible applicability.and use of such mat and maximal simplicity of its mat-core's fabrication.
With an advantage the geometrical parameters of equilateral trape zoids of the meandrical form of mat-core's distribution bar are set in such way, that the angle of trapezoid's imaginary longer base and its slanted side is from 45° up to 85°, and the length relation of slanted sides of the equilateral trapezoid to the length of its shorter base is within the brackets of 1,5:1 or up to 5:1.
Even more advantageous is, if the geometrical parameters, that is the shape of the equilateral trapezoid of the meandrically bent distribution bar of the structural core, i.e. the semiproduct mat-core of a three-dimensional mat is set in such way, that the angle of trapezoid's imaginary longer base and its slanted sides is of an angle 60° or up to 78° and the length's relation of slanted sides of the equilateral trapezoid to the length of its shorter base is within the brackets of 2:1 or up to 5:1. At any particular slant of trapezoid's sides and their length in relation to the length of trapezoid's shorter base being within the brackets shown above, it is easy by a simple structural calcnlatinq method to establish precisely the load-bearing SUBSTITUTE SHEET (RULE 26) proportion expressed by percentage of the proportion of the structual core's i.e. of the mat-core's trapezoidally bent distribution bars subjected to tensile forces, and thus to establish the portion by which the distribution bars participate in the overall load-bearing capacity of a certain structural mat-core's type, allowing for the selection of the most suitable one for a particular structural application.
The structural core i.e. mat-core, that is the semiproduct of the three-dimensional concrete reinforcing mat, containing only its meandri-cally bent distribution bars welded over its longitudinal load-bearing bars which form longitudinal edges of mat-core's ribs, may be also used - bent paralelly to and along of its load-bearing.bars into an opened or closed curve, or into a triangle, a quadrangle or a polygon containing therequired number of ribs with their load-bearing bars in vertical position, as reinforcing in vertical supports such as columns.
In order to achieve the bi-directional load-bearing capacity in a three-dimensional concrete reinforcing mat based on its structural core, it is feasible to attach to its structurally designated tensioned side instead of straight distribution bars the required additional load-bearing reinforcement, or an additional -on a structural core based three-dimensional mat perpendicularly laid and attached onto the previous one.
The structural core of the three-dimensional concrete reinforcing mat according to this invention is fabricated from. standardized reinfor-cing steel gradually - in the first stage the structural core and in the second stage the rest of the three-dimensional concrete reinforcing mat, the two stages being quantitatively and qualitatively different:
During the first fabrication stage done in conditions of factory mass-production, by a method of automated electrical resistance welding or chemical glueing into a configuration according to this invention, are affixed together meandrically bent distribution bars with straight load-bearing bars into a structural mat-core, that is into a semiproduct of a three-dimensional concrete reinforcing mat. 1n such way fabricated semiproduct, i.e. the structural mat-core, shaped into its longitudinal ribs formed by rows of equilateral trapezoids of its meandrically bent distribution bars, has guaranteed consistent geometrical parameters of its trapezoids and also the guaranteed required quality of all cross-welds and thus guaranteed its required load-bearing capacity.
During the second fabrication stage, carried out at the place of the three-dimensional concrete reinforcing mat's use, its structural core, SUBSTITUTE SHEET (RULE 26) 1 that is its semiproduct, on its structurally determined tensioned side, is only manually complemented into a physically complete three-dimensio-nal mat of required capacity, by tying on of straight distribution bars and of additional straight load-bearing bars, or instead of straight distribution bars by attaching of additional load-bearing reinforcement perpendicularly to the structural mat-core, thus making it load-bearing bi-directionally. If the structural mat-core serves as the reinforcement of a multispan concrete slab, then during the second stage it is supple-mented above slab's supports by inserting of a strip of ~ structural mat-core identical with the previous one.
It is the advantage of two-staged way of this three-dimensional con-crete reinforcing mat's fabrication, that at the end of the first fabri-cation stage the structural mat-core, that is the semiproduct iseconomi-cally transportable in bundles "on flat", and that relatively low weight of the structural core prior to its completion into a structurally and physically complete three-dimensional mat is suitable for use on sites without any available mobile mechanical lifting device. The completion of any structural mat-core's into a complete three-dimensional mat accor-ding to the requirements of its structural design, doesn't require specially qualified workforce, as all necessary straight distribution bars and additional load-bearing bars required for completion of structu-ral mat-cores into structurally and physically complete three-dimensio-nal mats, or any other required type of additional reinforcing material are delivered to the place of mat's use in required thicknesses and lengths, tied together into appropriately marked bundles, this arrange-ment saving production time on sites, and reducing losses of reinforcing material incured through its cut-offs, and it is also beneficial to the universality of the three-dimensional concrete reinforcing mats based on their structural cores, and it supports their general use.
Brief description of the drawings The invention will be illustrated on drawings, on which the unit of length used, doesn't have any specified definitive real value, except to express the relative relation between lengths of slanted sides and bases of trapezoids of meandrically bent distribution bars 1 of the structural core of a three-dimensional concrete reinforcing mat. All illustrations on drawings are shown in the logical sequence of the two-stage fabrication.
The illustrations 1 to 7 reflect the first fabrication stage, i.e.
the factory mass-rrnclnci.inn <,f the ~tr~~ctnral cnrP of the three-dimen-SUBSTITUTE SHEET (RULE 26) _ g_ 1 sionai concrete reinforcing mats.
The illustration Fig.1-shows schematically and also_l~n detail geo-metrically and structurally the.most advantageous meandrical form of distribution bars _1 in four basic types A, B, C and D of the semiproduct, that is of the structural core of the three-dimensional concrete rein-forcing mat assembled into the configuration according to this invention, and it also shows schematically an equilateral trapezoid within the width of one rib R of the structural mat-core, marked by symbols of its vari-ables.
On the illustration Fig.2 -in a cross-section of a rib R, is shown the configuration of distribution bars 1 and load-bearing bars 2, to-gether with the trigonometry of equilateral trapezoids of distribution bars _1 in all six structural types A, B, C, D, E, F of the semiproduct, i.e. of the structural core of the three-dimensional reinforcing mat constructed according to this invention, and the Fip.2 also shows the points for attaching of non-load-bearing stiffening bars S1 on slanted sides ~ of trapezoids in the type E, as well as points for attaching of stiffening bars S2 and S3 in the type F.
The illustration Fig.3 -in connection with Fig.1 and Fig.2 schemati-cally shows the structurally and constructionally important increase of "density" of ribs _R in the semiproduct, i.e. in the structural core of the three-dimensional concrete reinforcing mat made in accordance with this invention. The "density" increases from type A towards types D, E
and _F with maintained uniform bight _v in trapezoids of distribution bar _1 in alI six types of the structural core, while changing only the ratio of the length of the slanted side h~,~ to the length of the trapezoid's shorter base _b, which then for the type A is h~~2b,for the type H is h~H~3b, for the type C i s h~,~4b and for types D, E and F i s h ,~ 5b.
The illustration Fig.4 -in an alternative to the Fig.3 maintaining both -the uniform bight _v of equilateral trapezoids of the distribution bar _1, and the uniform ratio between the length of slanted sides/arms hw of trapezoids, and the length of their shorter bases b as h,~,:b=2:1 in all six types of the structural mat-core.
The illustration Fig.5 shows the configuration of distribution bars _1 and load-bearing bars _2 of the structural core of the three-dimensio nal concrete reinforcing mat, which is crucial to this invention.
The illustration Fig.6 shows the configuration of distribution bars _1 and load-bearing bars _2 in a cross-section of the same structural mat-core, with all symbols of its variables marked accordingly.
SUBSTITUTE SHEET (RULE 26) _g_ 1 The illustration Fig.7 shows the economically advantageous way of stacking and transporting in bulk of structural cores of three-dimensio-nal concrete reinforcing mats.
The illustrations Fig.B to Fig. l5 reflect the second fabrication stage, i.e. the manual physical completion of structural cores into com-plete three-dimensional concrete reinforcing mats, which is to be done strictly at their place of use.
The illustration Fig.B shows in a cross-section of a structural core the sequence of the core's completion into a structurally and physically complete three-dimensional mat by inserting and affixing of straight distribution bars _3, and of additional load-bearing bars 4 into their respective correct structural positions in the configuration of the structural core of the three-dimensional concrete reinforcing mat.
In the illustration Fig.9 the axonometrical view shoes a semiproduct, i.e. a structural core of a three-dimensional concrete reinforcing mat when it has been already completed the way shown in the Fig. B.
In the illustration Fig.lO -in a cross-section through the side-edge section of the three-dimensional mat completed as shown in Fig.9, there is shown that the straight distribution bars _3, as well as the additio-nal load-bearing bars _~1 are to be.attached only to the side of thestructu-ral mat-core of the three-dimensional mat, which has been structurally designated as the side subjected to tension.
In illustrations Fig. l1 and Fig. l2 is shown the correct way of longi-tudinal and transverse splicing of three-dimensional concrete reinforcing mats, which has to be carried out in compliance with Standards' require-ments for splicing of other existing types of reinforcing material.
The illustration Fig.l3 shows the possibility and the way how to change the typical one-directional load-bearing capability of the semi-product, i.e. of the structural core of a three-dimensional concrete reinforcing mat, into a bi-directional one, by attaching of perpendicu-larly across mat's load-bearing bars the required load-bearing cross-bars -usually to the mat's structurally designated tensioned side, hut sometimes even to the opposite side -the compressed one.
The illustrations Fig. l4 and Fig. l5 of cross-sections of concrete columns show yet another possible use of structural mat-cores - without straight distribution bars _3 and without the additional load-bearing bars _4 -by rolling of three or four ribs R of a mat-core -along its load-bearing hays 2 into the required polygonal shape.
SUBSTITUTE SHEET (RULE 26) WO 99127210 PCT/CZ9$/00004 1 Detailed description of the prefered structural core's formation.
The structural core of the three-dimensional concrete reinforcing mat as shown on illustration Fig.t to Fig.l5, vizually distinctive by its longitudinal ribs R, its fabrication width limited by the Interna-tional Transportation highway Code to max. 2400mm, and with the vari-able fabrication length of up to 6000mm -corresponding with the max.
web-span module of construction design, this structural core of the three-dimensional mat to be fabricated in configuration of its compo-nents according to this invention, from a certain number of smooth or deformed bars of standardized reinforcing steel as a mixed construction, i.e. in two qualitatively and quantitatively distinct fabricated stages.
In mat's first fabrication stage -as shown on illustrations Fig.1 to Fig.7, this structural core of the three-dimensional mat, fabricated in bulk, i.e. mass-produced as a semiproduct, i.e. as a mat-core, con-sisting of two components, that is distribution bars 1 and of straight, mutually parallel load-bearing bars _2 of the length equal to the requi-red length of a particular mat, those distribution bars 1 and load-bearing bars _2 mutually fast-fixed together by cross-joint welds through an automated process of electric-resistance welding, which allows for cross-welding even of thin steel bars or wires, or by an automated glueing process using chemical adhesiv:.~s - use of which prevents fabrica-tion, transport and/or use of structural mat-cores at atmospheric tempe-ratures below 0°C scale.
The distribution bars _1 of the structural mat-core, made in accordan-ce with this invention, are throughout their length, which is equal to the width IJ of the particular mat-core, cold-formed into a trapezoidal meander, with in its plane bent and formed equilateral trapezoids iden-tical in size and shape throughout the particular structural mat-core, and each two adjacent trapezoids of the meandrically bent distribution bar _1 will be mutually turned by an angle of 180° thus making them alternately opposing each other so, that their two adjacent slanted sides h;,l are throughout their length common and identical. The angle 9 (=theta) between slanted sides hw and the imaginary longer base c of the trapezoid plus the ratio of the length of slanted side h~ to the shorter base _b of the particular trapezoid do designate the structural and fabrication type of the semiproduct, that is of the type of the particular structural mat-core.
The four basic types of the structural core of the three-dimensio-nal concrete reinforcinc7 mat, i.e. semiprocdct made accnrdiry to this SUBSTITUTE SHEET (RULE 26) 1 invention, this types marked with capital letters A, B, C, D and two modified types by letters E and F as shown on Fig. l, Fig.2 and Fig.3 are fabricated as a semiproduct, i.e. as a structural core of three-dimensional mats of the above types, in. the length proportion of vari-ables of their distribution bars 1, asshown in following Tables1 and 2 Table 1 . Types _A, B, _C, _D, _E and _F, designated sizes of their angle 8 (=theta),~and the length-relations between their main variables v, hue, b, c.
Type ~ 8 v b h« c A 60° 1,73 1,0 2,0 3,0 +longitudinal load-bearing bars 2 -in twos -see:Fig.2A
g 70° 2,83 1,0 3,0 3,0 + ditto above - see Fig.28 C 75° 3,88 1,0 4,0 3,0 * ditto above - see Fig.2C
D 78° 4,90 1,0 5,0 3,0 + ditto above - see Fig.2D
E 78° 4,90 1 ,0 5,0 3,0 +ditto above -see Fig.2E +2 stiffening bars +3~$1 _S~ attached alongside of ribs R at the hlght of hyr:2 F 78° 4,90 1 ,0 5,0 3,0 +ditto above - see Fig.2F ~~ 2 stiffening +3~S2 bars ~ attached alongside of ribs R
at the hight of hy~:3 + 2 stiffening +3~S3 bars S3 attached algngside of ribs _R
at the hight of h~,,r. /3 PJote: The figure ~3~S1S2S3 means such length's addition to the imaginary _longer base c.
Symbols of variables - as shown in Tab.t and on the following Tab.2 and in Fig.1 throughout the Fig.lS:
~ ~ - angle theta between the slanted side h~,~ of the trapezoid and the imaginary longer base c,i.e.the slant of trapezoid's side and thus of the rib R
v - height of trapezoids, i.e. of the rib R
hw - lenght of the slanted side of the trapezoid, i.e.of the rib R
b - lenght of the shorter base of the trapezoid c - length of the imaginary longer base of the trapezoid r=~~-complementary angle to the angle ~ 0 , their sum being always equal to 180°
e=R - axial distance of two adjacent trapezoids of the same axial orien tation, i.e. the axial distance being the width of one rib R
t - thickness ~ of the distribution bar 1 of the structural mat-core m - spacing of meandrically bent distribution bars 1 along the entire length of the structural mat-core '/.
SUBSTITUTE SHEET (RULE 26~
1 I~J - fabrication width of the structural mat-core, that is the length of distribution bars 1 in their folded form, also the actual tenth of straight distribution bars 3 L - fabrication length of the structural mat-core, also the length of load-bearing bars 2 and of additional load-bearing bars 4 S1 S2 S3 - non-load-bearing bars longitudinally stiffening the slanted sides h~ of ribs _R of the structural mat-core of type _E or F, of the length identical to the length _L of the structural mat-core and their thickness t being equal to or thinner than ~
of the distribution bar 1 Longitudinal stiffening bars _S1 ~ S3 of the type _E and the type F of the semiproduct, i.e. of the structural core of the three-dimensional mat shown on Fig.2E and on Fig.2F are at the factory during the first product-ion stage of the structural mat-core's fabrication welded or glued onto 1,5~S protruding humps/steps cold-formed into each slanted side I~ of trapezoids within the meander-plane of folded meandrical form of distri-bution bars _1 with high trapezoids, i.e. with high ribs R only, at their appropriate heights as shown in the Fig.2E and in Fig.2F.
The increase of load-bearing capacity, or shear- and torsion-resistan-ce and of the overall stiffness -all those jointly reducing the deflec-tion of the structural core of a three-dimensional mat, foremostly depend upon the increase of density -that is upon the increase of the number of load-bearing ribs _R per one length's unit of the width of the structural core of the three-dimensional mat, this increase depending upon the type of the structural mat's core, i.e. on the size/value of its angle ~ as shown in the Table 2, developed from the Table 1 by maintaining of a uniform height _v=1,0 of trapezoids for all six types A, B, C, D, E and _F of the structural core of a three-dimensional mat. The Table 2 also contains the fabrication information on the length-relation, that is on the ratio of slanted sides h~ of trapezoids to the length of their shor-ter base _b, i.e. of the trapezoidal cross-section of the rib R of the structural mat-core, according to which for all types of structural cores it is expressed by the common formula: 1R=2(hy~~+b).
Table 2:
1 '1 Type~ v hw b R 1R=2(hw+b)R R
A 60 1,0 1,15610,578 4bA=2,312143,4682 1R5 0,75 B 70 1,0 1,06010,3534 4b8=1,413432,82692 2,0 1,0 C 75 1,0 1,03090,2577 4bC=1,030922,5773 2,5 1,25 D 78 1,0 1,02040,2041 4bD=0,81632,44896 3,0 1,5 (continues-'/.) SUBSTITUTE SHEET (RULE 26) _13_ 1 Type ~ ~ v hw b R 1R=2(hw+b) 1R 1R
E 78° 1,0 1,0204 0,2041 4bE=0,8163 2,44896 3,0 1,5 +3~S1 F 78° 1,0 1,0204 0,2041 4bF=0,8163 2,44896 3,0 1,5 ' +3PSS2 +3~S3 where: 1R - unfolded, that is straightened into a straight line-length of the distribution bars _1 of the structural core of the three-dimensional mat, which were bent as directed by this invention. This straightened length increases gradually from the minimum for the type A of the structural mat-core - to the maximum common for types D, E and F;
- the coefficient stating the length-relation, that is the ratio of straightened length of one trapezoid of the rib R
to the width R=4b, which is needed in order to establish the overall weight per 1mz of the fabricated structural mat-core, that weight dependant from the particular type 1 of the structural mat-core;
R - the multiplier-coefficient varying according to the type of the structural mat-core, serving for establishing of the value of the portion of length of the meandrically hent distribution bar _1, which is located in the structurally designated tensioned zone of the structural core of a par-ticular three-dimensional mat, the part which complements - that is adds to the overall capacity of all load-bearing bars of that particular mat.
This three informations, i.e. the length 1~ and the relation of varia-bles 1~:R, necessary for the selection of an economically andstructural-ly most advantageous structural mat-core's design and fabrication concer-ping all mentioned types A,B,C,D,E,F, and even all other -nontypified three-dimensional concrete reinforcing mats constructed in accordance with this invention - those three information data at the same time showing the impact of structural mat-core's fabrication weight, that is the importance of completion of each structural mat-core by adding of all required additional reinforcing steel bars -both distributing and load-bearing ones only at the place of the structural core's use, i.e.
during the second stage of fabrication, where the activity of "comple-ting" of the structural core of the mat as a mixed steel construction is the quantitative change, and the manner/way of completing by tying only of bars together - from tt~e strn ctiiral calculation's point of view is SUBSTITUTE SHEET (RULE 26) WO 99/27210 PCT/CZ9$/00004 1 a qualitative change.
The second fabrication stage -the manual one -of structural cores of three-dimensional concrete reinforcing mats -according to th a Claim 10 -is shown in Fig.8 to the Fig. l5 inclusive:
During the second fabrication stage -i.e. during the completion of the structural core into a structurally and physically complete three-dimensional concrete reinforcing mat at the place of its use, to the side/
face of the structural mat-core structurally designated as the tensioned one, are tied on regularly spaced straight distribution bars 3 of the length equal to the width of that structural mat-core, and usually of the same number and of the same thickness as distribution bars 1, and the total cross-sectional area Fa of straight distribution bars 3 and distribution bars _1 should equal 10% or up to 15% of the total cross-sectional area of load-bearing reinforcing bars of the concrete construc-tion part being executed.
Then follows tying on of additional straight load-bearing bars 4 of the structural mat-core's length, which are inserted and attached only into bottom corners of structurally designated tensioned part of trape-zoids, while the thickness t of additional straight load-bearing bars 4, by Standards allowed to be only 2mm thicker than the load-bearing bars2, must maintain the standardized spacing between load-bearing bars 2 and the additional straight load-bearing bars 4, which might require modifi-cation of the fabrication length of all shorter bases b of trapezoids of bars 1 of a particular structural mat-core.
To ensure that the designated load-bearing capacity of the executed reinforced concrete structure is being maintained -the fabricator of the structural mat-cores used in that structure; together with structural mat-cares will supply bundles of required straight distribution bars 3 and also bundles of additional straight load-bearing bars 4 of the appropriate thickness and length.
All fabricated structural cores of three-dimensional concrete rein-forcing mats made in accordance with this invention must be marked by their fabricator on attached to structural cores durable tags with the internationally recognizable distinguishing name mark "3D-mat" to be used in structural calculations, on drawings and on other documents, and with a capital letter-symbol of the structural mat-core's type, plus with the fabricator's structural cores' production catalog-number -this in-formations being the product's, that is the structural mat-cores' manda-tory guarantee of quality and of itsload-bearing capacity.
SUBSTITUTE SHEET (RULE 26) 1 All bars 1,2,3,4 as well as S1 ~ and ~ and also any other additio-nal load-bearing or distribution reinforcement used -for example as the reinforcement changing the typical one-directionally load-bearing struc-tural core of the three-dimensional mat into a bi-directionally load-s bearing mat, that reinforcement must be of the same identical Standards' quality as that of the three-dimensional mat's basic structural mat-core's bars 1,2, and also bars S1 -or ~ and S3 in case of a structural mat-core with high ribs R.
All tie-wire connections of a three-dimensional concrete reinforcing mat constructed according to this invention must be done with the stan-dardized black soft cold drawn tie-wire.
Testing of structural mat-cores' cross-welds for weld-shear strength and adhesion under a bending stress, has to be done in laboratory condi tions by Authorities concerned, or under their supervision by the struc tural mat-cores' fabricator.
The structural calculation of structural mat-cores, or on such structural cores based structurally and physically complete three-dimen-sional concrete reinforcing mats used without concrete as a load-bearing steel construction, can be done using the modified currently used formu-las for designing of use of load-bearing folded sheet-metal panels used in composite floors'~construction.
Industrial application The typifiable structural core of a three-dimensional concrete rein-forcing mat, fabricated in accordance with this invention, foremostly is to be used as the reinforcing material for concrete structures, con-crete panels and other concrete products not only for civil engineering structures, bridges and underground constructions for civilian use, but also for military purposes, and as part of security- and temporary structures, where this ctructural core of the three-dimensional mat due to its longitudinally formed ribs will serve mainly without its combina-nation with concrete, i.e. as selfsupporting load-bearing steel structu-re - that means as a finished product.
SUBSTITUTE SHEET (RULE 26)
Claims (7)
1. Structural core of the three-dimensional reinforcing steel mat characterized by that it consists of distribution bars(1) - each one bent throughout its entire length into the particular geometrical shape of a trapezoidal meander formed by a continuous row of all in the same, vertical plane positioned incomplete equilateral trapezoids of imaginary bases(c) and with shorter bases(b), slanted sides(h w) and of core's structural depth(v) as required, those trapezoids oriented mutually alternatively so, that slanted sides(h w) of each two adjoining mutually inversed trapezoids are identical and of the same length, the length of into a meander bent bars(1) as folded equalling the width(W) of each individual core, and the length of all parameters (c),(b),(h w) and (v) being constant throughout each particular structural core fabricated, - and of straight load-bearing bars(2) of mat-core's length factory-welded by the automated electric welding process perpendicularly to meandrically bent distribution bars(1) always into inside each of corner-bends of angle(~) formed by slanted sides(h w) and shorter bases(b) of their trapezoids - in this way forcing distribution bars(1) by their thus tensioned portions' load-bearing capacity percentage - determined by the particular shape of meandrically bent bars'(1) trapezoids of each individual mat-core - to contribute to the total load-bearing capacity of-at place of its use by attaching of bars(3) completed reinforcing steel mat - thus achieving the main objective of structural cores' design.
2. Structural core of the three-dimensional reinforcing steel mat according to claim 1, characterized by that with all its components at start of its fabrication - all without any exception factory-cut in their required lengths from one particular type of reinforcing steel bars of the same tensile strength - the structural core is to be fabricated in four main types A,B,C and D, which types differ by the angle(~) and the ratio of lengths of (h w) to (b) of trapezoids of structural core's distribution bars' (1) meandrical form, so that for the type A the angle(~) equals 120° and the ratio (h w):(b) is 2:1 , for the type B the angle (~) equals 110° and the ratio (h w):(b) is 3:1 , for the type C the angle (~) equals 105° and the ratio (h w):(b) is 4:1,and for the type D the angle (~) equals 102° and the ratio (h w):(b) is 5:1
3. Structural core of the three-dimensional reinforcing steel mat according to claim 1, characterized by that - destined for concrete slabs thicker than 300mm the structural core is also fabricated in type E of same angle(~) and the ratio (h w):(b) as the type C, and the type F of same angle(~) and the ratio (h w):(b) as the type D, but both types E and F differ from all four types A,B,C and D by slanted sides (h w) of trapezoids of all their distribution bars(1) formed as designed with one step/offset in case of the type E for factory welded-on bars/
/wires(s1), and two steps/offsets for welded-on bars/wires(s1) and (s2) in structural core's type F.
/wires(s1), and two steps/offsets for welded-on bars/wires(s1) and (s2) in structural core's type F.
4. ~Structural core of the reinforcing steel mat according to claim 1,2, and or 3, characterized by that to mat-core's one side designated as the tensioned one - laid between load-bearing bars(2) - are in addition factory-welded straight load-bearing bars(4) of required analythically determined number and section, factory-cut to mat-core's length from same type and tensile strength reinforcing steel as load-bearing bars(2), or bars(4) attached after the full set of bars(4) in an appropriately tagged bundle accompanying each particular mat-core which requires addition of bars'(4) load-bearing capacity - has been delivered to place of mat-core's use.
5. Structural core of the three-dimensional reinforcing steel mat according to claim 1, 2, 3 and 4, characterized by that definetly only after mat-core's delivery to place of its use - at least to its one side designated as the tensioned one - are attached under and parallel to each bar(1) - that is perpendicularly to mat-core's length - thin straight bars(3) factory-cut to length(W) from the same type and tensile strength reinforcing steel as distribution bars(1) - the full set of bars(3) in an appropriately tagged bundle accompanying each individual structural core fabricated - thus securing functional integrity of each particular geometrical shape of trapezoids of meandrically bent distribution bars(1) until the whole reinforcing steel mat's concreting in.
6. Structural core of the three-dimansional reinforcing steel mat according to claims 1,2,3,4 and 5, characterized by that by attaching perpendicularly across the mat-core's designated tensioned side of yet another course of load-bearing bars cut to length(W) of same type and tensile strength as all other components of that particular mat-core -it makes it load-bearing bidirectionally.
7. Structural core of the three-dimensional reinforcing steel mat according to claims 1, 2 or 3,and 4, characterized by that without attached bars(3) - each structural core of any of one of types A,B,C,D, E or F may be individually bent or rolled parallel to its ribs(R) -that is along its load-bearing bars(2) into an opened or closed curve, or into a triangle, a quadrangle or a polygon, - or two or more layers of mat-cores as whole units attached mutually alternatively perpendicularly to each other, and then as a whole positioned either horizontally or vertically may serve as reinforcement of particular special concrete structures.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CZPV3705-97 | 1997-11-21 | ||
| CZ973705A CZ285054B6 (en) | 1997-11-21 | 1997-11-21 | Structural core of three-dimensional reinforced concrete grillage and process for producing thereof |
| PCT/CZ1998/000004 WO1999027210A1 (en) | 1997-11-21 | 1998-02-05 | Structural core of the three-dimensional concrete reinforcing mat and method of its fabrication |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2282676A1 CA2282676A1 (en) | 1999-06-03 |
| CA2282676C true CA2282676C (en) | 2004-03-16 |
Family
ID=5467134
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002282676A Expired - Fee Related CA2282676C (en) | 1997-11-21 | 1998-02-05 | Structural core of the three-dimensional concrete reinforcing mat and method of its fabrication |
Country Status (5)
| Country | Link |
|---|---|
| AU (1) | AU5747298A (en) |
| CA (1) | CA2282676C (en) |
| CZ (1) | CZ285054B6 (en) |
| DE (1) | DE29820737U1 (en) |
| WO (1) | WO1999027210A1 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH695106A5 (en) * | 2001-01-23 | 2005-12-15 | Fischer Reinach Ag | A process for preparing a Schubarmierung in supported concrete floors. |
| DE10209046A1 (en) * | 2002-03-01 | 2003-09-18 | Badische Drahtwerke Gmbh | Reinforcing element used in the form of a braced girder as reinforcement in a reinforced concrete support comprises three reinforcing bars and connecting elements extending between and connecting the reinforcing bars |
| DE102009003813A1 (en) * | 2009-04-22 | 2010-10-28 | Christian Prilhofer | Reinforcing element, apparatus and method for producing a reinforcing element |
| CN109356326A (en) * | 2015-12-23 | 2019-02-19 | 王本淼 | A kind of cast-in-place cavity building roof is engraved with steel mesh with ribbing |
| DE102016106290A1 (en) | 2016-04-06 | 2017-10-12 | Daniel Hagmann | reinforcing element |
| CN106499121B (en) * | 2016-11-07 | 2018-12-11 | 青岛理工大学 | Explosion-proof reinforced concrete with negative Poisson ratio effect and preparation method thereof |
| CN110725477B (en) * | 2019-11-15 | 2020-10-09 | 广东博意建筑设计院有限公司 | Reinforcing steel bar layer at external corner part |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1864773A (en) * | 1930-03-25 | 1932-06-28 | Universal Pipe And Radiator Co | Reenforcing members for concrete |
| GB816059A (en) * | 1955-05-18 | 1959-07-08 | Fritz Grebner | Lattice girders and structural steel lattice framework |
| DE1973622U (en) * | 1967-08-26 | 1967-11-30 | Baustahlgewebe Gmbh | REINFORCEMENT FOR STRENGTHENING REINFORCED CONCRETE PANELS. |
| AT343438B (en) * | 1975-04-09 | 1978-05-26 | Bucher Franz | METHOD FOR PRODUCING A LATTICE OR BUCKLE BRACKET |
| GB1524824A (en) * | 1976-07-15 | 1978-09-13 | Gkn Reinforcements Ltd | Metal mesh |
| DE2703068A1 (en) * | 1977-01-26 | 1978-07-27 | Siegfried Dr Ing Krug | Concrete slab reinforcing grille - consists of upper and lower sets of bars joined by wave-form transverse elements |
| DE2706756A1 (en) * | 1977-02-17 | 1978-08-24 | Bucher Franz | Three:dimensional concrete reinforcing component - has protruding ends of secondary transverse section bent over to fit extension |
| AT349709B (en) * | 1977-02-18 | 1979-04-25 | Bucher Franz | REINFORCEMENT STRUCTURES |
| US4494576A (en) * | 1982-05-29 | 1985-01-22 | Concrete Pipe & Products Corp. | Reinforcing system for concrete pipe |
| CH688519A5 (en) * | 1994-06-24 | 1997-10-31 | Fischer Reinach Ag | Punching reinforcement For supported concrete floors in areas of their Props and processes for their preparation and bending machine. |
-
1997
- 1997-11-21 CZ CZ973705A patent/CZ285054B6/en not_active IP Right Cessation
-
1998
- 1998-02-05 AU AU57472/98A patent/AU5747298A/en not_active Abandoned
- 1998-02-05 CA CA002282676A patent/CA2282676C/en not_active Expired - Fee Related
- 1998-02-05 WO PCT/CZ1998/000004 patent/WO1999027210A1/en active Application Filing
- 1998-11-20 DE DE29820737U patent/DE29820737U1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| CZ370597A3 (en) | 1998-03-18 |
| AU5747298A (en) | 1999-06-15 |
| DE29820737U1 (en) | 1999-02-18 |
| CA2282676A1 (en) | 1999-06-03 |
| CZ285054B6 (en) | 1999-05-12 |
| WO1999027210A1 (en) | 1999-06-03 |
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