DK159794B

DK159794B - PROCEDURE FOR THE PREPARATION OF A BEAM OR PLATE ELEMENT OF STRETCHED CONCRETE AND REINFORCEMENT UNITS FOR USING THIS PROCEDURE

Info

Publication number: DK159794B
Application number: DK520588A
Authority: DK
Inventors: Erik Lind
Original assignee: Dansk Spaend As
Priority date: 1988-09-19
Filing date: 1988-09-19
Publication date: 1990-12-03
Also published as: EP0434753B1; ATE160840T1; DE68928472T2; EP0434753A1; DK520588A; DK520588D0; WO1990003479A1; DE68928472D1; DK159794C

Abstract

A prestressed concrete beam (1) is cast with a rectilinear longitudinal profile and a filling piece (13) extending from a surface of the beam (1) to the reinforcing strands (6) is embedded. After hardening of the concrete and removal of the filling piece (13) if necessary, the beam (1) is deflected in a predetermined angle by rotating the beam sections (2, 3) on either side of the recess (4) formed by the filling piece in such a direction that the recess is diminished, following which the beam sections (2, 3) are retained in the predetermined angle. A reinforcement assembly made in two equal halves and connected with a breakable joint may be embedded in the area of the recess to reinforce the beam sections (2, 3).

Description

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Opfindelsen vedrører en fremgangsmåde til fremstilling af et bjælke- eller pladeelement af strengbeton, ved hvilken fremgangsmåde armeringstrådene opspæn-des hovedsagelig retliniet gennem en støbeform, og ele-5 mentet støbes med et hovedsagelig retliniet længdeprofil.The invention relates to a method for producing a beam or slab element of reinforced concrete, in which method the reinforcing wires are mainly tensioned straight through a mold and the element is molded with a substantially rectilinear longitudinal profile.

Det er almindeligt at anvende bjælke- og pladeelementer af ovennævnte art til bygningskonstruktioner, især etagedæk og tagkonstruktioner, fordi sådanne ele-10 menter har en god styrke i forhold til deres vægt, og er billigere at fremstille end fx betonelementer med slap eller efterspændt armering, eller betonkonstruktioner støbt på stedet.It is common to use beam and slab elements of the above-mentioned type for building structures, especially floor decks and roof structures, because such elements have a good strength in relation to their weight, and are cheaper to manufacture than, for example, concrete elements with slack or prestressed reinforcement, or concrete structures cast on site.

Ved den kendte fremgangsmåde har det dog ikke 15 været muligt at støbe bjælke- eller pladeelementerne i tagform, altså at udforme bjælkeelementet som to ben, der danner en vinkel med hinanden, og pladeelementet som en tagflade med en rygning og to skrånende sideflader.In the known method, however, it has not been possible to mold the beam or plate elements in roof form, i.e. to design the beam element as two legs forming an angle to each other, and the plate element as a roof surface with a smoking and two sloping side surfaces.

20 Sådanne bjælkeelementer kan fremstilles ved, at to retliniede strengbetonelementer sammenstøbes, så de danner en vinkel med hinanden, og i sammenstøbningsområdet armeres med kabler, der efterspændes efter hærdning af betonen. Herved bliver bjælkerne dog dyre at 25 fremstille, og en væsenlig ulempe er endvidere, at store vinkelformede tagbjælker kan være vanskelige at transportere fra fremstillingsstedet til byggepladsen, idet eksisterende broer og luftledninger på transportruten sætter en grænse for elementernes størrelse.Such beam members can be made by molding two rectilinear reinforced concrete elements so that they form an angle to each other, and in the molding area are reinforced with cables which are tensioned after curing of the concrete. However, the beams thus become expensive to manufacture, and a significant disadvantage is that large angular roof beams can be difficult to transport from the manufacturing site to the construction site, as existing bridges and overhead lines on the transport route limit the size of the elements.

30 Fra DK fremlæggelsesskrift nr. 152 999 kendes yderligere en fremgangsmåde til fremstilling af et bjælke- eller pladeelement af beton med en forspændt flertrådsarmering og med en konkav underside, i hvilken armeringen er indlejret som en trækarmering. Ved denne 35 fremgangsmåde forløber armeringstrådene ubrudt mellem elementets ender og danner et eller flere knæk, hvor30 From DK Patent Specification No. 152 999, there is further known a method for producing a beam or slab element of concrete having a prestressed multi-thread reinforcement and with a concave underside in which the reinforcement is embedded as a wooden reinforcement. In this method, the reinforcing wires extend uninterruptedly between the ends of the element and form one or more knuckles, wherein

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2 trådene er fastholdt i et styr, der er indrettet til forud for betonudstøbningen at optage tværkræfterne fra armeringen i knækpunktet eller knækpunkterne, og som strækker sig til elementets trykside samt er indrettet 5 til efter betonens hærdning at fikseres i denne side af elementet.2, the wires are retained in a guide arranged prior to the concrete casting to absorb the transverse forces from the reinforcement at the break point or break points, extending to the pressure side of the element and arranged 5 to be fixed in this side of the element after the hardening of the concrete.

Ved denne fremgangsmåde resulterer armeringstrådenes forløb i meget store tværkræfter på armeringsstyr og forme under opspændingen, og i praksis kan der 10 ved denne fremgangsmåde kun fremstilles bjælke- og pladeelementer med en beskeden taghældning.In this method, the course of the reinforcing wires results in very large transverse forces on the reinforcing guide and molds during tensioning, and in practice only beam and slab elements with a slight pitch inclination can be produced in this method.

Det er hensigten med opfindelsen at angive en fremgangsmåde til fremstilling af bjælke- og pladeelementer af den indledningsvis nævnte art, der ikke har 15 de ovenfor beskrevne ulemper.SUMMARY OF THE INVENTION It is an object of the invention to provide a process for the manufacture of beam and slab elements of the type mentioned initially, which does not have the disadvantages described above.

Opfindelsen adskiller sig fra den indledningsvis angivne fremgangsmåde ved, at der mindst ét sted i elementet indstøbes et første udfyldningsstykke, der fra én overflade af ele-20 mentet strækker sig stort set til armeringstrådene, at det første udfyldningsstykke efter behov fjernes efter hærdning og forspænding af betonen, at elementet efter betonens hærdning og forspænding knækkes i en forudbestemt vinkel ved en sådan ind-25 byrdes drejning, af de på hver sin side af det nævnte sted liggende elementdele, at den af det første udfyldningsstykke dannede udsparing formindskes, og at elementdelene på hver sin side af det første udfyldningsstykke fastholdes i den forud bestemte vin-30 kel i forhold til hinanden.The invention differs from the method set forth at the outset in that at least one site is embedded in the element, a first filler piece extending from one surface of the element substantially to the reinforcing wires, that the first filler piece is removed after curing and pre-tensioning. the concrete, after the hardening and prestressing of the concrete, the element is broken at a predetermined angle at such a rotation, by the element portions on either side of said place, that the recess formed by the first filling piece is reduced and that the element parts of each side of the first filling piece is held in the predetermined angle relative to each other.

Armeringstrådene opspændes sædvanligvis i en spændebænk og ved fremstilling af fx et bjælkeelement lægges armeringstrådene ved bjælkefoden eller den del af bjælken, der senere danner bjælkens trækside, og 35 udfyldningsstykket, der hensigtsmæssigt har kileform, indlægges i støbeformen til den side, mod hvilken ele- 3The reinforcing wires are usually clamped in a clamping bench and in the manufacture of, for example, a beam element, the reinforcing wires are laid at the beam foot or the part of the beam which later forms the draw side of the beam and the filling piece which is suitably wedge-shaped is inserted into the mold,

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mentdelene skal drejes under knækoperationen, og fortrinsvis således, at det når ind til området ved armeringstrådene. Derefter udstøbes formen, og efter hærdningen af betonen afspændes armeringstrådene, hvorved 5 den ønskede forspænding opstår i betonen.the mandrel parts should be rotated during the cracking operation, and preferably so that it reaches the area of the reinforcing wires. The mold is then cast, and after the hardening of the concrete, the reinforcing wires are relaxed, whereby the desired prestressing occurs in the concrete.

Bjælkeelementet fremstår nu som et retliniet, forspændt strengbetonelement og kan i denne form transporteres til byggepladsen, uden at broer, luftledninger eller lignende installationer langs transportruten er 10 en hindring for transporten. Såfremt den side af elementet, hvor udfyldningsstykket er indlagt, i denne situation er elementets trykside, må udfyldningsstykket være udført således, at det kan optage de forekommende trykpåvirkninger.The beam element now appears as a straight, prestressed stretched concrete element and in this form can be transported to the construction site without bridges, overhead lines or similar installations along the transport route being an obstacle to the transport. If, in this situation, the side of the element where the filling piece is inserted is the printing side of the element, the filling piece must be designed so that it can absorb the pressure effects that occur.

15 Knækoperationen kan eksempelvis udføres ved brug af en montagekran, der løfter elementet ved enderne og har et sekundært spil, som kan hugges an i området ved knækpunktet. Herefter kan dette hæves i forhold til enderne, eventuelt ved sænkning af disse, indtil 20 den ønskede knækvinkel er opnået. Som følge af egenvægten vil elementet knække i det svageste tværsnit, dvs. ved den af udfyldningsstykket dannede udsparing.For example, the cracking operation can be performed using a mounting crane which lifts the element at the ends and has a secondary play which can be cut into the area at the breaking point. Thereafter, this can be raised relative to the ends, possibly by lowering them until the desired crack angle is achieved. Due to the self-weight, the element will break in the weakest cross section, ie. by the recess formed by the filling piece.

Der fremkommer her først en revne, som fra armeringstrådene løber ud mod elementets overflade modsat ud-25 sparingen, og ved fortsat løftning åbner revnen sig mere og mere, hvorunder elementdelene på hver sin side af brudstedet holdes sammen af de forspændte armeringstråde.Here, a crack first emerges which extends from the reinforcing wires to the surface of the element opposite to the recess, and upon continued lifting, the crack opens more and more, during which the element parts on each side of the fracture site are held together by the prestressed reinforcing wires.

Såfremt det nævnte udfyldningsstykke er frem-30 stillet af et deformerbart materiale, fx en skumplast, der er tilstrækkelig stiv til at modstå trykket fra betonen under dennes udstøbning og vibrering i støbeformen, men som kan deformeres uden at yde nogen nævneværdig modstand, når bjælkeelementet knækkes, kan udfyld-35 ningsstykket forblive på sin plads under knækoperationen. Er udfyldningsstykket derimod udført af eksempelvis stål eller træ, må det fjernes før knækningen.If said filler piece is made of a deformable material, for example a foam plastic which is sufficiently rigid to withstand the pressure of the concrete during its casting and vibration in the mold, but which can be deformed without providing any appreciable resistance when the beam member is broken , the filler piece may remain in place during the cracking operation. If, on the other hand, the filling piece is made of, for example, steel or wood, it must be removed before cracking.

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Når bjælkedelene på hver siri side af brudstedet danner den ønskede vinkel, fastholdes de i denne stilling. Dette kan fx ske ved, at i forvejen indstøbte beslag forbindes ved hjælp af svejsning eller på anden 5 egnet måde.When the beam portions on each siri side of the fracture site form the desired angle, they are retained in this position. This can be done, for example, by pre-embedding fittings by means of welding or in another suitable manner.

Ved fremstilling af elementet på den her beskrevne måde opnås et strengbetonelement med et knækket eller vinkelformet længdeprofil, og i hvilket de forspændte armeringstråde forløber ubrudt fra elemen-10 tets ene ende til den anden. Fremgangsmåden ifølge opfindelsen medfører den yderligere fordel, at elementet alt efter omstændighederne kan tildeles sin endelige form enten på fremstillingsstedet eller på byggepladsen. Når knækningen af elementet foretages samtidig 15 med, at dette rejses på sin endelige plads, kan der opnås en væsentlig arbejdstidsbesparelse.In preparing the element in the manner described herein, a reinforced concrete element having a cracked or angular longitudinal profile is obtained, in which the prestressed reinforcing wires extend uninterrupted from one end of the element to the other. The method according to the invention has the additional advantage that the element can, according to the circumstances, be assigned its final shape either at the manufacturing site or at the construction site. When the element is cracked at the same time as it is raised in its final place, a significant saving in working time can be achieved.

Ved fremgangsmåden ifølge opfindelsen kan der ikke blot fremstilles tagformede bjælke- eller pladeelementer men eksempelvis også portal- eller rammeele-20 menter, såsom 2- eller 3-charniersrammer med tag- og søjle- eller facadedele.In the method according to the invention, not only roof-shaped beam or slab elements can be produced, but also, for example, portal or frame elements, such as 2 or 3-carnery frames with roof and pillar or facade parts.

I en foretrukken udførelsesform af opfindelsen fastholdes elementdelene på hver sin side af det første udfyldningsstykke i den forudbestemte vinkel i forhold 25 til hinanden ved, at åbningen dannet mellem de mod hinanden vendende brudflader af elementdelene på hver sin side af nævnte sted udstøbes med beton eller udfyldes med et passtykke, der fastgøres til elementdelene.In a preferred embodiment of the invention, the element portions are retained on either side of the first filling piece at the predetermined angle relative to each other by the opening formed between the facing portions of the element portions on each side of said site with concrete or filled. with a passport piece attached to the element parts.

Udstøbning af den fremkomne åbning med beton kan 30 være hensigtsmæssig i de tilfælde, hvor elementet har et simpelt tværsnit, og hvor udstøbningen kan foregå hurtigt og uden kompliceret formarbejde, samt hvor arbejdsgangen tillader, at elementerne uden større omkostninger kan holdes i den ønskede vinkel i forhold 35 til hinanden, indtil den udstøbte beton er hærdet. Ved andre elementtyper kan der indsættes et passtykke i den 5Molding of the resulting opening with concrete may be convenient in cases where the element has a simple cross-section and where the molding can be carried out quickly and without complicated molding, and where the workflow allows the elements to be kept at the desired angle at no great cost. ratio 35 to each other until the cast concrete has hardened. For other item types, a passport can be inserted into the 5

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fremkomne åbning mellem brudfladerne, hvorved elementet, når det ikke mere holdes oppe ved knækpunktet, bibeholder sin form og straks er i stand til at overføre trykkræfter stammende fra egenvægten og eventuelle 5 ydre påvirkninger mellem elementdelene. Dette betyder, at der kan spares midlertidige understøtninger, og at montagekranen hurtigt kan frigøres til brug ved rejsning af et efterfølgende element.formed opening between the fracture surfaces, whereby the element, when no longer held at the breaking point, retains its shape and is immediately capable of transferring compressive forces arising from the self-weight and any external stresses between the element parts. This means that temporary supports can be saved and the mounting crane can be released quickly for use when erecting a subsequent element.

En udførelsesform for opfindelsen er ejendomme-10 lig ved, at der ud for det første udfyldningsstykke indstøbes et tværskot, der strækker sig fra elementets modstående overflade mod armeringstrådene, og at tværskottet fjernes under knækningen af elementet, ved at anvende et tværskot som beskrevet opnås en veldefineret 15 svækkelse af bjælkens tværsnit, og de mod hinanden vendende flader af bjælkedelene på hver sin side af brudstedet kan gives en ønsket form, hvilket fx letter tilpasningen af et passtykke.An embodiment of the invention is characterized in that, for the first filling piece, a transverse bulkhead extending from the opposing surface of the element to the reinforcing wires is embedded and that the transverse bulkhead is removed during the cracking of the element, using a transverse bulkhead as described. a well-defined weakening of the cross-section of the beam and the facing faces of the beam parts on either side of the breaking point can be given a desired shape, which facilitates, for example, the fitting of a pass piece.

I dette tilfælde kan tværskottet og passtykket 20 hensigtsmæssigt være støbt, fx. af beton, under anvendelse af et og samme sæt formsider. Herved kan det sikres, at de flader, der danner stødfugerne mellem det indsatte passtykke og det knækkede element, passer nøjagtigt til hinanden.In this case, the transverse bulkhead and fit piece 20 may conveniently be molded, e.g. of concrete, using one and the same set of moldings. In this way, it can be ensured that the surfaces forming the butt joints between the inserted passport and the cracked element exactly match each other.

25 I bjælke- eller pladeelementer med større for spændingskræfter er det nødvendigt, at der på hver side af knækpunktet indstøbes tværarmering i elementet. Herved kan tværkræfterne, der fremkaldes ved at armeringstrådene skifter retning i knækpunktet, overføres til 30 bjælkens trykside.25 In beam or slab elements with greater tension forces, it is necessary that embossing on each side of the breaking point in the element. Hereby, the transverse forces induced by the reinforcing wires shifting direction at the breaking point can be transmitted to the pressure side of the beam.

Da de trykkræfter, der overføres mellem de to dele af elementet er meget store i området ved den forspændte armering, foretrækkes det, at der på hver side af det første udfyldningsstykke indstøbes et forstærk-35 ningselement og at fladerne, der ligger an mod hinanden, udgøres af flader på forstærkningselementerne.Since the compressive forces transmitted between the two parts of the element are very large in the region of the prestressed reinforcement, it is preferred that on each side of the first filling piece, a reinforcing element is embedded and the surfaces abutting one another are constituted by surfaces of the reinforcing elements.

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Disse anlægsflader på forstærkningselementerne kan udgøres af stålplader, der tildeles en bestemt krumning, så at de under knækningen af elementet ruller på hinanden, og ved variation af fladernes krumningsra-5 dius er det muligt at opnå, at forspændingskraften holdes konstant eller varierer på ønsket måde under knækningen af elementet. Herved kan der kompenseres for de ændringer af forspændingskraften, der forekommer i den første tid efter udstøbningen af betonen og for andre 10 forhold, der påvirker forspændingskraften.These abutment surfaces of the reinforcing elements can be constituted by steel plates which are assigned a certain curvature so that during the cracking of the element they roll on one another and by varying the curvature radius of the surfaces it is possible to obtain that the biasing force is kept constant or varies in the desired manner. during the cracking of the element. This can be compensated for the changes in the prestressing force that occur in the first time after the casting of the concrete and for other conditions affecting the prestressing force.

En anden udførelsesform for opfindelsen er ejendommelig ved, at der anvendes forstærkningselementer, der samtidig er armeringsstyr til at fastholde armeringstrådene i en bestemt placering, som er forskellig 15 fra den placering, de har ved elementets ender. I knækpunktets nærhed er det ønskeligt, at armeringstrådene ligger i ét lag, der strækker sig vinkelret på knækretningen medens det ved elementets ender oftest er ønskeligt at have armeringstrådene placeret med rimelig stor 20 indbyrdes afstand og jævnt fordelt over tværsnittet for at også en god forankring og en passende fordeling af forspændingen i betonen.Another embodiment of the invention is characterized by the use of reinforcing elements which are at the same time reinforcement guide for holding the reinforcing wires in a particular location different from the position they have at the ends of the element. In the vicinity of the breaking point, it is desirable that the reinforcing wires lie in one layer extending perpendicular to the cracking direction, while at the ends of the element it is most desirable to have the reinforcing wires spaced apart relatively evenly and evenly distributed over the cross-section so that a good anchorage and an appropriate distribution of the prestress in the concrete.

Det er ønskeligt, at armeringstrådene efter knækoperationen forløber med en passende stor krum-25 ningsradius gennem knækzonen. Dette kan ifølge opfindelsen opnåes ved, at et andet udfyldningsstykke indlægges mellem armeringstrådene og det første udfyldningsstykke. Dette andet udfyldningsstykke kan have en plan eller rillet flade mod armeringstrådene og være 30 tykkest ud for knækpunktet, hvorfra det tilspidser ud mod enderne.It is desirable that, after the cracking operation, the reinforcing wires extend with a suitably large radius of curvature through the cracking zone. This can be achieved according to the invention by inserting a second filling piece between the reinforcing wires and the first filling piece. This second filling piece may have a flat or grooved surface against the reinforcing wires and be 30 thickest at the point of cracking from which it tapers to the ends.

Det andet udfyldningsstykke kan være udført af et deformerbart materiale, f. eks. en passende stiv skumplast. Under knækoperationen vil armeringstrådene 35 trykke på det andet udfyldningsstykke og presse det sammen, indtil armeringstrådene tilsidst hviler mod be- 7The second filling piece may be made of a deformable material, for example a suitable rigid foam plastic. During the cracking operation, the reinforcing wires 35 will press on the second filling piece and compress it until the reinforcing wires finally rest against the arm.

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tonen på den modsatte side af det andet udfyldningsstykke. Ved hensigtsmæssig formgivning af det andet udfyldningsstykke kan det sikres, at armeringstrådene får netop det ønskede forløb efter knækoperationen.the tone on the opposite side of the other fill piece. By appropriately shaping the second filler piece, it can be ensured that the reinforcing wires get exactly the desired course after the cracking operation.

5 Det andet udfyldningsstykke kan være indbygget i armeringsstyret, som tillige kan være bygget sammen med tværarmeringen.5 The second filling piece may be built into the reinforcement guide, which may also be built in conjunction with the cross reinforcement.

Et sådant aggregat er ifølge opfindelsen hensigtsmæssigt udført i to ens halvparter til indstøbning 10 på hver sin side af knækpunktet. De to halvparter er samlet indbyrdes forud for indstøbningen med en forbindelse, som sikrer en nøjagtig indbyrdes position under udstøbning og vibrering, men ikke er stærkere, end at den brydes, når knækoperationen indledes. Denne sammen-15 bygning af aggregatets to halvdele muliggør den foran omtalte justering af forspændingskraften.Such an assembly according to the invention is conveniently made in two identical half-parts for molding 10 on each side of the breaking point. The two halves are assembled together prior to the casting with a connection which ensures an exact mutual position during casting and vibration, but is not stronger than breaking when the cracking operation is initiated. This combination of the two halves of the unit enables the aforementioned adjustment of the biasing force.

I en anden udførelsesform if g. opfindelsen er armeringsaggregatet udført i ét stykke, der har kasseformet eller U-formet tværsnit, og hvis ender over en 20 passende længde er faststøbt i betonen på hver sin side af knækpunktet. Under knækoperationen overføres forspændingskraften direkte gennem det som armeringsstyr tjenende, gennemgående stykke og dette bukkes i en jævn bue under knækoperationen støttet af den indstøbte 2 5 tværarmering.In another embodiment of the invention, the reinforcing assembly is made in one piece having box-shaped or U-shaped cross-sections and whose ends over a suitable length are cast into the concrete on each side of the breaking point. During the cracking operation, the biasing force is transmitted directly through the reinforcing piece, which serves as a reinforcing guide, and is bent in a smooth arc during the cracking operation supported by the embedded cross-armor.

Opfindelsen vil nu blive nærmere forklaret ved hjælp af nogle udførelses former og med henvisning til tegningen, på hvilken fig. 1 er et sidebillede af en del af et bjælke-30 eller pladeelement ifølge opfindelsen, fig. 2 et sidebillede af elementet i fig. 1 efter at det er knækket, fig. 3 et sidebillede et af bjælkeparti, der skal danne et portal- eller rammehjørne, 35 fig. 4 samme bjælkeparti efter knækning, fig. 5 et sidebillede af en del af et bjælkeelement i en anden udførelsesform, 8The invention will now be explained in more detail by means of some embodiments and with reference to the drawing, in which fig. 1 is a side view of a portion of a beam or sheet member according to the invention; FIG. 2 is a side view of the element of FIG. 1 after it is broken; FIG. 3 is a side view of a beam portion forming a portal or frame corner; FIG. 4 shows the same beam section after cracking; FIG. 5 is a side view of a portion of a beam member in another embodiment;

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fig. 6 et sidebillede af et parti af bjælkeelementet i fig. 5 i større målestok, fig. 7 et snit efter linien VII-VII i fig. 6 fig. 8 et til fig. 6 svarende billede efter 5 knækning af elementet, fig. 9 et sidebillede af et armeringsaggregat ifølge opfindelsen, fig. 10 et endebillede af armeringsaggregatet i fig. 9, 10 fig. 11 et sidebillede af en del af et bjælke element med et armeringsaggregat i en anden udførelsesform, fig. 12 et snit efter linien XII-XII i fig. il og 15 fig. 13 et sidebillede svarende til fig. 11 ef ter knækoperationen.FIG. 6 is a side view of a portion of the beam member of FIG. 5 on a larger scale; FIG. 7 is a sectional view taken along line VII-VII of FIG. 6 FIG. 8 is a view of FIG. 6 shows a similar image after 5 cracking of the element; FIG. 9 is a side view of a reinforcement assembly according to the invention; FIG. 10 is an end view of the reinforcing assembly of FIG. 9, 10 FIG. 11 is a side view of a portion of a beam member with a reinforcing assembly in another embodiment; FIG. 12 is a sectional view taken along line XII-XII of FIG. 1 and FIG. 13 is a side view similar to FIG. 11 after the crack operation.

Fig. 1 viser en del af et bjælke- eller pladeelement af strengbeton, der er fremstillet ved, at armeringstråde 6 er opspændt retliniet gennem en stø-20 beform på hvis bund der forud for betonudstøbningen er anbragt et kileformet udfyldningsstykke 13, og hvori der endvidere er placeret to armeringsbøjler 7. Fig. 1 viser et udsnit af bjælkeelementet i et trin af fremstillingsprocessen, hvor betonen er istøbt og hærdet og 25 armeringstrådene 6 er afspændt. Udfyldningsstykket danner i elementet en kileformet udsparing, som går ind til armeringstrådene 6, og som har sider 5.FIG. 1 shows a portion of a reinforced concrete beam or slab element manufactured by reinforcing the reinforcing threads 6 straight through a casting mold on the bottom of which, prior to the concrete casting, is placed a wedge-shaped filling piece 13 and in which it is further located two reinforcing brackets 7. FIG. 1 shows a section of the beam element in a stage of the manufacturing process where the concrete is cast and hardened and the reinforcing wires 6 are relaxed. The filling piece forms in the element a wedge-shaped recess which goes into the reinforcing wires 6 and which has sides 5.

Ved et løft i bjælken i nærheden af udsparingen i en sådan retning at udsparingen har tendens til at 30 lukke sig, påføres bjælketværsnittet ved udsparingen et så stort bøjningsmoment, at bjælken knækker, hvorved der fremkommer en revne eller åbning begrænset af brudflader 8. Ved en yderligere løftning af bjælkens knækparti i forhold til bjælkeenderne, drejes de to bjælke-35 dele 2, 3 på hver sin side af brudstedet en ønsket vinkel i forhold til hinanden. Herefter fastholdes 9By a lift in the beam near the recess in such a direction that the recess tends to close, the beam cross-section of the recess is applied such a large bending moment that the beam breaks, thereby producing a crack or opening limited by fracture surfaces 8. further lifting the beam portion of the beam relative to the beam ends, the two beam members 2, 3 on each side of the breaking point are rotated at a desired angle to each other. Then 9 is retained

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bjælken, og der udstøbes som indikeret i fig. 2 beton 9 i åbningen mellem brudfladerne 8.the beam, and cast as indicated in FIG. 2 concrete 9 in the opening between the fracture surfaces 8.

Fig. 3 viser en del af et rammeelement fremstillet som et i hovedsagen retliniet strengbetonelement i 5 princippet som bjælkeelementet vist i fig. 1, men med den forspændte armering 6 placeret ved elementets overside. På begge sider af et udfyldningsstykke 13 er der indstøbt forankrede stålbeslag 20 i betonen. Udfyldningsstykket 13 forbliver på sin plads, indtil 10 knækket skal udføres og indgår indtil da i elementets trykside under lagring og transport. Under denne etape tjener beslagene 20 til kraftoverføring mellem udfyldningsstykket 13 og betonen.FIG. 3 shows a part of a frame element made as a generally rectilinear reinforced concrete element in principle 5 as the beam element shown in FIG. 1, but with the biased reinforcement 6 located at the upper side of the element. On both sides of a filling piece 13, anchored steel brackets 20 are embedded in the concrete. The filling piece 13 remains in place until the crack 10 is to be performed and until then is included in the pressure side of the element during storage and transport. During this stage, the brackets 20 serve to transmit power between the filling piece 13 and the concrete.

Fig. 4 viser elementet i fig. 3 efter gennemfø-15 relse af knækoperationen. Denne kan udføres som beskrevet for bjælkeelementet vist i fig. 2. Efter knæknin-gen holdes elementdelene 2 og 3 fast i den nye stilling ved sammensvejsning eller sammenboltning af beslagene 20. Den ved knækningen dannede, udvendige 20 reces kan om ønsket udstøbes eller udfyldes på et senere tidspunkt med beton 9 eller andet materiale.FIG. 4 shows the element of FIG. 3 after performing the cracking operation. This can be carried out as described for the beam element shown in FIG. 2. After the cracking, the element parts 2 and 3 are held in the new position by welding or bolting the brackets 20. The outer 20 formed by the cracking can, if desired, be cast or filled later with concrete 9 or other material.

Rammeelementet i fig. 4 kan være et delelement af en 3-charnier-ramme, en såkaldt halvramme, med tagdelen 2 og søjledelen 3. Elementet kan også være en 25 2-charnier-ramme, idet fig. 4 da illustrerer det ene af to symmetrisk anbragte knækpunkter. Evt. kan elementet have et tredie knækpunkt midt i elementdelen 2 analogt med fig. 2.The frame element of FIG. 4 can be a sub-element of a 3-charnier frame, a so-called half-frame, with the roof part 2 and the column part 3. The element can also be a 2-charnier frame, fig. 4 then illustrates one of two symmetrically arranged break points. Possibly. For example, the element may have a third breaking point in the middle of the element portion 2 analogous to FIG. 2nd

Fig. 5 viser et bjælkeelement fremstillet som 30 det i fig. 1 viste men med to indstøbte forstærkningsplader 11, der ligger an mod hinanden, og som i området ved armeringstrådene 6 er enkelt krumme, så de under knækningen af bjælken kan rulle på hinanden. Figuren viser yderligere et mellem forstærkningspladerne 35 li indsat første udfyldningsstykke 13 og et tværskot 14 af beton. Tværskottet udtages før knækningen af 10FIG. 5 shows a beam element made as shown in FIG. 1 but with two embedded reinforcing plates 11 which abut one another and which in the region of the reinforcing wires 6 are single curved so that during the cracking of the beam they can roll on each other. The figure further shows a first filler 13 inserted between the reinforcing plates 35l and a concrete bulkhead 14. The transverse bulkhead is removed before the crack of 10

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bjælken, og der fremkommer derved veldefinerede "brudflader" 8 i bjælken, samtidig med at der opnås en veldefineret placering af knækningsstedet. Som vist mere detaljeret i fig. 6 og 7 er der under armerings-5 trådene 6 indstøbt et andet udfyldningsstykke 15 af eksempelvis stift plastskum og med facon som en dobbelt kile, idet dets underside er udformet som to skrå flader 12, der hver er krummet som en del af en cylinderflade.the beam, thereby providing well-defined "fracture surfaces" 8 in the beam, while achieving a well-defined location of the cracking site. As shown in more detail in FIG. 6 and 7, a second filling piece 15 of, for example, rigid plastic foam and with the shape of a double wedge, is molded under the reinforcing threads 6, the underside of which is formed as two inclined faces 12, each curved as part of a cylinder surface.

10 Fig.8 viser, hvorledes der i bjælken i fig. 5-7 efter knækningen er indsat et passtykke 10 af beton i åbningen mellem fladerne 8 i bjælkedelene 2 og 3 på hver sin side af knækpunktet. De til fladerne 8 svarende flader af tværskottet 14 og passtykket 10 15 er støbt under anvendelse af samme formsider, så at passtykket 10's sider kan danne tætte fuger med fladerne 8. Til fastholdele af passtykket 10 kan der i ovennævnte formsider være udført noter, således at fladerne 8 og de tilsvarende flader i passtykket er 20 låst i forhold til hinanden, eller der kan være udformet spor i samlefladerne, i hvilke spor der senere istøbes beton.10 FIG. 8 shows how in the beam of FIG. 5-7 after the cracking, a pass piece 10 of concrete is inserted into the opening between the surfaces 8 of the beam portions 2 and 3 on each side of the cracking point. The surfaces corresponding to the faces 8 of the transverse bulkhead 14 and the passport 10 are molded using the same mold sides, so that the sides of the passport 10 can form dense joints with the surfaces 8. For retaining of the passport 10, notes may be made in the above-mentioned form sides, so that the faces 8 and the corresponding faces in the passport 20 are locked relative to each other, or grooves may be formed in the connecting faces, in which tracks are later poured concrete.

Af fig. 8 ses også, at armeringstrådene 6 under knækningen har presset det andet udfyldningsstykke 25 15 helt sammen og herefter trykker mod betonfladerne 12, der nu danner en kontinuerlig jævn flade, hvorved armeringstrådene har fået et jævnt cirkelbueformet forløb gennem knækzonen. Endvidere ses, at der ved sammenpresningen af det andet udfyldningsstykke 15 opstår 30 et hulrum 16 over armeringstrådene. Dette hulrum kan senere udstøbes med tyndtflydende støbemasse, f. eks. cementmørtel gennem en støbekanal 17 i passtykket 10.In FIG. 8 it is also seen that during the cracking the reinforcing wires 6 have pressed the second filling piece 15 completely together and then pressing against the concrete surfaces 12, which now form a continuous smooth surface, whereby the reinforcing wires have a smooth circular arc through the cracking zone. Furthermore, it is seen that upon compression of the second filling piece 15, a cavity 16 is formed over the reinforcing wires. This cavity can later be molded with thin liquid molding material, for example cement mortar through a casting channel 17 in the fitting piece 10.

Det i fig. 9 og 10 viste armeringsaggregat er 35 udført i stål som to sammenhængende, halvparter samlet ved en svejsning 18, som ikke er kraftigere, end at 11The FIG. The reinforcing assembly shown in Figures 9 and 10 is made of steel as two consecutive half-pieces assembled by a welding 18 which is not more powerful than 11

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den brydes under knækningen. Armeringsaggregatet er udført som en samlet enhed indeholdende forstærkningsplader 11, anlægsflader 12 for armeringstrådene efter knækning og tværarmeringer 7 samt indbyggede udfyld-5 ningsstykker 13 og 15.it breaks during the cracking. The reinforcing assembly is designed as a single unit containing reinforcing plates 11, abutment surfaces 12 for the reinforcing wires after cracking and cross reinforcements 7, and built-in filling pieces 13 and 15.

Det samlede aggregat placeres i støbeformen, inden armeringstrådene trækkes og spændes. Tværarmerin-gerne 7 er udformet som åbne bøjler med forankringsplader 19 foroven for at lette placeringen af 10 armeringstrådene. Forankringspladerne 19 fungerer samtidig som styr for tværskottet 14.The assembled assembly is placed in the mold before pulling and tightening the reinforcing wires. The cross reinforcements 7 are designed as open shackles with anchor plates 19 at the top to facilitate the placement of the 10 reinforcing wires. The anchor plates 19 simultaneously act as guides for the transverse bulkhead 14.

I fig. 11 og 12 er vist en del af en strengbe-tonbjælke 2,3 med et indstøbt armeringsaggregat af en alternativ type. Forstærkningsdelen eller armeringssty-15 ret 11 er her et gennemgående stålprofil, der har U-formet tværsnit og hvis ender er solidt indstøbt i hver sin elementdel 2 og 3. Profilet er dimensioneret til at bære armeringstrådenes fulde forspændingskraft og har ribber 11a til at medvirke ved overføring af forspæn-20 dingslasten mellem armeringsstyret og betonen og tvær-armeringerne 7 er svejst til styret. Alt efter den ønskede knækvinkels størrelse er der indsat et eller flere udfyldningsstykker 13 med tilhørende tværskot 14.In FIG. Figures 11 and 12 are shown part of a string concrete beam 2.3 with an embedded reinforcing assembly of an alternative type. The reinforcing member or reinforcing guide 11 is here a continuous steel profile having a U-shaped cross-section and whose ends are solidly embedded in each element part 2 and 3. The profile is designed to support the full biasing force of the reinforcing wires and has ribs 11a to assist in transfer of the bias load between the reinforcement guide and the concrete and the cross reinforcements 7 is welded to the guide. Depending on the size of the desired crack angle, one or more filling pieces 13 with associated cross-bulkhead 14 are inserted.

25 Fig. 13 viser det samme element efter udførelse af knækoperationen, som iøvrigt kan tænkes gennemført med samme midler som tidligere beskrevet, udfyldningsstykkerne 13 er i dette tilfælde udført af et holdbart og elastisk materiale, f.eks. gummi, som efterla-30 des i elementet og danner en jævnt krum overgang mellem elementdelene 2 og 3 og et mellem tværskottene liggende stykke 22. Armeringsstyret vil under knækoperationen blive kolddeformeret gennem knækzonerne. Til slut indsættes passtykkerne 10, som evt. kan låses i 35 position ved svejsning mellem indstøbte beslag 23 og forankringspladerne 19. En sådan låsning kan også op-FIG. 13 shows the same element after performing the cracking operation, which may otherwise be carried out with the same means as previously described. The filling pieces 13 are in this case made of a durable and resilient material, e.g. rubber, which is left in the element and forms an evenly curved transition between the element parts 2 and 3 and a piece 22. located between the transverse bulkheads. During the cracking operation, the reinforcement guide will be cold deformed through the crack zones. Finally, the pass pieces 10 are inserted, which may be inserted. may be locked in position by welding between embedded fittings 23 and the anchor plates 19. Such locking may also be provided.

Claims

12 DK 159794 B is achieved by an appropriate shaping of the corresponding faces in the butt joints between the element parts and the pass pieces. The reinforcing wires abut the bottom of the guide, and the cross-section of the guide is designed so that its center of gravity is precisely positioned relative to the reinforcing wires, so that a desired adjustment of the bias in the crack zones can be made during bending. 10 PATENT REQUIREMENTS

A method of making a beam or sheet member of reinforced concrete, wherein the method of reinforcing the wires is substantially straightened through a mold and the member is molded with a substantially rectilinear longitudinal profile, characterized in that at least one location in the member (1) is molded. a first filling piece (13) extending from one surface of the element (1) substantially to the reinforcing wires (6), the first filling piece (13) being removed as needed after curing and prestressing the concrete, that the element (1) ) after curing and prestressing of the concrete, while maintaining the prestressing over the full length of the element (1), at a predetermined angle, such intermittent rotation of the element portions (2,3) on each side of the said site is broken, the recess (4) formed by the first filling piece (13) is reduced and the element parts (2,3) on each side of the first filling piece (13) are fixed are held at the predetermined angle relative to each other.

Method according to claim 1, characterized in that the opening formed between the fracture faces (8) facing each other of the element parts (2, 3) on each side of said site is molded with concrete or filled. with a passport piece (10) attached to the element parts (2,3).

Method according to any one of the preceding claims, characterized in that in the element 5 (1) next to the first filling piece (13), a transverse bulkhead (14) extends from the opposite surface of the element (1) towards the reinforcing wires (6). ) and that the transverse bulkhead (14) is removed during the cracking of the element (l) ·

Method according to claim 3, characterized in that the transverse bulkhead (14) and the pass piece (10) are molded e.g. of concrete using one and the same set of form sides.

Method according to any one of the preceding claims, characterized in that on each side of the breaking point, cross reinforcement (7) is embedded in the element (1).

Method according to any one of the preceding claims, characterized in that on each side of the first filling piece (13) a reinforcing element (11) is embossed with surfaces which abut one another during the cracking operation.

Method according to claim 6, characterized in that reinforcing elements (11), which are simultaneously reinforcement guide (12), are used to hold the reinforcing wires (6) in a specific location different from the position they have at the ends of the element. .

Method according to any one of the preceding claims, characterized in that a second filling piece (15), preferably consisting of a deformable material and suitably with a cross-reinforcement, is embedded in the reinforcing guide (12), between the reinforcing wires (6). ) and the first filling piece (12).

A reinforcing assembly for use in the method according to any one of the preceding claims, characterized in that it is made in two equal halves for embedding on either side of the breaking point, which halves are mutually assembled prior to the embedding with a connection (18) which ensures an exact mutual position during casting and vibration but is not stronger than breaking when the cracking operation is initiated.

Reinforcement assembly for use in the method according to any one of claims 1-8, characterized in that it is made in one piece (11) having a box-shaped or un-shaped cross-section and whose ends are molded over a suitable length. on either side of the breaking point.