Reusable Structure for Use in Construction

The present application is a continuation of U.S. patent application Ser. No. 19/076,078, filed Mar. 11, 2025, and titled “REUSABLE STRUCTURE FOR USE IN CONSTRUCTION,” which is a continuation-in-part of U.S. patent application Ser. No. 18/737,941, filed Jun. 7, 2024, and titled “ENVIRONMENTALLY FRIENDLY REUSABLE STRUCTURE FOR USE IN CONSTRUCTION”, each of which is incorporated by reference in its entirety herein.

The present disclosure relates to reusable structures which may be used as a substitute for plywood and other materials used in construction or fabrication of items. The reusable structure finds particular use in forming concrete structures such as walls, floors, support columns, slabs, reinforced concrete beams, and the like.

Concrete structures are conventionally made with energy and resource intensive processes. From the creation of the constituents of concrete, such as cementitious materials and aggregate, to the casting and curing of concrete, there are many opportunities to reduce the carbon footprint of a concrete structure.

In forming a concrete structure, wooden panels traditionally help shape poured concrete and surround the concrete until the structure is cured. Such structures are erected one section at a time, and the wooden panels may be used to form another portion of the structure. Wooden panels, while currently relatively light-weight and moderately priced, require supporting frames, a form releasing agent (e.g., oil and an oiling procedure) to prevent adhesion of the wooden panels to the concrete, and will eventually degrade and become unusable over time. The wooden materials, with relatively short lifetimes under the harsh environment of setting concrete, also lead to the undesirable consumption of a large number of trees.

In order to extend the useful life of wooden panels for concrete forming, plastic coatings have been applied to the panels with some success, but such coatings undesirably increase the weight of the forms and panels. Coated wooden boards also suffer from delamination at the interface of the wood and plastic due to the alkaline nature of concrete lime, particularly at points where nails or other fixtures have been inserted to connect to a supporting frame.

In accordance with a first aspect, a reusable structural member is provided. The reusable structural member includes a structural profile with a length, a width, and a thickness, as well as a first side and a second side opposite the first side in which the first and second sides define the width and the length. The reusable structural profile also includes a first edge and a second edge opposite the first edge. The first edge and the second edge extend between the first and second sides define the thickness. The reusable structural profile also has a plurality of support beams, each support beam extending between the first side and the second side. A fastener is disposed at a first end of each of the plurality of support beams of the reusable structural profile. The reusable structural member further includes an interfacial layer and a groove disposed along the first edge and a tongue disposed along the second edge of the structural profile. In the structural member, the tongue is configured to be disposed in a groove of a second reusable structural profile to join the reusable structural profile and the second reusable structural profile together. The groove of the structural member is configured to receive a tongue of a third reusable structural profile to join the reusable structural profile and the third reusable structural profile together, in which the fasteners help secure the interfacial layer to the structural profile, and in which at least one of the support beams and the interfacial layer comprises recycled material.

In further accordance with the first aspect, the interfacial layer may be configured to contact concrete while concrete is poured and sets. The interfacial layer may be resistant to alkaline pH conditions, elevated temperatures, water or other liquid absorption, and abrasion by any of sand and aggregate.

In some forms, the recycled material may include recycled plastic. The recycled plastic may include any of the following: PP (polypropylene), PTFE (polytetrafluoroethylene), PEEK (polyether ether ketone), PEI (polyetherimide), PAI (polyamide-imide), PBI (polybenzimidazole), PET (polyethylene terephthalate), PVC (polyvinylchloride), and any combination thereof. In such forms, the interfacial layer may further include a layer of composite material that includes a recycled polymer, a recycled glass component, or both a recycled polymer and a recycled glass component.

In further accordance with the first aspect, the structural member also includes one or more open volumes, in which each of the one or more open volumes is bounded by the first side or the second side, and at least one of the plurality of support beams. The structural member also includes a filler disposed in the one or more open volumes. The filler can be injected, poured, sprayed, inserted, or pre-formed in the one or more open volumes. The filler can include any of the following: a foam (e.g., a closed-cell or open cell pour foam, a high-temperature foam, a silicone foam), a ceramic-based filler, a refractory material, a polymer, an epoxy filler, silicone, a gel (e.g., aerogel), vermiculite, a perlite-based filler, a hexagonal cell material, a corrugated cardboard, and a sprayed-in expanding material.

In accordance with a second aspect, an extruded structural profile for casting concrete is provided. The extruded structural profile includes a length, a width, and a thickness, and a first side and a second side that is opposite the first side. The first and second sides define the width and the length of the extruded structural profile. The extruded structural profile also includes a first edge and a second edge that is opposite the first edge, in which each of the first and second edges extend between the first and second sides and define the thickness. A plurality of support beams are also part of the extruded structural profile, and each support beam extends between the first side and the second side. The extruded structural profile also includes a fastener disposed at a first end of each of the plurality of support beams. The fastener is adapted to help secure an interfacial layer to the extruded structural profile. A groove that is disposed along the first edge is part of the extruded structural profile, as well as a tongue that is disposed along the second edge. The tongue is configured to be disposed in a groove of a second extruded structural profile to join the extruded structural profile and the second extruded structural profile together. The groove is configured to receive a tongue of a third extruded structural profile to join the extruded structural profile and the third extruded structural profile together.

In further accordance with the second aspect, the extruded structural profile is formed of a recycled metal. In some such extruded structural profiles, the recycled metal is recycled aluminum.

Further, in accordance with the second aspect, each of the fasteners is a female fastener that includes a recess into a corresponding support beam of the plurality of support beams in the extruded structural profile. Each female fastener may include a narrowed neck at an opening of the respective recess.

Alternatively, in accordance with the second aspect, each fastener of the extruded structural profile includes a protrusion extending from a corresponding support beam of the plurality of support beams, in which the protrusion extends beyond the first or second side of the structural profile.

In accordance with a third aspect, a method for making a reusable modular structural member for casing concrete is provided. The method includes forming first and second structural profiles. Each structural profile has a length, a width, and a thickness. The structural profile also has a first side and a second side which is opposite the first side, and the first and second sides define the width and the length of the structural profile. Each structural profile includes a first edge and a second edge that is opposite to the first edge. Each of the first and second edges extend between the first and second sides, as well as define the thickness of the structural profile. Each structural profile also includes a plurality of support beams, and a fastener disposed at a first end of each of the plurality of support beams. A groove that is disposed along the first edge and a tongue that is disposed along the second edge of the reusable structural member are also part of each structural profile. Each support beam extends between the first side and the second side. The method also includes connecting the first and second structural profiles by disposing the tongue of the first structural profile in the groove of the second structural profile, forming a connected structure in this way. The method further includes applying an interfacial layer on the connected structure, in which at least one of the support beams and the interfacial layer includes recycled material.

In further accordance with the third aspect, forming the first and second structural members includes extruding the first and second structural members using aluminum. In such methods, applying the interfacial layer of recycled material may include molding a polymer material to external portions of the connected structure.

In accordance with the third aspect, the method includes flowing the polymer material into a fastener, in which the fastener includes a recess in a corresponding support beam of the plurality of support beams or a protrusion extending from a corresponding support beam of the plurality of support beams away from the middle portion of the connected structure.

Further in accordance with the third aspect, the method further includes inserting a filler into one or more open volumes in the structural member in which the one or more open volumes is each bounded by the first side and the second side of the first or second structural profile and at least one of the plurality of support beams. The filler includes any of the following: a foamed material, a hexagonal cell material, a corrugated cardboard, and a sprayed-in expanding material.

In accordance with a fourth aspect, a system for shaping a cast concrete structure is provided. The system includes a first reusable structural member in accordance with the first aspect and a second reusable structural member having a similar configuration to that of the first reusable structural profile. The first reusable structural member and the second reusable structural member are removably jointed along edges having grooves and tongues, such that the joined edges form a dove tail joint.

In further accordance with the fourth aspect, the system further includes fittings which secure a third reusable panel in a fixed position relative to the first and second reusable panels.

The present disclosure is directed to a durable, modular, reusable (i.e., multi-use) structural member that aims to enable the creation of concrete structures in a way that has a lower carbon-foot print and is less toxic than conventional concrete casting forms (e.g., forms made partially or entirely of plywood). The reusable nature of the structural profiles described herein reduces the amount of lumber required to make these conventional concrete casting forms. At the same time, the materials, structure, and fabrication method of the structural member prevent delamination of the layers of the members that contact poured concrete, reduce the need for a releasing agent for the cured concrete, and create lightweight but strong structures that can easily be customized into various casting forms.

Turning to the Figures,illustrate an example of a structural profilethat is constructed in accordance with the teachings of the present disclosure and, as such, can be used for casting concrete. The structural profilehas a first edge, a second edgethat is opposite the first edge, a first side, a second sidethat is opposite the first side, a plurality of support beams, and a plurality of fasteners. The structural profileis generally rectangular in shape and has a length L, a width W, and a thickness T, with the width W being much greater than the thickness T. The first sideand second sidedefine the width W and the length L of the structural profile. The first edgeand the second edgedefine the thickness T of the structural profile. The structural profileis substantially symmetric about a horizontal axis AX located at a horizontal midline of the structural profile. The structural profilealso includes a grooveon the first edgeand a tongueon the second edgethat can be used to join the structural profileto an adjacent structural profile, as will be discussed in greater detail below. With the exception of the grooveon the first edgeand the tongueon the second edge, the structural profileis also substantially symmetric about a vertical axis AY located at a vertical midline of the structural profile.

The support beamsare generally configured to support the first and second sides,during use (e.g., when used to cast concrete). Each of the support beamsrun from the first sideto the second side(and vice-versa). Each support beamhas a first endthat is immediately adjacent the first sideof the structural profile, and, correspondingly, a second endof the support beamthat is immediately adjacent to the second side. In this example, the structural profileincludes four support beamsequally spaced apart from one another along the width W of the structural profile. In other examples, the structural profilecan include more or less support beamsand/or the support beamscan be spaced apart from one another in a different manner.

The fastenersare disposed along the first and second sides,of the structural profileand are generally configured to facilitate the attachment of an interfacial layer (e.g., interfacial sheetA orB shown in,) to the structural profile. That is to say, the fastenersare adapted to secure an interfacial layer to a structural profile. For example, the fastenerscan have features that help guide a material associated with the interfacial layer to flow into and/or around each fastener. Each of the fastenersofis a female fastener with a recess. The recessin this example has a substantially triangular shape, which may also be referred to as an arrowhead shape. In other examples, however, the recesscan have a different shape (e.g., a rectangular shape, an oval shape, or an irregular shape). Each fasteneralso includes a narrowed neckimmediately adjacent to the respective recess. More particularly, the narrowed neckis disposed at an opening of the respective recessand is symmetric about a midline MR of the recess. The narrowed neckis defined by rounded protrusionsfrom either the first or second side,that extend into the area adjacent to the recess. The substantially triangular shape of each recessis defined by an apexand a baseacross from the apexand partially defined by the neck. Each apexpoints to (i.e., is oriented toward) the midline of the structural profile, which is also the axis AX. The baseof each recessis immediately adjacent to either the first sideor the second sideof the structural profile, depending upon whether that fasteneris disposed in the first sideor the second side. Because each of the recessesin this example may resemble a regular triangle, the apexof each recesshas an angle of approximately 60°.

In the example shown in, the structural profileincludes eight fasteners, four fastenersdisposed along the first sideand four fastenersdisposed along the second sideand opposite the other four fasteners. Each of the eight fastenersis aligned with one of the support beams, such that the recessesinterface with a corresponding support beam. More particularly, the recessesdirectly interface with the first endor the second endof the corresponding support beam. Moreover, each of the support beamsis disposed between two opposing fasteners. In other examples, however, the structural profilecan include more or less than eight fastenersand/or the fastenerscan be arranged in a different manner.

shows the first edgeand the groovein circle B and the second edgeand the tonguein circle A, andis an enlarged view of a portionA of the structural profilewithin circle A. As illustrated in, the tongueextends outward from the second edgesuch that the tongueis configured to fit or slot into a grooveof an adjacent structural profileto join the two structural profilestogether. The tonguein this example extends outward from the second edgealong the horizontal axis AX, though the tonguecan extend outward from the second edgealong an axis that is parallel to or angled relative to the horizontal axis AX. The tonguemay include an oiling grooveat the center of the tongue. The oiling groovemay receive an oil or other fluid that serves as a lubricant for the dovetail joint created by the engagement between the joined tongueand the grooveof the adjacent structural profilewhen the two structural profilesare joined together.

In addition to the tongue, the second edgemay have additional featuresthat help to join the two structural profilestogether and/or enhance the adhesion or bonding between the structural profileand the interfacial layer attached thereto. These additional featuresmay be located symmetrically along the second edge, such that if the second edgewere rotated 180° about the axis AX, the location of the additional featureswould appear unchanged. In some examples, an adhesive may be added to the tongueor grooveto help join adjacent structural profilestogether. The adhesive may be glue, a pressure sensitive adhesive tape, an epoxy, or any other suitable means for enhancing the cohesion between two structural profiles. In some examples, the adhesive may be added to both the tongueand groovewhen joining adjacent structural profiles. Alternatively, in place of utilizing the tongueand the groovewhich form a dovetail joint to connect adjacent structural profiles, adhesive alone may be used to join the adjacent structural profilestogether.

is an enlarged view of a portionB of the structural profilewithin the circle B of. As illustrated in, the grooveis formed in the first edgesuch that the grooveis recessed relative to an outermost portion of the first edge. The grooveis thus configured to receive a tongueof an adjacent structural profileto join the two structural profilestogether. The groovein this example is centered along the horizontal axis AX, though the groovecan be centered along a different axis that is parallel to or angled relative to the horizontal axis AX.

As with the second edge, the first edgemay have additional featuresthat help to join the two structural profilestogether and/or enhance adhesion between the structural profileand the interfacial layer attached thereto. The additional featuresmay complement those additional featureson the second edge. In use, the additional featuresmay mate with the additional featuresof the second edge. More particularly, when the two structural profilesare joined together to form the dovetail joint, the additional featuresengage with complementary additional featuresso as to create a void into which material of the interfacial layer may flow, thus increasing or enhancing adhesion between the structural profileand the interfacial layer. Like the additional features, the additional featuresmay be located symmetrically along the first edgeabout the axis AX.

Turning back to, the structural profileincludes a plurality of open volumes. Each open volumeis bounded, in part, by the first and second sides,and at least one support beam. In some cases, the open volumewill be bounded by two support beams, while in other cases the open volumewill be bounded by one support beamand the first edgeor the second edge. Each open volumemay be filled or remain open. In some cases, conduit, pipes, fittings, and the like, may be disposed in or routed through one or more of the open volumesas needed during the concrete forming process. Alternatively, or additionally, a filler (not shown) may fill one or more of the open volume. The filler may be any of a natural material, a foamed material, a hexagonal cell material, a corrugated cardboard, a sprayed-in expanding material, and any other suitably light-weight material which increases the stiffness (e.g., resistance to compression and/or buckling) of the structural profile. The natural material may include any of balsa wood, cork, natural sponge, natural loofa, cotton, wool, and other light-weight, porous natural materials.

illustrate another example of a structural profilethat is constructed in accordance with the teachings of the present disclosure and, as such, can be used for casting concrete. The structural profileis similar to the structural profilein some ways, e.g., the structural profileincludes a first side, a second side, support beams, and open volumes. However, the structural profilediffers from the structural profilein other ways. More particularly, the structural profileincludes fastenersthat differ from the fasteners, a tongue edge(analogous to the second edgeof the structural profile), and a tonguethat is different from the tongueof the structural profile. Moreover, while not illustrated in, it will be appreciated that the structural profilealso includes a groove that is different from the groovebut is configured to receive the tongueof an adjacent structural profileto join the two structural profilestogether. In some examples, an adhesive (e.g., glue) may be added to the tongueand/or the groove to help join adjacent structural profilestogether. Alternatively, in place of utilizing the tongueand the groove to connect adjacent structural profiles, adhesive alone may be used to join the structural profilestogether.

Like the fasteners, the fastenersare disposed along the first and second sides,of the structural profileand are generally configured to facilitate the attachment of an interfacial layer or sheet (e.g., interfacial layerA orB shown in,) to the structural profile. However, unlike the fasteners, each of the fastenersis a protruding, or male, fastener with a pair of protrusionswhich extend beyond the first sideor the second sidefrom a proximal endto a distal end(i.e., the end furthest away from the first side). As best shown in, the fastenersin this example may be considered to resemble an anchor or a mammalian vertebrae. The protrusionsof these male fastenersextend outward from the first sideat an angle θ. This angle θ may range from about 15° to 45°, such as from about 20° to 40°, including from about 25° to 30°. The protrusionsin each pair are separated by a second angle ϕ. This second angle ϕ may range from about 75° to 120°, such as from about 80° to 110°, including from about 85° to 105°. Each protrusionis rounded at its distal end. However, there is a flattened endto each protrusionthat, in part, defines the anchor shape of the protrusion. In use, the protrusionsmay be surrounded by a portion of the material of the interfacial layer. Like a boat anchor has protrusions that dig into silt or sand beneath a vessel as it is dragged along a bay or harbor floor, preventing the vessel from drifting away with the current, the protrusionsmay aid in keeping an adjacent interfacial layer from slipping or skewing while the combination of the structural profileand interfacial layer are in use as part of a structural member.

As best illustrated in, the tongueof the structural profileextends outward from an outermost portion of the tongue edgesuch that the tongueis configured to fit or slot into a groove of an adjacent structural profileto join the two structural profilestogether. The structural profilealso includes an oiling grooveand additional featureson the tongue edge. The additional featureson the tongue edgeare shown as protrusions from the edgeand may serve a similar role of facilitating attachment of the interfacial layer to the structural profile. The oiling groove, which is shown as being in the middle of the tongue, may serve a similar purpose as the oiling grooveof the structural profile, i.e., the oiling grooveprovides a pathway for a lubricant or other fluid needed in the assembly of profiles of various sizes to create structural members dimensioned as needed (e.g., for the production of a concrete form).

show one example of a structural memberthat is constructed in accordance with the teachings of the present disclosure and, as such, can be used for casting concrete. The structural membergenerally includes the structural profileand one or more interfacial layers attached thereto. In this example, the structural memberincludes a first interfacial layerA and a second interfacial layerB attached to the first sideand the second side, respectively, of the structural profile. While the structural profileshown inis included in the structural memberin, the structural membercan instead include the structural profileshown in. The first and second interfacial layersA,B are uninterrupted layers of material that surround the structural profile, forming a modular structural member. As illustrated and as will be discussed in greater detail below, during manufacture of the structural member, some of the material of the interfacial layersA,B flows into, or infiltrates, the fastenersas well as some of the areas surrounding the dovetail joint. Further details about the interfacial layersA,B will be discussed in greater detail below.

shows another example of a structural memberthat is constructed in accordance with the teachings of the present disclosure and, as such, can be used for casting concrete. The structural memberincludes two identical structural profilesjoined together by a dovetail jointand then encapsulated by the interfacial layersA,B. The dovetail jointis defined by the tongueof one of the two structural profilesbeing inserted or disposed into the grooveof the other of the two structural profiles.

is a top-down cross-sectional view of the structural memberof, taken along the line FF. In this view, multiple structural profilescan be seen with an interfacial layer.

is an exploded view of the structural memberwhich displays the interfacial layersA,B and multiple structural profiles. It can be seen that the interfacial layersA,B include portions whichextend from the bulk of each layer into the recessesof fasteners. The interfacial layersA,B are shown as discontinuous, but the layers may be fabricated as a complete sheet and then attached to the corresponding side of the joined profilesor the layers may form a complete sheet after attachment to the corresponding side of the joined profilesand when in use., for example, illustrates the interfacial layersA,B are continuous layers on either side of the joined profiles.

The structural profiles described herein (e.g., the structural profiles,) are made of a suitably strong and lightweight material. The structural profiles described herein are preferably made of aluminum (e.g., a recycled aluminum). However, the structural profiles can instead be made of aluminum alloys, steel alloys, polymer composites that include glass or other fibers surrounded by polymers, or ceramics with suitable toughness. The structural profiles described herein are preferably made using extrusion, yielding extruded structural profiles. However, the structural profiles may be made using a different technique (e.g., injection molding, casting, additive manufacturing (e.g., 3D printing), and machining). By manufacturing the structural profiles using extrusion, for example, the length L and the thickness T of the structural profiles can be quickly and easily adjusted to satisfy end use requirements.

The structural profiles may, for example, have a width in the range of around 2.00 inches (5.08 cm) to around 40 inches (101.60 cm), such as around 2.25 inches (5.715 cm) to around 37.50 inches (95.25 cm), such as from around 2.50 inches (6.35 cm) to around 35.00 inches (88.90 cm), around 2.75 inches (6.985 cm) to around 32.50 inches (82.55 cm), around 3.00 inches (7.62 cm) to around 30.00 inches (76.20 cm), such as between around 4.00 inches (10.16 cm) and around 20.00 inches (50.80 cm), such as between around 5.00 inches (12.70 cm) and around 10 inches (25.40 cm), including around 5.75 inches (14.605 cm).

The thickness of the structural profile may, for example, be in the range of around 0.200 inches (0.508 cm) to around 10 inches (22.400 cm), such as from around 0.250 inches (0.635 cm) to around 8.000 inches (20.320 cm), around

0.300 inches (0.762 cm) to around 7.000 inches (17.780 cm), such as from around 0.350 inches (0.889 cm) to around 06.000 inches (15.240 cm), including from around 0.400 inches (1.016 cm) to around 5.000 inches (12.700 cm). The first side and the second side may have a thickness ranging from around 0.020 inches (0.0508 cm) to around 0.40 inches (1.016 cm), such as from around 0.025 inches (0.0635 cm) to around 0.2 inches (0.508 cm), including from around 0.02 inches (0.0508 cm) to around 0.10 inches (0.254 cm).

The support beams may have a thickness ranging from around 0.010 inches (0.0254 cm) to around 0.500 inches (1.270 cm), such as from around 0.025 inches (0.0635 cm) to around 0.250 inches (0.635 cm), such as from around 0.020 inches (0.0508 cm) to 0.100 inches (0.254 cm).

The pitch between support beams may range from around 0.200 inches (0.508 cm) to around 6.500 inches (16.510 cm), such as around 0.250 inches (0.635 cm) to around 6.000 inches (15.240 cm), from around 0.500 inches (1.270 cm) to around 5.000 inches (12.700 cm), including from around 1.000 inches (2.540 cm) to around 4.000 inches (10.16), such as from around 1.100 inches (2.794 cm) to around 3.25 inches (8.255 cm), including from around 1.050 inches (2.667 cm) to around 3.000 inches (7.620 cm).

The interfacial layers described herein are configured to withstand harsh environments and abusive use, such as contact with poured and curing concrete when the structural members including those interfacial layers are in use as a concrete form. In order for the structural members to be reusable a significant number of times, the interfacial layers must be able to endure extreme pH and elevated temperatures, such as the harsh environments created during concrete curing and poured concrete while still being able to release from cured concrete without loss of its integrity. Weight is also a consideration with the interfacial layers. For example, utilizing heavier interfacial layers may strengthen the resulting structural member but will also decrease the portability and useability of that structural member. To meet all of these requirements, the interfacial layer should be resistant to at least alkaline pH conditions, elevated temperature, embrittlement for UV or temperature exposure, water or other liquid absorption, and abrasion by sand and aggregate (e.g., stones or rocks in the concrete mixture). The interfacial layer may also have a surface roughness (or smoothness) which allows for easy release of cured concrete from a form constructed of structural members. Alternatively, or additionally, the interfacial layer may have a layer of non-stick material, such as a polyfluorene material, or a smooth and glassy material, which can decrease the likelihood of adhesion between the cured concrete and the structural member.

The interfacial layer(s) are preferably molded to the structural profile(s) using a molding apparatus. In some implementations, the interfacial layer(s) may be injection molded around the structural profile(s) using an injection molding apparatus. In some implementations, the interfacial layer(s) may be compression molded or vacuum molded to the structural profile(s). The interfacial layer(s) may be applied in a co-extrusion process or in a process using heated rollers or plates to allow the material of the interfacial layer(s) to conform to the outer portion of the structural profile(s). Further, portions of the interfacial layer(s) may be applied to the structural profile(s) using injection molding and other portions may be applied using compression molding (e.g., low-pressure compression molding), water pressure molding, vacuum molding, spraying, electrostatic deposition, dip coating, or other suitable methods. The structural profile(s) may be annealed after the interfacial layer(s) are applied. The annealing process may enhance bonding between the profile(s) and interfacial layer(s) as well as strengthen the overall structural member.

The materials used to form the interfacial layer(s) may include polymers, polymer composites, composites with recycled reinforcing materials (e.g., recycled glass fiber, recycled ceramic inclusions in a matrix of recycled metal), metal foils or sheets, and other materials which satisfy the criteria described above. Plastic used for interfacial layers may include any of the following, alone or in combination: PP (polypropylene), PTFE (polytetrafluoroethylene), PEEK (polyether ether ketone), PEI (polyetherimide), PAI (polyamide-imide), PBI (polybenzimidazole), PET (polyethylene terephthalate), PVC (polyvinylchloride), and the like. In some embodiments, the polymers, the composite materials, the reinforcing material, and/or the metal foils or sheets may be recycled materials. The interfacial layer(s) may alternatively or additionally include composites with virgin polymers and/or virgin reinforcing materials.

Various methods can be used to form a structural member (e.g., the structural member, the structural member) in accordance with the teachings of the present disclosure. One example of a methodof fabrication is shown in. The methodbegins with the formation of one or more structural profiles (e.g., structural profiles,) in step. When the structural member includes two or more structural profiles, the two or more structural profiles are connected (e.g., using the dovetail joint) to form a connected profile in step. The next stepis placing the profile into a molding apparatus (e.g., an injection molding apparatus, a compression molding apparatus). The interfacial layers, which in this example are made of recycled material, are applied to the profile via the molding apparatus, as in step. The result is a structural member that is lightweight, strong, and reusable.

Other examples of methods,for forming a structural member (e.g., the structural member, the structural member) are shown inand. One or more structural profiles are first created, preferably by extrusion, in the first step,. When the structural member includes two or more structural profiles, the second step,includes connecting the two or more structural profiles with one or more dovetail joints to form a connected profile. The next step,includes placing the profile into a molding apparatus. In the methodshown ininterfacial layers of recycled polymer material (e.g., recycled plastic) are applied to the profile via injection molding in step. Conversely, in the methodshown ininterfacial layers of preformed recycled polymer material are applied on the profile using compression molding in step. Alternatively, as indicated herein above, the interfacial layers may be formed of various types of materials and thus applied using techniques in addition to or different from injection molding and compression molding.

The structural members described herein may include any number of structural profiles coupled together, such that the structural members can have any number of different widths. The flexibility in the number of structural profiles, as well as the dimensions and shape of the profiles and overall structural members, facilitates customization as needed for a variety of configurations of concrete forms, and thus of concrete structures. These concrete structures may include curved structures. Furthermore, the lightweight nature of the structural members allows for facile construction of concrete forms in situ, e.g., at a job site, for even very tall concrete structures. At the same time, the robust nature of the structural members allows for the construction of concrete forms in most environments, such as in water, in cold environments, in areas susceptible to mold, rot, and mildew.

In some examples, multiple structural members may be connected via one or more dovetail joints which are created through a tongue slotting into a groove, preferably before attachment of the interfacial layer(s) but in some cases even after structural profiles are surrounded by interfacial layers. Joining structural members of various widths or varying configurations of joints and grooves may allow for curved or undulating forms.

The tongues,shown in the examples above are two of many configurations for a tongue for use with the structural profiles presented herein. These tongues,and their corresponding grooves connect two profiles of similar configuration to form a substantially flat or straight combined profile. Alternatively, or additionally, tongues may be used with corresponding grooves that allow for connection between adjacent structural profiles such that the combined profile has a curve or bend. The design of the tongues and grooves may be tailored for a variety of configurations, including differing radii of curvature, changing lengths, changing widths, and the like.