Anchor bolt and annularly grooved expansion sleeve assembly exhibiting high pull-out resistance, particularly under cracked concrete test conditions

• US 20100229641A1
• Filed: 05/20/2010
• Published: 09/16/2010
• Est. Priority Date: 06/05/2006
• Status: Active Grant

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Starozhitsky, Michael, Kobetsky, Robert G., Reiter, Matthew J., Broomfield, Donald
• Granted Patent: US 8,302,276 B2
• Time in Patent Office: Days
• US Class Current: 73/152.570
• CPC Class Codes: F16B 13/065 fastened by extracting the screw, nail or the like
• CPC Class Codes: G01N 2203/0016 Tensile or compressive
• CPC Class Codes: G01N 2203/0066 Propagation of crack
• CPC Class Codes: G01N 2203/0067 Fracture or rupture
• CPC Class Codes: G01N 2203/0246 Special simulation of "in situ" conditions, scale models or dummies
• CPC Class Codes: G01N 3/32 by applying repeated or pulsating forces
• CPC Class Codes: Y10T 29/49764 with testing or indicating
• CPC Class Codes: Y10T 29/49771 Quantitative measuring or gauging
• CPC Class Codes: Y10T 29/49776 Pressure, force, or weight determining
• CPC Class Codes: Y10T 29/49778 with aligning, guiding, or instruction

Abstract

A wedge-type anchor assembly, capable of meeting cracked concrete testing standards, comprises an anchor bolt component and a substantially C-shaped expansion sleeve component annularly disposed about the anchor bolt component. A plurality of annular grooves, threads, or teeth are disposed only about the forward end portion of the expansion sleeve component, as opposed to throughout the entire axial length thereof, so that when the anchor bolt component is moved axially through the expansion sleeve component, the maximum interference area (M.I.A.) and maximum interference volume (M.I.V.) can be generated between the anchor bolt component and the expansion sleeve component in a controlled and predictable manner, as well as between the expansion sleeve component and the internal peripheral side wall portions of a concrete substrate or substructure can be generated so as to enhance pull-out resistance and reliability of the anchor assembly within the concrete substructure or substrate.

Claims

1-20. -20. (canceled)

21. A method of performing cracked concrete testing within a borehole, defined within a concrete substrate, using an anchor assembly, comprising the steps of:

forming at least one cracked region within a concrete substrate;

connecting a component to said concrete substrate so as to cause said at least one cracked region of said concrete substrate to be expanded and contracted between OPENED and CLOSED positions;

inserting an anchor bolt assembly within a borehole defined within said at least one cracked region of said concrete substrate, wherein said anchor bolt assembly comprises an anchor bolt member having a longitudinal axis and an enlarged head portion disposed upon a forward end portion of said anchor bolt member, an expansion sleeve member annularly disposed around said anchor bolt member, and a plurality of annular grooves disposed only upon a forward external peripheral portion of said expansion sleeve member, while a rearward external peripheral portion of said expansion sleeve member is non-grooved and solid;

applying a predetermined load to said anchor bolt assembly by torquing said anchor bolt assembly to a predetermined level whereby said anchor bolt member will move axially rearwardly through said expansion sleeve member whereby said enlarged head portion of said anchor bolt member will initially progressively expand said forward portion of said expansion sleeve member so that said plurality of annular grooves will be progressively forced into engagement with internal peripheral side wall portions of said borehole defined within said concrete substrate so as to progressively define a progressively increased area and volume of interference with said internal peripheral side wall portions of said borehole defined within said concrete substrate, and subsequently, said enlarged head portion of said anchor bolt member will progressively expand said rearward portion of said expansion sleeve member so that said non-grooved solid portion of said expansion sleeve member will be progressively forced into engagement with said internal peripheral side wall portions of said borehole defined within said concrete substrate so as to achieve a maximum interference area (M.I.A.) and a maximum interference volume (M.I.V.) with said internal peripheral side wall portions of said borehole defined within said concrete substrate so as to enhance the holding power and pull-out resistance of said anchor assembly with respect to said borehole defined within said concrete substrate;

operating said component, connected to said concrete substrate, so as to cyclically expand and contract said at least one cracked region of said concrete substrate between said OPEN and CLOSED positions for a predetermined number of cycles and for a predetermined period of time; and

measuring the movement of said anchor bolt assembly within said at least one cracked region of said concrete substrate, while said at least one cracked region of said concrete substrate is being cyclically expanded and contracted between said OPENED and CLOSED positions, so as to effectively gauge the pull-out resistance of said anchor bolt assembly with respect to said concrete substrate.

22. The method as set forth in claim 21, further comprising the step of:

forming said at least one cracked region within said concrete substrate by using crack initiators.

23. The method as set forth in claim 22, further comprising the step of:

selecting said crack initiators from the group comprising wedge-type devices, plates, and hydraulic expansion tubes.

24. The method as set forth in claim 21, further comprising the steps of:

providing rebars within said concrete substrate;

using a hydraulic pump as said component connected to said rebars of said concrete substrate; and

operatively connecting said hydraulic pump to said rebars of said concrete substrate by hydraulic connectors.

25. The method as set forth in claim 21, further comprising the step of:

using a linearly variable displacement transformer (LVDT) to measure said movement of said anchor bolt assembly within said at least one cracked region of said concrete substrate, while said at least one cracked region of said concrete substrate is being cyclically expanded and contracted between said OPENED and CLOSED positions, so as to effectively gauge the pull-out resistance of said anchor bolt assembly with respect to said concrete substrate.

26. The method as set forth in claim 21, further comprising the step of:

providing the number of said plurality of annular grooves, disposed upon said forward external peripheral portion of said expansion sleeve member, within the range of three to eight.

27. The method as set forth in claim 21, further comprising the step of:

providing the plurality of annular grooves, disposed upon said forward external peripheral portion of said expansion sleeve member, with a predetermined pitch defined between successive adjacent grooves as based upon the number of grooves per inch which is within the range of twenty to thirty-two grooves per inch.

28. The method as set forth in claim 21, further comprising the step of:

providing all of said plurality of annular grooves, disposed upon said forward external peripheral portion of said expansion sleeve member, with a depth dimension which is within the range of 0.015-0.050 inches (0.015-0.050″

).

29. The method as set forth in claim 28, further comprising the step of:

providing all of said plurality of annular grooves, disposed upon said forward external peripheral portion of said expansion sleeve member, with the same depth dimension which is within the range of 0.015-0.050 inches (0.015-0.050″

).

30. The method as set forth in claim 28, further comprising the step of:

providing all of said plurality of annular grooves, disposed upon said forward external peripheral portion of said expansion sleeve member, with different depth dimensions within said range of 0.015-0.050 inches (0.015-0.050″

).

33. The method as set forth in claim 21, further comprising the step of:

providing said annular expansion sleeve member, disposed around said anchor bolt member, as a sheet member rolled upon itself so as to have a substantially C-shaped cross-sectional configuration.

34. The method as set forth in claim 33, further comprising the step of:

fabricating said annular expansion sleeve member from metal.

35. The method as set forth in claim 34, further comprising the step of:

fabricating said annular metal expansion sleeve member from low-carbon steel plated with zinc.

36. The method as set forth in claim 34, further comprising the step of:

fabricating said annular metal expansion sleeve member from carbon-steel plated with a zinc-tin composition.

37. The method as set forth in claim 21, further comprising the steps of:

providing said expansion sleeve member, annularly disposed around said anchor bolt member, with a rearwardly disposed body portion having a predetermined external diametrical extent; and

forming said plurality of annular grooves, disposed only upon said forward external peripheral portion of said expansion sleeve member, such that said plurality of annular grooves do not extend radially beyond said external diametrical extent of said rearwardly disposed body portion of said expansion sleeve member so as not to gouge internal peripheral side wall portions of the borehole defined within the substrate during installation of said anchor assembly into the borehole defined within the substrate.

38. The method as set forth in claim 21, further comprising the step of:

providing barbs upon said expansion sleeve member, annularly disposed upon said anchor bolt member, for effectively biting into, and becoming embedded within, internal peripheral surface portions of the concrete wall defining said borehole within said concrete substrate so as to thereby prevent rotation of said expansion sleeve component with respect to said borehole defined within said concrete substrate.

39. The method as set forth in claim 38, further comprising the step of:

providing said barbs as a plurality of barbs circumferentially spaced upon said expansion sleeve member annularly disposed upon said anchor bolt member.

40. The method as set forth in claim 39, further comprising the step of:

forming each one of said plurality of barbs such that each one of said plurality of barbs has a substantially triangular configuration.

41. The method as set forth in claim 39, further comprising the step of:

forming each one of said plurality of barbs such that each one of said plurality of barbs has a primary longitudinal axis which is disposed substantially parallel to said longitudinal axis of said expansion sleeve member.

42. The method as set forth in claim 39, further comprising the step of:

forming each one of said plurality of barbs such that each one of said plurality of barbs has a primary longitudinal axis which is disposed at a predetermined angle with respect to said longitudinal axis of said expansion sleeve member.

43. The method as set forth in claim 42, further comprising the step of:

forming each one of said plurality of barbs such that said predetermined angle, at which each one of said plurality of barbs is angularly offset with respect to said longitudinal axis of said expansion sleeve member, is approximately 20°

.