BEARING MEANS

Abstract: A bearing means (2) intended for bearing coaction between a supporting structural component and a supported structural component, said means being adapted for casting into one of said structural components and for coaction with a bearing member (23). The bearing means (2) comprises at least one substantially U-shaped section, the base (3) of which provides the bearing surface against the bearing member, and the legs (4) of which constitute fastening means for anchoring means (14) and stiffeners (6), which transmit bearing force to the concrete surrounding the bearing means and to adjacent reinforcement.

Description: BEARING MEANS The present invention relates to a bearing means intended f bearing coaction between a supporting structural component and a component that is supported therewith, said means being adapted for casting into one of said structural components and for coaction with a vertically arranged bearing member having great height in relation to its width and arranged in or on the other of said structural components. As intended here, a supporting structural component may be a column, wall or beam, while a supported structural component may be some form of beam, often a facade element, or a so-called "windowbac " . A bearing member of the kind intended here is often a steel flat with its face vertical, a so-called knife-edge bearing. A knife-edge bearing of a type in use is a steel flat with its face vertical which is cast into and anchored in a column. The flat is disposed to project at right angles from the sides of the column and is used as a bearing bracket for beams with so-called hidden bearings. The beam ends in such cases are formed -with slots in the concrete corresponding to the dimensions of the project¬ ing flat together with required tolerances. The slots are open from the beam end and a distance inwards on the underside of the beam, and are upwardly defined by a transversely positioned steel section cast into the concrete beam, the bottom surface of this section serving as supported bearing surface for the steel flat bracket in the column. The steel section in the beam is joined or fastened to so-called suspension reinforcement, which takes the bearing force further to the reinforcement zone of the concrete beam cross section, where the suspension reinforcement is anchored. After erection it is usual for the space between the steel flat bracket and the defining surfaces of the beam slot to be filled with a curing casting composition so that the flat is laterally stabilized against buckling when it is loaded. The invention primarily has the object of eliminating the suspension reinforcement and the transversely placed steel section (the yoke) cast into the beam. In accord¬ ance with the invention this takes place by the suspen¬ sion reinforcement and yoke being replaced by a single bearing means, comprising one or more interconnected U-sections, preferably made from steel. In using the bearing means in a supported beam or the like, it is cast into the end of a concrete beam in the direction thereof, with its open longitudinal parts opening substantially flush with the underside of the beam or close to the plane of the underside, and with an open transverse end at the end surface of the beam. The U-shaped section forms a slot in the beam end, the in- ternal dimensions of the slot together with increments for tolerances being adapted to the exterior dimensions of the "knife bracket" in a supporting bearing. The inner surface of the closed longitudinal part or web of the U section thus forms a bearing surface for the support- ed beam. The bearing means can be provided with force-trans¬ mitting means, which directly, e.g. by welding, and/or indirectly via flanges or stiffeners joined to the U section, surround and/or connect the means to longitudinal reinforcement in the beam end. In using the bearing means in a column or a like support¬ ing structural component, it is cast into the com¬ ponent at an optional height and in an attitude which is upside down in relation to the attitude it has in a supported structural component. The characterizing features of the invention are dis¬ closed in the accompanying claims. The end of the U section facing away from the beam end is preferably wholly or partially closed off using a plate sti . ffener, which also functions wholly or partially as end formwork of the slot when the beam is manufactured. A preferred embodiment is a U section or. interconnected U-sections which have been folded into a U shape from a flat steel blank, the thickness of which can vary from 2 to 20 mm or more. The U sections can be made with out¬ wardly projecting flanges (the £ - cross-section) and in cases where there are several U sections side by side they are suitably joined together via the abutting flanges In fabricating ..the bearing means from flat steel blanks, flaps can be folded out to about 90 to the longitudinal direction of the U section from its leg portion and/or the mentioned flanges, and with the aid of these flanges the bearing means can be joined directly or indirectly to the beam reinforcement in a concrete beam. Bearing means cast into beam ends in accordance with the invention to provide hidden bearings signify, apart from their being able to be manufactured efficiently from simple blanks of flat steel, a number of unique technical effects and possibilities: The U section is entirely or partially the formwork for the bearing slot when the beams are cast; similar bearing means to those for the supported bearings in beams may also serve as supporting bearings in such as columns, whereby the inventive concept is more universally applicable; - apart from the usual welded connection to anchoring means, the U section can be provided with flanges and/or flaps, which can be caused to join onto and / ' or surround the longitudinal beam reinforcement in the bearing zone, whereby the usual so-called sus¬ pension reinforcement in hidden bearing can be eliminated, and the resulting bearing means can be made to function as transverse end reinforcement; - if required, the bearing means can be directly connected for transmission of very large tensile forces to the longitudinal reinforcement in a beam; - after erecting a beam on a supporting knife edge bracket the bearing means is accessible for connect¬ ing the bracket to ' the means by welding, whereby the mentioned large tensile forces can be transmitted to the supporting structural component. The invention will now be described in the following with reference to the accompanying drawings, on which - Figure 1 is a perspective view of a beam end with a first embodiment of a bearing means in accordance with the invention, - Figure 2 is a perspective view of a beam end with a second embodiment of a bearing means in accordance with the invention, - Figure 3 is a section through the beam in Figure 2 to a smaller scale, - Figure 4 is a perspective view of a third embodiment of a bearing means in accordance with the invention, - Figure 5 is a plan seen from above of the bearing means according to Figure 4, - Figure 6 is a development of the blank for the bearing means in Figures 4 and 5, - Figure 7 is a longitudinal section along the line VII- VII in Figure 8 of a beam end with a fourth embodiment of a bearing means in accordance with the invention, - Figure 8 is a section in plan along the line VIII-VIII in Figure 7, - Figure 9 is a perspective view of a beam end with a fifth embodiment of a bearing means in accordance with the invention, - Figure 10 is a perspective view of an application of the invention between a column and a facade element, the bearing means being placed in the column, " - Figure 11 is a detail of the facade element of Fig. 10, the bearing means being situated in the element, - Figure 12 is a perspective view of a sixth embodiment of a bearing means in accordance with the invention cast into the top of a column, - Figure 13 is a perspective view of a seventh embodiment of a bearing means in accordance with the- invention, adapted for casting into a column and - Figure 14 is a perspective view of an eighth embodiment of a bearing means in accordance with the invention adapted for casting into a column, the view also showing the end of a knife edge bearing intended for coaction with the bearing means. Figure 1 is a parallel perspective view of the lower part of a concrete beam end 1 with a cast-in U-shaped steel section 2, which forms an ' open slot 7 in the beam end 1, the slot being defined by the legs 4 and base 3 of the U section, the bottom surface of the base 3 being the bearing surface of the supported element 1 against an unillustrated flat steel bracket, there also being shown a plate end stiffener 6. The legs 4 of the U section are joined to the base 3 and stiffener 6 by welds 5 and to a reinforcement rod 14 by welds 5' . Figure 2 is a parallel perspective view of a bearing means 8 made integrally in a U-shaped cross-section for the greater part of its length, with base 3 and legs 4. The means is cast into a beam end 1 with a recess 10 on its underside, in which opens out the slot 7 of the means. The means is defined at its end facing away from the beam end by a web portion folded inwards from one of the legs and forming a transverse stiffener 6' joined to the other leg 4 ' by a weld 5. The lower leg portions are both folded outwards 90° to form transverse flaps 1T, which are suitably provided with cutouts 12 forming seats for unillustrated tensile reinforcement rods. When the beam is cast, the recess 10 and space 13, at least under the stiffener 6', are filled with formwork. Figure 3 is a cross section of the lower part of the beam according to Figure 2, the section being taken through the inward end of the U section. From the Figure will be seen the folded-in stiffener 6' with the weld 5 against the other leg part 4 ' , and the outwardly folded flaps T1, which close round a part of the longitudinal main reinforcement 15. Figure 4 is a parallel perspective view of a U-shaped bearing means 8 with base 3, legs 4 and outwardly folded flange parts 16 and a plate stiffener 6 welded between the legs 4 at the inner end of the U section. The base 3 can be suitably provided with an opening 17 for accommodating an abutment or dowel on a coacting flat bracket. Flaps have been folded up 90° from the inner ends of the flanges 16, and are welded by welds 5 to the legs 4, whereby the ability of the rest of the flange parts 16 to transmit bearing force to the concrete is greatly improved. By at least a part of the reinforce¬ ment rods 15 at the beam end being placed in the cutouts or seats 12 in the flaps 18 the bearing means will function as end transverse reinforcement in the beam end and can thus replace horizontal transverse reinforcement which could otherwise be necessary. Figure 5 is a plan view seen from above of a bearing means similar to the one according to Figure 4, although with the difference that further parts of the flanges 16 are folded upwards into flaps 18' at the outward end of the means . These flaps are also welded to the legs 4 with welds 5 for the purpose of further increasing the effectiveness of the connection between the means and reinforcement 15 in respect of gripping round it and anchoring it. The flaps 18' , with their positions close to the beam end itself are well suited as support plates for pre- or after-stressed reinforcement anchorage of the screw, tapering sleeve or shims type. Figure 6 illustrates a development of a steel " flat blank, from which the mean ' s according to Figure 5 can be fabric¬ ated by punching, sawing, folding and supplementary welding. Accordingly, the cutouts or reinforcement seats 12 are stamped out and slits 20 are sawn for flaps 18, 18' and stiffener 6, the U-shaped section 8 then being produced with the flanges 16 by folding about folding lines 19, while flaps and stiffeners are folded about the folding lines 19' . Figures 7 and 8 are respectively a longitudinal section and a plan section through a bearing means comprising two U-shaped sections 8 similar to the one according to Figure 2, the sections being united by a common web 21 between the opposing legs 4 of the U 'Sections. A flap 22 of the flange 21 is folded up 90 nearest the beam end and welded to the legs 4 by welds 5. Both the flap 22 and flaps 11 (cf Figure 2) can have cutouts or seats 12 for reinforcement 15 and together with the welded flaps 6' they give transverse stiffening to the whole bearing means. The means is cast into the beam end 1 flush with the bottom of a recess 10, and has been supplemented by vertical recesses 25, which are partially defined by the flaps 6' , bases 3' and legs 4' of the U sections. The bearing brackets 23 from the supporting structural componen 27 have an extension 24 to which a vertical dowel 26 is welded, and which is inserted in the space 25 on erection. The recess 10, spaces 25, re¬ maining space in the slots 7 and possibly also the gap 28 between beam end and supporting structural component are finally filled with a curing casting composition via a duct not illustrated here, and against unillustrated sealing members. Figure 9 is a parallel perspective view of a bearing means cast into the beam end 1 and comprising two U-shaped sections 8 united by a common web 21 therebetween and with outer flanges 16. Each flange 16 is either folded up along its longitudinal free edge 31 or is longitudinal¬ ly stiffened by having a reinforcement rod 32 welded to it. The slots 7 are defined at the end of the U-section facing away from the end of the beam by plate stiffeners 6. Hori¬ zontal end transverse reinforcement 29 above the means is cast into the concrete and the beam is also provided with conventional vertical stirrup reinforcement 30 spaced from the inner end of the bearing means. The greater part of the longitudinal main reinforcement 15 of the beam 1 is placed within the space between the two U sections 8, whereby this reinforcement will be surrounded and carried by the bearing means, which can be further anchored to the -concrete by having reinforcement rods 14 welded to it, if necessary. Figure 10 is a parallel perspective view of a supporting column 27 and a supported beam 32 with an L-shaped cross- section, the beam being a so-called windowback and having a bearing surface 45 for an unillustrated floor structure. The supporting bearing in the column 27 comprises a cast-in U section 33 with a steel flat 34 welded to the ends of the legs of the section 33 by welds 5, the project¬ ing portions of the flat 34 forming flange parts 34' enablin the means to transmit forces from the flat force trans¬ mission member 23. For transmitting horizontal tensile forces between the element 32 and column 27 or an unillust¬ rated element on the other side of the column, there is a horizontal hole 43 in the column 27, through which a bolt 44 passes, the bolt being anchored to the L section 42 by a nut, this section being in turn welded to an attachment plate 41 cast into and anchored ' to the end of the element 32. Figure 11 is a detail of a bearing between a column and a windowback element of " the type illustrated in Fig. 10. However, the arrangemant here is such that the bearing means 8 is situated in the supported element 32 instead of in the column. The force transmission member or "knife- edge bearing" 23 is accommodated by the bearing means 8, which has flanges 16 anchored in the concrete in the lower portion of the element 32 by reinforcement rods 14 welded to the flanges. After erection the bearing plate 23 can be 'welded along the length of the U section to the bearing means at the underside of the beam, and the tolerance space in the slot 7 can be filled with a curing casting composition. Figure 12 illustrates the use of a bearing means with U-shaped sections 8 joined together- via a web portion 21 in a supporting bearing at the top 45 of a column. The knife-edge bearing flat 23, which is anchored in an unillustrated connecting beam in this case, has its underside engaging against the base 3 of the U section, and can optionally be attached to the legs 4 by welds 5". The bearing force is transmitted to the column top 45 via the. legs 4 of the U-section from the web portion 21 and the reinforcement rods 46 welded to the outer legs 4 by welds 5' . Possible splitting-off effects from bearing forces are taken up by end stiffcncrs 6 and transverse reinforcement 47. Figure 13 illustrates a bearing means which can be cast into a concrete column at optional height with the U-shaped sections 8 open towards at least one unillustrated column side surface and where, for example, two U sections are joined together by the web 21. The U sections can be provided with flanges 50 or 16 with downwardly folded flaps 18, to which transverse reinforcement 49 in the column can be connected. The flange part 50, which is a separate detail, is extended over and welded to the U section, so that it constitutes formwork for a rect¬ angular slot in the column, in which the knife-edge bearing 23 and shim plates 51 for filling up free space can be inserted. The flange 16 is folded out from the outer leg 4. Figure 14 illustrates a bearing means 8 for a supporting bearing which is adapted to be cast on edge into a column at optional height with at least one of its openings open¬ ing out into the plane of a column side. The means has a U-shaped section comprising base 3 and legs 4 and 4", as well as a flange part 52 folded inwards from the leg 4, this part being welded to the leg 4' . A steel supporting plate 55 has been joined by tack welds 5" to the outer surface of the base 3. Reinforcement rods 46, preferably of ribbed type, are welded to the legs 4 and 4" by welds 5', and extend upwards in the column. The bearing forces are transmitted to the base 3 in the supporting bearing means via a steel block 53 engaging against the base 3 at the bottom of the bearing means and welded to the latter at its front edge, with the object of placing the compression center as near to the side of the column as possible. When fitting the knife-edge bearing 23, which can be anchored in an unillustrated, supported, structural element, the abutment 54 is placed behind the block 53. The bearing means can be made such as to pass all the way through the column cross-section between two opposing sides of the column. In such a case, a bearing plate form¬ ing brackets on either side of the column can be taken through the opening in the bearing means such as to be supported by the blocks 53.

Claims: CLAIMS 1. A bearing means (2;8) intended for bearing coaction between a supporting structural component and a supported structural component, said means being adapted for casting into one of said structural components and for coaction with, vertically arranged bearing member (23) having great height in relation to its width and arranged in or on the other of sai structural components, c h a r a c t e r i z e d i n that the means comprises at least one substantially U-shaped section the base (3) ofwhich provides the bearing surface for the bearing member (23) and the legs (4) of which constitute attachment means for anchoring means ( 14, 15; 46, 49 ) and stiffeners (6,6* ;22) which transmit bearing force to the concrete surrounding the bearing means and to adjacent reinforcemen . 2. Bearing means as claimed in claim 1, c h a r a c¬ t e r i z e d in that its legs (4) have flanges (16. ? 21 ) folded out from the plane of the respective leg. 3. Bearing means as claimed in claim 2, comprising a plurality of interconnected U-shaped sections, c h a r¬ a c t e r i z e d in that the sections are joined via a web or webs (21). 4. Bearing means as claimed in any one of claims 1-3, c h a r a c t e r i z e d in that anchoring reinforcement rods (14,15) are fastened to the legs (4) and/or flanges (T6). 5. Bearing means as claimed in any one of claims 1-4, c h a r a c t e r i z e d in that the U-shaped section at its end facing away from its open end is completely or partially closed off by a plate stiffener (6;6 r ) . 6. Bearing means as claimed in claim 5, c h a a c¬ t e r i z e d in that the stiffener (6,6') is a part of a leg ( 4 ) . 7. Bearing means as claimed in any one of the preceding claims, c h a r a c t e r i z e d in that outside the U section there are arranged stiffeners ( 18;22) joined to the legs (4) and/or the flanges (16). 8. Bearing means as claimed in claim 7, c h a r a c¬ t e r i z e d in that the stiffeners ( 18;22) comprise leg and/or flange portions. 9. Bearing means as claimed in claim 7 or 8, c h a r- a c t e r i z e d in that the stiffeners (18;22) have seats in the form of cutouts (12) or holes for reinforce¬ ment rods (15). 10. Bearing means as claimed in any one of the preceding claims, c h a r a c t e r i z e d in that the U-shaped section (2;8) or a plurality of interconnected such sections is or are made integrally by folding a flat plate blank.

Inventors: BERNANDER KARL GUSTAV, BERNANDER, KARL, GUSTAV
Applicants: STRAENGBETONG AB, AB STRAENGBETONG
Application year: 1988
Main classification: E04B1
IPC codes: E04B1