Additively-constructed cellular building elements and structures

Abstract

Sub-panel, panel, and connecting coupler building elements are provided that can be manufactured by additive manufacturing and then be joined together in modular fashion to produce structures suitable for use as shelters or other buildings or structures. Each sub-panel includes one or more whole or partial cells, each of which defines a cavity, which ensures light weight and can house insulative material, lighting fixtures, utility elements, or a transparent window structure. Cell sidewalls can be joined to form a modular panel. Multiple panels may be joined by their edges in a generally planar configuration to form walls. Connector elements may include at least one cell and at least one connecting flange. The sidewall of each cell or connecting flange may be joined to another cell or panel to interconnect walls in predefined orientations. Sub-panels and / or panels may be manufactured and stockpiled, and be deployed as needed for assembly on site.

Description

ADDITIVELY-CONSTRUCTED CELLULAR BUILDING ELEMENTS AND STRUCTURESCROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority, under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 63 / 549,243, filed February 2, 2024, the entire disclosure of which is hereby incorporated herein by reference.FIELD OF THE INVENTION

[0002] The present invention relates generally to building construction elements, and more particularly to versatile cellular building construction elements that are suitable for manufacture via additive manufacturing techniques.DISCUSSION OF RELATED ART

[0003] Natural disasters such as earthquakes, hurricanes, flooding, tornados, and wildfires can destroy residential, commercial and other building structures. In the case of residential structures for example, this creates an urgent need for construction of replacement shelters to house displaced individuals and communities. Therefore, one of the most important factors to consider when developing sheltering systems is rapid deployment in terms of assembling and disassembling the shelter units (wall panels, roofing systems, and flooring). In addition, integrating architectural and building science features and utilities such as heating and cooling systems, power, lighting, water and sewer piping, and communications into such shelters poses additional challenges to conventional sheltering systems and rapid response teams.

[0004] Various conventional bu ilding materials and methods are known in the art. More recently, additive construction techniques have been using in building construction, and in particular, in the construction of housing buildings. Exemplary additive construction of housing led by industry (COBOD or ICON) relies on newly-developed gantry systems to build houses in a layer-by-layer approach, with the end product mimicking conventional construction using mortar and bricks.

[0005] More recently, additive construction machines and methods have been developed to “print” structures using a bead / flow of a concrete mix material. More particularly, additive construction with concrete is a growing form ofadditive manufacturing that relies on depositing special concrete mixes, which are specially designed to meet printability requirements, in continuous filaments / beads and layers to build customized and optimized designs. Like additive manufacturing processes, such additive construction uses pre-defined printing paths to deposit concrete through a printing nozzle, giving geometric freedom that is not possible with conventional construction methods. Such 3D printing with concrete provides exceptional opportunities to construct buildings and other structures by effectively manufacturing them using 3D printing / additive manufacturing techniques to produce structures that are structurally robust and capable of providing all basic utilities and shelter / living support.

[0006] What is needed is a novel approach to building construction, and building construction elements / materials.SUMMARY

[0007] The present invention provides a novel approach to building construction, namely the construction of novel cellular building elements (e.g., panels) that can be constructed using additive manufacturing techniques (e.g., 3-D printing of a concrete mix), and then bejoined together in somewhat modularfash ion to produce structures suitable for use as shelters and / or other buildings or structures. Such cellular building elements and structures may be configured to integrate architectural and building science features and utilities such as heating and cooling systems, power, lighting, water and sewer piping, and communications and / ortheircomponent parts.

[0008] More particularly, the present invention provides multi-functional, additively constructed building elements that are made up of repeating cells. The building element may be constructed as a panel that is versatile in form and use. For example, the panels can be used in the construction of building structures as load- bearing wall elements that can accommodate various heating / cooling / power / lighting / water / sewer / communications, etc. utilities components within their structure while maintaining a desired aesthetic appearance, while enabling architects and builders to optimize structural performance due to their cellular design. The seamless incorporation of essential elements such as thermal insulation, wiring, piping, power, lighting, communication, and plumbing structuresinto the building elements (e.g., panels) and simplifies the building construction process and reduces the requirement for post-construction utility placement.

[0009] In accordance with the present invention, the multiple building elements (e.g., panels) may be joined together to assemble them into a desired structure (e.g., walls of a home). In certain embodiments, the building elements include structures that facilitate joining them together, e.g., via fasteners, clamps / mechanical couplers, adhesives / sealants, etc. The building elements may be configured as modular units so that they are readily interchangeable and / or compatible for joining together with each other. Accordingly, relatively modest number of “standard” modular building elements may be used to assemble a much larger number of various buildings / structures of various configurations using different combinations of the “standard” building elements joined together if different configurations.

[0010] By way of example, the additively constructed building elements of the present invention may be used to construct rapidly deployable shelters after major hazards to house impacted individuals, e.g., within a few days to a few weeks. For example, modular building elements may be printed off-site elements, e.g., in advance of a natural disaster, and then can be rapidly transported to a future natural disaster site and be assembled into suitable building structures rapidly.BRIEF DESCRIPTION OF THE FIGURES

[0011] An understanding of the following description will be facilitated by reference to the attached drawings, in which:

[0012] Figs. 1A, 1 B and 1 C are perspective views showing exemplary 3D printing of exemplary end, intermediary, and main cellular-unit modular sub-panel building elements, respectively, in accordance with an exemplary embodiment of the present invention;

[0013] Fig. 2 is a side view of the exemplary end, intermediary, and main cellular-unit modular sub-panel building elements of Figs. 1A-1 C shown in aligned adjacent positions for nesting and mating with each other;

[0014] Fig. 3 is a perspective view showing alignment and joining of multiple exemplary cellular-unit modular sub-panel building elements to assemble an exemplary cellular-unit modular panel building element;

[0015] Fig. 4 is a side view of the exemplary cellular-unit modular panel building element;

[0016] Fig. 5 is a side view of two cellular-unit modular panel building elements joined together in a planar configuration;

[0017] Fig. 6 is a perspective view of the exemplary cellular-unit modular panel building element of Fig. 4 with exemplary selective filling of cells with spray foam insulative material;

[0018] Fig. 7 is a perspective view of the exemplary cellular-unit modular panel building element of Fig. 4 with exemplary selective filling of cells with sheet foam insulative material and an exemplary lighting unit;

[0019] Fig. 8 is a side perspective view showing exemplary 3D printing of an exemplary columnar cellular connector building element, in accordance with an exemplary embodiment of the present invention;

[0020] Fig. 9 is a top perspective view of the columnar cellular connector building element of Fig. 8, for joining two modular panel building elements at a 90- degree angle in a corner configuration;

[0021] Fig. 10 is a top view of an exemplary alternative columnar cellular connector building elementfor joining three modular panel building elements at 90- degree angles in an edge / T configuration;

[0022] Fig. 11 is a top view of another exemplary alternative columnar cellular connector building elementforjoining fourmodular panel building elements at 90-degree angles in an interior / X configuration;

[0023] Figs. 12A and 12B are perspective and top views, respectively, showing the connector building element of Fig. 9 joining two modular panel building elements in a corner configuration;

[0024] Fig. 12C shows the two modular panel building elements of Figs. 12A and 12B with insulative material and lighting units added;

[0025] Figs. 13A and 13B are perspective and top views, respectively, showing two modular panel building elements joined together in an oblique-angle configuration as joined by an alternative columnar cellular connector;

[0026] Fig. 14 illustrates an exemplary robotic manufacturing system for manufacturing cellular-unit modular sub-panel building elements, and assembling the cellular-unit modular sub-panel building elements into cellular-unit modular panel building elements; and

[0027] Fig. 15 shows a load-displacement curve from testing of a wall-type building element panel sample, along with photographs of thewall sample at different loading stages throughout the test.DETAILED DESCRIPTION

[0028] The present invention provides a novel approach to building construction and building construction elements. The present invention provides versatile cellular building construction system including elements that are suitable for manufacture via additive manufacturing (e.g., “3D-printing”) techniques. The present invention enables printing of structural panels in modular units, allowing integration of window and door openings, integration of utilities concurrently during additive construction or after, and inclusion of insulative and / or electrically-powered lighting unit elements. It also eliminates hard interfaces between the layers that may result in “cold joints” that hinder the overall structural performance. The reason for cold joints in the current additive construction techniques is that the wait time exceeds the curing (or a substantial portion of the curing) time, due to printing the full panel height / size instead of printing the panel in small modular segments, as contemplated herein, such that a poor bond is formed between material of successive additive manufacturing sessions. The present invention is capable of improving the structural, architectural, and functionality of structures, buildings, houses, and shelters through additive construction of innovative concepts. Structures can be easily erected, reconfigured, assembled, reused multiple times for many different purposes.

[0029] The present invention provides novel building elements in the nature of cellular-unit sub-panels and panels, and cellular columnar connectors. Each sub-panel, panel and columnar connector may be made up of uniform (or non- uniform) repeatin g / adjacent cells. The cellular-unit sub-panels, panels and cellular columnar connectors are manufactured using additive manufacturing techniques, such as 3-D printing, using suitable conventional building materials, such as a concrete or cementitious mix. The cellularunits may have any suitable configuration, such as a hexagonal, octagonal, circular or other shape.

[0030] These relatively small (e.g., modular) sub-panel units are then collected and arranged in different configurations to build-up any type of structures, such as wall panels, walls, columns, beams, etc. The individual sub-panel units canbe connected (in any desired arrangement) using any available anchoring or connecting mechanisms (clamps, silicone / bonding agents, etc.). Silicone / bonding agent can be applied between the subpanel units to form completed wall panels / beams / columns, etc., and to join wall panels / beams / columns to create a building structure and allow for proper sealing against air and water intrusion. In certain embodiments, finished panels may be constructed in relatively small sizes, and a plurality of the panels may be joined to form relatively larger walls, etc. In certain embodiments, finished panels have a rectangular perimeter edge, or elongated flat surfaces, to facilitate joining of panels to each other, to columnar connectors, etc.

[0031] Generally, the subpanels have a cellular structure. The cells may have any suitable shape or configuration. In certain embodiments, the cells have a polygonal shape, and each polygon defines sidewall surfaces (e.g., flat surfaces) normal to directions in which panels are likely to be joined, e.g., at O, 45, 90, 135, 180, 225, 270 and 315 degrees. These surfaces of adjacent sub- panels / panels / connectors can be placed in abutting relationship relative to each other to proving mating lands having surface areas that may be coated with silicone / bonding agents to join them together. In other embodiments, the cells may be circular or have other non-uniform-polygonal shapes. Any suitable cell shape may be used in accordance with the present invention.

[0032] In certain embodiments, the cells of the subpanel and the cells of the columnar units are similar in shape. In certain embodiments, a columnar connector may be printed to have a height equal or approximately equal to a height of a panel to which it is to be mated. In certain embodiments, the columnar connectors may be formed of one or more similar cells, and each cell may be formed adjacent a respective connecting flange. Each connecting flange has a surface that may be placed in abutting relationship with another connecting flange or a sub-panel or panel to proving mating lands having surface areas that may be coated with conventional commercially-available silicone / bonding agents to join them together. In certain embodiments, individual connectors may be readily matable to orient the respective connective flanges at angles of 45, 90, 135, 180, 225, 270 and 315 degrees relative to each other.

[0033] The individual cells of each subpanel and / or columnar connector may then be filled according to the desired application. For example, to provideenergy savings / thermal efficiency, cellular units can be filled selectively with any suitable insulative material (such as spray foam, sheet foam, or any other type of insulation). Other cellular units can selectively serve as windows by closing them up using proper glass unit inserts or overlays. Other cellular units can selectively be used to house embedded lighting systems, utilities infrastructure such as cabling and piping, and any other necessary features.

[0034] In certain embodiments, a plurality of different cellular subpanels may be constructed to be modular in nature and configurable in a plurality of different arrangements to form panels of many different sizes and configurations, using only a small number of different subpanels. For example, Fig. 2 shows three different modular cellular subpanels that may be joined to form panels of many different sizes, with each panel being comprised of multiple cells, and with each panel having a rectangular perimeter, although such a perimeter is not required in accordance with the present invention.

[0035] Cellular subpanel building elements may be designed to be modular, to have desired configurations, to be combinable into desired configurations, and to handle desired structural loads. By way of example, cellular subpanel building elements may be designed using conventional computer aided design (CAD) and slicing software to develop suitable geometry and / or other code for controlling conventional 3-D concrete mix printing equipment, in connection with the present invention, as will be appreciated by one of ordinary skill in the art.

[0036] Various conventional concrete mix materials are known in the art, and any suitable concrete mix material may be used according to the desired load bearing characteristics, environmental characteristics at the printing site, etc., as will be appreciated by one of ordinary skill in the art. Exemplary concrete mixes may include one or more of cement, silica fume, fly ash, sand, water, binder and aggregate, among other materials, as will be appreciated by those skilled in the art. Printing parameters such as speed of printing, nozzle size, print width and height, and extrusion rates for the concrete mix flow may be controlled as known in the art, according to the material used and the desired load bearing characteristics, environmental characteristics at the printing site, etc., as will be appreciated by one of ordinary skill in the art.

[0037] The sub-panel and panel building elements have a repeating cellular design, which makes the materials relatively light in weight, yet capable ofbearing structural loads required in building construction. The elements consist of cellular units printed individually and connected to form the walls, etc. Since the cellular units are printed individually, a post-printing process is used to form a wall system using external anchoring (e.g., C-clamps, pip hose clamps), fasteners (e.g., bolt, ll-bolt, etc.) or adhesive (e.g., silicone). Voids in the cells allow for the integration of utilities and insulative materials. To provide heat insulation and energy saving, cellular units can be filled with insulative materials such as spray foam, insulation foam, or any type of insulation. Other selective cells can serve as windows by covering them with plexiglass or other transparent or translucent material. Other cellular units can serve as hosts to embed lighting systems, utilities, piping, and any necessary features. For proper sealing and water intrusion prevention, silicone between the units is used.

[0038] After individual walls are assembled, they can be connected using clamping systems in different configurations (corner, edge, and interior connections) using columnarunits. These multi-functional walls can revolutionize the construction and housing industry through ease of assembly and deconstruction making them the preferable options for temporary shelters during and after extreme natural or anthropogenic hazards. Structural elements may be fabricated off -site with all necessary utilities embedded within.

[0039] Figs. 1A, 1 B and 1 C are perspective views showing exemplary 3D printing of exemplary end, intermediary, and main cellular-unit sub-panels 10, 20, 30, respectively. As discussed above, each sub-panel may be manufactured using by conventional 3D-printing equipment to print a suitable concrete mix in the desired cellular pattern to form the desired sub-panels, according to the intended design for a particular project.

[0040] Fig. 2 is a side view of the end, intermediary, and main cellular-unit modular sub-panel building elements of Figs. 1A-1 C, shown in aligned adjacent positions for nesting and mating with each other. As will be appreciated from Fig. 2, each cellular sub-panel 10, 20, 30 includes one or more whole cells 40 and partial cells 50 based on a common cell design, namely, a hexagonal cell design in this exemplary embodiment. Each whole cell 40 and each partial cell 50 includes a sidewall 60 serving as a boundary to define a central cavity 64 bounded by the sidewall 60, as best shown in Fig. 2 These sidewall surface of adjacent sub- panels / panels / connectors can be placed in abutting relationship relative to eachother to provide mating lands having surface areas that may be coated with silicone / bonding agents to join them together.

[0041] Fig. 3 is a perspective view showing alignment and joining of multiple exemplary cellular-unit modular sub-panel building elements 10 / 20 / 30 to assemble an exemplary cellular-unit modular panel building element, in this case a modular panel 100 (e.g., wall panel), as shown in Figs. 3 and 4. The sub-panels are modular in th at they are designed to abut andfitwith each other to form a continuous building element structure, as shown in Figs. 3 and 4. In this example, the individual modular sub-panel building elements 10 / 20 / 30 are assembled by coating the abutting portions of adjacent sidewalls 60 of abutting cells 40, 50 with silicone rubber or other adhesive / sealant and clamping them together, and waiting the adhesive / sealant to cure, at which point the clamps can be removed and they have been assembled into a unitary building element panel 100, as best shown in Fig. 3.

[0042] The panel 100 is modular in that it is designed such that portions of respective sidewalls of various cells cooperate to form a joining edge 110 that is configured to mate with a respective joining edge of another panel 100, as will be appreciated from Fig. 4. In this exemplary embodiment, multiple respective sidewalls 60 of multiple adjacent cells / partial cells 40 / 50 cooperate to collectively form substantially linear / planar joining edges 110, as shown in Fig. 4.

[0043] In the example of Fig. 4, the cells of the panel 100 define four joining edges 110 oriented in a rectilinear arrangement, such that the panel 100 has an overall rectilinear shape, as will be appreciated from Fig. 4. Accordingly, two panels 100 may be arranged side to side, or end to end, with their respective joining edges 110 abutting, and those abutting joining edges may be coated with silicone rubber or other adhesive / sealant and may be clamped such that after curing, the two panels 100 have been assembled into a unitary structural element, such as a wall. This may be repeated as needed to form a wall with desired dimensions. Fig. 5 is a side view of two cellular-unit modular panel building elements 100 joined together in a planar configuration, to form an exemplary wall 190.

[0044] As referred to above, the individual cells 40, 50 may then be filled according to the desired application. Fig. 6 is a perspective view of the exemplary cellular-unit modular panel building element 100 of Fig. 4 with exemplary selective filling of cells 40, 50 with spray foam insulative material 180. Fig. 7 is aperspective view of the exemplary cellular-unit modular panel building element 100 of Fig. 4 with exemplary selective filling of cells with sheet foam insulative material 190. Accordingly, the insulated wall panels 100 of Figs. 6 and 7 may be used in the construction of a shelter or other building or structure to provide a thermal insulative effect.

[0045] In the example of Fig. 6, two cavities 64 of two cells were not filled with insulative foam but ratherthose cavities were left unfilled and void. Accordingly, these cells may be used, for example, as a window in the wall panel 100. The window may be left open, may be filled with a suitable glass or transparent / translucent structure, and / or all or a port of the panel 100 may be covered with a sheet of plexiglass or other transparent or translucent material.

[0046] Further, in the example of Fig. 7, one cavity 64 of one of the cells was not filled with insulative form and was instead filled with an exemplary lighting unit 188, but as a battery-powered LED lighting equipment in a housing configured to fit within the cell (e.g., hexagonal in shape), as will be appreciated from Fig. 7.

[0047] Fig. 8 is a side perspective view showing exemplary 3D printing of an exemplary columnar cellular connector building element 200, in accordance with an exemplary embodiment of the present invention. Fig. 9 is a top perspective view of the columnar cellular connector building element 200 of Fig. 8.

[0048] Columnar connector building elements 200 may be used to join together two or more other building elements, such as modular panel building elements. The columnar connector building elements 200 may be 3D printed in similarfashion with similar materials to those described above. The columnar connector building elements may include one or more cells 240. Each cell 240 may have a configuration that is the same as, or different form, any cells of the other building elements being joined. Each cell is printed to have a sidewall 260 having a surface 270. The sidewall surface 270 of the cell 260 of the columnar connector building element 200 may be placed in abutting relationship to a respective sidewall surface 270 of another cell 260 of another columnar connector 200. In certain embodiments, individual cells of the columnar connector building elements may be readily matable to orient the respective connective cells at angles of 45, 90, 135, 180, 225, 270 and 315 degrees relative to each other. Other angular positions may be obtained according to the shape of the cell. The sidewall surfaces 270 eachprovide mating lands having surface areas that may be coated with silicone / bonding agents to join them together as described in greater detail below.

[0049] Further, each cellular columnar connector building element 200 includes a connecting flange 210. Each connecting flange 210 has a respective sidewall surface 280. The sidewall surface 280 of the connecting flange 210 of the columnar connector building element 200 may be placed in abutting relationship to a joining edge 110 of a cellular panel building element 100. The sidewall surface 280 provides a land having a surface area that may be coated with silicone / bonding agents to join the connecting flange 210 and associated cell 260 / columnar connector building element 200 to the cellular panel building element, as described in greater detail below.

[0050] In the example of Figs. 8 and 9, the columnar cellular connector building element 200 includes two cells 260 that are hexagonal in shape, and two associated connecting flanges, and the cells and connecting flanges 210 are 3D- printed together as a unitary body with the cells and connecting flanges in a fixed relative orientation. Figs. 8 and 9 show an exemplary columnar cellular connector building element 200 configured for joining two modular panel building elements 100 at a 90-degree angle in a corn er configuration, by bonding the surfaces 280 of the connecting flanges 210 of the columnar cellular connector building elements 200 to the joining edges 110 of two different panels 100. Figs. 12A and 12B are perspective and top views, respectively, showing the connector building element of Fig. 9 joining two modular panel building elements in a corner configuration. Fig. 12C shows the two modular panel building elements of Figs. 12A and 12B with insulative material and lighting units added within the cells, in a manner similar to that described above.

[0051] Fig. 10 is a top view of an exemplary alternative columnar cellular connector building element 200 for joining three modular panel building elements 100 at 90-degree angles in an edge / T-configu ration. Fig. 11 is a top view of another exemplary alternative columnar cellular connector building element 200 for joining four modular panel building elements 100 at 90-degree angles in an interior / X configuration. These connector configurations are useful as modular or “standard” connector building elements for houses and other structure that typically include external and internal walls commonly joined at 90-degree angles. Accordingly, it will be appreciated that wall panel building elements 100 may be joined in many differentdesired configurations to provide many different floorplans using just the modular panels 100 and these three configurations of connector building elements 200.

[0052] Figs. 13A and 13B are perspective and top views, respectively, showing two modular panel building elements joined together in an oblique-angle configuration as joined by an alternative columnar cellular connector. In this case, for example, each cellular columnar connector building element 200 includes only one cell and one connecting flange, and multiple connector building elements 200 may be in tercon nected / bonded on the surfaces 270 of the cells at a variety of angles, according to the polygonal configuration of the cells 260. In certain embodiments, individual connector building elements may be readily matable to orient the respective connecting flanges 210 at angles of 45, 90, 135, 180, 225, 270 and 315 degrees relative to each other. Any suitable configuration of the cells may be employed in accordance with the present invention.

[0053] Fig. 14 illustrates an exemplary robotic manufacturing system 500 for manufacturing cellular-unit modular sub-panel building elements, and assembling the cellular-unit modular sub-panel building elements into cellular-unit modular panel building elements. More particularly, the system 500 includes one or more conveyor belts 510, a robotic 3D-printing system 520 for printing concrete to create cellular subpanel building elements, a pick-and-place robotic arm system 530 for arranging the sub-panel building elements into a suitable arrangement for bonding to form a panel building element 100, a first robotic arm system 540 for delivering sealant / adhesive to join / seal the sub-panels to form the panel, a second robotic arm system 550 for filling cellswith insulative foam, and a third robotic arm system 560 for joining the insulative form and cells together, as shown inf Fig. 14. The individual systems may have any suitable configuration for manufacture of panel building elements in this or a similar manner. Subsequently, the panels may be assembled to form a structure as desired, as will be appreciated from the description above. The exemplary robotic manufacturing system 50 for manufacturing cellular-unit modular sub-panel building elements, and assembling the cellular-unit modular sub-panel building elements into cellular-unit modular panel building elements, allows 3D printers to print the components and robots to aid in the assembly of wall or other structures.

[0054] Accordingly, the present invention provides for additive construction (e.g., 3D-printing) of small-scale modular subpanel and connector structures that canbe combined to form modular panels and other structures to enable simple construction of large-scale bui Idin gs / structu res having a wide variety of configurations, by joining panels and connectors together through relatively simple clamping and adhesive bonding / sealing material application. These multi-purpose structures can revolutionize construction and housing industry through ease of assembly and deconstruction making them the preferable options for temporary shelters during and after extreme natural or manmade hazards. New housing systems can also be envisioned where all structural elements are fabricated off -site with all necessary utilities already embedded.

[0055] As will be appreciated by those skilled in the art, the building elements and construction techniques described herein are suitable for use in the construction of houses, shelters, storage structures, jobsite trailers, wind turbine towers, buildings, bridges, and other types of structures. In certain embodiments, the building elements and construction techniques described herein provide one or more of the following advantages: reducing carbon emission from construction materials by using low carbon materials and less materials; easy deployment; lightweight using lightweight materials and cellular designs; positively impact the lives of those in need of temporary housing and storage, while providing a pathway toward the development of deployable structures for other civilian and military applications; easy deployment of shelters after major events such as hurricanes and earthquake to house impacted population; military application for deployment of troops; benefits to FEMA and DHS for post-disaster recovery; ease of manufacture; ease of storage and transport; mobile structures; readily de-constructable (e.g., prior to a hurricane) and then re-assemblable (e.g., after the hurricane passes); and environmental friendliness, with less emissive materials for 3D-printing.

[0056] As mentioned above, conventional concrete 3-D printing equipment maybe used, such as the commercially-available Scara Elite Roadrunner, a rail track, a mixing station, and a concrete pump.

[0057] An exemplary building element was printed with hexagonal cells oriented such that parallel edges are in the vertical direction of the wall (gravity), so they act as vertical collectors for the stresses creating compression -only nodes (C-C- C) connection with the inclined edges. The nominal thickness of each hexagonal edge may be 12.7 millimeters resulting in a nominal thickness of 25.4 millimeters when the hexagonal cells connect. To form a wall, three different cellular units arerequired to ensure a rectangular wall: (1 ) main cellular unit or Section 1 , (2) intermediate cellularunit or Section 2, and (3) end cellular unit or Section 3. Cellular units may have an overall length of 610 millimeters and an average thickness (in the printing direction) of 90 millimeters. The exemplary main cellular unit (Section 1 ) consists of three full hexagonal cells with a nominal wall thickness of 12.7 millimeters except for the vertical interior walls which have a nominal wall thickness of 25.4 millimeters. The exemplary intermediate cellular unit (Section 2) consists of two full hexagonal cells (interior), and two half hexagonal cells (exteriors) with a nominal wall thickness of 12.7 millimeters except for the vertical interior walls which have a nominal wall thickness of 25.4 millimeters. The exemplary nominal hexagonal cell height is 235 millimeters for both the main and intermediate cellular units. The exemplary end cellular units are similar to the half-split of the intermediate cellular unit (split into half horizontally) with a total depth of 177 millimeters. Two multifunctional wall segments were additively constructed with a total height of 1180 millimeters, a width of 610 millimeters, and a thickness of 90 millimeters. These dimensions resulted in seven different sections per wall (three main cellular units, two intermediate cellular units, and two end cellular units). To connect the two walls in a corner configuration, the columnar unit was additively constructed using two vertical octagonal cells, each with end brackets. The two octagonal cells are connected during the additive construction process at one of the inclined edges. Vertical octagonal cells forming columnar units provide flexibility in forming corner, edge, interior, or even angled connections. The depth of the octagonal cell is 101.2 millimeters with 12.5 millimeters wall thickness with an end bracket of 25.4 millimeters in thickness and 101 .2 millimeters in width. Two octagonal cells form a corner connection where the two cells join at one of the inclined cell stems. Three octagonal cells form an edge connection where two octagonal cells in the continuous direction connect with the third octagonal cell in the terminated direction. Four octagonal cells form an interior connection where each octagonal cell connects to the adjacent cells. The vertical octagonal cells provide opportunities to connect the walls not only in orthogonal directions but also in inclined angles (45, 135, 225, and 315 degrees) by just connecting the brackets to the inclined walls instead.

[0058] The hexagonal cells within the wall provide multi-functionality for the wall. To provide thermal insulation, cells may be filled with precut hexagonal insulative units using commercially-available Kingspan Green Guard® GG25 LGXPS. The hexagonal insulative material units are connected to the printed cellular units using silicone rubber. Selective cellularunits can form window openings. Other selective cellular units can accommodate battery-powered lighting within the insulative materials. Since the system is proposed for rapidly deployable, multifunctional structures, the proposed wall seeks to integrate as much living support for individuals impacted by natural disasters in need of temporary shelters. Therefore, the battery-powered lighting was embedded in the wall to reduce hurdles on emergency responders (such as the Federal Emergency Management Agency (FEMA)) to provide lighting to the shelters without external power sources.

[0059] In an example, fourteen wall cellular units (six main cellular units, four intermediate cellular units, and four end cellular units) were additively constructed, with each segment reaching 16 to 17 layers for a height of 90 millimeters. The printing speeds ranged from 20 to 35 mm per second, while the extrusion rate varied from 95 to 115% the default value which is a function of nozzle size and printing speed. Slower speeds allowed for improved bonding between layers without hindering the extrusion of the material. Furthermore, the buildability of the layers was acceptable without notable layer deformation, so the layers were able to withstand the weight of the sequential layers. The nozzle (8 mm) extruded the material at a consistent rate, and a layer height of 5-6 mm, and each layer took about 50 seconds to complete. After the completion of each print, the printed cellular unit was enclosed using a glass tank to keep the moisture and prevent shrinkage during the early age of hydration. After 24 hours, the glass tank was removed, and the specimen was fully cured.

[0060] The corner column connection was also additively constructed to the required height. In total, the column required 200 layers for a height of 1180 millimeters. The successful print of this corner columnar unit reviles the robustness of the developed 3D printed mix especially for buildability. Furthermore, two sample prints were completed for the edge and interior columns to confirm the prints can be successful.

[0061] Each wall was assembled separately using seven cellular units. The units were arranged and spaced to ensure a 12.7-millimeter gap between the units to allow for the silicone rubber to fill the gap. Baker rods of 12.7 millimeters in thickness and C-clamps were used to align the wall to ensure uniform width and length of the wall panel. Then, silicone rubber liquid was used to seal the cellularunits on plastic boards by pouring the silicone into every cell with a height of 2-3 millimeters to allow the silicone to seal the unit to the board. The silicone was allowed for two to three hours to cure before sealing the perimeter of the wall and any gaps using spray foam. Then, joints between the cellularunits were sealed using silicone rubber. Hotwire was used to cut segments of insulative material into the proper shape. The cut insulative material (foam) pieces were then placed in the appropriate cell including the battery-powered lighting unit and placeholders for the stainless-steel adjustable pipe hose clamp around the perimeter. The gaps between the foam units and the cellular units were then filled with silicone to ensure an integral wall segment. The wall segment was connected to a wooden board using U- bolts. Finally, the second wall segment was connected to the columnar unit and the pipe hose straps were used to connect the wall segments with the columnar units at three locations along the height.

[0062] Using such additive construction of form-free elements will enable rapid printing of the cellular units with a reduction of labor time and elimination of formwork. Traditional pre-fabrication relies on concrete casting which may not be suitable for the sizes of the cellular units and may lead to heavierwall designs that will hinder transportability, assembly, and disassembly, major criteria for rapidly deployable shelters. The flexibility in designs such as the size of the cells, number of beads, number of layers, integration of utilities, and building science components, make it suitable for robotic and additive construction through assembly / assembly lines.

[0063] An exemplary wall panel was assembled using additively constructed wall segments to assembly a wall 610 millimeters long and 550 millimeters tall. The wall dimensions were chosen to test the interaction between various materials used in the wall, such as 3D printed concrete cells, silicone rubber, and insulation foam on the performance. Even though the height of the wall was only 610 mm and wall height may be a key factor if a real application requires very tall walls, the cellular wall panel is for rapidly deployable one-story shelters, therefore, it is expected the actual wall will be at a range of 2-3 meters, making the buckling of the wall not a design issue. Furthermore, two columnar units (l-shape) were additively constructed and connected to each end of the wall to provide the same boundary conditions. The columnar units were not included in the load-carrying capacity test, instead onlybeing utilized to restrain lateral movement of the wall. Adding the two columnar units to the loading plate would result in much higher load-carrying capacity since they are rigid compared to the wall, which will result in inaccurate load-carrying capacity for the wall. Insulation foam, silicone rubber, and pipe hose straps were also used to assemble the wall. However, additional steps were needed to prepare the structure fortesting. Firstly, the top surface where the loading would be applied required a smooth finish. Due to the layering in additive construction, the top surface of the wall structure is not smooth which can affect the loading capacity. Hydrostone, a high plaster material with high compressive strength, was coated onto the surface and cured to form a smooth finish on the structure. Furthermore, a spreader beam was placed on top of the Hydrostone finish to distribute the loading from the actuator across the entire wall segment. Hydrostone finish was also applied on the bottom of the wall structure to create a smooth support as well. The specimen was aligned in the hydraulic press frame and the actuator head was lowered to the spreader beam to ensure all loading would be concentric, as any eccentric loading would cause undesired moments and rotation of the specimen.

[0064] The wall was tested using a hydraulic press for load-bearing capacity. After assembling the wall with Hydrostone and aligning the steel beam to distribute the loading across the wall, the actuator applied the load to the beam which distributed the load uniformly on top of the wall. Fig. 15 shows the loaddisplacementcurve from the testing, with photographs of the wall sample at different loading stages throughout the test. The wall reached a maximum loading of around 10 millimeters (0.4 inches) at 18.6 kilonewtons (4189 lbs). After reaching its maximum loading capacity, the wall experienced ductile failure with the loading slowly decreasing as displacement increases. Concrete is typically known as being a brittle material, so it is believed that the addition of foam and silicone rubber allowed for more ductility, as the concrete was not taking the brunt of the loading. As displacement continued to increase, the columnar connections began to separate from the wall, and cracks in the concrete were observed. Additionally, the foam inside the hexagonal cells experienced deformation. The structure failed around 11 kilonewtons and 47 millimeters due to the wall sliding out of the loading setup.

[0065] Given that the specimen is 610 millimeters high, the load-carrying capacity of the structure can be calculated by dividing peak force by wall length. The maximum load-carrying capacity was found to be 30.56 kilonewtons per meter(kN / m). This maximum capacity was compared to other common interior wooden stud walls, and specified in the National Design Specifications for Wood Construction (NDS).

[0066] While there have been described herein the principles of the invention, it is to be understood by those skilled in the art that this description is made only by way of example and not as a limitation to the scope of the invention. Accordingly, it is intended by the appended claims, to cover all modifications of the invention which fall within the true spirit and scope of the invention.

Claims

What is claimed is:1 . A building element system comprising: a set of discrete subpanels, each of said set of discrete subpanels being constructed by an additive manufacturing technique and defining a plurality of open cells, a plurality of distinct subpanels being joinable in nesting fashion to form a panel defining a joining edge usable to join adjacent panels by the respective joining edges.

2. The building element system of claim 1 , wherein each of said set of discrete subpanels is constructed of a cementitious material.

3. The building element system of claim 1 , wherein each of said plurality of open cells is uniform in shape.

4. The building element system of claim 1 , wherein each of said plurality of open cells is polygonal in shape.

5. The building element system of claim 1 , wherein each said panel defines a plurality of flat edges.

6. The building element system of claim 1 , wherein said panel is rectangular in shape, with two pairs of flat edges that are parallel to each other.

7. The building element system of claim 1 , wherein said plurality of open cells are filled with an insulative material.

8. The building element system of claim 1 , wherein at least one of said plurality of open cells is filled with a glass material to provide a window.

9. The building element system of claim 1 , wherein at least one of said plurality of open cells is filled with an electrically-powered lighting unit.

10. A building element system comprising: a plurality of different sub-panel building elements, each of said plurality of different sub-panel building elements being constructed by an additive manufacturing technique and defining a plurality of open cells defined by respective sidewalls, said plurality of different sub-panel building elements being arrangeable in nested fashion, with portions of their respective sidewalls in an abutting relationship so that those portions may be joined to form a panel building element having a joining edge along its perimeter; and a plurality of columnar connector building elements, each of said plurality of columnar connector building elements being constructed by the additive manufacturing technique and defining at least one open cell defined by a respective sidewall, and at least one connecting flange having a respective sidewall surface; the respective joining edge of each panel being configured to abut and be joined to another joining edge of another panel or the respective sidewall surface of a respective connecting flange of a respective columnar connector building element.11 . The building element system of claim 10, wherein each of said plurality of different sub-panel building elements and each of said plurality of columnar connector building elements is constructed of a cementitious material.

12. The building elementsystem of claim 10, wherein each of said plurality of open cells is uniform in shape.

13. The building elementsystem of claim 10, wherein each of said plurality of open cells is polygonal in shape.

14. The building element system of claim 10, wherein each joining edge is flat.

15. The building element system of claim 10, wherein said panel building element is rectangular in shape, with two pairs of flat joining edges that are parallel to each other.

16. The building element system of claim 10, wherein said plurality of open cells are filled with a thermally insulative material.

17. The building element system of claim 10, wherein at least one of said plurality of open cells is filled with a transparent or translucent material to provide a window.

18. The building element system of claim 10, wherein at least one of said plurality of open cells is filled with an electrically-powered lighting unit.

19. The building element system of claim 10, wherein at least one of said plurality of columnar connector building elements comprises at least two connecting flanges having respective sidewall surfaces arranged to join panels at approximate right angles.

20. The building element system of claim 10, wherein at least one of said plurality of columnar connector building elements comprises at least three connecting flanges having respective sidewall surfaces arranged to join panels at approximate right angles.21 . The building element system of claim 10, wherein at least one of said plurality of columnar connector building elements comprises at least four connecting flanges having respective sidewall surfaces arranged to join panels at approximate right angles.

22. A robotic manufacturing system for manufacturing cellular-unit modular sub-panel building elements and assembling the cellular-unit modular sub-panel building elements into cellular-unit modular panel building elements, the robotic manufacturing system comprising: a robotic 3D-printing sub-system operable to printing cellular sub-panel building elements on said at least one conveyor belt; a pick-and-place robotic arm sub-system operable to arrange sub-panel building elements into an arrangement for bonding to form a panel building element; a first robotic arm sub-system operable to deliver adhesive to join the subpanel building elements to form the panel building elements; a second robotic arm sub-system operable to selectively fill cells of the panel building elements;a third robotic arm sub-system operable to join any filling material to the panel building elements; and at least one conveyor belt operable to transport materials among the subsystems.

Images