Method and system for constructing large, continuous, concrete slabs

• US 20030115823A1
• Filed: 02/04/2003
• Published: 06/26/2003
• Est. Priority Date: 08/04/2000
• Status: Active Grant

• Current Assignee: Building Innovations Pty., Ltd.
• Original Assignee: Building Innovations Pty., Ltd.
• Inventors: Colefax, Robert Foster, Getaldic, Miro, Colefax, Warwick Ian
• Granted Patent: US 7,069,703 B2
• Time in Patent Office: Days
• US Class Current: 52/677
• CPC Class Codes: E01C 11/106 Joints with only prefabricated packing; Packings therefor
• CPC Class Codes: E01C 11/18 for cement concrete pavings prefabricated reinforced units E01C5/08
• CPC Class Codes: E01C 9/001 Paving elements formed in situ; Permanent shutterings therefor removable shutterings E01C19/502; moulding machines therefor E01C19/508; Inlays or reinforcements which divide the cast material in a great number of individual units reinforcement girders which do not break the cohesion of the covering material E01C11/16, E01C11/185
• CPC Class Codes: E02D 27/01 Flat foundations
• CPC Class Codes: E04C 5/04 Mats combined with reinforcing elements protruding out of the plane of the mat E04C5/0627; three-dimensional mats E04C5/0636; bases for plaster E04F13/04

Abstract

A method and system are provided for constructing large, continuous, concrete slabs without using conventional shrinkage joints. The system comprises a grid of closely-spaced crack inducers (2) arranged relative to a concrete-pouring surface and adapted to be covered by concrete. The crack inducers (2) may be connected to one another with connectors (10). The crack inducers (2) are of a size, shape and spacing to promote formation of fine cracks in the vicinity of the inducers (2) throughout the slab when the concrete sets.

Claims

1. A method of constructing a large continuous concrete slab, said method comprising the steps of:

arranging a plurality of closely spaced crack inducers relative to a concrete-pouring surface;

pouring concrete onto said concrete-pouring surface to completely cover said inducers; and

allowing said concrete to set to form a slab;

wherein said inducers are of a size, shape and spacing to promote fine cracking in their vicinity throughout the area of the slab such that said slab has a continuous top surface and does not require the installation of shrinkage control joints through the top surface to prevent uncontrolled cracking.

2. The method of claim 1, wherein said slab has a surface area of at least about 300 m².

3. The method of claim 1, wherein said concrete-pouring surface is a prepared ground surface.

4. The method of claim 1, wherein said fine cracks are generally less than about 0.5 mm in width.

5. The method of claim 1, wherein said crack inducers are arranged substantially parallel to one another.

6. The method of claim 1, wherein said crack inducers are arranged as a grid.

7. The method of claim 1, wherein said crack inducers are arranged as a rectangular grid comprising a first group of spaced, substantially parallel inducers, and a second group of spaced, substantially parallel inducers perpendicular to the first group.

8. The method of claim 1, wherein said crack inducers are spaced at about 800 mm to 3000 mm centres.

9. The method of claim 1, wherein said crack inducers are spaced at about 800 mm to 1000 mm centres.

10. The method of claim 1, wherein said crack inducers are used to reticulate services.

11. The method of claim 1 further comprising a step of stabilising at least one crack inducer prior to pouring the concrete.

12. The method of claim 11, wherein said crack inducer is stabilised by anchoring said inducer to the concrete-pouring surface with a fastener.

13. The method of claim 11, wherein said crack inducer is stabilised by connecting said inducer to at least one other inducer.

14. The method of claim 13, wherein said crack inducers are connected to one another with connectors.

15. The method of claim 14, wherein said connectors are attachable to crack inducers of slightly varying diameter.

16. The method of claim 14 further comprising a step of holding at least one of said connectors relative to the concrete-pouring surface before pouring the slab.

17. The method of claim 16, wherein said connector is held in position with a slab reinforcing member placed atop the connector, wherein said connector functions as a bar chair.

18. The method of claim 16, wherein said connector has securing means for being held against the concrete-pouring surface.

19. The method of claim 1, wherein said crack inducers comprise conduits.

20. The method of claim 1, wherein said crack inducers comprise bamboo.

21. A crack inducer system for inducing cracks in a large continuous concrete slab, said system comprising a plurality of closely spaced crack inducers arranged relative to a concrete-pouring surface and adapted to be completely covered by concrete, wherein said crack inducers are of a size, shape and spacing to promote fine cracking in their vicinity throughout the area of the slab when said concrete sets, and wherein said slab has a continuous top surface and does not require the installation of shrinkage control joints through the top surface to prevent uncontrolled cracking.

22. The system of claim 21, wherein said crack inducers are elongate.

23. The system of claim 21, wherein said crack inducers are elongate and circular, rectangular or triangular when viewed in transverse cross section.

24. The system of claim 21, wherein at least one of said crack inducers comprises two or more elongate members stacked or bundled together.

25. The system of claim 21, wherein at least one of said crack inducers comprises a conduit or a piece of bamboo.

26. The system of claim 25, wherein said conduit is a plastic pipe.

27. The system of claim 21, wherein said crack inducers are arranged substantially parallel to one another.

28. The system of claim 21, wherein said crack inducers are arranged as a grid of any suitable pattern.

29. The system of claim 21, wherein said crack inducers are arranged as a rectangular grid comprising a first group of spaced, substantially parallel inducers, and a second group of spaced, substantially parallel inducers perpendicular to the first group.

30. The system of claim 21, wherein said crack inducers are spaced at about 800 mm to 3000 mm centres.

31. The system of claim 21, wherein said crack inducers are spaced at about 800 mm to 1000 mm centres.

32. The system of claim 21, further having connectors connecting at least some of said crack inducers to one another.

33. The system of claim 21, wherein at least one of said connectors comprises a body and at least two arms extending from the body, wherein each said arm is attachable to an end of a said crack inducer.

34. The system of claim 33, wherein each said arm is attachable to crack inducers of slightly varying diameter.

35. The system of claim 33, wherein each said arm is of hollow construction.

36. The system of claim 33, wherein each said arm is provided by at least one blade that extends from the body and which friction fits within an end of a said crack inducer.

37. The system of claim 36, wherein each said arm comprises two blades that intersect at a midpoint such that an end of each said arm is cross-shaped when viewed in transverse cross section.

38. The system of claim 37, wherein said blades have ends that are tapered to facilitate attachment to said crack inducers.

39. The system of claim 33, wherein said connector has four arms extending radially from the body.

40. The system of claim 33, wherein said connector is an electrical junction box or fitment.

41. The system of claim 33, wherein said connector has securing means for being held against the concrete-pouring surface.

42. The system of claim 41, wherein said securing means is provided by the body having at least one aperture through which a fastener can extend.

43. The system of claim 33, wherein the body of said connector has at least one upstanding wall, a top region of which provides support for a reinforcing member.

44. The system of claim 43, wherein said connector has four upstanding walls and the top region of each wall has a retainer extending therefrom for engaging a reinforcing member.

45. The system of claim 33, wherein said connector comprises a cylindrical body with four arms extending radially from the body, wherein each arm comprises two blades that intersect at a midpoint such that an end of each arm is cross-shaped when viewed in transverse cross section, and said connector can be secured to the surface with a fastener extending through the cylindrical body.

46. The system of claim 45, wherein said connector further comprises a ground-bearing base from which extends the cylindrical body, said base having a plurality of apertures through which fasteners can extend.

47. The system of claim 46, wherein said connector further has a raised reinforcement lip extending about a periphery of the base, and said lip is continuous with some of the blades of the arms.

48. The system of claim 33, wherein said connector comprises:

a body comprising;

a ground-bearing base having a plurality of apertures through which fasteners can extend to secure the connector to the surface;

four walls that extend upwardly from the base and which intersect at a central location of the body; and

a retainer that extends from a top of each said wall, wherein said retainer is adapted to retain a slab reinforcing member; and

arms in the form of blades that extend radially from an edge of each said wall and from said base.

49. The system of claim 48, wherein said connector comprises corrosion-resistant or non-corrosive material.

50. The system of claim 33, wherein said connector is produced by plastic injection moulding.