Title:
STRUCTURAL ELEMENT
Kind Code:
A1


Abstract:
A structural element is disclosed that is shaped as at least one of a plank, a post, and a board. The structural element comprises a fiber reinforced ceramic cement body having at least an outer layer having a hardness and ductility suitable for receiving and holding a nail. Also disclosed is a structural element having a body at least partially shaped as at least one of a plank, a post, and a board. The body comprises at least an internal layer comprising fiber reinforced ceramic cement, and at least an external layer comprising a material suitable for receiving and holding a nail.



Inventors:
Lam, Thomas (COQUITLAM, CA)
Application Number:
12/140046
Publication Date:
12/17/2009
Filing Date:
06/16/2008
Primary Class:
International Classes:
E04C3/29
View Patent Images:
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Primary Examiner:
IMANI, ELIZABETH MARY COLE
Attorney, Agent or Firm:
Burdick Patents (Boise, ID, US)
Claims:
1. A structural element shaped as at least one of a plank, a post, and a board, comprising: a fiber reinforced ceramic cement body having at least an outer layer having a hardness and ductility suitable for receiving and holding a nail.

2. The structural element of claim 1 in which the fiber reinforced ceramic cement body comprises magnesium oxide and a binder.

3. The structural element of claim 2 in which the binder comprises magnesium chloride.

4. The structural element of claim 1 in which at least the outer layer of the fiber reinforced ceramic cement body comprises a filler.

5. The structural material of claim 3 in which the filler comprises at least one of sawdust, straw, wood fiber, and particulate matter.

6. The structural material of claim 4 in which at least the outer layer comprises less than or equal to 30% by weight of filler.

7. The structural material of claim 4 in which the filler comprises a fine powder between 120 and 270 mesh.

8. The structural element of claim 1 in which the outer layer is water resistant.

9. The structural element of claim 1, further comprising a core.

10. The structural element of claim 9 in which the core is a hollow core.

11. The structural element of claim 10 in which the hollow core is formed within a tube of material.

12. The structural element of claim 9 in which the core comprises at least one of ceramic cement, wood, plant material, bamboo, paper, plastic fragments, and particulates.

13. The structural element of claim 1 in which the fiber reinforced ceramic cement body further comprises at least a fiber reinforced layer and a ceramic cement layer.

14. The structural element of claim 1 in which the fiber reinforced ceramic cement body comprises at least one of fiberglass and hemp.

15. The structural element of claim 1 in which the outer layer comprises at least one pigment.

16. The structural element of claim 1 further comprising a protective overlayer comprising at least one of plastic, rubber, hemp, and fiberglass.

17. The structural element of claim 1 in which the fiber reinforced ceramic cement body is cylindrical.

18. The structural element of claim 17 in which fiber within the fiber re-inforced ceramic cement body is formed in one or more tubular layers.

19. A structural element having a body at least partially shaped as at least one of a plank, a post, and a board, the body comprising: at least an internal layer comprising fiber reinforced ceramic cement; and at least an external layer comprising a material suitable for receiving and holding a nail.

20. The structural element of claim 19 in which the external layer comprises ceramic cement.

21. The structural element of claim 20 in which at least the external layer comprises a filler.

22. The structural material of claim 21 in which the filler comprises at least one of sawdust, straw, wood fiber, and particulate matter.

23. The structural material of claim 21 in which at least the ceramic cement comprises less than or equal to 30% by weight of filler.

24. The structural material of claim 21 in which the filler comprises a fine powder between 120 and 270 mesh.

25. The structural element of claim 19 in which the external layer has a hardness and ductility suitable for receiving and holding a nail.

26. The structural element of claims 19 in which the fiber reinforced ceramic cement comprises magnesium oxide and a binder.

27. The structural element of claim 26 in which the binder comprises magnesium chloride.

28. The structural element of claim 19 in which the external layer is water resistant.

29. The structural element of claim 19, further comprising a core.

30. The structural element of claim 29 in which the core is a hollow core.

31. The structural element of claim 30 in which the hollow core is formed within a tube of material.

32. The structural element of claim 29 in which the core comprises at least one of ceramic cement, wood, plant material, bamboo, paper, plastic fragments, and particulates

33. The structural element of claim 19 in which the internal layer comprises at least a fiber reinforced layer and a ceramic cement layer.

34. The structural element of claim 19 in which at least the internal layer comprises at least one of fiberglass and hemp.

35. The structural element of claim 19 in which the external layer comprises at least one pigment.

36. The structural element of claim 19 in which the external layer further comprises at least one of plastic, rubber, hemp, and fiberglass.

37. The structural element of claim 19 in which the body is cylindrical.

38. The structural element of claim 17 in which fiber within at least the internal layer is formed in one or more tubular layers.

Description:

TECHNICAL FIELD

This document relates to structural elements, including structural elements shaped as at least one of a plank, post and a board.

BACKGROUND

Wooden posts are susceptible to rotting, insect infestation, fire damage, and may leach hazardous treating chemicals into the environment. In addition, the strength of wood as a structural element is limited, and wood may fray or crack under heavy loads. Further, wood structural elements generally have a short lifetime after which they must be replaced in order to maintain structural stability.

Ceramic structural elements are typically brittle and tend to crack or break when a sufficient force is imparted unto them.

SUMMARY

A structural element is disclosed that is shaped as at least one of a plank, a post, and a board. The structural element comprises a fiber reinforced ceramic cement body having at least an outer layer having a hardness and ductility suitable for receiving and holding a nail.

In some embodiments, the fiber reinforced ceramic cement body comprises magnesium oxide and a binder. In further embodiments, the binder comprises magnesium chloride.

In some embodiments, at least the outer layer of the fiber reinforced ceramic cement body comprises a filler.

Also disclosed is a structural element having a body at least partially shaped as at least one of a plank, a post, and a board. The body comprises at least an internal layer comprising fiber reinforced ceramic cement, and at least an external layer comprising a material suitable for receiving and holding a nail.

In some embodiments, the external layer comprises ceramic cement.

In some embodiments, the external layer has a hardness and ductility suitable for receiving and holding a nail.

In some embodiments, the fiber reinforced ceramic cement comprises magnesium oxide and a binder. In further embodiments, the binder comprises magnesium chloride.

In some embodiments, the external layer comprises ceramic cement and a filler.

These and other aspects of the device are set out in the claims, which are incorporated here by reference.

In some embodiments, the structural elements disclosed herein may be wood mimicking structures, which are longer-lasting, stronger, and cheaper than traditional wood products.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments will now be described with reference to the figures, in which like reference characters denote like elements, by way of example, and in which:

FIG. 1 is a top plan section view of a structural element.

FIG. 2 is a top plan section view of a structural element with numerous tubular layers.

FIG. 3 is a top plan section view of a structural element that has a fiber-reinforced ceramic cement body.

FIG. 4 is a side elevation view, in section, of a mould for a structural element.

FIG. 5 is a perspective view of a structural element shaped as a square post.

FIG. 6 is a perspective view of a structural element shaped as a plank.

FIG. 7 is a perspective view of a structural element shaped as a round post.

FIG. 8 is a perspective view of a structural element shaped as a board.

DETAILED DESCRIPTION

Immaterial modifications may be made to the embodiments described here without departing from what is covered by the claims.

Many structures employ structural elements made of wood, plastic, and metal, among other types of materials, in order to maintain shape and support weight and structure. Wood structural elements are typically cheap, and easy to obtain, but have limited strength and weather resistance. In addition, wood structural elements may be susceptible to infestations by insects, which may also weaken and destroy the structural element over time. Wood may be chemically treated to resist insects and weather, but, as these types of chemical treatment are often applied in the form of hazardous chemicals, such structural elements may pose an environmental hazard. However, wood has a pleasant aesthetic appeal. Plastic structural elements are less prone to environmental or insect degradation, but are far more expensive than wood, and often appear very different from wood aesthetically. Metal structural elements, such as steel structural elements, are extremely strong and durable, but are typically prohibitively more expensive than wood structural elements. Despite the high cost, in some instances steel structural elements may be required, as a wood structural element may not have the structural load capacity required to accomplish the desired goal. Further, steel structural elements may be susceptible to rusting, and may also have to be chemically treated in order to withstand various weather conditions. Steel structural elements by themselves may not have a pleasant aesthetic appeal, and may need to be painted or covered in order to appeal to the eye.

Structural elements will often form the backbone of a structure, such as by inclusion in the frame of a house, for example. In other cases, structural elements may stand alone, such as in the case of fence posts, where individual structural elements cooperate to define a fence surrounding a desired area.

Referring to FIG. 1, a structural element 10 is illustrated. Referring to FIGS. 5-8, structural element 10 may be shaped as at least one of a plank (shown in FIG. 6), a post (shown in FIGS. 5 and 7), and a board (shown in FIG. 8). Referring to FIG. 1, in some embodiments, structural element 10 may have a body 12. Body 12 may be at least partially shaped as at least one of a plank, a post, and a board. Body 12 may be, for example, cylindrical. Referring to FIG. 1, body 12 may be a fiber reinforced ceramic cement body 13, for example. In addition body 13 may be cylindrical. Body 13 may have at least an outer layer 14 having a hardness and ductility suitable for receiving and holding a nail. Referring to FIG. 2, for example, outer layer 14 may be, for example, an external part of body 13. In some embodiments, outer layer 14 is prepared so that it will absorb the force of a nail without fracturing.

Referring to FIG. 1, fiber reinforced ceramic cement body 13 may comprise magnesium oxide and a binder. The binder may be, for example, binder cement. In some embodiments, the binder comprises magnesium chloride. At least the outer layer 14 of the fiber reinforced ceramic cement body 13 may comprise a filler, for example. The filler may comprise at least one of sawdust, straw, wood fiber, and particulate matter, for example. In some embodiments, the outer layer 14 comprises less than or equal to 30% by weight of filler. In some embodiments, outer layer 14 comprises between 10 and 30% by weight of filler. The filler may further comprise a fine powder between, for example, 120 and 270 mesh. In some embodiments, outer layer 14 is water resistant. The amount of filler used in outer layer 14 may determine the water resistance of outer layer 14. In other embodiments, the amount of filler is used to control or modify the hardness of the outer layer 14. In some embodiments, filler may be used to soften or modify the composition throughout the entire structural element 10. In some embodiments, the filler may make the ceramic cement as soft, or sufficiently as soft as, natural wood. This way, structural element 10 may provide a cheaper alternative to wood that can be used in all of the same applications as wood.

Structural element 10 may further comprise a core 20. Referring to FIG. 2, core 20 may be, for example, a hollow core. The hollow core may be formed within a tube of material 22, for example a PVC pipe, or a paper tube. Referring to FIG. 3, core 20 may comprise at least one of ceramic cement, wood, plant material, bamboo, paper, and plastic fragments, for example. In other embodiments, core 20 may comprise particulates.

Referring to FIG. 1, in some embodiments, body 12 may have at least an internal layer 16 comprising fiber reinforced ceramic cement. The fiber reinforced ceramic cement may comprise magnesium oxide and a binder, for example. The binder may comprise magnesium chloride, for example. Fiber reinforced body 13 may further comprise at least a fiber reinforced layer 24 and a ceramic cement layer 26. Referring to FIG. 2, layers 24 and 26 may surround core 20 if present. In some embodiments, the at least an internal layer 16 may comprise at least fiber reinforced layer 24 and ceramic cement layer 26, as illustrated, for example. The at least an internal layer 16 may comprise at least one of fiberglass and hemp, for example. Referring to FIG. 1, the fiber reinforced ceramic cement body 13 may comprise at least one of fiberglass and hemp. In further embodiments, fiber reinforced layer 24 may comprise at least one of fiberglass or hemp, for example. In some embodiments, at least one of fiber reinforced body 13 and internal layer 16 may comprise mesh, such as steel of fabric mesh, for example. The fiber reinforced layer 24 may have fibers oriented in a direction along the length of the structural element 10, for example. Referring to FIG. 2, fiber within the fiber re-inforced ceramic cement body 13 may be formed in one or more tubular layers, such as layers 24. In embodiments with internal layer 16, fiber within the at least an internal layer 16 may be formed in one or more tubular layers, such as layers 24. Fiber may refer to any type of fiber used to reinforce the ceramic cement, for example. Tubular, in this document, may refer to circular, elliptical, or curved layers, for example. It should be understood that the layers may not be tubular in some cases, for example in the case where structural element 10 is formed with a non-circular cross-section, for example a square or rectangular cross-section. In some embodiments of a structural element 10 with a non-circular cross-section, structural element 10 may have, for example, tubular or rectangular internal layers. In other embodiments of a structural element 10 with a non-circular cross-section, structural element 10 may have, for example, layers with cross-sections that correspond to the cross-section of structural element 10. For example, a hexagonally cross-sectioned structural element 10 may have layers that have hexagonal cross-sections or other geometrically-shaped cross-sections.

As illustrated in FIG. 1, fiber reinforced layer 24 and ceramic cement layer 26 may be distinctly defined. Referring to FIG. 2, embodiments are possible with a plurality of layers 24 and 26. A plurality of layers 24 may be used to increase at least one of the tensile strength, impact resistance, flexural strength, and compression ratio strength of the structural element 10. Each of layers 24 and 26 may be composed of plural layers. Layers 24 and 26 may alternate, as illustrated, or, in some embodiments, multiples of layers 24 or multiples of layers 26 may be placed side by side. Ceramic cement layers 26 may have different compositions from one another, in order to impart various properties to structural element 10. Referring to FIG. 3, in some embodiments, fiber reinforced layer 24 may be positioned external to body 12.

Referring to FIG. 1, in embodiments where internal layer 16 is present, body 12 may also have at least an external layer 18 comprising a material suitable for receiving and holding a nail. Referring to FIG. 2, external layer 18 may be, for example, outer layer 14. Additional layers may be present, for example, in between layers 16 and 18, between layers 24 and 26, and/or between core 20 and internal layer 16. The additional layers are not required to comprise fiber reinforcing or ceramic cement, for example. Referring to FIG. 1, external layer 18 may comprise ceramic cement. External layer 18 may have a hardness and ductility suitable for receiving and holding a nail. In some embodiments, external layer 18 comprises ceramic cement. In further embodiments, at least external layer 18 comprises a filler, for example. The filler may have all the same characteristics as the filler of the outer layer 14, for example. For example, the filler may comprise at least one of sawdust, straw, wood fiber, and particulate matter. In addition, the ceramic cement comprises less than or equal to 30% by weight of filler. Further, the filler may comprise a fine powder between 120 and 270 mesh. The external layer 18 may be water resistant. The water resistance may be imparted by the inclusion of the filler, for example. In other embodiments, the amount of filler is used to control or modify the hardness of the external layer 18.

In some embodiments, outer layer 14 may comprise at least one pigment. In some embodiments, the external layer 18 may comprise at least one pigment. The at least one pigment may be, for example, ferric oxide pigments. Various pigments may be used, in order to give structural element 10 different colors, such as dark brown, natural, and red for example. Referring to FIG. 2, the pigment may impart a desired color to structural element 10, in order to add aesthetic appeal. In some embodiments, the at least one pigment or pigments may be chosen to give structural element 10 the appearance of any of a variety of wood types. Outer layer 14, if external, may also be textured to add to this effect. In this way, structural element 10 may mimic the appearance of wood. In addition, structural element 10 may be textured to mimic the appearance of other materials, such as steel.

Referring to FIG. 1, structural element 10 may further comprise a protective overlayer 28 comprising, for example, at least one of plastic, rubber, hemp, and fiberglass. Protective overlayer 28 may be positioned, for example, over outer layer 14. Referring to FIG. 1, in some embodiments protective overlayer 28 is external layer 18. However, in other embodiments, external layer 18 may be, for example, positioned beneath protective overlayer 28. In some embodiments, protective overlayer 28 may impart UV protection to the materials comprising structural element 10. In other embodiments, protective overlayer 28 may simply be a thin physical barrier to impart further protection to structural element 10 from damage. In some embodiments, protective overlayer 28 may impart the water resistance of, or water resistance in addition to the water resistance of, at least one of the external layer 18 and the outer layer 14.

The desired structural element 10 made may be, for example, a 3″×8′ round post (illustrated in FIG. 7), a 4″×4″×8′ square post (illustrated in FIG. 5), a 3″×8′ round hollow post (illustrated in FIG. 2), a 1.5″×5.5″×8′ or 0.75″×5.5″×8′ plank (illustrated in FIG. 6), or a 1.5″×8′×8′ board (illustrated in FIG. 8). The dimensions of the exemplary structural elements 10 shown in the Figures are not to scale and are not intended to be limiting.

Referring to FIG. 1, an exemplary procedure for constructing a post is disclosed. In order to make the ceramic cement, MgCl is dissolved into water at a ratio of, for example, 100 kg of MgCl to 85 kg of water. In some embodiments, 0.5-1.2 kg of MgCl may be mixed with every 1.0 kg of water. In some embodiments, MgCl-6H2O may be used in place of, or in combination with, MgCl. During the dissolution, the temperature may be maintained, for example, between 20 and 30 C. MgO is then mixed with the dissolved MgCl at a ratio of, for example, 1.2 kg of MgO to 1.0 kg of MgCl. In some embodiments, 0.5-1.2 kg of MgO may be mixed with every 1.0 kg of MgCl.

The mixture of MgO, MgCl, and water may then be split up to make the various compositions of the, as desired, layers 14, 16, 18, 24, 26, and 28, and core 20, that may contain ceramic cement. Each layer in structural element 10 may have a different composition, such as for example a different percentage of filler, or a different type of ceramic cement. In other embodiments, the mixture may be used to make one composition that is used for each layer in structural element 10. Either way, if filler is required, filler is added to at least a portion of the mixture as desired. The filler may be, for example, ground fiber such as sawdust, straw, or wood fiber. As mentioned above, the filler may be ground into fine powder between 120-270 US standard mesh, for example. The amount of filler added to the mixture may be varied in order to achieve the desired level of hardness. In some embodiments, the filler will effectively soften the ceramic cement, making it more ductile in order to receive and hold a nail or staple, for example. In general, for some types of filler, if the percentage of filler exceeds 30%, the water resistance of the resulting ceramic cement may be negatively affected, and the material may not be stable.

The at least one pigment may be added to the mixture that will make up the external layer 18 and/or outer layer 14. However, the pH level may need to be approximately 7, or adjusted to approximately 7.

Referring to FIG. 4, the correct materials that will make up structural element 10, such as for example core 20, internal layer 16, outer layer 14, and external layer 18 for example, may be properly positioned and layered within a cavity 30 defined by a mould 32. Cavity 30 may have the size and shape of the desired structural element 10. Mould 32 may be, for example, made from wood, metal, steel, or aluminum. Referring to FIG. 1, an exemplary layout of the positioning of the layers is illustrated. Mould 32 may comprise, for example, two complementary halves 34. Once the halves 34 are filled, the halves 34 may be closed tightly, and any excess material is squeezed out. The cavity 30 may be textured on the inside, in order to impart a desired textured appearance to structural element 10. The structural element 10 is then allowed to dry, and then removed from mould 32. In some embodiments, structural element 10 may be allowed to dry under heat, for example in a kiln. The structural element 10 may be kept inside the mould 32 until it is set, and has formed the required shape. The amount of time that structural element 10 may be required to remain in mould 32 may be determined based upon at least one of the ambient temperature, pressure, and humidity. In some embodiments, the structural element 10 may remain inside mould 32 overnight. Once removed from mould 32, the newly formed structural element 10 may be stored in a temperature and moisture control room at, for example, a temperature of 23 C or greater and 65% humidity until totally dried. Structural element 10 may require, for example, 8 or more hours of drying time outside of mould 32.

The core 20, if made by ceramic cement, may be moulded in a fashion similar to the above described procedure prior to making the structural element 10.

Test Results

Flexural Testing. ASTM D195-05a modified. 3.0 mm/minute crosshead speed. Tests performed using a third point loading rectangular beam (modified) edge apparatus over a 1219 mm span. Test performed on round posts as received but calculations performed assuming rectangular dimension (using post diameter). Posts tested at full diameter as received. For round posts with two and six layers 24, the posts showed an average modulus of elongation of 3.77 and 8.34 GPa, respectively. Modulus of elongation refers to the deflection (amount of bend) for a given unit of load per area of material. For round posts with two and six layers 24, the posts showed an average modulus of rupture of 16.1 and 39.6 MPa, respectively. Modulus of rupture refers to the break strength of the material per unit area. The test method and equipment used was designed for evaluation of rectangular materials. Since the posts were in a round configuration, the reported strength values will have some degree of error since the modulus values are calculated using rectangular dimensions (with the diameter of the post being the width and depth of material). The results reported should still be valid for comparison of different post materials tested using the same sample configuration

Impact Testing. ASTM D6110-06 modified. Specimens cut approximately 13 mm×13 mm×125 mm long along the length of post. Test specimens cut from an area from ¼″ to ¾″ below the outer surface of the posts so as to allow segments of both mineral layers (of different composition) to be contained in the test specimens. No post core material was contained in the test specimens. No notching of specimens. 16 foot/pound pendulum and 100 mm span used for testing. For round posts with two and six layers 24, the posts showed an average impact resistance of 26±16.0 and 34.3±12.8 kJ/m2, respectively. Average impact resistance refers to the amount of energy required to break a given area of test material.

Tensile Testing. ASTM D638-03. 5.0 mm/minute crosshead speed. Test specimens cut from an area from ¼″ to ¾″ below the outer surface of the posts so as to allow segments of both mineral layers (of different composition) to be contained in the test specimens. No post core material was contained in the test specimens. For round posts with two and six layers 24, the posts showed an average modulus of elongation of 7.0 and 15.8 GPa, respectively. Modulus of elongation refers to the deflection (amount of stretch) for a given unit of load per area of material. For round posts with two and six layers 24, the posts showed an average maximum stress (break strength) of 11.3 and 88.5 MPa, respectively.

Compression Ratio. A structural element 10, shaped as a hollow post (illustrated in FIG. 7) with 14 layers, tested for compression ratio exceeded 350 kg at the mid-point of the post, with a deflection angle of less than 1″. This result demonstrates that structural element 10 is stronger than average wood (for example spruce) posts.

Ceramic cement may refer to any type of ceramic material that is suitable for use in the structural elements 10 disclosed herein. Examples include structural, refractory, technical, earthenware, whiteware, porcelain, bone china, stoneware, clay-based, alumina or zirconia oxides, carbides, borides, nitrides, silicides, pottery, and glass-based ceramics. In further embodiments, ceramic cement refers to MgO-based ceramics, such as in the example disclosed herein.

At least one of external layer 18 and outer layer 14 may require a thickness suitable to receive a nail, in the event that the drive of a nail may fracture internal layers of more brittle material in structural element 10.

The structural element 10 disclosed herein is environmentally friendly, rot resistant, insect resistant, fire resistant, aesthetically appealing, and lasts far longer than traditional wood structural elements. Structural element 10 may be used like wood, allowing a user to nail, staple, cut and/or pound element 10 into the ground, for example. Structural elements 10 may be used in, for example, vineyards, homes and gardens, fences, and in commercial, industrial, and residential settings. Structural elements 10 may be made from natural earth mineral and fiber, and contain no toxic chemicals required for the preservation of the product. In addition, structural element 10 may not require painting, as the appearance of structural element 10 may be complete upon removal from the mould 32 (shown in FIG. 4).

In the claims, the word “comprising” is used in its inclusive sense and does not exclude other elements being present. The indefinite article “a” before a claim feature does not exclude more than one of the feature being present. Each one of the individual features described here may be used in one or more embodiments and is not, by virtue only of being described here, to be construed as essential to all embodiments as defined by the claims.