GB2240795A - Floor structure - Google Patents

Abstract

In order to provide a floor structure having space for mechanical and electrical services (e.g. air-conditioning, lighting, heating, security and communication systems) the floor structure is formed by mounting in position at least one floor support structure comprising a substantially horizontal slab member 1, which is supported by upstanding beam members 2 which are configured so that the upper portions of the beam members 2 project upwards from the slab member 1, and thereafter placing a raised floor system 16, 19 on the support structure. The floor structures may be assembled from a number of abutting floor support structures. Beams 2 and slabs 1 may be formed separately or as integral units, e.g. of concrete reinforced with steel wires or I-beams. <IMAGE>

Description

FLOORING SYSTEM This invention relates to a method of forming a floor, in particular but not exclusively it relates to a floor constructed from pre-cast concrete units pre-stressed concrete units or structural steel sections, or any combination of these.

In constructing buildings, particularly multi-storey buildings, the floor structure between two storeys of the building will comprise members defining the structural floor surface and beam members or the like supporting these members. In addition, a raised floor may be constructed on top of the structural floor surface. Service systems, for instance heating, lighting, communication systems, security systems and power, may also have to be accommodated.

One method of assembling such a floor comprises supporting the structural floor surface on top of steel or reinforced concrete or steel beams. A raised floor may be then constructed on top of the floor surface.

Air-conditioning systems can be suspended beneath the structural floor and supporting beams, and a ceiling installed beneath the air-conditioning system.

This method of constructing a floor leads to the floor being very deep (for example, 1200mm or more in depth).

The process of assembling the air-conditioning systems, installing heating, lighting, security etc. systems (for example in cable trays) in the ceiling. space is inconvenient, and adds to the time taken to fit the raised floor and ceiling.

Part of the great depth of this floor is accounted for by the construction of a floor surface on top of supporting beams which are supported by vertical structural columns. Floor structures integrally formed with beam members have been used as units to assemble a floor, but there is still a need for a system for constructing a floor without the floor structure being too deep. It is also desirable to provide a floor system in which the units from which the floor surface is constructed are self-supporting between the columns.

The invention The invention provides a method of forming a floor structure as set forth in Claim 1 or 32, preferred features of the method being given in Claims 2 and 3, a floor structure as set forth in Claim 4 or 33, prefered features of the floor structure being set forth in Claims 5 to 26; and a building as set forth in Claim 27 or 34.

The invention will be further described by way of example with reference to the accompanying drawings in which: Brief description of drawings Figure 1 shows a plan view of an embodiment of a floor support structure for use with the invention; Figure 2 shows a vertical section along II - II of Figure 1; Figure 3 shows a plan view of another embodiment of the floor support structure for use with the invention; Figure 4 shows a vertical section along IV - IV of Figure 3; Figure 5 shows a plan view of another embodiment of the floor support structure for use with the invention; Figure 6 shows a vertical section along VI - VI of Figure 5; Figures 7a and 7b show a cross-section of a structure according to Figures 5 and 6; Figures 8a and 8b show a cross-section of a further embodiment of a structure according to Figures 5 and 6;; Figures 9a, 9b and 9c show embodiments of the beam member of any of Figures 1 to 6 and 8a and 8b; Figure 10 shows a perspective view of a floor constructed according to the invention, with a raised floor assembled on top.

Description of the preferred embodiments Figures 1 and 2 Figures 1 and 2 schematically show a first embodiment of the invention in which the floor support structure is constructed from horizontal units which comprise a slab member 1 integrally formed with two upstanding beam members or ribs 2 the upper portions of which project substantially above the slab member 1. These units are of rectangular plan.

The structure is assembled by positioning the units in abutting configuration so that they are supported by structural vertical columns 3 of the building and abut along lines between the centres of the columns 3 defining a rectangular horizontal grid.

The length a may be in the range 3000 to 9000 mm or more, preferably 6000 to 7500 mm. Dimension b between column centres may be from 3000 to 9000 mm, preferably 7500 mm. The upstanding beam members are constructed parallel to dimension b.

The beam members 2 are constructed so that their outer vertical faces 5 abut faces 4 of the columns 3. The beam members 2 are accordingly located close to the edges of the slab members, the slab member protruding one half column's length beyond the outer faces 5 of the beam members 2. Thus as shown in Figure 2, a trough of a width substantially equal to the width of a column 3 is formed between abutting units. The beam members 2 provide the necessary support for the slab members 1 of the units, and as shown in Figure 2 do not project below the slab member 1. The beam members 2 may be reinforced by reinforcing means in the form of steel rods 6 running parallel with the beam members 2 and located below the upstanding part of the beam members 2.Cut-outs 7 may be provided in the trough or in the slab between beam members 2 of abutting units for the vertical distribution of electrical and mechanical services or air conditioning in the building. These cut-outs may be placed in a wide variety of places, thus providing great flexibility of distribution of services and air conditioning.

As shown in Figure 2 the height of the beam member 2 above the slab member 1 is d, the thickness of the slab member 1 is c and the width of the beam member 2 is e.

The ratio of c to a is between 1 to 40 and 1 to 20, and is preferably 1 to 30. The ratio of d to a is between 1 to 10 and 1 to 20, preferably 1 to 15. The ratio of c to d is between 1 to 1 and 1 to 5, preferably 1 to 2. The ratio of e to b is between 1 to 10 and 1 to 60, and is preferably 1 to 20. In the preferred embodiment, c is between 100 mm and 250 mm, d is between 100 and 500 mm (preferably 350 mm), and e is between 100 and 400 mm.

Figures 3 and 4 Figure 3 shows schematically a second embodiment of the floor support structure which is substantially similar to the embodiment shown in Figure 1, but in which the units are divided into sub-units 12 and 13 along the width b and assembled from sub-units 13 which are supported on the vertical columns 3 of the building, and central sub-units 12 suspended between them as shown in Figure 4. The sub-units 12 are about one half of the width b wide such that the joints between sub-units are not at positions of maximum bending moment.

This embodiment allows large units to be transported easily. The units may be assembled from the sub-units on site the complete unit being then positioned as a single piece.

Figures 5 and 6 Figure 5 shows schematically yet another embodiment of the floor support structure which is substantially similar to the embodiment of Figure 1, but in which the slab member 1 is formed without any beam members, two parallel adjacent beam members 2 being integrally formed to make a member for supporting the slab member 1, a trough being defined between the beam members 2, the inner sides 14 of which trough abut faces 4 of the vertical columns 3.

In all of the above embodiments, the upstanding beam members 2 are substantially the only means of support for the horizontal slab members 1. It should be noted that there are two beams per slab member, which are located with their centres approximately a bay length apart, thus forming an open channel of approximately bay width.

Figures 7a, 7b, 8a, 8b, 9a, 9b and 9c The slab members 1 the beam members 2 and the column members 3 of Figures 1 to 6 may be made of steel members with structural finishes or of concrete reinforced with steel rods or beams.

Figure 7a shows a cross-section of a structure according to figures 5 and 6, in which the beam members 2 comprise steel structures and the slab members 1 comprise concrete slabs. The beam members 2 comprise I-section beams with their webs vertical. The base of the trough is defined by a concrete block 28 between the beam members 2. The surface on which a raised floor may be constructed comprises a structural topping 23 applied to the surfaces of the slab members 1 and the concrete block 28 comprising concrete reinforced by steel rods 24 passing through the structural topping 23 and the beam members 2. The space between the structural topping 23, the beam member 2 and the slab member 1 is filled with a concrete in fill 26 closed off with a fire-proof surround 25. A further fire-proof surround 27 surrounds the top exposed parts of the steel beam members 2.The beam members 2 project below the level of the slab member 1, but only by a very small amount, for example less than 150m, preferably about 90mm. A duct for the vertical distribution of services may be formed in the trough between the beam members 2, passing through the structural topping and the concrete block 28. This duct may be of width approximately 100 to 600 mm preferably 300 mm.

Figure 7b shows how the beam member may be adapted at the edge of the floor, where it meets the wall. The structural topping 23 and its reinforcement 24 are continued to the edge of concrete wall planks 30 which are adjacent a column 3. A small concrete block 29 is provided between the beam member 2 and the concrete wall plank 30 and the I-section steel member of the beam member 2 has its lower part embedded in concrete 26, as in Figure 7. A structural finish comprising eg. bricks 31 may be applied to the outside of the wall.

Figure 8a shows a cross-section of a structure according to Figures 5 and 6, in which the beam members 2 and the slab members 1 are made from reinforced concrete. A duct 32 for the vertical distribution of services of width 100 mm to 400 mm, preferably 300 mm is provided.

Further ducts 33 for lateral distribution of services may also be formed in the beam members 2. The widths of the ledge 34 on which the slab members rest is between 50 and 300 mm, preferably 100 mm. The width h between the external faces of the beam members 2 may be between 300 mm and 1500 mm, preferably 700 mm. The depth i of the floor units beneath the flange 35 which engages the ledge 34 is between 60 mm and 250 mm, preferably 125 mm. The depth g of the trough beneath the tops of the beams 2 is from 90 mm to 350 mm, preferably 180 mm.

Figure 8b shows the structure according to Figure 8a adapted to form a junction with a wall. A column 3 of width substantially equal to the width of the trough is shown, and a concrete wall plank 30 is shown abutting the column 3. This concrete wall plank rests on one of the beam members 2. On the outward side of the structure, ledge 34 is missing. A structural finish 31 is applied as in Figure 7b.

In all of the above embodiments the slab member 1 may be pre-stressed in the known manner with steel rods running at right angles to the axes of the beam members 2 so that the slab member 1 is cambered upwards with the axis of the camber parallel to the axes of the beam members 2. With the sizes a and b of the slab hereinbefore quoted, the preferred radius of camber is 3000 to 10000mm, corresponding to a camber height of 5 to 20mm.

The beam members of any of the embodiments shown in figures 1 to 6 and 8a and 8b may be reinforced with steel beams, instead of steel rods.

Figure 9a shows a perspective drawing of a corner of a unit in which the beam member 2 is constructed from a steel beam 10. The steel beam 10 is completely embedded in the beam member 2 except at the corner, where it is exposed so that a connection may be made between the steel beam 10 and the vertical face 4 of a column 3.

Figures 9b and 9c show beam members reinforced with steel I-section beams 8 or 9. As shown in Figure 8, the beam may be only partially embedded in the slab member 1 or, as shown in figure 9, the beam 9 may be completely embedded in the unit.

Figure 10 Figure 10 is an isometric view showing a raised floor system 15 mounted above the slab member 1. The raised floor system 15 comprises floor tiles 19 supported at their corners by floor surface support members in the form of pedestals 16, so that a space 17 is formed between the raised floor 15 and the slab member 1. This space 17 provides a clear area for air conditioning and services. The components of these systems are thus easily and fully accessible. The beam members 2 project into this space. This space is thus longitudinally divided by the upstanding beam members 2 defining channels for air-conditioning systems 18 which may be conveniently located in the underfloor space 17. This allows the respective ceiling above the floor to be clear of air-conditioning apparatus.

The fire resistance of the structure is enhanced by the upstanding beam members 2 providing fire barriers in the underfloor space.

The space 17 may also be used to house electrical and mechanical services (for example heating, lighting, security, communication and power supply systems and their supply and control systems). If the raised floor does not touch the tops of the beam members 2, the space between the tops of the beam members 2 and the bottom of the raised floor may be sealed with rockwool or other suitable material, preferably being fire resistant and insulating. All the services for the building may be located in the underfloor space, so that the ceiling need have no services in it at all. Ceiling finishes or tiles may then be fixed directly to the bottom of the slab member 1.

Vertical distribution of services is achieved by the provision of cut-outs 20 and 21 in the slab 1 or the trough between the beam members 2 respectively.

The services may then reach the rest of the area by going over the beam members 2 (as the raised floor may be spaced above the the tops of the beam members 2) as shown by cables 23.

The delivery of electrical services into the troughs has the advantage that the troughs may be constructed so as to contain any fire spreading from the floor beneath via the service distribution holes.

Lateral distribution holes 19 may be provided in the beams themselves for lateral distribution of air conditioning and services in a similar way to Figure 8a.

Referring to Figure 10, the height of the raised floor above the tops of the upstanding beam members 2 may be 25 to 200 mm. Taking into account the width of the slab member c, the height of the upstanding beam members 2 (which may be 100 to 600 mm) and the depth of steel beam members projecting below the slab, if present, as in Figure 7a (which may be about 90mm), the total depth f of the floor, as shown in Figure 10, may be between 300 and 900 mm and is preferably 600 mm, though this may vary with structural factors, such as the width of the spans and the loading.

The present invention has been described above purely by way of example, and modifications may be made within the spirit of the invention. The invention also consists of any individual feature described herein or apparent from the drawings or any combination of such features or any generalisation of such features or combination.

Claims (34)

Claims.

1. A method of forming a floor structure, comprising mounting in position a floor support structure comprising: at least one substantially horizontal slab member whose upper surface is for supporting floor surface support members; and beam members for supporting said at least one slab member, configured so that at least the upper portions of the beam members project upwards from the slab member; and thereafter mounting on the support structure a floor surface supported on floor surface support members.

2. The method of Claim 1, wherein a floor surface is mounted on the floor surface support members so that the floor surface is supported with a space between it and the upper surface of the slab member, the beam members projecting into this space.

3. The method of Claim 1 or 2, wherein a raised floor, comprising floor tiles supported at their corners by floor surface support members, is constructed on top of the floor support structure.

4. A floor structure comprising: a substantially horizontal slab member; beam members for supporting the slab member, configured so that at least the upper portions of the beam members project upwards from the slab member; and a floor surface supported on floor surface support members, the floor surface support members being supported by an upper surface of the slab member.

5. The floor structure of Claim 4, wherein the slab member is substantially only supported by the beam members.

6. The floor structure of Claim 4, wherein there are two substantially parallel said beam members, each being located at a position adjacent to and substantially parallel to one of two respective substantially parallel edges of the slab.

7. The floor structure of Claim 4, wherein the beam members are formed integrally with the slab member, forming a single unit.

8. The floor structure of Claim 7, wherein the beam members comprise steel beams.

9. The floor structure of Claim 8, wherein only the lower portions only of the beam members are embedded in the slab member.

10. The floor support structure of Claim 7, wherein the structure comprises concrete reinforced with reinforcing members under tension embedded in the structure beneath the upstanding parts of the beam members.

11. The floor structure of Claim 4, wherein a central portion of the slab member is formed separately from the outer portions of the slab member, the beam members being integrally formed with the outer portions of the slab member, and the central portion being supported between the two outer portions of the slab member.

12. The floor structure of Claim 4, wherein the beam members and slab members are formed separately.

13. The floor structure of Claim 4, wherein the beam members comprise steel beams.

14. The floor structure of Claim 11 or 12, wherein the beam members comprise concrete reinforced with reinforcing members under tension embedded in the lower portions of the beam members and extending substantially parallel to the beam members.

15. The floor structure of Claim 12, wherein units having the beam members comprise two parallel beam members separated by a trough, the trough having holes through its base at intervals for vertical columns to pass through.

16. The floor structure of any of Claims 4 to 15, wherein the slab member is cambered upwards, the axis of the camber being parallel to the axis of at least one of the beam members.

17. The floor structure of any of Claims 4 to 16, wherein the horizontal dimensions of the slab member are approximately 3000 to 9000mm long in the direction normal to the axis of at least one of the beam members, and 3000 to 9000mm long in the direction parallel to the axis of at least one of the beam members.

18. The floor structure of any of Claims 4 to 17, wherein the thickness of the slab member is between 100 and 250mm.

19. The floor structure of any of the Claims 4 to 18, wherein the height of the beam member above the slab la 100 to 500mm.

20. The floor structure of any of Claims 4 to 19, wherein the ratio of the thickness of the slab to its length in the direction normal to the axis of at least one of the beams is between 1: 40 and 1: 20.

21. The floor structure of any of Claims 4 to 20, wherein the ratio of the height of the beam members above the slab to the length of the slab member in the direction normal to the axis of at least one of the beam members is approximately 1: 15.

22. The floor structure of any of Claims 4 to 21, wherein the ratio of the thickness of the slab member to the height of the beam members is between 1:1 and 1: 5.

23. The floor structure of any of Claims 4 to 22, wherein the ratio of the width of the beam members to the length of the beam members is between 1: 10 and 1: 60.

24. The floor structure of Claim 4, wherein the floor surface and floor surface support members are demountably mounted on the slab member.

25. The floor structure of Claim 4, wherein the floor surface is mounted on the floor surface support members so that the floor surface is supported with a space between it and the upper surface of the slab member, the beam members projecting into this space.

26. The floor structure of Claim 24 or 25, wherein the floor surface comprises floor tiles supported at their corners by the floor surface support members.

27. A building having a floor constructed according to the method any of Claims 1 to 3.

28. A building having the floor structure of any of Claims 4 to 26.

29. The building of Claim 27 or 28, wherein the floor support structure is supported on vertical columns.

30. The building of Claim 29, wherein slab members are positioned horizontally in substantially abutting configuration, wherein slots are formed in the slab members through which vertical structural columns of the building pass and wherein vertical faces of the beam members abut faces of the vertical columns.

31. The building of Claim 29, wherein the slab members are fixed to the structural vertical columns of the building via the beam members.

32. A method of forming a floor, substantially as herein described with reference to the accompanying drawings.

33. A floor structure substantially as herein described with reference to the accompanying drawings.

34. A building constructed substantially as herein described with reference to the accompanying drawings.