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
  • E04B5/16—Load-carrying floor structures wholly or partly cast or similarly formed in situ
  • E04B5/17—Floor structures partly formed in situ
  • E04B5/23—Floor structures partly formed in situ with stiffening ribs or other beam-like formations wholly or partly prefabricated
  • E04B5/29—Floor structures partly formed in situ with stiffening ribs or other beam-like formations wholly or partly prefabricated the prefabricated parts of the beams consisting wholly of metal
• • 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
  • E04B5/36—Floor structures wholly cast in situ with or without form units or reinforcements with form units as part of the floor
  • E04B5/38—Floor structures wholly cast in situ with or without form units or reinforcements with form units as part of the floor with slab-shaped form units acting simultaneously as reinforcement; Form slabs with reinforcements extending laterally outside the element
  • E04B5/40—Floor structures wholly cast in situ with or without form units or reinforcements with form units as part of the floor with slab-shaped form units acting simultaneously as reinforcement; Form slabs with reinforcements extending laterally outside the element with metal form-slabs

Definitions

• the present invention relates to shear connectors; shear connectors are used in the fabrication of composite steel and concrete structures, e.g. bridges and buildings, to transfer shear forces between steel beams and a body of concrete, thus limiting relative movement (or slip) at the steel/concrete interface so that the system acts as a unit that resists longitudinal bending and prevents uplift between the steel and the concrete.
• Known shear connectors are metal plates or studs that are welded to the beam prior to casting of the concrete; when the concrete is cast, the shear connectors are embedded in concrete and as a result prevent lateral movement between the concrete and the beam. It is a time-consuming and awkward task to arrange these shear connectors on the beam and to weld them in place.
• the aim of the present invention is to provide a method of constructing a concrete structure using a novel shear connector that is quicker and easier to secure to steel beams than known shear connectors; the present invention also provides the novel shear connector itself and an assembly including both the novel shear connector and shuttering.
• a shear connector for use in connection with commercially-available corrugated sheet shuttering of dimensions commonly used in the building art, characterised in that the shear connector comprises an elongate strip of corrugated material having corrugations extending transverse to its length, wherein the distance between adjacent corrugations of the shear connector strip is identical to the distance between adjacent corrugations of the said shuttering, wherein the shear connector corrugations have a height that exceeds the height of the corrugations of the shuttering by at least 25 mm, wherein each shear connector corrugation has a base matched in shape to the shape of the bases of the corrugations of the shuttering and wherein the base of each shear connector corrugation has a width (when viewed in longitudinal section) that is less than the width of the bases of the shuttering corrugations.
• the width of the shear connector strip is preferably less than the width of the base of each corrugation of the shuttering so that the strip can be located in, and extend along the length of, a single corrugation of the shuttering; more preferably, the width of the strip is smaller by at least 10 mm than the width of the base of a shuttering corrugation.
• Corrugated profiled steel shuttering commonly used in the art at the present time have dimensions as follows (in mm):
• corrugation base width 62 137 137 114 87 110
• the shear connector of the present invention preferably has one or more ribs on the shoulders of the corrugations to reinforce the strip. If the bases of the shuttering corrugations have ribs, then the bases of the shear connector corrugations should also be provided with such ribs to match those of the shuttering.
• the width of the shear connector strip (i.e. the width of the shear connector taken in transverse section) is in the range of from 30 to 110mm, more preferably 35 to 100mm, e.g.40 to 90mm; typically, the width will be approximately 50 to 80mm.
• the length of the shear connector is indeterminate since it will depend on the length of the beam used; the shear connector need not extend along the whole length of the beam.
• the shear connector of the present invention is preferably made of sheet steel having a thickness of at least 1.2mm, e.g about 2mm and preferably having the following specification: BS 2989 sheet Z28 G275 N steel (normal spangle-finish zinc coating of 275 g/m 2 total mass on both sides, the steel having a minimum yield strength of 280 N/mm 2 ).
• BS 2989 sheet Z28 G275 N steel normal spangle-finish zinc coating of 275 g/m 2 total mass on both sides, the steel having a minimum yield strength of 280 N/mm 2 .
• a method of constructing a concrete structure, which structure is supported by or otherwise in contact with a structural beam comprises laying corrugated shuttering against the beam, placing a shear connector on the shuttering so that it overlies the beam, securing the shear connector to the beam and casting a body of concrete on the shuttering so that the shear connector is embedded in the concrete when set, characterised in that the shear connector is a corrugated strip which is either located in and extends along a single corrugation in the shuttering or the troughs of the corrugations in the shear connector strip are located in respective troughs of the corrugations of the shuttering.
• an assembly comprising a beam having fixed thereto a sheet of corrugated shuttering and a shear connector, characterised in that the shear connector is an elongate corrugated strip extending along the length of the beam and either (a) the corrugations of the shuttering extend along the length of the beam and the shear connector strip is located in and extends along a corrugation in the shuttering or (b) the corrugations of the shuttering extend transversely across the beam and the troughs of the shear connector corrugations are located in respective troughs of the shuttering corrugations. It is preferred that the difference in height between the peaks of the shear connectors and the peaks of the shuttering is at least 50 mm.
• Fig. 1 is an end view, which is partly cut away, of part of a cast concrete floor and shows a beam, a sheet of corrugated shuttering whose corrugations extend across the beam, a shear connector, a reinforcing steel mesh and a layer of cast concrete
• Fig. la is a cross sectional view along line la-la in Fig 1,
• Fig.2 is an axisonometric view of the arrangement of the beam, the corrugated sheet shuttering and the shear connector shown in Fig.l.
• Fig. 3 is an end view, which is partly cut away, of a cast concrete floor and shows a beam, a sheet of corrugated shuttering whose corrugations extend along the beam, a shear connector and a layer of concrete.
• Fig.4 shows, in section, several forms of commercially available corrugated sheet shuttering and shear connectors for use with such shuttering.
• One method of building bridges or buildings etc. involves the constuction of a framework consisting of steel beams.
• Floors are formed between the beams by laying sheets of corrugated shuttering (or decks) between the beams and pouring a layer of concrete onto the shuttering which, when set, constitutes the floor; as in standard practice in cast concrete, reinforcing material (mesh or bars) is incorporated into the concrete floor.
• shear connectors are fixed to the beam and extend into, and are therefore embedded in, the concrete layer.
• FIG.l A cast concrete floor using a shear connector of the present invention is shown in Fig.l while Fig. 2 shows only the beam, the sheet shuttering and the shear connector.
• an I-section steel beam 10 which has a top flange 12 joined by a web 14 to a bottom flange 16, forms part of the framework of a building.
• Sheets 18 of corrugated metal shuttering are laid between the beams of a floor to form a continuous base or deck on which concrete can be poured;
• Fig. 2 shows a relatively narrow section of sheet shuttering 18 but it will be appreciated that the shuttering extends further both in the lateral direction (shown by arrows A) and in the longitudinal direction (shown by arrows B).
• the shear connector of the present invention is a strip of corrugated steel 20 which is placed on the sheet shuttering 18 with its corrugations fitting into the corrugations of the sheet shuttering; as can be seen in Fig. 1 and 2, the shear connector 20 overlies the beam 10 and is fixed to the flange 12 of the beam 10 by explosive pins 22 of a type that are available commercially from Hilti AG of Switzerland. Alternatively, the shear connector 20 may be fixed to the beam by any other means that enables the shear connector 20 to withstand horizontally-acting forces.
• the corrugations of the shuttering run perpendicular to the beam 10.
• the connector 20 which is identical to that shown in Figs.1 and 2
• the connector 20 is located in, and extends along, one corrugation of the shuttering 18. It is fixed to the flange 12' of beam 10' by means of explosive pins 22, two pins being used in each corrugation of the strip.
• the width of the shear connector strip W3 must be smaller than the width W- ⁇ of the base of the corrugatons.
• a reinforcing steel mesh 23 (shown in Figs. 1 and 3) is then laid over the shuttering 18 and concrete is poured onto the shuttering to a thickness of approximately 130-150 mms (although the precise thickness will have to be calculated on standard engineering principles, depending on the forces that the floor will have to encounter).
• the concrete is shown shaded in parts of Figs. 1 and 3 and is indicated by the reference numeral 24 while the top level of the concrete is indicated at 26. As is apparent, the concrete penetrates into the space 28 (see Fig.
• the dimensions of the shear connector 20 depend on the type of shuttering 18 that is used; the criteria for the dimensions of the shear connector are as follows:
• the period P of the shear connector i.e. the distance between adjacent peaks of the corrugations, must be substantially identical to the period of the corrugations in the shuttering 18 in order that the corrugations of the shear connector can fit into those of the shuttering
• the width W2 of the base of each trough of the shear connector must be smaller than the width W2 of the base of each troug in the shuttering; again this is necessary to allow the shear connector to fit into the corrugations of the shuttering and to provide a gap 30 between the side walls of the shuttering and the side walls of the shear connector
• the height £_2 of the shear connector must be sufficiently large to provide a gap 28 of height H- ⁇ between the peaks of the shuttering 18 and the peaks of the shear connector 20.
• Height H ⁇ must allow the concrete to penetrate into the gap and generally must be at least 25 mm and more typically at least 35 mm; if the concrete does not penetrate into gap 28, the keying of the shear connector into the concrete will be impaired and, as is apparent, this will reduce its effectiveness
• the width 3 of the shear connector strip 20 must be smaller (preferaby by at least 10 mm) than the width W-* ⁇ of the base of the corrugations of the shuttering.
• the I-beam 10, 10' and the sheet shuttering 18 are standard commercial products and will not be described in further detail.
• the shear connector is made of type BS 2989 sheet Z 28 G 275 N steel having a thickness of 1 to 3 mm, e.g. 1.2 to 2 mm, and which has been cold formed into the shape shown in Figs. 1, 2 an 4.
• the shear connector may have reinforced ribs 30 pressed into the shoulders of its corrugations as shown on one of the corrugations in Fig.1 and in more detail in Fig. la.
• Fig.4 shows cross-sections of six types of sheet shuttering 18 and associated shear connectors 20.
• the dimensions of the shear connectors are given below. It will be seen that a single size of shear connector (type 1) can be used with any of the first four forms of sheet shuttering illustrated while shear connector types 2 and 3 are used for the fifth and sixth forms of shuttering; the shear connectors have the following dimensions, in mm:
• width of the corrugation trough (dimension 2 in Figs. 1 and 4): 35 55 55
• width of corrugation peak (dimension W4 in Fig 4): 55 55 55
• shear connector strip width of shear connector strip (dimension 3 in Fig. 3): 50 75 80

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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)
• Forms Removed On Construction Sites Or Auxiliary Members Thereof (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10619994

Family Applications (1)

Country Status (5)

Cited By (7)

Citations (7)

• 1987
  • 1987-07-02 GB GB878715619A patent/GB8715619D0/en active Pending
• 1988
  • 1988-07-04 EP EP19880905941 patent/EP0365580A1/en not_active Withdrawn
  • 1988-07-04 AU AU19876/88A patent/AU1987688A/en not_active Abandoned
  • 1988-07-04 JP JP50553888A patent/JPH03500556A/ja active Pending
  • 1988-07-04 WO PCT/GB1988/000521 patent/WO1989000223A1/en not_active Application Discontinuation

Patent Citations (7)

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