CONNECTORS FOR JOINING TIMBER STRUCTURES

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from U.S. application No. 63/569,387 filed 25 Mar. 2024 entitled A CONCRETE CONNECTOR FOR JOINING TIMBER BUILDING ELEMENTS (A.K.A. TIMBER CONCRETE NODE OR TCN). This application claims the benefit under 35 U.S.C. § 119 of U.S. application No. 63/569,387 filed 25 Mar. 2024 entitled A CONCRETE CONNECTOR FOR JOINING TIMBER BUILDING ELEMENTS (A.K.A. TIMBER CONCRETE NODE OR TCN) which is hereby incorporated herein by reference for all purposes.

FIELD OF THE INVENTION

The present invention relates to timber connectors, in particular those for use to join mass timber structural components in building constructions. cl BACKGROUND

Mass timber structures (including solid heavy timber and engineered timber) require connections between timber structural components, including beams, columns, posts, purlins, and walls. These connections are typically made with metal ‘hangers’ that are screwed or nailed into the beams/columns/purlins/walls. High-capacity metal hangers exist, but they are expensive and susceptible to damage by fire. To protect against fire, they require supplemental protection via coatings or sacrificial timber cover. Metal hangers typically require tight installation tolerances. For beams connecting on either side of a single timber column two metal hangers are typically required.

There is a general desire for improved connectors for timber structures, and more particularly, for joining mass timber structures.

The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.

SUMMARY

The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.

Aspects of the present invention pertain to a structural connector. The structural connector is made of a material comprising concrete. The concrete connector is a fire-resistant connector. The concrete connector may be made of reinforced concrete configured to join mass timber structural components. Such concrete connectors may be referred to as a “Timber Concrete Node”, or “TCN”). The TCN can join mass timber structural components efficiently and securely. The TCN may be made in a variety of shapes and sizes, to suit the size of the timber structural components that are desired to be joined and the strength required for the connection. The TCN advantageously eliminates the need for costly and fire-susceptible metal connectors or hangers. In some embodiments, the TCN incorporates void channels that are cast into the concrete to accommodate fasteners such as self-tapping screws, thereby facilitating robust fastening to timber elements. Additionally, the TCN may provide alternative fastening options such as supplementary plates, rods, or dowels cast into the concrete. The modular design of the TCN allows the connector to support a wide range of structural demands while maintaining easy handling and installation. The TCN design facilitates onsite casting or pre-casting. With lightweight, normal weight, or ultra high-performance reinforced concrete, the TCN ensures structural integrity while providing a durable and versatile solution for assembling mass timber structures.

In some embodiments, in the most basic form, the TCN is a rectangular prism of precast concrete which attaches to the top side of a column. The TCN cantilevers beyond the face of the column and supports the bottom of 1 or 2 beams (which may be notched so the bottom of the beam is flush with the bottom of the TCN). In some embodiments, The TCN has a width which is the same or substantially the same as the timber elements that it is connecting. In some embodiments, the TCN has a width which is less than that of the timber. In such embodiments, the concrete connector may be partially surrounded by the timber.

Aspects of the present invention pertain to structural assemblies comprising at least two timber structural components being joined by one or more concrete connectors. The at least two timber structural components may comprise timber purlins, beams, columns, posts, walls, etc.

Further aspects of the invention and features of specific embodiments of the invention are described below.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.

FIG. 1 is an exploded view illustrating a concrete connector used to join two timber columns to two adjoining timber beams.

FIG. 2 is a perspective view illustrating an assembled structure of FIG. 1.

FIG. 3 is a perspective view illustrating an assembled structure comprising two beams joined to two columns with a concrete connector according to another example embodiment of the invention. In this embodiment, the column has a width greater than that of the concrete connector, so that the column partially encompasses the connector.

FIG. 4 is a perspective view illustrating an assembled structure comprising two beams joined to two columns with a concrete connector according to another example embodiment of the invention. In this embodiment, the beam and the column have a width greater than that of the concrete connector, so that the beam and the column are arranged to encompass the connector.

FIG. 5A is an exploded view illustrating a concrete connector used to join a continuous column to two adjoining beams according to an example embodiment of the invention.

FIG. 5B is perspective view illustrating an assembled structure of FIG. 5A.

FIG. 6A is an exploded view illustrating an “I”-shaped concrete connector used to join two spliced columns to two adjoining beams according to an example embodiment of the invention.

FIG. 6B is perspective view illustrating an assembled structure of FIG. 6A.

FIG. 7A is an exploded view illustrating the use of a plurality of concrete connectors to join a continuous column to two adjoining beams according to an example embodiment of the invention.

FIG. 7B is a perspective view illustrating an assembled structure of FIG. 7A.

FIG. 8 is a perspective view illustrating an assembly comprising a plurality of purlins, beams and columns being joined by a plurality of concrete connectors according to an example embodiment of the invention.

FIG. 9 is a close-up view of FIG. 8 showing the connections between the timber structural components with the concrete connectors according to an example embodiment of the invention.

FIG. 10 is a front cross-sectional view of an example concrete connector showing the mounting channels and the fasteners inserted through the mounting channels for joining the timber components to one another according to an example embodiment of the invention. The mounting channels may be cast into the concrete.

DESCRIPTION

Throughout the foregoing description and the drawings, in which corresponding and like parts are identified by the same reference characters, specific details have been set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail or at all to avoid unnecessarily obscuring the disclosure.

Definitions

“Timber” refers to wood extracted from trees that is suitable for use as a structural component in the construction of buildings, bridges, and other structures. The timber as used herein includes unprocessed timber (or raw timber) and processed timber. One non-limiting example of a type of “processed timber” is “mass timber”.

“Timber structural components” or “timber structures” are solid, structural, load-bearing components that are made with timber, such as purlins, beams, columns, posts, walls, etc.

“Mass timber” refers to a type of solid or engineered wood products that is suitable for use as a structural component in the construction of buildings, bridges, and other structures. Mass timber is typically made by fastening multiple layers of wood products such as by glue, nail, dowel, etc. to produce a larger structural component such as panels, posts and beams, etc. Non-limiting examples of mass timber products include cross-laminated timber (CLT), dowel-laminated timber (DLT), nail-laminated timber (NLT), glue-laminated timber (Glulam or GLT), laminated strand lumber (LSL), laminated veneer lumber (LVL), parallel strand lumber (PSL), etc.

“Concrete” refers to a material composed of binder(s) and aggregates such as sand and gravel. As used herein, “concrete” includes any suitable type of concrete including but is not limited to one or more of ordinary or normal strength concrete (e.g., concrete that uses the common mix design of 1:2:4 of cement, sand and aggregates), lightweight concrete (e.g., concrete which has a density of less than about 1920 kg/³), high-density concrete, high-strength concrete (e.g., concrete mix that is greater than about 40 megapascal (40 MPa), high-performance concrete (HPC), ultra high-performance concrete (UHPC), reinforced concrete, etc. In some preferred embodiments, the concrete comprises a self-consolidating concrete with small aggregate to reduce voids and produce a high-quality surface finish.

“Precast” means that the material (e.g., concrete) is cast into the desired form before being transported to the site of installation. For example, the concrete may be poured into a preshaped mold at a plant, and left to cure in a suitable environment. Once cured, the mold is removed and reused. The precast concrete may be transported to the site of installation.

Example Embodiments

Referring to FIGS. 1 to 10, in one embodiment, the invention is a structural connector 20 adapted to join timber structural components 10. The structural connector 20 is made of a material comprising an amount of concrete that is more than 90% of the total volume of the connector, and in some embodiments, more than 95%, and in some embodiments, more than 97%. In some example embodiments, the total volume of voids in the concrete connector 20 is in the range of from about 1% to about 5%, and in some example embodiments, between about 2% to about 3%. The voids may for example be provided to accommodate one or more fasteners and/or reinforcing members. As used herein the term “about” provides literal support for the exact numerical value that it precedes, the exact numerical value ±5%, as well as all other numerical values that are near to or approximately equal to that numerical value.

The structural connector 20 (which may be referred to herein as a concrete connector 20) of the present invention is highly resistant to fire, thereby making such connector an attractive alternative to the conventional metal connectors for timber structural components that are used in building constructions. The concrete connector described herein may also be referred to herein as a “Timber Concrete Node” or “TCN”.

In some embodiments, the connector is made of a material comprising fiber-reinforced concrete. The fibers in the fiber-reinforced concrete may be distributed throughout the concrete mix. The fibers that make up the fiber-reinforced concrete may for example comprise one or more of natural fibers (e.g., plant fibers), synthetic fibers (e.g., polypropylene fiber (PP), polyvinyl alcohol fiber (PVA), polyethylene fiber (PE) and nylon (PA), etc.), glass fibers, and steel fibers. In some embodiments, the amount of fibers in the fiber-reinforced concrete is not more than about 2% of the total volume of the concrete and in some embodiments, not more than about 1% v/v, and in some embodiments, not more than about 0.5% v/v.

In some embodiments, one or more reinforcing members 23 are embedded in the concrete of the concrete connector 20 (see e.g., FIG. 10). The one or more reinforcing members 23 are provided to increase tensile strength of the concrete. The reinforcing member 23 may for example be arranged to extend along a longitudinal axis of the concrete connector, or in along a direction that is transverse to the longitudinal axis of the concrete connector 20. The one or more reinforcing members may be precast into the concrete.

In some embodiments, the reinforcing member 23 comprises one or more reinforcing bars (or rebar) such as steel reinforcing bars. However, other suitable reinforcing members may be used such as but is not limited to bars such as fiberglass bars, threaded rods, mesh panels, etc. In embodiments in which a plurality of reinforcing members are provided, the plurality of reinforcing members may be arranged to extend in one axis direction of the concrete connector 20.

In some embodiments, the concrete connector 20 is made of a fiber-reinforced concrete that is additionally reinforced by one or more reinforcing members such as one or more rebars.

In some embodiments, the compressive strength of the concrete connector 20 is about 25 to about 35 MPa, and in some embodiments, greater than about 150 MPa. The concrete can be made from conventional mix designs or very high strength formulations in the case of ultra-high performance concrete.

Referring to FIG. 10, in some embodiments, one or more mounting channels 30 are defined within the concrete connector 20. The mounting channel 30 may be precast into the concrete. In some embodiments, the mounting channel 30 extends along the longitudinal axis of the concrete connector 20, from one surface to an opposite surface of the concrete connector 20. In some embodiments, the mounting channel 30 extends along a direction transverse to the longitudinal axis of the concrete connector 20, from one surface to an opposite surface 21 of the concrete connector 20. A fastener 32 may be insertable through each one of the mounting channels 30 for fixedly securing the concrete connector 20 to the timber structural component 10. The fastener 32 is arranged to protrude from the surface 21 of the concrete connector.

Any suitable fasteners 32 which can penetrate timber structural components 10 to securely attach the connector 20 thereto may be used, including but are not limited to partially threaded and/or fully threaded screws (e.g., self-tapping screws), rod, dowel, plate, etc. The fastener 32 may be oriented orthogonal (i.e.,) 90° relative to the surface 21 of the concrete connector 20, or inclined at an angle (such as by about 15 to 45°) relative to the surface 21 of the concrete connector 20 so that the fastener 32 approach the wood end grain at an angle.

In some example use embodiments, at least one concrete connector 20 is arranged between two timber structural components 10 which are desired to be joined. One concrete connector 20 may however be joined to more than two timber structural components 10.

Referring to FIGS. 7A and 7B, in some embodiments, a plurality of concrete connectors 20 are fixed connected together to form a combined concrete connector 20 which allows it to comprise two lighter weight parts that combine to have the same bending resistance as if it was one solid cast part. In some embodiments, one or more reinforcing members 21 such as steel bolts is used to secure the plurality of concrete connectors 20 to form the combined concrete connector 20. As an example, the reinforcing member 21 may be inserted through a precast mounting channel 30 provided in the concrete.

The concrete connector 20 may comprise a shape and/or dimension that is suitable for connecting the timber structural components 10 which are desired to be joined. The concrete connector 20 described herein may be used to join any combination of timber purlins, beams, columns, posts, walls, etc. For example, the concrete connector 20 may be used to join purlin to beam, purlin to wall, purlin to column, beam to wall, beam to beam, beam to column, and when used as a splice, the concrete connector 20 may also be used to join column to column, or post to post.

FIGS. 1-7B illustrate different relative sizes and/or shapes of the concrete connector 20 for arranging the concrete connector 20 to join a plurality of timber structural components 10. FIGS. 1-9 also illustrate example configurations of arrangement between the concrete connector 20 to join the plurality of timber structural components 10.

In some example embodiments, the concrete connector 20 has a shape of a rectangular prism. The concrete connector 20 may comprise a rectangular-shaped cross-section along a longitudinal axis of the connector 20. FIGS. 1 to 5 illustrate example embodiments of how the concrete connector 20 may be arranged to join one or more columns to one or more beams.

In some example embodiments, the concrete connector 20 is arranged such that surfaces of the connector 20 are positioned to contact a respective end of one or more beams and columns. In some embodiments, the concrete connector 20 has a width which is the same or substantially the same as the timber structural components 10 which the connector 20 is arranged to join.

In some example embodiments, the concrete connector 20 is arranged to be received within a receiving slot of one or more of the timber structural components 10 which the connector 20 is arranged to connect. In some embodiments, the concrete connector 20 has a width which is less than that of the one or more timber structural components 10 which the connector 20 is arranged to connect.

In some example embodiments, the concrete connector 20 is arranged such that surfaces of the connector 20 are positioned to contact a respective end of one or more beams and columns. In the FIGS. 1 and 2 embodiments, an end 50 of a timber column 60 is joined to a lateral face 40 of the concrete connector 20. An end 90 of the second timber column 61 may be arranged to contact the opposing second lateral face 41 of the concrete connector 20. Two adjoining timber beams 62, 64 each comprises a recessed corner edge 66, 68. Each of the recess corner edges 66, 68 are dimensioned to contact a respective base 42, 44 and a respective portion of the lateral face 41 of the concrete connector 20. A plurality of mounting channels 30A, 30B, 30C may extend along a direction transverse to the longitudinal axis of the concrete connector 20, from one lateral face 40 to the opposing second lateral face 41. A fastener may be inserted through each one of the mounting channels 30A, 30B, 30C to secure the concrete connector 20 to the beams 62, 64. In the FIGS. 1 and 2 embodiments, the width of the concrete connector 20 is the same as, or similar to, that of the column 60, 61 and the beams 62, 64.

FIG. 3 illustrates an embodiment in which the width of the concrete connector 20 is less than that of the column 60. In such embodiment, the column 60 may comprise a receiving slot 66 at an end 50 thereof. The concrete connector 20 may be inserted through the receiving slot 66 of the column 60. In such embodiments, the column 60 may be arranged to partially encompass the concrete connector 20.

FIG. 4 illustrates an embodiment in which the width of the concrete connector 20 is less than that of the columns 60, 61 and the beams 62, 64. In such embodiments, the column 60 comprises the receiving slot 66 at the end 50 thereof. The beams 62, 64 each comprise a receiving slot 70, 72 at the respective ends 74, 76 thereof. The concrete connector 20 may be inserted through the receiving slot 66 of the column 60, and the receiving slots 70, 72 of the beams 62, 64. In such embodiments, the column 60, and the beams 62, 64 both encompass the concrete connector 20.

FIGS. 5A and 5B illustrate an embodiment in which a continuous timber column 60 is provided. In such embodiments, a receiving channel 78 is defined through the column 60 between opposing lateral faces 80, 82 of the column 60. The receiving channel 78 is dimensioned for receiving the concrete connector 20. The recessed corner edges 66, 68 of the beams 62, 64 are arranged in contact with the respective bases 42, 44 and respective portions of the lateral face 40 of the concrete connector 20.

FIGS. 6A and 6B illustrate an embodiment in which the concrete connector 20 has an “I”-shaped cross-section along the longitudinal axis of the connector 20. An “I”-shaped concrete connector 20 may desirably reduce the weight of the connector 20 and/or increase the thickness of the remaining timber on the face of the column. In some embodiments, the “I”-shaped cross sectional concrete connector 20 is joined to an end 50 of a timber column 60 on a lateral face 40 of the connector 20. In such embodiments, the concrete connector 20 comprises a receiving slot 86 (one is not shown) each defined on a respective opposing lateral faces 43 (one is not shown) of the connector 20. The lateral face 43 is orthogonal to the lateral face 40 on which the connector 20 is joined to the timber column 60. The receiving slots 86 are each dimensioned to be received within a receiving channel 88 defined at an end 90 of the second timber column 61. When assembled, the end 90 of the second timber column 61 may be in contact with the end 50 of the timber column 60.

FIGS. 7A and 7B illustrate an embodiment in which a plurality of concrete connectors 20 which are coupled together (e.g., by bolting) to form one combined concrete connector 20 for connecting beams 62, 64 to the continuous column 60. FIGS. 7A and 7B illustrate the coupling of two concrete connectors 20A,B which comprise a “T”-shape along the longitudinal axis of connector 20; however, this is not mandatory. The concrete connectors 20A,B may have any suitable shapes such as a rectangular prism.

FIG. 8 illustrates an example structural assembly which comprises a plurality of purlins 90 joined to a plurality of beams 62, 64 and columns 60 by a plurality of concrete connectors 20.

FIG. 9 is a close-up view showing one of the connections between the purlin 90, beams 62, 64 and column 60 with two concrete connectors 20A, 20B.

As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the scope thereof. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.