Classifications

• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
  • E04B5/00—Floors; Floor construction with regard to insulation; Connections specially adapted therefor
  • E04B5/02—Load-carrying floor structures formed substantially of prefabricated units
  • E04B5/04—Load-carrying floor structures formed substantially of prefabricated units with beams or slabs of concrete or other stone-like material, e.g. asbestos cement
  • E04B5/043—Load-carrying floor structures formed substantially of prefabricated units with beams or slabs of concrete or other stone-like material, e.g. asbestos cement having elongated hollow cores
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
  • E04B5/00—Floors; Floor construction with regard to insulation; Connections specially adapted therefor
  • E04B5/02—Load-carrying floor structures formed substantially of prefabricated units
  • E04B5/04—Load-carrying floor structures formed substantially of prefabricated units with beams or slabs of concrete or other stone-like material, e.g. asbestos cement
  • E04B5/06—Load-carrying floor structures formed substantially of prefabricated units with beams or slabs of concrete or other stone-like material, e.g. asbestos cement with beams placed against one another optionally with pointing-mortar
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
  • E04B5/00—Floors; Floor construction with regard to insulation; Connections specially adapted therefor
  • E04B5/16—Load-carrying floor structures wholly or partly cast or similarly formed in situ
  • E04B5/32—Floor structures wholly cast in situ with or without form units or reinforcements
  • E04B2005/322—Floor structures wholly cast in situ with or without form units or reinforcements with permanent forms for the floor edges
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
  • E04B5/00—Floors; Floor construction with regard to insulation; Connections specially adapted therefor
  • E04B5/16—Load-carrying floor structures wholly or partly cast or similarly formed in situ
  • E04B5/32—Floor structures wholly cast in situ with or without form units or reinforcements
  • E04B2005/324—Floor structures wholly cast in situ with or without form units or reinforcements with peripheral anchors or supports

Definitions

• the invention relates to a method for attaching a hollow-core slab to a supporting structure such as a beam.
• the invention further relates to an end attachment of a hollow-core slab and the use thereof.
• Hollow-core slabs are nowadays commonly used in construction engineering.
• HoUow-core slabs are rectangular-shaped slab elements manufactured in an element plant and reinforced with prestressing steel strands, having holes, i.e. hollows in the longitudinal direction of the slab.
• hollow-core slabs are supported at their ends by beams made of steel or reinforced concrete or by a load-bearing wall structure so that the lower surface of the end of the slab rests against the surface of the supporting structure.
• ledge beams are commonly employed where a slab rests on a ledge on a side of the beam, close to the lower edge of the beam. Secure attachment of the hollow-core slab to the supporting structure is ensured by installing at the joint the necessary joint and tie bar reinforcements and filling the gaps between the slab and the beam as well as the end portions of the hollows with cement grout cast on the site.
• a bearer for a hollow-core slab where an end of the hollow-core slab rests on an L-shaped profile. At the ends of the bearer there are support elements by means of which the bearer is supported on adjacent supporting structures.
• the bearer for a hollow-core slab presented in this solution is thus in fact a short beam used when the end of a hollow-core slab is located at an aperture.
• the bearer disclosed is used to transfer the loads of a hollow-core slab thus situated onto hollow-core slabs next to the aperture.
• the hollow-core slabs adjacent to the aperture must be supported from each end on the supporting structures in a conventional way because the solution disclosed cannot be used to transfer loads of a hollow-core slab onto a support structure, such as a beam, at the end of the hollow-core slab.
• the object of the invention is to provide a new method of supporting a hollow-core slab on a supporting structure, especially on a bending beam.
• hollow-core slabs are supported on a supporting structure by means of an end attachment attached to an end of the hollow-core slab.
• the method according to the invention can be used to significantly reduce the disadvantages and drawbacks associated with the prior-art method of installation of hollow-core slabs.
• the basic idea of the invention is as follows: In the method according to the invention a separate end attachment is fixed on one end or both ends of a ready-made hollow-core slab.
• the end attachment comprises a support plate placed against the lower surface of the end portion of the hollow-core slab, a vertical plate attached substantially in vertical position to an edge of the support plate, and brackets by means of which the end attachment and the hollow-core slab attached thereto may be supported on a supporting structure.
• the basic idea of the invention is that when the slab is installed on the site it will not be attached by its end direct to the supporting structure, such as a beam, but the reaction of support of the slab will be transferred onto the beam through the support plate, vertical plate and brackets in the end attachment.
• the end attachment is attached to the end of the hollow-core slab already at the element plant immediately after the slab has been cut.
• An advantage of the invention is that it enhances the operation of the joint between the hollow-core slab and beam because the end attachment provides the hollow-core slab with a fixed and reliable lower support structure.
• the hollow-core slab is always supported by its lower end, as stipulated in the type approval certificate, and no reaction of support can be transferred onto the beam, at least to a significant extent, through the grouting of the end portion of the hollow-core slab.
• Another advantage of the invention is that a hollow-core slab equipped with an end attachment can be supported by many kinds of beam structure since the end attachment can be shaped suitable for different beams.
• the beam need not have a ledge below the hollow-core slab.
• the reaction of support of the hollow-core slab can also be transferred upwards from the lower edge of the beam, say onto the top part of the beam.
• On top of the beam there is more room for the support structure, greater support widths can be used, and the installation of the slab is easier.
• a further advantage of the invention is that it makes the installation work of a hollow-core slab quicker, for a hollow-core slab with an end attachment will not require grouting to the same extent as a hollow-core slab attached using a conven- tional technique. Moreover, the grouting is less important from the point of view of the operation of the joint, so the number of detrimental faults decreases. If necessary, a hollow-core slab may be attached to the beam completely without grouting, which means the structures may be realized so as to be easily disassembled.
• a still further advantage of the invention is that it enhances the load-bearing capac- ity of hollow-core slabs. Because of the end attachment the lower edge of the hollow-core slab is not in direct contact with the bearing beam so that bending in the beam will not cause deformations at the end of the hollow-core slab. Because of the smaller deformations, the bearing capacity of the hollow-core slab is not decreased, which usually happens with hollow-core slabs supported by bending beams.
• a yet further advantage of the invention is that it is simple in structure, low in manufacturing costs and well suited to industrial manufacture.
• Fig. 1 shows by way of example a side view of a hollow-core slab supported on a beam and equipped with an end attachment according to the invention
• Fig. 2 shows by way of example an advantageous embodiment of an end attachment according to the invention depicted at an angle from the front, and
• Figs. 3a to 3e show by way of example some advantageous embodiments of an end attachment according to the invention.
• Fig. 1 shows by way of example in the longitudinal direction a cross section of a hollow-core slab 100 supported on a beam 200 and having an end attachment 1 according to the invention at its end.
• the hollow-core slab is a rectangular-shaped slab-like concrete building component manufactured at a hollow-core slab plant and comprising two substantially parallel sides, two ends, and an upper surface and lower surface.
• the hollow-core slab comprises hollows 102 in the longitudinal direction of the slab as well as longitudinal reinforcements, which usually are prestressing steel strands. Due to the structure of the hollow-core slab the slab is installed in the building practically always in a manner where that surface of the slab which is closer to the main part of the reinforcement of the slab is positioned as the lower surface of the slab.
• the lower surface of the hollow-core slab refers just to that surface of the slab which in a completed building will be the lower surface of the slab.
• the upper surface of the slab refers to the surface opposite to the lower surface.
• the end attachment 1 comprises a support plate 2 placed against the lower surface of the end portion of the hollow-core slab, and a vertical plate 3 attached by its edge or surface to an edge of the support plate.
• the vertical plate is as long as the support plate but it may also be shorter and it may be comprised of two or more separate components.
• the vertical plate is attached to the support plate so that they form an angle which is advantageously a right angle.
• the support plate 2 and vertical plate 3 together form a profile known as an L profile.
• the length of the support plate 2 may be advantageously selected such that it extends, on the lower surface of the hollow-core slab, substantially across the whole width of the hollow-core slab, but the length of the support plate may also be something else than the width of the hollow-core slab.
• the width of the support plate 2 may be selected suitable, however such that the width is at least the support width specified in the type approval certificate of the hollow-core slab.
• the vertical plate 3 comprises brackets bent at an angle from the plane of the vertical plate.
• the brackets which there may be one or more, are elements made of preformed metal plate, bar or pipe, protruding from the plane of the vertical plate and attached at one end or edge to the vertical plate 3, with a second end or edge pointing away from the hollow-core slab.
• the bracket shown in Fig. 1 is a protrud- ing attachment element 4 attached to a beam 200 so that a side of the attachment element is placed, when installed, against a surface 202 of the beam. Furthermore, the end of the attachment element of Fig. 1 is bent at an angle in order to lock the attachment element 4 onto a locking groove 204 in the beam.
• the end attachment 1 further comprises an anchoring element 6 through which the end attachment is attached to the hollow-core slab 100.
• the anchoring element is a rod-like or strip-like protrusion one end of which is attached to the vertical plate 3 and the other end of which extends into a hollow 102 in the hollow-core slab 100.
• the anchoring element may be a solid part or it may be tubular, in which case its hollow inner section may be used e.g. as an installation conduit for electric cables.
• the anchoring element is attached to the hollow-core slab advantageously through grouting 8, i.e. by pouring cement grout in the hollow 102. When the grouting has cured the anchoring element 6 and the whole end attachment are firmly attached to the end of the hollow-core slab.
• plugs 10 shaped to fit the hollow, confining the grouting area to the end section of the hollow.
• These plugs may be separate parts or advantageously plastic or metal parts integral with the anchoring element 6.
• the anchoring element may be attached to the hollow-core slab also without grouting, say, by being mechanically wedged against the walls of the hollow 102.
• the end attachment may be attached to the end of the hollow-core slab also by means of a combination of mechanical attachment and grouting so that the end attachment is first mechanically attached to the end of the hollow-core slab at the hollow-core slab plant, and the hollow-core slab is installed in its place using this mechanical attachment.
• the fastening of the end attachment is completed on the site by means of grouting in which cement grout is injected in the hollow of the hollow- core slab.
• Fig. 2 shows by way of example another advantageous embodiment of an end attachment according to the invention depicted at an angle from the front.
• the end attachment is shown detached from the hollow-core slab 100.
• the end attachment comprises a vertical plate 3 of substantially the same length as the support plate 2, and an attachment plate 5 of substantially the same length as the vertical plate.
• the vertical plate 3 is attached by a first edge to a first edge of the support plate.
• the attachment plate 5, in turn, is attached by a first edge to a second edge of the vertical plate 3 in a substantially horizontal position so that a second edge of the attachment plate points in a substantially opposite direction than the second edge of the support plate 2.
• the end attachment 1 is attached by means of a single attachment plate 5.
• the attachment plate there may additionally be a locking edge 7 bent at an angle from the plane of the attachment plate to lock the end attachment onto the supporting structure, such as a beam 200, if the latter comprises a locking groove 204.
• the end attachment may be manufactured e.g. by forming a single metal plate into a form resembling the Z profile described above or by joining together different metal profiles and/or platelike parts e.g. by welding.
• the end attachment 1 shown in Fig. 2 naturally comprises also the anchoring elements 6 mentioned in the explanation of Fig. 1, used to attach the end attachment to the hollow-core slab 100.
• the anchoring elements which advantageously may be deformed steel bars, are attached by a first end to the vertical plate 3 of the end attachment e.g. by welding.
• Anchoring elements may be attached to the end attachment so that there is an anchoring element in every hollow 102 of the hollow-core slab or only in some of the hollows.
• Fur- thermore there may be more than one anchoring element in one hollow.
• An anchoring element is attached to a hollow 102 in the hollow-core slab by grouting 8, i.e. by pouring cement grout in the hollow.
• the end attachment 1 shown in Fig. 2 may be equipped with stiffener plates 12a attached by a first edge to the support plate 2, and by a second edge, next to the first edge, to the vertical plate 3.
• Stiffener plates can be used to enhance the stiffness of the end attachment and prevent the bending of the support plate under loads coming from the hollow-core slab 100.
• the quantity of stiffener plates can be selected according to the stiffness required of the end attachment. If stiffener plates 12a are used in the end attachment, notches 104 must be made at the end of the hollow-core slab 100 where the stiffener plates are to be attached so that the end attachment may be attached to the end of the hollow-core slab in such a manner that the surface of the vertical plate 3 is placed against the end plane of the hollow-core slab.
• the cross-sectional drawings of the end section of a hollow-core slab shown in Figs. 3a, 3b, 3c, 3d and 3e illustrate, by way of example, some advantageous embodiments of the end attachment according to the invention.
• the end attachment of Fig. 3a includes a small triangular stiffener plate 12a which adds the stiffness of the end attachment and prevents the support plate 2 from bending.
• the end attachment includes a plug 10 attached to an anchoring element 6, with a gasket 11 made from a flexible material attached to the edge of the plug.
• the end attachment is attached to the hollow-core slab through grouting 8 which may fill the end of the hollow, confined by the plug 10, either completely or in part.
• the shape of the attachment plate 5a is an L profile.
• the end attachment comprises a tall rectangular stiffener plate 12b with a planar projection 14 at the upper edge thereof.
• the stiffener plate 12b with the projec- tion 14 forms at the same time an attaching means for the end attachment because now the hollow-core slab with the end attachment can be attached to the supporting structure by the projection 14.
• the stiffener plate 12b the height of which equals the height of the whole hollow-core slab requires that notches 104 for the stiffener plate have to be provided also at the upper edge of the hollow-core slab.
• the end attachment employs a large polygon-shaped stiffener plate 12c comprising a support bracket 16, which supports the attachment plate 5a, and a fixing bracket 18 extend- ing inside a hollow 102 in the hollow-core slab 100.
• the width of the fixing bracket may be equal to or smaller than the diameter of the hollow 102.
• the fixing bracket 18 serves at the same time as an anchoring element 6 so that no separate anchoring element is needed.
• a plug 10 may be attached at the end of the fixing bracket.
• the end attachment comprises two substantially rectangular suspension plates 13, the height of which equals the thickness of the hollow-core slab 100, attached in vertical position at opposing ends of the support plate 2 so that the suspension plates are placed against the sides of the hollow-core slab, i.e. in the seams between adjacent hollow-core slabs in a finished structure.
• the support plate 2 and vertical plate 3 form a single structure but the attachment plate 5b is a separate rectangular flat element located on the upper surface of the hollow-core slab 100, parallel to the plane of the upper surface of the hollow-core slab. The attachment plate 5b.
• the length of which substantially equals the width of the end section of the hollow-core slab is connected to the support plate 2 through the suspension plates 13 so that one suspension plate is attached by a first end to a first end of the support plate 2 and by a second end to a first end of the attachment plate 5b.
• the other suspension plate is attached by a first end to a second end of the support plate and by a second end to a second end of the attachment plate 5b.
• the support plate, attachment plate and suspension plates thus form a ring-like structure around the whole end section of the hollow-core slab.
• the stiffener plates 12a depicted in Fig. 3a it is also possible to use the stiffener plates 12a depicted in Fig. 3a.
• the end attach- ment comprises, in addition to the anchoring element 6, a second anchoring element 6b.
• the both anchoring elements are located in one and the same hollow 102 in the hollow-core slab.
• the lower anchoring element 6 in the drawing is attached by a first end to the vertical plate 3 and by a second end to the plug 10.
• the upper anchoring element 6b in the drawing which is substantially longer than the lower anchoring element, is also attached by a second end to the plug.
• the upper anchoring element 6b is, however, so long that its first end extends longer than the plane of the vertical plate 3 in the direction of the hollow-core slab.
• the upper anchoring element is attached at the area between the first and second end to the attachment plate 5c and thus also functions as a support for the attachment plate at the same time.
• the attachment plate 5c may be a straight flat element, as shown, or it may be an L profile.
• a hollow-core slab 100 is first manufactured using a manufacturing method for hollow-core slabs.
• An end attachment according to the invention is then attached to an end of a completed hollow-core slab.
• a completed hollow-core slab refers in this description to a hollow-core slab cast in a hollow-core slab machine onto a casting table and cut into size.
• the end attachment may be attached to the end of the hollow-core slab on the building site, in storage or advantageously at the element plant immediately after the slab has been cut.
• the hollow-core slab with the end attachment is installed on the building site so that the support brackets, i.e. the attachment elements 4 or the attachment plate 5. are attached to a supporting structure such as a beam 200.
• the brackets are arranged in the end attachment so that the hollow-core slab may be supported by means of the end attachment on a supporting structure, such as a beam, located specifically at the end of the hollow-core slab.
• This attachment may be advanta- geously realized so that a surface of the attachment element 4 or attachment plate 5 is placed against a surface of the supporting structure 202.
• the hollow-core slab itself rests by its lower surface on the support plate of the end attachment and the loads of the hollow-core slab are transferred to the supporting structure through the end attachment.
• the gap between the supporting structure and the end section of the hollow-core slab may be filled with cement grout, if necessary.
• the method and end attachment according to the invention can be used to support all those hollow-core slabs that reach the support.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Bridges Or Land Bridges (AREA)
• Rod-Shaped Construction Members (AREA)
• Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
• Joining Of Building Structures In Genera (AREA)
• Load-Engaging Elements For Cranes (AREA)
• Conveying And Assembling Of Building Elements In Situ (AREA)
• Dowels (AREA)
• Separation Using Semi-Permeable Membranes (AREA)
• Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (6)

Cited By (3)

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Citations (5)

• 1999
  • 1999-12-30 FI FI992817A patent/FI19992817A/fi unknown
• 2000
  • 2000-12-22 EP EP00988828A patent/EP1242696B1/de not_active Expired - Lifetime
  • 2000-12-22 DE DE60020165T patent/DE60020165T2/de not_active Expired - Lifetime
  • 2000-12-22 AU AU25185/01A patent/AU2518501A/en not_active Abandoned
  • 2000-12-22 AT AT00988828T patent/ATE295450T1/de not_active IP Right Cessation
  • 2000-12-22 WO PCT/FI2000/001139 patent/WO2001049951A1/en active IP Right Grant

Patent Citations (5)

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