Patent Application
20240279940
Concrete is a mixture of cement, water, and aggregates. Known for its strength, durability, low maintenance, energy efficiency, and relatively low cost, concrete is one of the most frequently used building materials used for constructing buildings, bridges, roads, sidewalks and other structures. In some structures, concrete is used in combination with reinforcement bars (herein, rebars). The combination of concrete and rebars is known as reinforced concrete and is widely used to mitigate the weak tension of concrete by distributing the tensile forces evenly across the structure and support heavy loads.
Some examples of the disclosed technology provide a column shoe assembly. A shoe body can include an access opening and a lower rod (e.g., rebar) opening that defines a connection axis to receive a threaded rod (e.g., rebar) end.
In some examples, a threaded connection can be included on an upper side of the shoe body, opposite the lower rod opening, to secure the shoe body to an upper rod section.
In some examples, as measured along a cross section perpendicular to the connection axis, a first material thickness of the shoe body between the connection axis and the access opening can be between 2 times and 8 times a second material thickness of the shoe body opposite the connection axis from the access opening, inclusive.
Some examples of the disclosed technology provide a column shoe assembly that includes a column shoe secured within cured concrete. A recess box can cover an access opening of the column shoe. The recess box can include threaded openings exposed to the outside of the cured concrete, and threaded fasteners arranged within the threaded openings to urge the recess box away from the column shoe.
Some examples of the disclosed technology provide a method of connecting concrete sections. A first concrete section can be provided with a protruding threaded rod, and a second concrete section can be provided, including a column shoe assembly (e.g., as described above or elsewhere herein). The first and second concrete sections can be aligned to insert the threaded rod into the column shoe assembly. The threaded rod can be secured within the column shoe assembly.
In some examples, a column shoe can be accessed by advancing threaded fasteners of a recess box toward the column shoe.
Some examples of the disclosed technology provide a column shoe assembly. A shoe body can include an internal cavity that is closed continuously around a rear side and at opposite lateral sides by a rear wall and side walls of the shoe body. A lower rod (e.g., rebar) opening can be aligned to receive a first section of rod (e.g., rebar) along a connection axis into the internal cavity. An upper wall can secure to a second section of rod opposite the lower rod opening. An access opening can open into the internal cavity at a front side of the shoe body, with a rim of the shoe body extending around the access opening. The rim can include, as measured along a cross section perpendicular to the connection axis, a first material thickness that is larger, at a location between the connection axis and the access opening, than a second material thickness of the shoe body along the rear wall.
Some examples of the disclosed technology provide a column shoe assembly. An integrally formed column shoe includes a shoe body that defines an internal cavity with a rear wall, a lower rod (e.g., rebar) opening that opens into the internal cavity and defines a connection axis, a front access opening into the internal cavity on an opposite side of the connection axis from the rear wall, and a thickened rim extending along a perimeter of the front access opening. A first section of rod (e.g., rebar) can extend through the lower rod opening along the connection axis, the first section of rod being threadedly secured within the internal cavity with a threaded fastener can be fully within the internal cavity and accessible via the front access opening for threaded adjustment along the first section of rod. A second section of rod (e.g., rebar) can be secured to an upper side of the shoe body to extend away from the column shoe opposite the lower rod opening.
Some examples of the disclosed technology provide a method of connecting concrete sections. The method can include providing a first concrete section with a first threaded rod protruding from an end of the first concrete section. A second concrete section can be provided with a column shoe assembly embedded therein. The column shoe assembly can include a column shoe with a shoe body that includes an internal cavity with a rear wall, a lower opening that opens into the internal cavity, a front access opening into the internal cavity on an opposite side of the connection axis from the rear wall, and a thickened rim extending along a perimeter of the front access opening. A second rod can be secured to an upper side of the shoe body, opposite the lower opening, and extending from the column shoe within the second concrete section. The first and second concrete sections can be aligned to insert the first threaded rod through the lower opening, along a connection axis, into the internal cavity of the column shoe. The first threaded rod can be threadedly secured within the internal cavity by accessing the first threaded rod within the internal cavity via the front access opening.
The accompanying drawings, which are incorporated in and form a part of this specification, illustrate examples of the disclosed technology and, together with the description, serve to explain the principles of examples of the disclosed technology:
Before any examples of the disclosed technology are explained in detail, it is to be understood that the disclosed technology is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosed technology is capable of other examples and of being practiced or of being carried out in various ways.
The following discussion is presented to enable a person skilled in the art to make and use examples of the disclosed technology. Various modifications to the illustrated examples will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other examples and applications without departing from examples of the disclosed technology. Thus, examples of the disclosed technology are not intended to be limited to examples shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected examples and are not intended to limit the scope of examples of the disclosed technology. Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of examples of the disclosed technology.
In some construction operations, reinforced concrete is pre-cast at a prefabrication site (e.g., a dedicated facility) to form a section of a structure (e.g., walls or columns). Various sections can then be transported to an installation site to be joined together into a larger assembled structure, typically with various rebar connectors used to join the rebar of adjacent sections of the concrete.
Some concrete sections in particular can be configured as columns, to be stacked onto supporting foundations to assemble a larger structure (e.g., stacked onto a foundation provided by an earlier-installed column). However, a variety of section forms are possible. Correspondingly, discussion of columns in particular examples herein can generally apply to a variety of other concrete sections, in some cases.
When pre-cast columns (for example) are added to existing structure, the columns may need to be adjusted into a final alignment (e.g., to be plumb). Embedding column shoes into the columns can provide one way of making these adjustment. With this approach, threaded rods embedded in a base section extend upwardly from the base to receive threaded nuts (and washers, etc., as appropriate). A column can be lowered onto these rods, so that the threaded rods are received into column shoes within the column, and the column shoes are seated on the nuts (or washers, etc.). With the column shoes thus seated, the nuts can then be adjusted, as needed, until the column is appropriately aligned. Finally, another nut can be secured on the threaded rod above the column shoe to lock the column shoe, and the column, in place. With the column shoe assembly thus secured, if the column shoes and associated parts (e.g., nuts and threaded rods) are strong enough, other support for the column can then sometimes be removed before any required mortar cures, without adding any additional bracing.
Examples of the disclosed technology can provide improved column shoe assemblies for concrete structures. For example, some configurations can include improved connections between rebar (or other rods) and column shoe bodies and improved structural configurations for load distribution during transfer of loads between assembled concrete structures (e.g., via load paths extending through structures of, or attached to, a column shoe).
In some configurations, column shoes can be connected with threaded connections to rebar (or other rod) sections within the corresponding pre-cast concrete sections. Some arrangements can allow coaxial alignment between rebars (or other rods) on opposed sides of the column shoe, with corresponding improvements in load bearing in concrete assemblies.
In some configurations, column shoe bodies can have improved distribution of material thickness for load distribution and access, including with off-centered material distribution as indicated by varied material thickness at different locations with a horizontal cross-section. (As used herein, reference to material thickness refers to a thickness measured locally perpendicular to an inner or outer surface of a body (e.g., an internal wall of a cavity of column shoe).) For example, relative to a cross-section perpendicular to a loading axis, some configurations can include 2 to 8 times greater wall thickness at a first (e.g., front) side of a column shoe than at an opposed second (e.g., back) side. Thus, for example, column shoe walls may be 2 to 8, or 3 to 5 times thicker on one side of an axis of load transmission. In some examples, in particular, part or all of a rim at a front access opening of a column shoe can exhibit material thickness that is 2 to 8 times (or otherwise) greater than a material thickness at a rear wall of the column shoe.
In various combinations (e.g., alone or together), these and other features disclosed herein can provide improved column shoe assemblies and corresponding concrete structures, as compared to conventional systems. For example, some column shoe assemblies (and column shoes) as disclosed herein can be rated at full rebar (or rod) strength, while still requiring relatively low material usage and providing easy access for adjustments of assembled structures.
As also generally noted above, discussion herein applies generally to assembly of prefabricated concrete sections, and examples of the disclosed column shoes can be used to secure a wide variety of concrete forms together. Some examples may be particularly useful for securing and aligning column sections. In this regard, the figures presented herein illustrate example column shoes as part of pre-cast columns that are mounted on simple bases (e.g., rectangular foundations). However, column shoes according to this disclosure (e.g., as shown in the figures) can be used in other types of concrete sections, including as part of a foundation, as part of a pre-cast wall, etc. Correspondingly, discussion herein of foundations is generally applicable to concrete sections of a variety of types, including other columns, walls, etc. that are arranged, relatively, as a base to support a section that includes a column shoe.
The second section 104 includes an upper face 116 that is arranged opposite the lower surface 112 of the first section 102, and generally includes one or more protruding threaded rods. In some examples, a foundation may include a protruding threaded rod at each corner or in various other spatial arrangements, to engage with corresponding column shoes in a supported section. In the example shown, the second section 104 includes an adapter 122 (e.g., a threaded coupler, as shown) at which a protruding threaded rod (e.g., threaded rebar 124) can be secured. However, a threaded rod (e.g., the threaded rebar 124) may be otherwise tied to the section 104 (e.g., directly embedded therein).
In this regard, threaded rods in general can include a variety of configurations. For example, some threaded rods can be all-thread rods with a threaded portion integrally machined along an entire length of the rod. Other threaded rods can be threaded only along part of a length of the rod (e.g., at one or both ends of a section of rebar). Correspondingly, discussion or illustration of a particular type of threaded rod (e.g., rebar) in some examples below should not be regarded as limiting.
With the threaded rebar 124 received into the column shoe assembly 140 and the column shoe 150 seated on a nut 170 or other suitable fastener, the first section 102 and the second section 104 of the concrete structure may be separated by a gap 130. A height of the gap 130 may be adjusted before or after installing the section 102, by adjusting the nut 170 (or other fastener(s)) along the threaded rebar 124.
In the example shown, the second rebar 108 extends upward along the longitudinal axis LA and is substantially coaxially aligned (e.g., concentric with) the first rebar 106. As also discussed below, such an alignment between the rebars can beneficially allow force to be transmitted into, through, and out of a column shoe assembly along a single axis (e.g., the central longitudinal axis LA, as shown for the column shoe assembly 140). In contrast, conventional designs typically result in axial misalignment between rebars above and below a column shoe, with correspondingly detrimental loading patterns.
Generally, a column shoe can be formed as an integral casting (or otherwise) using a variety of suitably strong materials (e.g., ductile iron, tempered ductile iron, etc.). A body of a column shoe can also take a variety of forms, including those with improved material distribution as further discussed below.
Referring now to
The access opening 164 can provide access to secure a nut 172—and thereby the column shoe 150—onto the rebar 124 and thereby tie the embedded rebars 106, 108 together via the column shoe 150. In particular, the access opening 164 opens into the internal cavity 162 from a front surface at a front side 165 of the shoe body 161 (i.e., along the front wall 160, as shown).
In some examples, the front wall 160 and the side walls 158 defines a rim 166 of the shoe body 161 that extends around the access opening 164. In this regard, a relatively large size for the access opening 164 (and the cavity 162) may be preferred, to provide maximum clearance for adjustment relative to a supporting section.
The cavity 162 generally includes rounded internal corners to provide improved stress distributions during axial loading. The cavity 162 is also generally larger than the nut 172 to accommodate different tools to fasten the nut 172, and an internal surface of the bottom wall 154 may be flat in order to be flush with a corresponding washer.
In different examples, different arrangements can be used to secure rebar of a concrete section to a column shoe embedded in the concrete. Generally, a rebar of the concrete section can be secured at an upper side 168 of the shoe body 161, opposite of the lower rebar opening 184. As shown in
As another example configuration, the rebar can be directly connected to a column shoe. For example, as shown in
Alternatively, the rebar 106 can be otherwise secured to the column shoe 150. In some examples, the rebar 106 and the column shoe 150 can be secured together using a coupler or other fastening mechanism. For example, a coupler can be secured to a column shoe (e.g., bolted or welded thereto, or integrated therewith), and set screws or other fasteners then used to secure the rebar 106 to the coupler. In some examples, the rebar 106 and the column shoe 150 can be welded together.
In either case, as shown in
Referring now to
In comparison to the column shoe 150, however, and as further discussed below, the column shoe 250 includes a reduced wall thickness along various sections. Thus, the column shoe 250 can provide reduced weight, as compared to the column shoe 150, without significant loss of structural strength.
Referring now to
In comparison to the column shoes 150, 250, however, the column shoe 350 includes a still further reduced wall thickness along various sections. Thus, the column shoe 350 can provide reduced weight, as compared to the column shoes 150, 250, without significant loss of structural strength. Additionally, the column shoe 350 can exhibit an access opening 364 that is larger than the openings 164, 264 (e.g., wider or taller), as can correspond to a larger size for the internal cavity 362 or otherwise provide for improved adjustment and securement of the column shoe assembly 340 (e.g., using a wrench or other hand tool (not shown) inserted into the column shoe via the access opening 364).
As generally discussed above, particular configurations of material thickness around an internal perimeter of a column shoe cavity can provide particularly improved column shoes. In this regard,
In particular, for the example shown, wall thickness is greater toward a front (or access) side 265 of the column shoe 250 and is less toward a rear (or closed) side of the column shoe 250. Or, more generally, wall thickness is generally greater on one side of the longitudinal axis LA than on another (e.g., the front side rather than the back). Thus, for example, the rear wall exhibits a first material thickness T1 that is significantly smaller than a second material thickness T2 exhibited by the side walls 258. In some examples, a maximum or mean value of the thickness T2 may be between 2 and 8 times greater than a maximum or mean value of the thickness T1, respectively (e.g., in particular, between 3 and 5 times greater).
In some examples, the thickness T2 varies along relevant side walls (e.g., between a front and a rear of the column shoe). For example, as shown in
In some configurations, the thickness T2 can taper to be thinner closer to a front opening than at a location of maximum thickness (e.g., at a location between the front opening 264 and the longitudinal axis LA). As illustrated in the example of
Similarly, in some examples, a front face 269 of the rim 266, along the front side 265 of the column shoe 250, can extend rearwardly from a front face 271 of the shoe body 261, toward a maximum location of the material thickness T2. For example, as shown in
As illustrated, the wall thickness T2 can change generally linearly between the rear wall 256 and the front wall 260 (e.g., with a single maximum value at the location 267 between the connection axis CA and the front side 265 of the column shoe 250), although other configurations are possible. Further, some examples, can include internal voids or other structures as appropriate (e.g., as produced using optimized additive manufacturing designs).
In contrast to the column shoe 250, the side walls 358 of the column shoe 350 exhibit a more pronounced thickened rim around the access opening 364, with relative thin sections extending rearward therefrom. In particular, in the illustrated example, the relatively small thickness T1 extends from the rear wall 356 onto the side walls 358, then along the side walls 358 to a forward side of the longitudinal axis LA, where the side walls 358 widen relatively abruptly to the relatively uniform larger thickness T2. In other examples, however, other configurations are possible, including with differently shaped thickened rims.
Thus, the design of both of the column shoes 250, 350 can concentrate a relatively large amount of material of the column shoe 350 forward of the longitudinal axis LA (e.g., onto the rim around the access opening 364, in particular). Correspondingly, relative to expected loads during service, the column shoes 250, 350
In some examples, the first material thickness T1 can be between about 3/16″ and about ½″ or between about 3/16″ and about ¾″. In some example, the second material thickness can be between about ¾″ and about 1¼″, or between about 1″ and about 1¼″.
A method of using the column shoe assembly 140 of
Concrete for the first section 102 can be similarly set around the rebar 106 and the column shoe 150. Then, referring to
Once the sections 102, 104 are appropriately seated and aligned, the nut 172 can be secured onto the threaded rebar 124 via the access opening 164 (e.g., using a wrench or other hand tool, not shown). This can correspondingly secure the column shoe 150 to the threaded rebar 124 and thus tie together the rebar 106, 108 and the sections 102, 104. In particular, the nut 172 can be tightened to secure the threaded rebar 124 the internal cavity 162 via access through the access opening 164 along the front wall 160 (e.g., also through a cavity left by removal of a recess body, as further discussed below). Thus installed, the column shoe assembly 140 can transmit both tension and compression loads between the first and second sections 102, 104, while allowing easy and relatively fine adjustments in alignment between the sections 102, 104.
As noted above, some column shoes can include rearwardly extending (e.g., angled) front faces, including along a thickened front rim that surrounds a front access opening of the relevant column shoe. As illustrated in
Generally, an opening may need to be provided in a concrete section for access to a column shoe (e.g., the opening 110 of
In some examples, a recess body may support a plurality of fasteners arranged to be advanced relative to the recess body (e.g., through corresponding holes) to urge the recess body away from the relevant column shoe. In some examples of the disclosed technology, one or more threaded holes or other features can be included in a recess box to facilitate easier removal of the recess box, after the concrete is set, to access the column shoe. Referring again to
Referring now to
In some examples, a recess body can be seated on a front rim (or otherwise) along side walls of a shoe body. Thus, for example, the recess body can help to preserve clearance for accessing the access opening of the shoe body with a tool (e.g., preserving a large value for the range R1 as discussed relative to
In some examples, the one or more attachment features 720 of the recess body 710 may include discrete protrusions 750 that extend into the access opening to removably secure the recess body 710 to the shoe body 361. For instance, the recess body 710 may include a first protrusion 752 and a second protrusion 754 that extends away from the inner surface 728 of the recess body 710. In some examples, the protrusions 750 may include a hook or other shaped end to secure the recess body 710 to a shoe body.
Thus, for example, the boss 724 or the protrusions 750 (or other attachment features) can aid securing the recess body 710 to the shoe body 361 during formation of the concrete section 104. Relatedly, the hole 714 can be used to urge the recess body 710 away from the shoe body 361 to access the column shoe 350. For example, an operator may advance a pin or a rod 760 through the hole 714 to contact the shoe body 361 (e.g., advance a set screw that is recessed into the hole 714, to contact a front face of the shoe body 361). As noted above, in some cases the rod 760 can be configured as a relatively short set screw. In some examples, as illustrated in
As shown in the succession from
In some examples, the second concrete section 104 can be prefabricated with the recess body 710 removably covering the access opening 364 of the shoe body 361 (or the opening 264 of the shoe body 261, etc.). Correspondingly, to secure the first concrete section 102 and the second concrete section 104 using the threaded rebar 124, the recess body 710 may be removed from the second concrete section to expose the access opening 364 (or 264, etc.).
As also generally noted above, the column shoe assemblies 240, 340 illustrated in
In some implementations, devices or systems disclosed herein can be utilized, manufactured, installed, etc. using methods embodying aspects of the disclosed technology. Correspondingly, any description herein of particular features, capabilities, or intended purposes of a device or system should be considered to disclose, as examples of the disclosed technology a method of using such devices for the intended purposes, a method of otherwise implementing such capabilities, a method of manufacturing relevant components of such a device or system (or the device or system as a whole), and a method of installing disclosed (or otherwise known) components to support such purposes or capabilities. Similarly, unless otherwise indicated or limited, discussion herein of any method of manufacturing or using for a particular device or system, including installing the device or system, should be understood to disclose, as examples of the disclosed technology, the utilized features and implemented capabilities of such device or system.
In this regard, for example, some examples of the disclosed technology can include prefabricating concrete structures using the column shoe assemblies as disclosed herein (or components thereof), or securing concrete structures together using the column shoe assemblies disclosed herein (or components thereof). Similarly, some examples can include manufacturing or using sets of substantially identical column shoes or column shoe assemblies (e.g., of one or more sizes) for prefabrication or for on-site operations.
It is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
As used herein, unless otherwise limited or defined, “or” indicates a non-exclusive list of components or operations that can be present in any variety of combinations, rather than an exclusive list of components that can be present only as alternatives to each other. For example, a list of “A, B, or C” indicates options of: A; B; C; A and B; A and C; B and C; and A, B, and C. Correspondingly, the term “or” as used herein is intended to indicate exclusive alternatives only when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” For example, a list of “one of A, B, or C” indicates options of: A, but not B and C; B, but not A and C; and C, but not A and B. A list preceded by “one or more” (and variations thereon) and including “or” to separate listed elements indicates options of one or more of any or all of the listed elements. For example, the phrases “one or more of A, B, or C” and “at least one of A, B, or C” indicate options of: one or more A; one or more B; one or more C; one or more A and one or more B; one or more B and one or more C; one or more A and one or more C; and one or more of A, one or more of B, and one or more of C. Similarly, a list preceded by “a plurality of” (and variations thereon) and including “or” to separate listed elements indicates options of multiple instances of any or all of the listed elements. For example, the phrases “a plurality of A, B, or C” and “two or more of A, B, or C” indicate options of: A and B; B and C; A and C; and A, B, and C.
Also as used herein, unless otherwise limited or defined, “integral” and derivatives thereof (e.g., “integrally”) describe elements that are manufactured as a single piece without fasteners, adhesive, or the like to secure separate components together. For example, an element stamped or cast as a single-piece component from a single piece of sheet metal or a single mold (etc.), without rivets, screws, or adhesive to hold separately formed pieces together, is an integral (and integrally formed) element. In contrast, an element formed from multiple pieces that are separately formed initially, then later connected together, is not an integral (or integrally formed) element.
Also as used herein, unless otherwise limited or specified, “substantially identical” refers to two or more components or systems that are manufactured or used according to the same process and specification, with variation between the components or systems that are within the limitations of acceptable tolerances for the relevant process and specification. For example, two components can be considered to be substantially identical if the components are manufactured according to the same standardized manufacturing steps, with the same materials, and within the same acceptable dimensional tolerances (e.g., as specified for a particular process or product).
Unless otherwise specified or limited, the terms “about” and “approximately”, as used herein with respect to a reference value, refer to variations from the reference value of ±20% or less (e.g., ±15, ±10%, ±5%, etc.), inclusive of the endpoints of the range. Similarly, as used herein with respect to a reference value, the term “substantially equal” (and the like) refers to variations from the reference value of less than ±5% (e.g., ±2%, ±1%, ±0.5%) inclusive. Where specified in particular, “substantially” can indicate a variation in one numerical direction relative to a reference value. For example, the term “substantially less” than a reference value (and the like) indicates a value that is reduced from the reference value by 30% or more (e.g., 35%, 40%, 50%, 65%, 80%), and the term “substantially more” than a reference value (and the like) indicates a value that is increased from the reference value by 30% or more (e.g., 35%, 40%, 50%, 65%, 80%).
Additionally, unless otherwise specified or limited, “substantially coaxial” indicates that the described elements have axes that are substantially parallel with each other and are aligned so that extension of the axis one of the elements intersects an axial end of another of the elements (e.g., at or within a diameter thereof, within 50% of a diameter thereof, within 25% of a diameter thereof, or within 5%—or less—of a diameter thereof). Correspondingly, for example, substantially coaxial sections of rebar on opposing sides of a column shoe can extend substantially in parallel with each other, along a substantially identical axis, to provide single-direction load transmission across the column shoe as further detailed above.
Also as used herein, unless otherwise defined or limited, ordinal numbers are used for convenience of reference, based generally on the order in which particular components are presented in the relevant part of the disclosure. In this regard, for example, designations such as “first,” “second,” etc., generally indicate only the order in which a thus-labeled component is introduced for discussion and generally do not indicate or require a particular spatial, functional, temporal, or structural primacy or order.
The previous description of the disclosed examples is provided to enable any person skilled in the art to make or use the disclosed technology. Various modifications to these examples will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other examples without departing from the spirit or scope of the disclosed technology. Thus, the disclosed technology is not intended to be limited to the examples shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
This application claims priority to U.S. provisional patent application No. 63/486,369, filed Feb. 22, 2023, the entirety of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63486369 | Feb 2023 | US |
