Sleeve Device For Increasing Shear Capacity

Abstract

A sleeve device for increasing shear capacity of a reinforced concrete slab includes a hollow member, stud members, and head members. The hollow member is positioned on and fastened to a bottom formwork defining the reinforced concrete slab. The hollow member creates a void in the reinforced concrete slab. The stud members are connected to opposing sides of the hollow member directly or using connectors. A first stud member is connected to an upper portion of the hollow member and oriented in a downward direction. A second stud member is connected to a lower portion of the hollow member and oriented in an upward direction. The head members are operably coupled to distal ends of the stud members and embedded in the reinforced concrete slab. The head members transfer shear forces across the sleeve device through an interaction between the head members and the concrete surrounding the stud members.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of provisional patent application No. 61/859,396 titled “Sleeve Device For Increasing Shear Capacity”, filed in the United States Patent and Trademark Office on Jul. 29, 2013. The specification of the above referenced patent application is incorporated herein by reference in its entirety.

BACKGROUND

Reinforced concrete flat slabs are extensively used in the building construction industry. During a manufacturing process, utility pipes are typically positioned adjacent to concrete columns due to architectural or mechanical constraints. To position a utility pipe through a reinforced concrete slab, holes have to be created in the reinforced concrete slab. There are several conventional methods employed to create holes in cast-in-place concrete slabs. One method for creating a hole is by using a formwork that includes a section defining a hole positioned in a specified location inside the formwork. Concrete is then poured inside the formwork around the section that defines the hole to create a reinforced concrete slab with a hole. After the concrete is cured, the formwork is removed.

Another conventional method to form a void during the concrete pour is to use sleeves. The sleeves are retained in the reinforced concrete slab. Although these voids allow mechanical piping to run through the reinforced concrete slab, these voids reduce the structural capability of the concrete and the sleeves. The sleeves are generally made of tube shaped steel that offers no structural capacity due to a lack of bond between concrete and steel tubes. Since pipe penetrations reduce shear capacity of reinforced concrete slabs and in some cases cause shear failures, design engineers often have to check moment and shear capacities of reinforced concrete slabs when sleeves are placed in close proximity to supports such as concrete columns. In many cases, structural modifications are required to compensate for the loss of shear capacity caused by pipe penetrations. The structural modifications comprise, for example, increasing slab thickness, providing column capital, etc., which are costly and space consuming.

Hence, there is a long felt but unresolved need for a sleeve device that reinforces concrete slabs while allowing penetrations to be in close proximity to concrete columns, adds structural capacity to the concrete slabs, minimizes the work and effort required from an engineer, and allows architects and mechanical engineers more flexibility in locating mechanical piping.

SUMMARY OF THE INVENTION

This summary is provided to introduce a selection of concepts in a simplified form that are further disclosed in the detailed description of the invention. This summary is not intended to identify key or essential inventive concepts of the claimed subject matter, nor is it intended for determining the scope of the claimed subject matter.

The sleeve device disclosed herein addresses the above stated needs for reinforcing concrete slabs while allowing penetrations to be in close proximity to concrete columns, adding structural capacity to the concrete slabs, minimizing the work and effort required from an engineer, and allowing architects and mechanical engineers more flexibility in locating mechanical piping. The sleeve device disclosed herein transfers shear forces and compensates for concrete slab shear capacity loss due to penetrations proximal to concrete columns. The sleeve device disclosed herein is a device, for example, made of metal attached to a concrete structure such as a reinforced concrete slab and configured to transfer shear forces in the reinforced concrete slab.

The sleeve device disclosed herein increases shear capacity of a reinforced concrete slab. The sleeve device disclosed herein comprises a hollow member, stud members configured, for example, as bent headed studs, and head members configured, for example, as bent stud heads. The hollow member is positioned on and fastened to a bottom formwork defining the reinforced concrete slab. The hollow member comprises an inner space configured to create a void in the reinforced concrete slab by pouring of concrete around an outer wall of the hollow member. The stud members are connected to the opposing sides of the hollow member either directly or using connectors. A first stud member is connected to an upper portion of the hollow member and oriented in a downward direction. A second stud member is connected to a lower portion of the hollow member and oriented in an upward direction. The head members are operably coupled to the distal ends of the stud members and embedded in the reinforced concrete slab. The head members are configured to transfer shear forces through an interaction between the head members and the concrete surrounding the stud members.

After concrete is cast around the sleeve device, the sleeve device is embedded in the reinforced concrete slab and works together with the rest of the reinforced concrete slab. The shear forces within the reinforced concrete slab are transferred from the reinforced concrete slab to a first head member on one opposing side of the hollow member through an internal bearing stress at the first head member and then as a tension from the first head member to the first stud member. The tension in the first stud member is then transferred through the hollow member on to the other opposing side of the hollow member, to the second stud member on the other opposing side of the hollow member, and then to a second head member. After receiving the transferred tension, the second head member transfers the shear forces through an internal bearing stress at the second head member, for example, to an opposing side slab, a reinforced concrete column, a supporting column, a wall concrete, or other support. When the shear forces are transferred across the sleeve device, the sleeve device increases the shear capacity in the reinforced concrete slab and compensates for the loss of the shear capacity in the reinforced concrete slab.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description of the invention, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, exemplary constructions of the invention are shown in the drawings. However, the invention is not limited to the specific methods and structures disclosed herein. The description of a method step or a structure referenced by a numeral in a drawing carries over to the description of that method step or structure shown by that same numeral in any subsequent drawing herein.

FIG. 1A exemplarily illustrates a top perspective view of a sleeve device for increasing shear capacity of a reinforced concrete slab, showing the sleeve device positioned in a bottom formwork.

FIG. 1B exemplarily illustrates an enlarged view of a portion marked X in FIG. 1A, showing the sleeve device.

FIG. 2 exemplarily illustrates a partial sectional view of the sleeve device.

FIG. 3 exemplarily illustrates a top plan view of the sleeve device.

FIG. 4A exemplarily illustrates an isometric view of an embodiment of the sleeve device, showing a hollow member of the sleeve device having a square cross section.

FIG. 4B exemplarily illustrates an isometric view of an embodiment of the sleeve device, showing the hollow member of the sleeve device having an octagonal cross section.

FIG. 4C exemplarily illustrates an isometric view of an embodiment of the sleeve device, showing the hollow member of the sleeve device having a rectangular cross section.

FIG. 5A exemplarily illustrates an isometric view of an embodiment of the sleeve device, showing stud members of the sleeve device configured as bent plates affixed to the hollow member of the sleeve device.

FIG. 5B exemplarily illustrates an isometric view of an embodiment of the sleeve device, showing the stud members of the sleeve device configured as corrugated plates affixed to the hollow member of the sleeve device.

FIG. 5C exemplarily illustrates an isometric view of an embodiment of the sleeve device, showing the stud members of the sleeve device configured as bent reinforcing bars affixed to the hollow member of the sleeve device.

FIG. 5D exemplarily illustrates an isometric view of an embodiment of the sleeve device, showing the stud members of the sleeve device configured as straight headed studs affixed to the hollow member of the sleeve device.

FIG. 6 exemplarily illustrates an isometric wireframe view, showing bent headed studs of the sleeve device positioned in a different orientation within a concrete beam.

FIG. 7A exemplarily illustrates a perspective view of multiple sleeve devices positioned in a reinforced concrete slab.

FIG. 7B exemplarily illustrates an enlarged view of a portion marked Y in FIG. 7A.

FIG. 8 illustrates a method for increasing shear capacity of a reinforced concrete slab.

FIG. 9 exemplarily illustrates a side view of a reinforced concrete slab with the sleeve device, showing shear forces acting on the reinforced concrete slab, internal bearing stresses at bent stud heads of the sleeve device, and tension within bent headed studs of the sleeve device.

FIG. 10A exemplarily illustrates a top plan view of a reinforced concrete column and a reinforced concrete slab, showing a shear critical section of the reinforced concrete slab.

FIG. 10B exemplarily illustrates a top plan view of a reinforced concrete column and a reinforced concrete slab with a sleeve formed in the reinforced concrete slab, proximal to the reinforced concrete column, and showing a shear critical section of the reinforced concrete slab.

FIG. 10C exemplarily illustrates a top plan view of a reinforced concrete column and a reinforced concrete slab with the sleeve device positioned in the reinforced concrete slab, proximal to the reinforced concrete column, and showing a shear critical section of the reinforced concrete slab.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1A exemplarily illustrates a top perspective view of a sleeve device 100 for increasing shear capacity of a reinforced concrete slab 602 exemplarily illustrated in FIGS. 7A-7B, showing the sleeve device 100 positioned in a bottom formwork 110. As used herein, “shear capacity” refers to maximum shear stress that a concrete structure, for example, a connection between a reinforced concrete slab 602 and a reinforced concrete column 702 exemplarily illustrated in FIGS. 7A-7B, can withstand before shear failure of the concrete structure. Also, as used herein, “shear stress” refers to an external force acting on a structure or a surface parallel to a plane of the structure or the surface per unit area. The sleeve device 100 disclosed herein is a cast-in-place sleeve device, for example, made of steel used in a concrete structure, for example, a reinforced concrete slab 602. The sleeve device 100 disclosed herein comprises, for example, bent headed studs 104 and 105 or bent rebars welded to a hollow member 101 on opposing sides 101d and 101e of the hollow member 101 respectively, to increase shear capacity around a reinforced concrete slab-column joint 701 exemplarily illustrated in FIGS. 7A-7B. As used herein, “bent headed stud” refers to a reinforced metallic bar used in concrete construction, capable of carrying load across a shear plane or a bending plane.

The sleeve device 100 disclosed herein comprises the hollow member 101, stud members configured, for example, as bent headed studs 104 and 105, and head members configured, for example, as bent stud heads 106 and 107 as exemplarily illustrated in FIGS. 1A-1B. For purposes of illustration, the detailed description refers to stud members configured as bent headed studs 104 and 105; however the scope of the sleeve device 100 disclosed herein is not limited to the stud members being configured as bent headed studs 104 and 105, but may be extended to include stud members configured, for example, as bent plates 115 and 116, corrugated plates 117 and 118, bent reinforcing bars 119 and 120, straight headed studs 121 and 122, etc., as exemplarily illustrated in FIGS. 5A-5D, and functionally equivalent members.

As exemplarily illustrated in FIGS. 1A-1B, the hollow member 101 of the sleeve device 100 is positioned on and fastened to a bottom formwork 110 defining a reinforced concrete slab 602 exemplarily illustrated in FIGS. 7A-7B. The hollow member 101 comprises an inner space 102 configured to create a void 103 in the reinforced concrete slab 602 by pouring of concrete 111 around an outer wall 101c of the hollow member 101. The inner space 102 is an empty volume defined within the hollow member 101. After the sleeve device 100 is positioned on the bottom formwork 110, concrete 111 is poured around the outer wall 101c of the hollow member 101 and allowed to cure. After a predefined curing period, the inner space 102 of the hollow member 101 of the sleeve device 100 that is embedded in the reinforced concrete slab 602 defines the void 103 in the reinforced concrete slab 602. The void 103 created by the inner space 102 of the hollow member 101 can be of multiple geometric shapes that suitably allow components, for example, piping, duct work, air passages, fluid passages, etc., to pass through. The void 103 can also be configured in multiple geometric shapes for visual purposes, or other architectural or mechanical needs, etc. The hollow member 101 is further configured to transfer a tension force from the bent headed stud 104 to the bent headed stud 105.

The bent headed studs 104 and 105 of the sleeve device 100 exemplarily illustrated in FIGS. 1A-3, are connected to the opposing sides 101d and 101e of the hollow member 101 respectively. In an embodiment, the bent headed studs 104 and 105 of the sleeve device 100 are connected to the opposing sides 101d and 101e of the hollow member 101 using connectors 108 and 109 respectively. In another embodiment, the bent headed studs 104 and 105 of the sleeve device 100 are welded directly to the opposing sides 101d and 101e of the hollow member 101 respectively, without the connectors 108 and 109. The bent headed studs 104 and 105 are, for example, small diameter steel bars. A first bent headed stud 104 is connected to an upper portion 101a of the hollow member 101 and oriented, for example, in a downward direction. A second bent headed stud 105 is connected to a lower portion 101b of the hollow member 101 and oriented, for example, in an upward direction. The first bent headed stud 104 oriented in the downward direction and the second bent headed stud 105 oriented in the upward direction restrain the reinforced concrete slab diagonal crack widths due to shear stresses. The first bent headed stud 104 is, for example, a bent shear stud or a rebar welded at the upper portion 101a of the hollow member 101. The second bent headed stud 105 is, for example, another bent shear stud or rebar welded at the lower portion 101b of the hollow member 101.

The bent stud heads 106 and 107 of the sleeve device 100 are operably coupled to the distal ends 104a and 105a of the bent headed studs 104 and 105 respectively, and embedded in the reinforced concrete slab 602 exemplarily illustrated in FIGS. 7A-7B. The bent stud heads 106 and 107 are configured to transfer shear forces through an interaction between the bent stud heads 106 and 107 and the concrete 111 surrounding the bent headed studs 104 and 105. The bent stud heads 106 and 107 are, for example, stud head shaped enlarged metallic members capable of resisting a force or a load and transferring the force or the load to the bent headed studs 104 and 105. The bent stud heads 106 and 107 resist the tension from the bent headed studs 104 and 105 respectively, for transferring the shear stresses formed in the reinforced concrete slab 602 across the sleeve device 100. The sleeve device 100 is preassembled and can be installed on site by unskilled labor without using any special tools.

After concrete 111 is cast around the sleeve device 100, the sleeve device 100 is embedded in the reinforced concrete slab 602 and works together with the rest of the reinforced concrete slab 602 exemplarily illustrated in FIGS. 7A-7B. The shear forces within the reinforced concrete slab 602 are transferred from the reinforced concrete slab 602 to the first bent stud head 106 on one opposing side 101d of the hollow member 101 through an internal bearing stress at the first bent stud head 106, and then as a tension from the first bent stud head 106 to the first bent headed stud 104. As used herein, “internal bearing stress” refers to an internal stress caused by compressive forces due to triaxial stresses between a concrete structure, for example, the reinforced concrete slab 602, the reinforced concrete column 702, etc., exemplarily illustrated in FIGS. 7A-7B, and the bent stud heads 106 and 107. The tension in the first bent headed stud 104 is then transferred through the hollow member 101 to the second bent headed stud 105 on the other opposing side 101e of the hollow member 101, and then to a second bent stud head 107. After receiving the tension through the hollow member 101, the second bent stud head 107 transfers the shear forces through an internal bearing stress at the second bent stud head 107, for example, to the reinforced concrete column 702, or an opposing side slab, or a wall concrete, another support, etc.

When a penetration is made in a reinforced concrete slab 602 located near a reinforced concrete column 702 as exemplarily illustrated in FIGS. 7A-7B, the reinforced concrete slab 602 undergoes a shear capacity loss and tends to fail when loaded with variable loads. The sleeve device 100 disclosed herein compensates for the shear capacity loss due to the creation of the void 103 by transferring shear forces in the mature reinforced concrete slab 602. The sleeve device 100 disclosed herein is used in monolithic poured concrete slabs 602 which are positioned proximal to reinforced concrete columns 702. The sleeve device 100 disclosed herein transfers shear forces by attaching bent headed studs 104 and 105 horizontally to the connectors 108 and 109 welded on the opposing sides 101d and 101e of the hollow member 101 respectively, and on the upper portion 101a and the lower portion 101b of the hollow member 101.

FIG. 1B exemplarily illustrates an enlarged view of a portion marked X in FIG. 1A, showing the sleeve device 100. In an embodiment, the sleeve device 100 disclosed herein further comprises mounting rings 112 rigidly connected to and extending outwardly from the opposing sides 101g and 101h of the lower portion 101b of the hollow member 101. The mounting rings 112 are configured to fasten the hollow member 101 to the bottom formwork 110 exemplarily illustrated in FIG. 1A, that defines the reinforced concrete slab 602 exemplarily illustrated in FIGS. 7A-7B, to secure the sleeve device 100 in place. In an embodiment, the mounting rings 112 for fastening or nailing down the sleeve device 100 can be altered or removed. The materials used for manufacturing the sleeve device 100 are, for example, any high or low strength steel, alloy or other metal, carbon fiber or other composite material, etc. The size of the sleeve device 100 can be increased or decreased depending on the requirements. In an embodiment as exemplarily illustrated in FIGS. 1A-1B, the hollow member 101 of the sleeve device 100 is of a generally cylindrical shape. The cross section A-A of the hollow member 101 is, for example, of a circular shape. The hollow member 101 can be configured in multiple shapes that allow multiple insertions, for example, mechanical structures and electrical components to be inserted through the void 103 created in the reinforced concrete slab 602, or insertions that require an opening for mechanical purposes, architectural purposes, or other purposes.

The sleeve device 100 can be made, for example, in a shop. In an example of making the sleeve device 100, a steel fabricator cuts a steel pipe to an appropriate length to create the hollow member 101. The steel fabricator then shop welds stud members, for example, the bent headed studs 104 and 105 to the hollow member 101, where a first bent headed stud 104 oriented in a downward direction is welded to the upper portion 101a of the hollow member 101 via a connector 108, and a second bent headed stud 105 oriented in an upward direction is welded to a lower portion 101b of the hollow member 101 via a connector 109. The bent headed studs 104 and 105 and the bent stud heads 106 and 107 are prefabricated, or fabricated on site by welding the bent stud heads 106 and 107 of predefined sizes to predefined lengths of the bent headed studs 104 and 105. The mounting rings 112 or form tabs are welded to the bottom plane 101f of the hollow member 101.

The sleeve device 100 can be located anywhere on the reinforced concrete slab 602 exemplarily illustrated in FIGS. 7A-7B, proximal to slab supports such as columns and walls. The sleeve device 100 is used, for example, in flat plate cast-in-place concrete construction in two way slabs, one way slabs, slabs with beams, or any other type of slab system. The sleeve device 100 is further used, for example, in a reinforced concrete beam 601 either horizontally as exemplarily illustrated in FIG. 6 or vertically, on concrete walls or columns, in brackets, capitals, corbels, buttresses, ramps, stairs, or any other portion of a building transferring loads. The sleeve device 100 is further used, for example, in concrete on a steel deck, in precast members such as bridge components, marine components, facades, plank, T shaped bridge components, double T bridge components, etc.

FIG. 2 exemplarily illustrates a partial sectional view of the sleeve device 100. The hollow member 101 of the sleeve device 100 is positioned between the bent headed studs 104 and 105. The bent headed studs 104 and 105 of the sleeve device 100 are connected on the opposing sides 101d and 101e of the hollow member 101, for example, via the connectors 108 and 109 respectively. The first bent headed stud 104 is connected to one opposing side 101d of the hollow member 101, at the upper portion 101a of the hollow member 101 and extends outward from the outer wall 101c of the hollow member 101 to connect to the first bent stud head 106 at the distal end 104a of the first bent headed stud 104. Similarly, the second bent headed stud 105 is connected to the other opposing side 101e of the hollow member 101, at the lower portion 101b of the hollow member 101 and extends outward from the outer wall 101c of the hollow member 101 to connect to the second bent stud head 107 at the distal end 105a of the second bent headed stud 105. The first bent headed stud 104 is located near the upper portion 101a of the hollow member 101. The first bent stud head 106 is affixed to the distal end 104a of the first bent headed stud 104. On the other opposing side 101e of the hollow member 101, the second bent headed stud 105 extends away from the upper portion 101a of the hollow member 101. The second bent stud head 107 is affixed to the distal end 105a of the second bent headed stud 105. The concrete 111 exemplarily illustrated in FIG. 1A, is cast around the hollow member 101 to create the void 103 in the reinforced concrete slab 602 exemplarily illustrated in FIGS. 7A-7B.

FIG. 3 exemplarily illustrates a top plan view of the sleeve device 100. The mounting rings 112 are rigidly connected at the bottom plane 101f of the hollow member 101 exemplarily illustrated in FIG. 1B, and on diametrically opposing sides 101g and 101h of the hollow member 101. The mounting rings 112 are oriented perpendicular to an axis line 113 that connects the bent headed studs 104 and 105. The mounting rings 112 that protrude outwardly from the bottom plane 101f of the hollow member 101, affix the hollow member 101 to the bottom formwork 110 exemplarily illustrated in FIG. 1A, such that the bottom base plane 112a of each mounting ring 112 is oriented at the same level as the bottom plane 101f of the hollow member 101 as exemplarily illustrated in FIG. 2. Holes 114 defined in the mounting rings 112 are positioned outside the outer wall 101c, that is, the outer diameter of the hollow member 101. The bent headed studs 104 and 105 are located on the outer wall 101c of the hollow member 101 and midway between the mounting rings 112 that are positioned near the bottom plane 101f of the hollow member 101.

FIGS. 4A-4C exemplarily illustrate isometric views of different embodiments of the sleeve device 100, showing different cross sections of the hollow member 101. In an embodiment, a cross section B-B of the hollow member 101 is of a square geometric shape as exemplarily illustrated in FIG. 4A. In this embodiment, the hollow member 101 is of a generally cubic shape. In another embodiment, a cross section C-C of the hollow member 101 is of an octagonal geometric shape as exemplarily illustrated in FIG. 4B. In this embodiment, the hollow member 101 is of a generally octagonal shape. In another embodiment, a cross section D-D of the hollow member 101 is of a rectangular geometric shape as exemplarily illustrated in FIG. 4C. In this embodiment, the hollow member 101 is of a generally cuboidal shape.

FIGS. 5A-5D exemplarily illustrate isometric views of different embodiments of the sleeve device 100, showing different configurations of the stud members of the sleeve device 100. In an embodiment, the hollow member 101, the stud members, and the head members of the sleeve device 100 are of predefined sizes configured to accommodate different opening sizes of the void 103 exemplarily illustrated in FIG. 1A, and structural capacities of the reinforced concrete slab 602 exemplarily illustrated in FIGS. 7A-7B. The transfer of tension to and from the hollow member 101 may be performed using multiple methods. The head members of the sleeve device 100 are configured in multiple shapes to generate tensile stresses in the stud members.

In an embodiment as exemplarily illustrated in FIG. 5A, the stud members are bent plates 115 and 116 affixed to the opposing sides 101d and 101e of the hollow member 101 respectively, for transferring tension to and from the hollow member 101. In another embodiment as exemplarily illustrated in FIG. 5B, the stud members are corrugated plates 117 and 118 affixed to the opposing sides 101d and 101e of the hollow member 101 respectively, for transferring tension to and from the hollow member 101. In another embodiment as exemplarily illustrated in FIG. 5C, the stud members are bent reinforcing bars 119 and 120 affixed to the opposing sides 101d and 101e of the hollow member 101 respectively, for transferring tension to and from the hollow member 101. In another embodiment as exemplarily illustrated in FIG. 5D, the stud members are straight headed studs 121 and 122 affixed to the opposing sides 101d and 101e of the hollow member 101 respectively, for transferring tension to and from the hollow member 101.

Although the detailed description refers to the stud members of the sleeve device 100 configured as bent headed studs 104 and 105 exemplarily illustrated in FIGS. 1A-4C, bent plates 115 and 116, corrugated plates 117 and 118, bent reinforcing bars 119 and 120, and straight headed studs 121 and 122 for transferring tension to and from the hollow member 101, the scope of the sleeve device 100 disclosed herein is not limited to stud members being configured as bent headed studs 104 and 105, bent plates 115 and 116, corrugated plates 117 and 118, bent reinforcing bars 119 and 120, and straight headed studs 121 and 122, but may be extended to include stud members configured as corrugated fins, angles, etc., and other tension developing affixations for transferring tension to and from the hollow member 101. Further, the method for transferring tension to and from the hollow member 101 may be performed using multiple other methods comprising, for example, affixing alternative headed stud members (not shown) as substitutes for the bent headed studs 104 and 105 to the hollow member 101, configuring ridges (not shown) within the hollow member 101, etc.

FIG. 6 exemplarily illustrates an isometric wireframe view, showing bent headed studs 104 and 105 of the sleeve device 100 positioned in a different orientation within a reinforced concrete beam 601. The reinforced concrete beam 601 is fixedly attached to a reinforced concrete slab 602, which is supported by reinforced concrete columns 603 and 604. In an embodiment, the bent headed studs 104 and 105 are configured to be rotated, replaced, and repositioned to transfer tension to and from the bent headed studs 104 and 105 and the hollow member 101 in different ways and in multiple directions, for example, along different axes.

The sleeve device 100 is constructed of any suitable material capable of transferring loads. The components of the sleeve device 100, for example, the hollow member 101, the bent headed studs 104 and 105, and the bent stud heads 106 and 107 can be rearranged in multiple orientations to accommodate penetrations in the reinforced concrete slab 602. The sleeve device 100 can be rotated, for example, at a right angle to create a void 103 in a horizontal direction within the reinforced concrete beam 601. As exemplarily illustrated in FIG. 6, the sleeve device 100 is repositioned in the reinforced concrete beam 601 by tilting the sleeve device 100 at an angle, for example, about 90 degrees. When the sleeve device 100 is tilted, the bent headed studs 104 and 105 are also rotated and repositioned within the reinforced concrete beam 601. Furthermore, as exemplarily illustrated in FIG. 6, multiple bent headed studs 104 and 105 are connected to the hollow member 101 to increase the shear transfer capacity of the sleeve device 100.

FIG. 7A exemplarily illustrates a perspective view of multiple sleeve devices 100a, 100b, and 100c positioned in a reinforced concrete slab 602, proximal to a reinforced concrete column 702. As exemplarily illustrated in FIG. 7B, which shows an enlarged view of a portion marked Y in FIG. 7A, each of the sleeve devices 100a, 100b, and 100c comprises the hollow member 101, the bent headed studs 104 and 105, and the bent stud heads 106 and 107 as disclosed in the detailed description of FIGS. 1A-3. The sleeve devices 100a, 100b, and 100c are used in concrete construction, for example, in cast-in-place reinforced concrete slabs 602. A user places each hollow member 101 at a predetermined position in the bottom formwork 110 as exemplarily illustrated in FIG. 1A. As exemplarily illustrated in FIG. 7A, the sleeve device 100c is positioned in a perpendicular direction with respect to the other two sleeve devices 100a and 100b.

The sleeve devices 100a, 100b, and 100c are positioned on the bottom formwork 110 with the upper portion 101a of each hollow member 101 exemplarily illustrated in FIGS. 1A-1B, above an upper portion of the bottom formwork 110. The mounting rings 112 exemplarily illustrated in FIG. 7B, fasten the sleeve devices 100a, 100b, and 100c to the bottom formwork 110 defining the reinforced concrete slab 602 and secure the sleeve devices 100a, 100b, and 100c in place. The second bent headed stud 105 of each of the sleeve devices 100a, 100b, and 100c is oriented in an upward direction closest to the reinforced concrete column 702, and the first bent headed stud 104 of each of the sleeve devices 100a, 100b, and 100c is oriented in a downward direction away from the reinforced concrete column 702. The concrete 111 is poured into the bottom formwork 110 as exemplarily illustrated in FIG. 1A, and cast around the hollow member 101 of each of the sleeve devices 100a, 100b, and 100c. Each hollow member 101 defines a void 103 in the reinforced concrete slab 602 formed inside the bottom formwork 110 and the void 103 remains free of concrete 111.

The sleeve devices 100a, 100b, and 100c are embedded in the reinforced concrete slab 602 close to reinforced concrete columns 702. The sleeve devices 100a, 100b, and 100c are fastened onto the bottom formwork 110 exemplarily illustrated in FIG. 1A, and embedded in the monolithically poured reinforced concrete slab 602 depending on the locations of the penetrations. By restraining crack widths in the reinforced concrete slab 602, the bent stud heads 106 and 107 prevent failure due to shear stresses within a threshold shear absorption range of the sleeve devices 100a, 100b, and 100c and result in a larger shear critical section size for the slab-column joint 701 between the reinforced concrete column 702 and the reinforced concrete slab 602. The “threshold shear absorption range” of the sleeve device 100a, or 100b, or 100c is defined by the American Concrete Institute (ACI) in Building Code Requirements for Structural Concrete, ACI 318, chapter 11. The sleeve devices 100a, 100b, and 100c compensate for shear capacity loss at the slab-column joint 701 between the reinforced concrete column 702 and the reinforced concrete slab 602, for example, due to pipe penetrations, by welding the bent stud heads 106 and 107 attached to the distal ends 104a and 105a of the bent headed studs 104 and 105 on the opposing sides 101d and 101e of the hollow member 101 exemplarily illustrated in FIG. 2, respectively of each of the sleeve devices 100a, 100b, and 100c.

Consider an example where a reinforced concrete slab 602 is positioned such that an edge 602a of the reinforced concrete slab 602 is proximal to a reinforced concrete column 702 and an edge 602b of the reinforced concrete slab 602 is distal to the reinforced concrete column 702 as exemplarily illustrated in FIG. 7A. A hole is cast in the reinforced concrete slab 602 that is proximal to the reinforced concrete column 702 for the purposes of passing a piping or duct work. The effective shear force on the edge 602a of the reinforced concrete slab 602 proximal to the reinforced concrete column 702 will be higher than the effective shear force on the edge 602b of the reinforced concrete slab 602 distal to the reinforced concrete column 702. The difference in effective shear force on the edges 602a and 602b causes a difference in shear stress adjacent to the hole on an upper section and a lower section of the hole as indicated by the block arrows in FIG. 7B. An increase in the load in the hole of the reinforced concrete slab 602 increases the shear stress across the hole and increases the risk of a shear failure in the reinforced concrete slab 602 at the formed hole. Therefore, the reinforced concrete slab 602 is subjected to a loss of shear capacity due to the formed hole. To prevent the shear failure of the reinforced concrete slab 602, the sleeve device 100 exemplarily illustrated in FIGS. 1A-6, is used during construction of the reinforced concrete slab 602 to form the void 103 in the reinforced concrete slab 602 instead of forming the hole in the reinforced concrete slab 602 with a conventional sleeve.

When the shear forces within the reinforced concrete slab 602 are transferred across the sleeve device 100 as disclosed in the detailed description of FIG. 1A and FIG. 9, the sleeve device 100 compensates for the loss of shear capacity in the reinforced concrete slab 602 that would have resulted while using a conventional sleeve, and increases the shear capacity of the reinforced concrete slab 602 compared to that of a reinforced concrete slab 602 with a conventional sleeve. Therefore, the shear capacity of the reinforced concrete slab 602 with the sleeve device 100 disclosed herein is high when compared with that of a reinforced concrete slab 602 with a conventional sleeve. While a conventional sleeve reduces the shear capacity of the reinforced concrete slab 602 by displacing an area equivalent to the cross section of the conventional sleeve, a shear sleeve, that is, the sleeve device 100 has the ability to equal or exceed the shear capacity of the equivalent concrete section.

The size of the sleeve device 100 can be estimated by first calculating an equivalent loss of shear capacity based on a size of a hole formed in a reinforced concrete slab 602 exemplarily illustrated in FIG. 10B. The loss of shear capacity is based on an equivalent cross section of the sleeve device 100. The cross section area (a) of the sleeve device 100 is calculated by multiplying the sleeve device diameter (D) with the sleeve device height (h) in accordance with the formula:

a=(D*h)

When used in a two way slab, the loss of shear capacity (V) can be calculated by multiplying the cross section area (a) with 4 times the square root of strength (fc) of the reinforced concrete slab 602 in accordance with the formula:

V=a*4*√{square root over (f′c)}

where “fc” is strength of the reinforced concrete slab 602, for example, about 5000 pounds per square inch (psi). Consider an example where the sleeve device diameter (D) is 8 inches (″) and the thickness of the reinforced concrete slab 602 constructed of 5000 psi concrete is 12″. Therefore, the equivalent loss of shear capacity is (8*12)*4*√5000=27152 lbs. The sleeve device 100 can then be designed to meet or exceed the calculated value of the equivalent loss of shear capacity. The bent stud heads 106 and 107 of the sleeve device 100 are designed to develop the required load, and the bent headed studs 104 and 105 are designed to develop the appropriate tension. The connection between the bent headed studs 104 and 105 and the bent stud heads 106 and 107 respectively is designed to transfer the appropriate tension. The wall thickness of the sleeve device 100 is designed to accommodate the appropriate shear.

FIG. 8 illustrates a method for increasing shear capacity of a reinforced concrete slab 602 exemplarily illustrated in FIGS. 7A-7B. The sleeve device 100 comprising the hollow member 101, the stud members configured, for example, as bent headed studs 104 and 105, and the head members configured, for example, as bent stud heads 106 and 107 as exemplarily illustrated in FIGS. 1A-3 and as disclosed in the detailed description of FIGS. 1A-3, is provided 801. The sleeve device 100 is positioned and fastened 802 to a bottom formwork 110 defining the reinforced concrete slab 602. Pouring concrete 111 around an outer wall 101c of the hollow member 101 of the sleeve device 100 creates 803 a void 103 in the reinforced concrete slab 602 as exemplarily illustrated in FIG. 1A. Shear forces from within the reinforced concrete slab 602 are transferred 804 to the first bent stud head 106 on one opposing side 101d of the hollow member 101 through an internal bearing stress at the first bent stud head 106. The internal bearing stress from the first bent stud head 106 is transferred 805 to the first bent headed stud 104 as a tension. The tension from the first bent headed stud 104 is transferred 806 through the hollow member 101 to the second bent headed stud 105 on the other opposing side 101e of the hollow member 101. The tension from the second bent headed stud 105 is transferred 807 to the second bent stud head 107. The second bent stud head 107 transfers 808 the shear forces through the internal bearing stress at the second bent stud head 107, for example, to a reinforced concrete column 702 or a support, after receiving the transferred tension in the second bent stud head 107. The shear forces transferred across the sleeve device 100 increase the shear capacity in the reinforced concrete slab 602 and compensate for a loss of the shear capacity in the reinforced concrete slab 602.

FIG. 9 exemplarily illustrates a side view of a reinforced concrete slab 602 with the sleeve device 100, showing shear forces 901 and 909 acting on the reinforced concrete slab 602, internal bearing stresses 902 and 908 at the bent stud heads 106 and 107 of the sleeve device 100, and tension 903 and 907 within the bent headed studs 104 and 105 of the sleeve device 100. The shear forces 901 within the reinforced concrete slab 602 are transferred from the reinforced concrete slab 602 to the first bent stud head 106 on one opposing side 101d of the hollow member 101 through an internal bearing stress 902 at the first bent stud head 106, and then as a tension 903 from the first bent stud head 106 to the first bent headed stud 104. The tension 903 in the first bent headed stud 104 is then transferred through the hollow member 101 as shear forces 904, 905, and 906. The shear forces 904, 905, and 906 within the hollow member 101 are transferred to the second bent headed stud 105 on the other opposing side 101e of the hollow member 101 as tension 907, which is transferred to the second bent stud head 107. After receiving the tension 907 through the hollow member 101, the second bent stud head 107 transfers the shear forces 909 through an internal bearing stress 908 at the second bent stud head 107 to the reinforced concrete column 702, for example, an opposing side slab, a wall concrete, another support, etc., as exemplarily illustrated in FIGS. 7A-7B.

FIG. 10A exemplarily illustrates a top plan view of a reinforced concrete column 702 and a reinforced concrete slab 602, showing a shear critical section 602c of the reinforced concrete slab 602. As used herein, “shear critical section” refers to a section in the reinforced concrete slab 602, which defines a slab-column joint punching shear capacity. The reinforced concrete slab 602 exemplarily illustrated in FIG. 10A is free of penetrations. Consider an example where the reinforced concrete slab 602 of thickness (d), for example, 12″ is supported by a reinforced concrete column 702 of dimensions 12″ by 12″ or 1 foot (′) by 1′ as exemplarily illustrated in FIG. 10A. Consider the shear critical section 602c to be at a distance (d/2) away from the reinforced concrete column 702 and is therefore 6″ from the reinforced concrete column 702. The perimeter (P) of the shear critical section 602c can be calculated as 24″*4 or 2′*4. The area (A) of the shear critical section 602c is the multiplication product of the perimeter (P) of the shear critical section 602c and the thickness (d) of the reinforced concrete slab 602. Therefore, the area (A) of the shear critical section 602c is [(24″*4)*12″]=1152 square inches.

Nominal shear capacity (Vn) of the reinforced concrete slab 602 at the reinforced concrete column 702 is the sum of shear capacity (Vc) of the reinforced concrete slab 602 and shear capacity (Vs) of shear reinforcement, that is, the sleeve device 100 in accordance with the formula:

Vn=Vc+Vs

The shear capacity (Vc) of the reinforced concrete slab 602 is 4 times the multiplication product of the area (A) of the shear critical section 602c and the square root of the strength (fc) of the reinforced concrete slab 602 in accordance with the formula:

Vc=A*4*√{square root over (f′c)}

where “fc” is the strength of the reinforced concrete slab 602, for example, about 5000 pounds per square inch (psi). Therefore, the shear capacity (Vc) of the reinforced concrete slab 602 is 1152*4*√5000=325835 lbs. The shear capacity (Vs) of the sleeve device 100 is zero since the reinforced concrete slab 602 is free of penetrations and therefore free of the sleeve device 100. Therefore, the nominal shear capacity (Vn) of the reinforced concrete slab 602 at the reinforced concrete column 702 is 325835+0=325835 lbs.

FIG. 10B exemplarily illustrates a top plan view of a reinforced concrete column 702 and a reinforced concrete slab 602 with a sleeve 1001 formed in the reinforced concrete slab 602, proximal to the reinforced concrete column 702, and showing a shear critical section 602c of the reinforced concrete slab 602. Consider an 8″ core formed sleeve 1001 in the reinforced concrete slab 602 as exemplarily illustrated in FIG. 10B. The area (A) of the shear critical section 602c is calculated as A=[(24″*4)−8″]*12″=1056 square inches. Then, the shear capacity (Vc) of the reinforced concrete slab 602 can be calculated as 1056*4*√5000=298682 lbs. Therefore, the nominal shear capacity (Vn) of the reinforced concrete slab 602 at the reinforced concrete column 702 without the sleeve device 100 is 298682+0=298682 lbs. Thus, the 8″ core formed sleeve 1001 reduces the nominal shear capacity (Vn) of the reinforced concrete slab 602 at the reinforced concrete column 702 by 27153 lbs.

FIG. 10C exemplarily illustrates a top plan view of a reinforced concrete column 702 and a reinforced concrete slab 602 with the sleeve device 100 positioned in the reinforced concrete slab 602, proximal to the reinforced concrete column 702, and showing a shear critical section 602c of the reinforced concrete slab 602. The sleeve device 100 comprising the stud members configured, for example, as bent headed studs 104 and 105, and head members configured, for example, as bent stud heads 106 and 107 is embedded in the reinforced concrete slab 602 for increasing the shear capacity in the reinforced concrete slab 602 when compared to the nominal shear capacity (Vn) of the reinforced concrete slab 602 at the reinforced concrete column 702 due to the formed sleeve 1001 exemplarily illustrated n FIG. 10B. The sleeve device 100 bridges the penetration created in the reinforced concrete slab 602 by the formed sleeve 1001 and increases the perimeter (P) of the shear critical section 602c of the slab-column connection. Consider the sleeve device 100 is a rigid sleeve device and the associated deformation of the sleeve device 100 is negligible under shear forces. The enhanced shear capacity of the sleeve device 100 that is required to compensate the lost nominal shear capacity (Vn) is controlled by the dimensions of the bent headed studs 104 and 105 and the bent stud heads 106 and 107 of the sleeve device 100. When the sleeve device 100 is embedded in the reinforced concrete slab 602 and is configured to provide for the lost nominal shear capacity (Vn)=27153 lbs of the reinforced concrete slab 602 due to the formed sleeve 1001, the total nominal shear capacity (Vn) of the reinforced concrete slab 602 at the reinforced concrete column 702 becomes equal to or larger than the nominal shear capacity (Vn)=325835 lbs of the reinforced concrete slab 602 at the reinforced concrete column 702 before penetration of the reinforced concrete slab 602 with the formed sleeve 1001. Thus, the sleeve device 100 disclosed herein compensates the lost shear capacity of the reinforced concrete slab 602.

The foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention disclosed herein. While the invention has been described with reference to various embodiments, it is understood that the words, which have been used herein, are words of description and illustration, rather than words of limitation. Further, although the invention has been described herein with reference to particular means, materials, and embodiments, the invention is not intended to be limited to the particulars disclosed herein; rather, the invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims. Those skilled in the art, having the benefit of the teachings of this specification, may effect numerous modifications thereto and changes may be made without departing from the scope and spirit of the invention in its aspects.

Claims

1. A sleeve device for increasing shear capacity of a reinforced concrete slab, said sleeve device comprising:

a hollow member positioned on and fastened to a bottom formwork defining said reinforced concrete slab, said hollow member comprising an inner space configured to create a void in said reinforced concrete slab by pouring of concrete around an outer wall of said hollow member;

stud members connected to opposing sides of said hollow member, wherein a first of said stud members is connected to an upper portion of said hollow member and oriented in a downward direction, and wherein a second of said stud members is connected to a lower portion of said hollow member and oriented in an upward direction; and

head members operably coupled to distal ends of said stud members and embedded in said reinforced concrete slab, said head members configured to transfer shear forces through an interaction between said head members and said concrete surrounding said stud members, wherein when said shear forces are transferred across said sleeve device, said sleeve device increases said shear capacity in said reinforced concrete slab and compensates for a loss of said shear capacity in said reinforced concrete slab.

2. The sleeve device of claim 1, wherein said shear forces within said reinforced concrete slab are transferred from said reinforced concrete slab to a first of said head members on one of said opposing sides of said hollow member through an internal bearing stress at said first of said head members and then as a tension from said first of said head members to said first of said stud members, wherein said tension in said first of said stud members is transferred through said hollow member to said second of said stud members on another of said opposing sides of said hollow member, and then to a second of said head members, and wherein after receiving said transferred tension, said second of said head members transfers said shear forces through an internal bearing stress at said second of said head members to one of a reinforced concrete column, a slab, and a support.

3. The sleeve device of claim 1, wherein said stud members are bent headed studs affixed to said opposing sides of said hollow member, wherein said bent headed studs are configured to transfer tension to and from said hollow member.

4. The sleeve device of claim 3, wherein said head members are bent stud heads operably coupled to said distal ends of said bent headed studs and embedded in said reinforced concrete slab, wherein said bent stud heads are configured to transfer said shear forces through an interaction between said bent stud heads and said concrete surrounding said bent headed studs.

5. The sleeve device of claim 1, wherein said stud members are bent plates affixed to said opposing sides of said hollow member, wherein said bent plates are configured to transfer tension to and from said hollow member.

6. The sleeve device of claim 1, wherein said stud members are corrugated plates affixed to said opposing sides of said hollow member, wherein said corrugated plates are configured to transfer tension to and from said hollow member.

7. The sleeve device of claim 1, wherein said stud members are straight headed studs affixed to said opposing sides of said hollow member, wherein said straight headed studs are configured to transfer tension to and from said hollow member.

8. The sleeve device of claim 1, wherein said stud members are bent reinforcing bars affixed to said opposing sides of said hollow member, wherein said bent reinforcing bars are configured to transfer tension to and from said hollow member.

9. The sleeve device of claim 1, wherein said head members are configured in multiple shapes to generate tensile stresses in said stud members.

10. The sleeve device of claim 1, wherein said hollow member is one of a generally cylindrical shape, a cubic shape, a cuboidal shape, and an octagonal shape.

11. The sleeve device of claim 1, wherein a cross section of said hollow member is of a geometric shape comprising at least one of a circular shape, a square shape, a rectangular shape, and an octagonal shape.

12. The sleeve device of claim 1, wherein said hollow member, said stud members, and said head members are of predefined sizes configured to accommodate different opening sizes of said void and structural capacities of said reinforced concrete slab.

13. The sleeve device of claim 1, wherein said stud members are further configured to be rotated and repositioned to transfer tension to and from said stud members and said hollow member in a plurality of directions.

14. The sleeve device of claim 1, wherein said stud members are directly welded to said opposing sides of said hollow member.

15. The sleeve device of claim 1, wherein said stud members are connected to said opposing sides of said hollow member using connectors.

16. A sleeve device for increasing shear capacity of a reinforced concrete slab, said sleeve device comprising:

a hollow member positioned on and fastened to a bottom formwork defining said reinforced concrete slab, said hollow member comprising an inner space configured to create a void in said reinforced concrete slab by pouring of concrete around an outer wall of said hollow member;

bent headed studs connected to opposing sides of said hollow member, wherein a first of said bent headed studs is connected to an upper portion of said hollow member and oriented in a downward direction, and wherein a second of said bent headed studs is connected to a lower portion of said hollow member and oriented in an upward direction; and

bent stud heads operably coupled to distal ends of said bent headed studs and embedded in said reinforced concrete slab, said bent stud heads configured to transfer shear forces through an interaction between said bent stud heads and said concrete surrounding said bent headed studs, wherein when said shear forces are transferred across said sleeve device, said sleeve device increases said shear capacity in said reinforced concrete slab and compensates for a loss of said shear capacity in said reinforced concrete slab.

17. The sleeve device of claim 16, wherein said shear forces within said reinforced concrete slab are transferred from said reinforced concrete slab to a first of said bent stud heads on one of said opposing sides of said hollow member through an internal bearing stress at said first of said bent stud heads and then as a tension from said first of said bent stud heads to said first of said bent headed studs, wherein said tension in said first of said bent headed studs is transferred through said hollow member to said second of said bent headed studs on another of said opposing sides of said hollow member, and then to a second of said bent stud heads, and wherein after receiving said transferred tension, said second of said bent stud heads transfers said shear forces through an internal bearing stress at said second of said bent stud heads to one of a reinforced concrete column, a slab, and a support.

18. The sleeve device of claim 16, wherein said hollow member is one of a generally cylindrical shape, a cubic shape, a cuboidal shape, and an octagonal shape.

19. The sleeve device of claim 16, wherein a cross section of said hollow member is of a geometric shape comprising at least one of a circular shape, a square shape, a rectangular shape, and an octagonal shape.

20. The sleeve device of claim 16, wherein said hollow member, said bent headed studs, and said bent stud heads are of predefined sizes configured to accommodate different opening sizes of said void and structural capacities of said reinforced concrete slab.

21. The sleeve device of claim 16, wherein said bent stud heads are configured in multiple shapes to generate tensile stresses in said bent headed studs.

22. The sleeve device of claim 16, wherein said bent headed studs are further configured to be rotated and repositioned to transfer tension to and from said stud members and said hollow member in a plurality of directions.

23. The sleeve device of claim 16, wherein said bent headed studs are directly welded to said opposing sides of said hollow member.

24. The sleeve device of claim 16, wherein said bent headed studs are connected to said opposing sides of said hollow member using connectors.

25. A method for increasing shear capacity of a reinforced concrete slab, said method comprising:

providing a sleeve device comprising: a hollow member comprising an inner space; stud members connected to opposing sides of said hollow member, wherein a first of said stud members is connected to an upper portion of said hollow member and oriented in a downward direction, and wherein a second of said stud members is connected to a lower portion of said hollow member and oriented in an upward direction; and head members operably coupled to distal ends of said stud members and embedded in said reinforced concrete slab;

positioning and fastened said sleeve device to a bottom formwork defining said reinforced concrete slab;

creating a void in said reinforced concrete slab using said hollow member of said sleeve device by pouring concrete around an outer wall of said hollow member;

transferring shear forces from within said reinforced concrete slab to a first of said head members on one of said opposing sides of said hollow member through an internal bearing stress at said first of said head members;

transferring said internal bearing stress from said first of said head members to said first of said stud members as a tension;

transferring said tension from said first of said stud members through said hollow member to said second of said stud members on another of said opposing sides of said hollow member;

transferring said tension from said second of said stud members to a second of said head members; and

transferring said shear forces to one of a reinforced concrete column, a slab, and a support through an internal bearing stress at said second of said head members,

after receiving said transferred tension in said second of said head members, wherein when said shear forces are transferred across said sleeve device, said sleeve device increases said shear capacity in said reinforced concrete slab and compensates for a loss of said shear capacity in said reinforced concrete slab.

26. The method of claim 25, wherein said head members of said sleeve device are configured to transfer said shear forces through an interaction between said head members and said concrete surrounding said stud members of said sleeve device.

27. The method of claim 25, wherein said stud members of said sleeve device are bent headed studs affixed to said opposing sides of said hollow member, wherein said bent headed studs are configured to transfer said tension to and from said hollow member.

28. The method of claim 27, wherein said head members of said sleeve device are bent stud heads operably coupled to said distal ends of said bent headed studs and embedded in said reinforced concrete slab, wherein said bent stud heads are configured to transfer shear forces through an interaction between said bent stud heads and said concrete surrounding said bent headed studs.

29. The method of claim 25, wherein said stud members of said sleeve device are one of bent plates, corrugated plates, straight headed studs, and bent reinforcing bars affixed to said opposing sides of said hollow member to transfer said tension to and from said hollow member of said sleeve device.

30. The method of claim 25, wherein said head members of said sleeve device are configured in multiple shapes to generate tensile stresses in said stud members.

31. The method of claim 25, wherein said hollow member of said sleeve device is one of a generally cylindrical shape, a cubic shape, a cuboidal shape, and an octagonal shape.

32. The method of claim 25, wherein a cross section of said hollow member of said sleeve device is of a geometric shape comprising at least one of a circular shape, a square shape, a rectangular shape, and an octagonal shape.

33. The method of claim 25, wherein said hollow member, said stud members, and said head members of said sleeve device are of predefined sizes configured to accommodate different opening sizes of said void and structural capacities of said reinforced concrete slab.

34. The method of claim 25, further comprising rotating and repositioning said stud members to transfer said tension to and from said stud members and said hollow member in a plurality of directions.