CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. provisional Application No. 63/182,659 entitled “Centralizer” filed April 30, 2021. Each of the patent applications and publications listed in this paragraph is hereby incorporated herein by reference in its entirety as an example.

BACKGROUND

Technical Field

[0002] The centralizer relates to centralizers that provide support for and centrally position prestressed steel, such as rebar, inside a bore hole to provide a minimum grout cover within the earth retention system.

Description of Related Art

[0003] A soil and rock anchor system was designed in 1965 as the “New Austrian Tunneling Method” for excavating rock in a tunnel project, historically referred to as rock bolts. The concept combined the use of neat cement grout and rebar with use of shotcrete on the face of the excavation as a support.

[0004] In 1972 soil nails were developed in France to stabilize a slope for a railroad project and from the success of this project it started to expand to other European countries and is now used globally.

[0005] An earth retention system (ERS) built in the U.S. was used in deep excavation on a Hospital project in 1976 located in Portland, Oregon. In 1979 the U.S. Department of Federal Highway Administration (FHWA) authorized a study for construction utilizing earth retention systems to provide adequate information for state highway agencies, to develop a manual for standard design and to promote this novel construction technique.

[0006] U.S. Patent No. US5588784A discloses a soil or rock nail wall with an outer face and method of constructing the same. The method includes excavating soil in successive sections to expose each level for inserting the soil or rock nail and constructing the outer face of the wall. This is comprised of drilling a bore hole perpendicular to the vertical exposed earth. Then inserting a soil or rock nail into the bore hole and grouting the bore hole. Next the outer face or wall is constructed, and shotcrete added. Then the process starts over, down to the desired depth.

[0007] A Multi-purpose adjustable centralizer system with tool is disclosed in U.S.

Patent No. US6102118A. In this document, a centralized system comprises a plurality of straps and two collars on each end. The straps and collars are individual components that are combined to make a centralizer after the straps are inserted in the collars. The centralizer is then tied to rebar with one or more ties, which can be time-consuming and result in undesirable increases in cost and losses in efficiency.

SUMMARY OF SELECTED EMBODIMENTS OF THE INVENTION

[0008] In a first embodiment, a centralizer for centering rebar within a bore hole is provided. The centralizer comprises a first sleeve section, a second sleeve section and a radially protruding section. The first sleeve section comprises a first aperture. A referential central axis of the centralizer passes through the first sleeve section, the referential central axis being a straight line, and the centralizer configured to receive the rebar along the referential central axis. The second sleeve section comprises a second aperture through which the referential central axis passes, and the second sleeve section is spaced from the first sleeve section in a direction along the referential central axis. The radially protruding section is directly or indirectly connected to the first sleeve section and the second sleeve section, and an outer surface of the radially protruding section is configured to form a convex surface that extends radially outwardly from the referential central axis. The first sleeve section comprises a first threaded interior surface configured to engage a threaded outer surface of the rebar and to impede the ability of the rebar to slip through the first sleeve section along the referential central axis.

[0009] In a second embodiment, a method of using a centralizer for centering rebar within a bore hole is provided. The method comprises securing the centralizer on the rebar at a first position adjacent to a first end of rebar. The method also comprises inserting the centralizer on the rebar into the bore hole.

[0010] In a third embodiment, a system comprising the centralizer and rebar is provided.

[0011] Other aspects, embodiments and features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. The accompanying figures are schematic and are not intended to be drawn to scale. In the figures, each identical, or substantially similar component that is illustrated in various figures is represented by a single numeral or notation. For purposes of clarity, not every component is labeled in every figure. Nor is every component of each embodiment of the invention shown where illustration is not necessary to allow those of ordinary skill in the art to understand the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 depicts a schematic illustration of centralizer as shown in a perspective view from the front, left and top of the centralizer.

[0013] Figure 2 is a schematic illustration of the front of the centralizer of Figure 1.

[0014] Figure 3 is a schematic illustration of the left side of the centralizer of Figure 1.

[0015] Figure 4 is a schematic illustration of the top of the centralizer of Figure 1.

[0016] Figure 5 is a schematic illustration of a plurality of the centralizers of Figure 1 being used to center rebar within a bore hole.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0017] An earth-retaining system (ERS) can involve use of a reinforcing structure with a bore hole into which a passive reinforcement (e.g., passive reinforcement in the form of a rod or cylinder optionally with a twisted, threaded or helical exterior surface, passive metal reinforcement, passive metal alloy reinforcement, passive steel reinforcement, bar, rebar) is inserted and grouted to retain the remaining soil. The load of the remaining soil is then transferred from the passive reinforcement (e.g., bar) as the weight of the soil undergoes an axial force, stretching the passive reinforcement (e.g., bar). The axial force is then transferred through the grout at the surface to the surface of the surrounding soil and causes a shear stress that decreases as it passes the weight of the earth retention system into the surrounding soil.

[0018] With all the pressure that is on the surrounding soil and earth retention system, the coincident placement of the rock anchor or soil nail by a centralizer is an integral component in the construction of the earth retention system.

[0019] An ERS can include some type of rock anchor or soil nail for use in a permanent or temporary anchored system. This approach is designed to construct an anchored wall built to stabilize an excavation or slope. The ERS is built prior to construction of a foundation in the subsurface layer of earth to evenly distribute the building load through the earthen layers. After the rock anchor or soil nail is grouted, the placement of the rebar cannot be inspected. Accordingly, it is useful to accurately position the rebar before it is grouted. Centralizers can be helpful to position the rebar, but previously required ties to secure the centralizers to the rebar before use of the rebar in a bore hole. Application of ties to rebar can be time-consuming and result in undesirable increases in cost and losses in efficiency. Additionally, the costs in time and money can be multiplied many times over for sing construction project because multiple centralizers can used on a single piece of rebar in a single bore hole, and multiple bore holes can be required for the construction project.

[0020] Advantageously, the present disclosure provides a centralizer that does not require a tie, which centralizer can be referred to as a no-tie centralizer. An embodiment of a centralizer is provided that can be used in an earth retention system to centralize a single passive reinforcement (e.g., steel reinforcement, rebar) in a bore hole. Accordingly, the centralizer can be configured to be attached to and to surround a single reinforcement.

[0021] Also disclosed is a system that comprises a centralizer designed to be installed on rebar in a bore hole without the centralizer needing to be tied to the rebar.

[0022] Upon installation of the no-tie centralizer, the rebar can be placed coincident the center axis of a bore hole, and the centralizer (e.g., a first and/or second threaded interior surface of the centralizer) can be configured to engage a threaded outer surface of the rebar, which therefore impedes the ability of the rebar to slip through the first and/or second sleeve section along a referential central axis of the centralizer.

[0023] In some embodiments, the centralizer can be made from any material or selection of materials selected from the group consisting of metals, metal alloys, polymers, plastics, thermoplastics, and moldable materials. In some embodiments, the centralizer is made of a moldable material or materials, which can be selected, for example, from the group consisting of polymers, plastics, and PVC (i.e., polyvinyl chloride).

[0024] In some embodiments, a radially protruding section of the centralizer comprises a plurality of radially protruding elements 0116 (e.g., portions, ribbons, strips or bands), and the plurality of a radially protruding elements curve outwardly from the referential central axis.

[0025] The components of the centralizer can form one and only one continuous solid structure. [0026] An embodiment of a centralizer 0100 for centering rebar 0200 within a bore hole 0202, will now be described with reference to Figures 1 to 5. The centralizer 0100 comprises a first sleeve section 0102, a second sleeve section 0104, and a radially protruding section 0106.

As can be seen, the centralizer 0100 has a referential central axis 0108 that is a straight line (e.g., as illustrated by the dashed line in Figure 1), and the centralizer 0100 is configured to receive the rebar 0200 along the referential central axis 0108 (e.g., as illustrated in Figures 1 and 5).

[0027] In some embodiments, the centralizer can be used for centering rebar in a bore hole 0202 that is a drilled hole.

[0028] With further reference to Figure 1, the first sleeve section 0102 comprises a first aperture 0110, and the referential central axis 0108 of the centralizer 0100 passes through the first sleeve section 0102.

[0029] As illustrated, the second sleeve section 0104 comprises a second aperture 0112 through which the referential central axis 0108 passes. The second sleeve section 0104 is spaced from the first sleeve section 0102 in a direction along the referential central axis 0108.

Although not illustrated, in some embodiments, the centralizer can comprise a single sleeve section (e.g., a first sleeve section 0102) and the first sleeve section can extend from the location of the first sleeve section 0102 (e.g., as illustrated in Figure 1) to the location of the second sleeve section 0104 (e.g., as illustrated in Figure 1).

[0030] In some embodiments, the radially protruding section 0106 is directly or indirectly connected to the first sleeve section 0102 and optionally the second sleeve section 0104 if one is present. Additionally, in some embodiments, an outer surface of a radially protruding section 0106 can be configured to form at least one convex surface that extends radially outwardly from the referential central axis 0108. In some embodiments, the at least one convex surface can be a single continuous convex surface rather than a plurality of convex surfaces (e.g., portions, ribbons, strips or bands) that extend radially outwardly from the referential central axis 0108 as illustrated in Figure 1.

[0031] In some embodiments, the first sleeve section 0102 comprises a first threaded interior surface 0114. The threaded interior surface 0114 can be configured to engage a threaded outer surface of the rebar 0200 and to impede the ability of the rebar 0200 to slip through the first sleeve section 0102 along the referential central axis 0108. [0032] In some embodiments, the threaded interior surface can be configured to engage a threaded outer surface of the rebar 0200, for example, so that the rebar 0200 can be screwed into or fixed in place relative to the first sleeve section 0102, so that the rebar 0200 can be inserted through the centralizer 0100, so that the rebar 0200 can be inserted through the second sleeve section 0104, or any combination thereof. In some embodiments, the first sleeve section 0102 does not comprise a threaded interior surface.

[0033] In some embodiments, the first threaded interior surface can be molded to fasten the centralizer 0100 to the rebar 0200 when the centralizer 0100 is in use.

[0034] In some embodiments, the first threaded interior surface can be configured so that, when the first sleeve section 0102 is in place around the rebar 0200, the rebar 0200 cannot be moved directly along the referential central axis 0108 of the centralizer 0100 without the centralizer 0100 rotating relative to the rebar 0200. In some embodiments, the first sleeve section 0102 can be provided with a discontinuity (e.g., at least partially in the direction of the referential central axis 0108) so that the first sleeve section can be separated along the discontinuity and so that the rebar 0200 can be moved directly along the referential central axis 0108 of the centralizer 0100 without the centralizer 0100 rotating relative to the rebar 0200. Accordingly, in some embodiments, the first sleeve section 0102 can be provided with a discontinuity (e.g., at least partially in the direction of the referential central axis 0108) so that the first sleeve section 0102 can be separated along the discontinuity and placed around rebar at a particular position on the rebar without having to thread the first sleeve section 0102 along the rebar from an end of the rebar to the particular position on the rebar. In some embodiments, it can be useful for the first sleeve section and/or the centralizer 0100 to be sufficiently flexible to be provided in a parted configuration where the discontinuity of the first sleeve section is parted sufficiently for rebar to pass through the parted discontinuity (e.g., to be parted a distance that is at least equal to the inner diameter of the first sleeve section in a rebar-gripping configuration before the discontinuity is parted) and sufficiently elastic for the first sleeve section to return to a rebar-gripping configuration that is configured to grip the rebar. In some embodiments, the first sleeve section 0102 does not comprise a discontinuity (e.g., can form a complete circuit along a perimeter surrounding the referential central axis 0108.)

[0035] In some embodiments, the first sleeve section 0102 can have a cylindrical shape. [0036] In some embodiments, the first sleeve section 0102 can be positioned concentric, parallel, coincident, or any combination thereof with the referential central axis 0108 of the centralizer 0100, the central axis of the bore hole 0202, the second sleeve section 0104 or any combination thereof.

[0037] In some embodiments, the second sleeve section 0104 can have a cylindrical shape.

[0038] With reference again to Figure 1, in some embodiments, the second sleeve section 0104 can have a threaded interior surface. The threaded interior surface can be configured to engage a threaded outer surface of the rebar 0200 so that the rebar 0200 can be screwed into or fixed into place relative to the second sleeve section 0104, so that the rebar 0200 can be inserted through the centralizer 0100, so that the rebar 0200 can be inserted through the first sleeve section 0102, or any combination thereof.

[0039] In some embodiments, the second sleeve section 0104 comprises a second threaded interior surface configured to engage the threaded outer surface of the rebar 0200 and to impede the ability of the rebar 0200 to slip through the second sleeve section 0104 along the referential central axis 0108. In some embodiments, the second sleeve section 0104 does not comprise a second threaded interior surface.

[0040] In some embodiments, the second threaded interior surface can be molded to fasten the centralizer 0100 to the rebar 0200 when the centralizer 0100 is in use.

[0041] In some embodiments, the second threaded interior surface can be configured so that, when the second sleeve section 0104 is in place around the rebar 0200, the rebar 0200 cannot be moved directly along the referential central axis 0108 of the centralizer 0100 without the centralizer 0100 rotating relative to the rebar 0200. In some embodiments, the second sleeve section 0104 can be provided with a discontinuity (e.g., at least partially in the direction of the referential central axis 0108) so that the second sleeve section 0104 can be separated along the discontinuity and so that the rebar 0200 can be moved directly along the referential central axis 0108 of the centralizer 0100 without the centralizer 0100 rotating relative to the rebar 0200. Accordingly, in some embodiments, the second sleeve section 0104 can be provided with a discontinuity (e.g., at least partially in the direction of the referential central axis 0108) so that the second sleeve section 0104 can be separated along the discontinuity and placed around rebar at a particular position on the rebar without having to thread the second sleeve section 104 along the rebar from an end of the rebar to the particular position on the rebar. In some embodiments, it can be useful for the second sleeve section and/or the centralizer 0100 to be sufficiently flexible to be provided in a parted configuration where the discontinuity of the second sleeve section is parted sufficiently for rebar to pass through the parted discontinuity (e.g., to be parted a distance that is at least equal to the inner diameter of the second sleeve section in a rebar gripping configuration before the discontinuity is parted) and sufficiently elastic for the second sleeve section to return to a rebar-gripping configuration that is configured to grip the rebar. In some embodiments, the second sleeve section 0104 does not comprise a discontinuity (e.g., can form a complete circuit along a perimeter surrounding the referential central axis 0108.)

[0042] In some embodiments, the second sleeve section 0104 has a cylindrical shape that can optionally be positioned concentric, parallel, coincident, or any combination thereof with the referential central axis 0108 of the centralizer 0100, the central axis of the bore hole 0202, the first sleeve section 0102 or any combination thereof.

[0043] In some embodiments, the radially protruding section 0106 can be located between the first sleeve section 0102 and the second sleeve section 0104.

[0044] In some embodiments, the radially protruding section 0106 is a bow spring section (e.g., comprising a bow spring or a plurality of bow springs).

[0045] In some embodiments, the radially protruding section 0106 or the bow string section can be configured to flex from an unflexed configuration into a flexed configuration in response to a radially inwardly directed force (e.g., a force that is greater than or equal to a flexing force), and to return to the unflexed configuration when the force is removed (e.g., when a force greater than or equal to the flexing force is no longer applied to a radially protruding section 0106 section).

[0046] In some embodiments, a radially protruding section 0106 can be configured so an outer surface of a radially protruding section 0106 is configured to extend beyond the outer surface of the first sleeve section 0102 and the outer surface of the second sleeve section 0104 in a direction radially outwardly from the referential central axis 0108.

[0047] In some embodiments, the radially protruding section 0106 can be configured to position the rebar 0200 away from the inner surfaces of the bore hole 0202.

[0048] In some embodiments, the radially protruding section 0106 can comprise at least one bowed component (e.g., 1, 2, 3, or a plurality of bowed components). [0049] In some embodiments, a radially protruding section 0106 comprises a plurality of a radially protruding section 0106 components (e.g., at least two, two, three, or four) that are mutually spaced.

[0050] In some embodiments, the centralizer 0100 can be configured so that it can be formed in a mold.

[0051] In some embodiments, the components of the centralizer 0100 can form one and only one continuous solid structure.

[0052] In some embodiments, the first sleeve section 0102, the second sleeve section 0104, a radially protruding section 0106, any component of the centralizer 0100, or any combination thereof can be molded and can also be formed from a single piece of moldable or molded material.

[0053] In some embodiments, the components of the centralizer 0100 can be separable components that are joined together to form the centralizer 0100.

[0054] In some embodiments the centralizer serves to space (e.g., space evenly) the rebar from an inner surface of the bore hole.

[0055] In some embodiments, the centralizer can be used in forming an earth retention system, for example, a rock-and-soil anchor wall.

[0056] In some embodiments, when securing the centralizer on the rebar at a first position adjacent to a first end of rebar, the end of the centralizer closest to the first end of the rebar can be no more than 10 ft., 9 ft., 8 ft., 7 ft., 6 ft., 5 ft., 4 ft., 3 ft., 2 ft., 1 ft., 6 inches, 3 inches, 2 inches, 1 inch, or 1/2 inch from the first end of the rebar, and/or at least 10 ft., 9 ft., 8 ft., 7 ft., 6 ft., 5 ft., 4 ft., 3 ft., 2 ft., 1 ft., 6 inches, 3 inches, 2 inches, 1 inch, or 1/2 inch from the first end of the rebar.

[0057] In some embodiments, a method comprises placing the rebar coincident with the center axis of the bore hole and filling the bore hole with a material (e.g., grout, cement, or neat cement grout) to fix the centralizer and the rebar coincident in the bore hole.

[0058] In some embodiments, the number of centralizers in the plurality of centralizers can be given by dividing the distance between the first position and the second position by a number from 2 to 10 ft. In some embodiments, a spacing quotient is the distance between the first position and the second position divided by a difference, the difference obtained by subtracting one from the number of centralizers in the plurality of centralizers, and the spacing quotient is to be less than 10 feet.

ADDITIONAL EMBODIMENT CLAUSES

[0059] 1. A centralizer for centering rebar within a bore hole, the centralizer comprising:

[0060] a first sleeve section, the first sleeve section comprising a first aperture, a referential central axis of the centralizer passing through the first sleeve section, the referential central axis being a straight line, and the centralizer configured to receive the rebar along the referential central axis;

[0061] a second sleeve section, the second sleeve section comprising a second aperture through which the referential central axis passes, and the second sleeve section spaced from the first sleeve section in a direction along the referential central axis; and

[0062] a radially protruding section, directly or indirectly connected to the first sleeve section and the second sleeve section, an outer surface of the radially protruding section optionally configured to form a convex surface, the radially protruding section extending radially outwardly from the referential central axis;

[0063] optionally an outer surface of the radially protruding section configured to form a convex surface that extends radially outwardly from the referential central axis;

[0064] optionally the first sleeve section comprising a first threaded interior surface configured to engage a threaded outer surface of the rebar and to impede the ability of the rebar to slip through the first sleeve section along the referential central axis;

[0065] optionally the radially protruding section configured to be provided in a configuration so that an outer surface of the a radially protruding section extends beyond the outer surface of the first sleeve section and the outer surface of the second sleeve section in a direction radially outwardly from the referential central axis; and

[0066] optionally the centralizer configured optionally the centralizer configured to be coupled (e.g., fixed or attached) to the rebar without a coupling device (e.g., a tie) that is not a sleeve section of the centralizer.

[0067] 2. The centralizer of any preceding clause, wherein the radially protruding section comprises a plurality of a radially protruding elements, and the plurality of a radially protruding elements curve outwardly from the referential central axis. [0068] 3. The centralizer of any preceding clause, wherein the radially protruding elements are equally spaced along the circumference of a circle concentric with the referential central axis.

[0069] 4. The centralizer of any preceding clause, wherein the centralizer comprises a minimum of four radially protruding elements.

[0070] 5. The centralizer of any preceding clause, wherein the centralizer comprises a plurality of a radially protruding elements extending lengthwise between the first sleeve section and the second sleeve section

[0071] 6. The centralizer of any preceding clause, wherein the centralizer consists of one and only one piece comprising the first sleeve section, the second sleeve section, and the radially protruding section.

[0072] 7. A method of using a centralizer (optionally the centralizer of any preceding clause) for centering rebar within a bore hole, the method comprising: securing the centralizer on the rebar at a first position adjacent to a first end of rebar; and inserting the centralizer on the rebar into the bore hole, optionally the end of the centralizer closest to the first end of the rebar is no more than 10 ft., 9 ft., 8 ft., 7 ft., 6 ft., 5 ft., 4 ft., 3 ft., 2 ft., 1 ft., 6 inches, 3 inches, 2 inches, 1 inch, or 1/2 inch from the first end of the rebar, and optionally the end of the centralizer closest to the first end of the rebar is at least 10 ft., 9 ft., 8 ft., 7 ft., 6 ft., 5 ft., 4 ft., 3 ft., 2 ft., 1 ft., 6 inches, 3 inches, 2 inches, 1 inch, or 1/2 inch from the first end of the rebar;

[0073] optionally the centralizer configured to be coupled (e.g., fixed or attached) to the rebar without a coupling device (e.g., a tie) that is not a sleeve section of the centralizer.

[0074] 8. The method of any preceding clause, in which a plurality of centralizers comprising the centralizer are each installed along the rebar, optionally wherein each centralizer in the plurality of centralizers is installed at a separation distance from adjacent centralizers in the plurality of centralizers, optionally wherein the separation distance between any two adjacent centralizers in the plurality of centralizers ranges from 1 feet to 10 feet, optionally wherein the end of the centralizer closest to the first end of the rebar is from 0 to 3 feet, or 1 to 2 feet, or about 1.5 feet from the first end of the rebar; and optionally the radial distance from the referential central axis of the centralizer to the outer edge of each of the radially protruding sections is 1/8 to 3/4 inch (e.g., 1/4 or 1/2 inch) less than a radius of the bore hole, optionally wherein the centralizer is arranged and/or configured so that 1/4 inch to 3/4 inch (e.g., 1/4 or 1/2 inch) of grout can be positioned between the outer edge of each of the radially protruding sections and the surface of the bore hole.

[0075] 9. The method of any preceding clause, the method comprising: filling the bore hole with grout, optionally neat cement grout optionally after the step of inserting the centralizer.

[0076] 10. The method of any preceding clause, the method comprising: allowing the grout to cure so that the centralizer and the rebar are fixed in position relative to the bore hole.

[0077] 11. The method of any preceding clause, the method comprising: securing a second centralizer on the rebar at a second position adjacent a second end of the rebar, the second end of the rebar being opposite the first end of the rebar; and inserting the second centralizer on the rebar into the bore hole, optionally the end of the second centralizer closest to the second end of the rebar is no more than 10 ft., 9 ft., 8 ft., 7 ft., 6 ft., 5 ft., 4 ft., 3 ft., 2 ft., 1 ft.,

6 inches, 3 inches, 2 inches, 1 inch, or 1/2 inch from the second end of the rebar, and optionally the end of the second centralizer closest to the second end of the rebar is at least 10 ft., 9 ft., 8 ft.,

7 ft., 6 ft., 5 ft., 4 ft., 3 ft., 2 ft., 1 ft., 6 inches, 3 inches, 2 inches, 1 inch, or 1/2 inch from the second end of the rebar.

[0078] 12. The method of any preceding clause, in which a plurality of centralizers comprising the centralizer and the second centralizer are each installed along the rebar at a separation distance, optionally wherein the separation distance between any two centralizers in the plurality of centralizers is at least 1/2 inch, 1 inch, 2 inches, 3 inches, 6 inches, 1 foot, 2 feet, 3 feet, 4 feet, 5 feet, 6 feet, 7 feet, 8 feet, 9 feet or 10 feet, no more than 1/2 inch, 1 inch, 2 inches, 3 inches, 6 inches, 1 foot, 2 feet, 3 feet, 4 feet, 5 feet, 6 feet, 7 feet, 8 feet, 9 feet or 10 feet, or any combination thereof; optionally wherein the end of the centralizer closest to the first end of the rebar is from 0 to 3 feet, or 1 to 2 feet, or about 1.5 feet from the first end of the rebar, and optionally wherein the end of the second centralizer closest to the second end of the rebar is from 0 to 3 feet, or 1 to 2 feet, or about 1.5 feet from the second end of the rebar; optionally the end of the centralizer closest to the first end of the rebar is at least 1/2 inch from the first end of the rebar; optionally, the radial distance from the referential central axis of the centralizer to the outer edge of each of the radially protruding sections is 1/8 to 3/4 inch (e.g., 1/4 or 1/2 inch) less than a radius of the bore hole, optionally wherein the centralizer is arranged and/or configured so that 1/4 inch to 3/4 inch (e.g., 1/4 or 1/2 inch) of grout can be positioned between the outer edge of each of the radially protruding sections and the surface of the bore hole; and optionally the end of the second centralizer closest to the second end of the rebar is at least 1/2 inch from the second end of the rebar.

[0079] 13. The method of any preceding clause, the method comprising securing a third centralizer around the rebar at a third position, wherein the third position is between the first position and the second position.

[0080] 14. The method of any preceding clause, the method comprising positioning a plurality of centralizers around the rebar between the first position and the second position.

[0081] 15. The method of any preceding clause, wherein the centralizer positions the rebar concentrically with the center axis of the bore hole to within a tolerance that is 0 to 10% of a bore hole dimension, the bore hold dimension being the diameter of the bore hole or the longest distance across the bore hole in a direction perpendicular to the center axis of the bore hole.

[0082] 16. A method of using a centralizer (optionally of any preceding clause) for centering rebar within a bore hole, the method comprising: securing the centralizer on the rebar at a position located on the rebar; inserting the centralizer, on the rebar, into the bore hole, the centralizer configured to space the rebar (e.g., more evenly space the rebar) from the wall or walls of the bore hole, optionally the radial distance from the referential central axis of the centralizer to the outer edge of each of the radially protruding sections is 1/8 to 3/4 inch (e.g., 1/4 or 1/2 inch) less than a radius of the bore hole, optionally wherein the centralizer is arranged and/or configured so that 1/4 inch to 3/4 inch (e.g., 1/4 or 1/2 inch) of grout can be positioned between the outer edge of each of the radially protruding sections and the surface of the bore hole; and optionally filling the bore hole with grout (e.g., neat cement grout) to fix the rebar permanently in the bore hole; optionally wherein the centralizer comprises: a first sleeve section optionally having a rounded shape (e.g., cylindrical shape; having an inner surface, the inner surface having a concave shape; or any combination thereof); and a second sleeve section optionally having a rounded shape (e.g., cylindrical shape; having an inner surface, the inner surface having a concave shape; or any combination thereof); optionally the first sleeve section comprising a first threaded interior surface configured to engage a threaded outer surface of the rebar and to impede the ability of the rebar to slip through the first sleeve section along a referential central axis of the centralizer; optionally the second sleeve section comprising a second threaded interior surface configured to engage the threaded outer surface of the rebar and to impede the ability of the rebar to slip through the second sleeve section along the referential central axis of the centralizer; optionally the first and second threads configured to engage (e.g., fix) the inner surface of the centralizer with the outer surface of the rebar optionally without the centralizer needing to be tied to the rebar with a tie or otherwise coupled to the rebar with a coupling device that is not a sleeve section of the centralizer; and optionally the centralizer configured to be coupled (e.g., fixed or attached) to the rebar without a coupling device (e.g., a tie) that is not a sleeve section of the centralizer.

[0083] 17. The method of any preceding clause, wherein the first and second threaded interior surfaces are each configured to engage a threaded outer surface of the rebar and to impede the ability of the rebar to slip through the first and second sleeve section along the referential central axis.

[0084] 18. The method of any preceding clause, wherein the first and second threaded interior surfaces are configured to engage a threaded outer surface of the rebar and to impede the ability of the rebar to slip through the first and second sleeve section along the referential central axis.

[0085] 19. A system comprising the centralizer of any preceding clause and a passive reinforcement (e.g., passive reinforcement in the form of a rod or cylinder; passive reinforcement with a twisted, threaded or helical exterior surface; passive metal reinforcement; passive metal alloy reinforcement; passive steel reinforcement; bar; rebar; or any combination thereof) positioned within the first sleeve section and the second sleeve section of the centralizer.

[0086] 20. The centralizer, method, or system of any preceding clause, wherein the centralizer comprises any feature described in this disclosure.

[0087] Although various embodiments have been described using a bar or rebar, in additional embodiments, the term “bar” and/or the term “rebar” can be replaced with “passive reinforcement” or any example of a passive reinforcement described in this disclosure, for example, passive reinforcement in the form of a rod or cylinder; passive reinforcement with a twisted, threaded or helical exterior surface; passive metal reinforcement; passive metal alloy reinforcement; passive steel reinforcement; bar; rebar; or any combination thereof.

[0088] Although various embodiments have been described using a “threaded interior surface,” in additional embodiments, the term “threaded” can be replaced with “textured” or the “threaded interior surface” can be replaced with any example of a textured surface, for example, a surface configured to provide adequate friction with the passive reinforcement (e.g., rebar) in order to avoid the threaded interior slipping against the passive reinforcement when the centralizer is inserted, on the passive reinforcement, into the bore hole. Examples of textured surfaces include, but are not limited to, ridged surfaces, corrugated surfaces, and rough surfaces.

[0089] Although the term “comprising” has been used in this disclosure, in additional embodiments, “comprising” can be replaced with “consisting essentially of’ or “consisting of.”

[0090] Although the centralizer, a system comprising the centralizer and a method of using the centralizer have been described by way of preferred embodiments, it will be evident that other adaptations and modifications can be employed without departing from the spirit and scope thereof. The terms and expressions employed herein have been used as terms of description and not of limitation; and thus, there is no intent of excluding equivalents, but on the contrary it is intended to cover any and all equivalents that may be employed without departing from the spirit and scope of the invention.