CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and all of advantages of U.S. Prov. Appl. Nos. 62/394,902, filed on 15 September 2016, and 62/412,472, filed on 25 October 2016, the contents of which are herein incorporated by reference.

FIELD OF THE INVENTION

[0002] The present invention generally relates to a method of forming a composite structural element and, more specifically, to a method of forming a composite structural element from a structural element defining an interior cavity, and to a composite structural element formed in accordance with the method.

DESCRIPTION OF THE RELATED ART

[0003] Conventional structural elements formed from steel and/or concrete are known to deteriorate over time, decreasing their long-term durability and structural integrity. In particular, steel structural elements are prone to losing their structural integrity due to corrosion when exposed to wet weather conditions and the like. Corrosion is especially a problem for steel structural elements used in coastal areas, which can be compounded by seawater.

[0004] Concrete structural elements are also subject to deterioration over time when exposed to water. For example, in areas that are subject to the changing weather conditions, moisture trapped in the concrete structural elements may freeze and expand, thus resulting in the cracking of the concrete structural elements.

[0005] Furthermore, the effectiveness of conventional reinforcing methods for structural elements is limited, as corrosion is also known to occur to the steel reinforcing bars used inside concrete structural elements. Conventional techniques, such as epoxy coating and painting and/or galvanizing or passivating the steel reinforcing bars, have not been successful over long periods of time, especially in severe weather environments.

[0006] In addition to water-based deterioration, both concrete and steel structural elements can fail in known seismic zone areas. Observations from earthquakes have shown that pile-type structural elements, such as foundations, are susceptible to significant damage when subjected to loads induced by large seismic events. For example, typical pile-type structural column foundations are susceptible to severe damage in cases of liquefaction and lateral spreading of surrounding soil. For instance, the liquefaction and lateral spreading of the surrounding soil is known to damage the pile-type structural columns via deformation and the like, especially in instances where the surrounding soil contains soil layers with large differences in stiffness.

SUMMARY OF THE INVENTION [0007] The present invention provides a method of forming a composite structural element from a structural element. The structural element extends for a distance along an axis between first and second ends and defines an interior cavity. The method comprises (i) disposing a flexible glass fiber sleeve in the interior cavity of the structural element. The flexible glass fiber sleeve defines a first cavity. The method further comprises (ii) disposing a flexible carbon fiber sleeve in the first cavity of the flexible glass fiber sleeve to give a composite sleeve. The flexible carbon fiber sleeve defines a second cavity, and thus the composite sleeve defines at least the second cavity. Finally, the method comprises (iii) disposing a filler composition into the second cavity to form the composite structural element.

[0008] A composite structural element formed in accordance with the method is also provided.

[0009] The present invention further provides a composite structural element. The composite structural element comprises a core. The composite structural element also comprises a carbon fiber sleeve disposed about and adjacent the core. The composite structural element further comprises a glass fiber sleeve disposed about and adjacent the carbon fiber sleeve. The composite element additionally comprises a structural element disposed about and adjacent the glass fiber sleeve.

DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 shows a structural element disposed about a flexible glass fiber sleeve;

[0011] Figure 2 shows a structural element disposed about a flexible glass fiber sleeve and the flexible glass fiber sleeve disposed about a flexible carbon fiber sleeve;

[0012] Figure 3 shows a flexible carbon fiber sleeve disposed about a filler composition;

[0013] Figure 4 shows a composite structural element formed in accordance with one embodiment of the method; and

[0014] Figure 5 shows a cross-section of one embodiment of the composite structural element.

DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention provides a method of forming a composite structural element. The composite structural element is formed from a structural element and is typically used as a component, e.g. a load-bearing component, of a structure, such as a building, bridge, foundation, or the like. The method and elements disclosed herein can be utilized for constructing new structures and structural elements, retrofitting existing structures and structural elements, or repairing or rehabilitating structures and structural elements damaged by corrosion, deterioration, warp, excessive loading, or the like. The composite structural element and the structural element may independently be any component of the structure, such as a beam, pole, column, strut, stud, pile, bollard, and the like. As will be described in further detail below, the composite structural element may be of any suitable size or proportion, and may have any cross-sectional shape (e.g. circular, elongate, or square cross-section) or configuration (e.g. a flange).

[0016] The composite structural element may be present in a variety of locations, such as on, in, or partially in the ground, under or partially under water, and combinations thereof. In certain embodiments, the composite structural element is at least partially submerged in water. In particular embodiments, the composite structural element is at least partially underground. In specific embodiments, the composite structural element is underground. The same applies to the structural element.

[0017] The structural element extends between a first end and a second end, which are separated by a distance along an axis A. The distance between the first and second ends can be any distance, such as a distance of from about 1/24 to about 10,000 feet. Typically, the distance between the first and second ends is a distance of from about 1 to about 200, about 5 to about 150, or about 10 to about 100 feet.

[0018] The structural element may have other portions extending from the axis A. For example, in some embodiments the structural element may be bifurcated. The structural element also presents an exterior surface having a perimeter extending for a distance around a plane lying perpendicular to the axis A (i.e., a cross-section). The exterior surface presents a shape of the structural element. The shape of the structural element may be any shape, such as cubic, cylindrical, pyramidal, conical, prismatic, trapezoidal, and the like, and combinations thereof. In specific embodiments, the shape of the structural element is a concentric cylinder, such that the perimeter of the exterior surface of the structural element is a circumference. The structural element further includes an exterior radius extending radially from a position on the axis A to a position on the exterior surface. The exterior radius can be any distance, such as a distance of from about 1/12 to about 100 feet, although distances outside of this range are also contemplated. Typically, the exterior radius will be a distance of from about 1/6 to about 75, about 1/5 to about 50, about 1/4 to about 25, or about 1/3 to about 10 feet. It is to be appreciated that the structural element may comprise multiple exterior radii, each independently of the same or different distance, depending on the shape of the structural element, the position on the axis A the exterior radius extends from, the position on the exterior surface each exterior radius extends to, or combinations thereof. It is to be appreciated that the terms "radius" and "radii" are meant to refer to distances related to any shape described, and is thus not limited to distances of circular shapes. The same reference is true for the terms "radius" and "radii" used below. [0019] The structural element also defines an interior cavity. The interior cavity may extend along the axis A for at least a portion of the distance between the first and second ends of the structural element. Alternatively, the interior cavity may extend in a different direction than the axis A. The interior cavity may have any shape, such as cubic, cylindrical, pyramidal, conical, prismatic, trapezoidal, spherical, and the like, and combinations thereof. Accordingly, the interior cavity may have any cross-sectional shape, such as circular, square, rectangular, triangular, trapezoidal, star, and the like. Additionally, the shape and/or cross-sectional shape of the interior cavity may be the same or different than the shape and/or cross-sectional shape of the structural element. In some embodiments, the interior cavity has a uniform cross-sectional shape. In other embodiments, the interior cavity has multiple cross-sectional shapes, each independently the same or different as one another. Typically, the shape of the interior cavity is cylindrical such that the cross-sectional shape of the interior cavity is circular. Furthermore, the interior cavity can be concentric or eccentric to the structural element. The interior cavity can also be centered around the axis A, or off-centered with respect to the axis A. In some embodiments, the interior cavity is centered around the axis A. In certain embodiments, the interior cavity is concentric with the structural element and both the interior cavity and the structural element are centered around the axis A. It is to be appreciated that the structural element may define any number of interior cavities, each independently the same or different as one another. Accordingly, in some embodiments, the structural element defines a single interior cavity. In other embodiments, the structural element defines more than one interior cavity, such as 2, 3, 4, 5, 6, 7, 8, 9, or 10 interior cavities.

[0020] The structural element may have an interior radius extending radially from the axis A to an interior surface defining the interior cavity, which may be uniform or nonuniform depending on a shape of the structural element. The interior radius can be any distance less than the distance of an exterior radius extending radially from the same position on the axis A to an exterior surface of the structural element along the same plane. For example, the interior radius can be from about 1/24 to about 99 feet, although distances outside of this range are also contemplated. Typically, the interior radius will be a distance of from about 1/12 to about 75, about 1/8 to about 50, about 1/6 to about 25, or about 1/5 to about 10 feet. In some embodiments, the interior radius is a distance of from about 10 to about 99, about 15 to about 95, or about 20 to about 90 percent of the distance of the exterior radius extending radially from the same point on axis A.

[0021] It is to be appreciated that the structural element may comprise multiple interior radii, each independently of the same or different distance, depending on the shape of the interior cavity, the position on the axis A each interior radius extends from, the position on the interior surface each interior radius extends to, or combinations thereof. It is also to be appreciated that the difference between interior and exterior radii extending from a same position on the axis A may be referred to as a thickness of the structural element. In other words, the structural element has a thickness equal to the difference between the exterior radius and the interior radius. The thickness of the structural element may be any distance in accordance with the description of the interior and exterior radii above. The thickness may be uniform or non-uniform. Additionally, the structural element may comprise multiple thicknesses, each independently a distance depending on the shape and dimension of the structural element, the shape and dimension of the interior cavity, the position on the axis A each radius extends from, the position on the interior or exterior surface each radius extends to, or combinations thereof.

[0022] The method includes (i) disposing a flexible glass fiber sleeve in the interior cavity of the structural element. In general, the flexible glass fiber sleeve has a height extending between first and second ends. In certain embodiments, the height of the flexible glass fiber sleeve extends between the first and second ends for a distance along an axis B. The height of the flexible glass fiber sleeve can be any distance, such as a distance of from about 1/24 to about 10,000 feet. Typically, the height of the flexible glass fiber sleeve is a distance of from about 1/24 to about 200, about 1/16 to about 175, about 1/8 to about 150, about 1/4 to about 125, about 1/2 to about 100, about 2/3 to about 75, about 3/4 to about 50, about 5/6 to about 25, or about 1 to about 10 feet. It is to be appreciated that the flexible glass fiber sleeve need not be linear. Rather, the flexible glass fiber sleeve is flexible, and may thus be curved, arcuate, bent, folded, rolled, and the like, or combinations thereof. Furthermore, because the flexible glass fiber sleeve is flexible, it may take any shape and the shape may be dynamic. Moreover, the shape of the flexible glass fiber sleeve may be complimentary to a container in which the flexible glass fiber sleeve is disposed and expanded. Therefore, it is also to be appreciated that the dimensions and ranges used herein to describe the flexible glass fiber sleeve may apply to the flexible glass fiber sleeve in any state of expansion or nonexpansion, such as in a natural state or an expanded state.

[0023] Typically, the flexible glass fiber sleeve is in the form of a balloon or bladder. The flexible glass fiber sleeve also presents at least an exterior surface and an interior surface. The exterior and interior surfaces of the flexible glass fiber sleeve may be, independently, of any shape, texture, and/or contour, such as smooth, rough, textured, and the like, or combinations thereof. Accordingly, it is to be appreciated that the exterior and interior surfaces of the flexible glass fiber sleeve may be the same or different. In some embodiments, the exterior and/or interior surface of the flexible glass fiber sleeve is substantially smooth. In certain embodiments, the exterior and/or interior surface of the flexible glass fiber sleeve is textured.

[0024] The exterior surface of the flexible glass fiber sleeve has a perimeter extending for a distance around a plane lying perpendicular to the axis B (i.e., a cross-section). The exterior surface presents a shape of flexible glass fiber sleeve. The shape of the flexible glass fiber sleeve may be any shape, such as cubic, cylindrical, pyramidal, conical, prismatic, and the like, and combinations thereof. In specific embodiments, the shape of the flexible glass fiber sleeve is a concentric cylinder, such that the perimeter of the exterior surface of the flexible glass fiber sleeve is a circumference. The flexible glass fiber sleeve further includes an exterior radius extending radially from a position on the axis B to a position on the exterior surface. The exterior radius of the flexible glass fiber sleeve can be any distance, such as a distance of from about 1/12 to about 100 feet, although distances outside of this range are also contemplated. Typically, the exterior radius of the flexible glass fiber sleeve will be a distance of from about 1/6 to about 75, about 1/5 to about 50, about 1/4 to about 25, or about 1/3 to about 10 feet.

[0025] It is to be appreciated that the flexible glass fiber sleeve may comprise multiple exterior radii, each independently of the same or different distance, depending on the shape of the flexible glass fiber sleeve, the position on the axis B the exterior radius extends from, the position on the exterior surface of the flexible glass fiber sleeve each exterior radius extends to, or combinations thereof.

[0026] The flexible glass fiber sleeve also has an interior surface defining a first cavity, and an interior radius extending radially from the axis B to the interior surface of the flexible glass fiber sleeve. The first cavity extends along the axis B for at least a portion of the distance between the first and second ends of the flexible glass fiber sleeve. The first cavity may have any shape, such as cubic, cylindrical, pyramidal, conical, prismatic, trapezoidal, spherical, and the like, and combinations thereof. Accordingly, the first cavity may have any cross-sectional shape, such as circular, square, rectangular, triangular, trapezoidal, star, and the like. Additionally, the shape and/or cross-sectional shape of the first cavity may be the same or different than the shape and/or cross-sectional shape of the flexible glass fiber sleeve. In some embodiments, the first cavity has a uniform cross- sectional shape. In other embodiments, the first cavity has multiple cross-sectional shapes, each independently the same or different as one another. Typically, the shape of the first cavity is cylindrical such that the cross-sectional shape of the first cavity is circular. Furthermore, the first cavity can be concentric or eccentric to the flexible glass fiber sleeve. The first cavity can also be centered around the axis B, or off-centered with respect to the axis B. In some embodiments, the first cavity is centered around the axis B. In certain embodiments, the first cavity is concentric with the flexible glass fiber sleeve and both the first cavity and the flexible glass fiber sleeve are centered around the axis B. It is to be appreciated that the shape, cross-sectional shape, and dimensions of the first cavity described herein may apply to the first cavity of the flexible glass fiber sleeve upon expansion or in a natural state. Furthermore, the first cavity may have the same or different shape and/or cross-sectional shape upon expansion compared to the natural state.

[0027] The interior radius can be any distance less than the distance of an exterior radius extending radially from the same position on the axis B, such as a distance of from about 1/24 to about 99 feet, although distances outside of this range are also contemplated. Typically, the interior radius will be a distance of from about 1/24 to about 95, about 1/16 to about 85, about 1/12 to about 75, about 1/8 to about 50, about 1/6 to about 25, or about 1/5 to about 10 feet. In some embodiments, the interior radius is a distance of from about 10 to about 99, about 15 to about 95, or about 20 to about 90 percent of the distance of the exterior radius extending radially from the same point on axis B.

[0028] It is to be appreciated that the flexible glass fiber sleeve may comprise multiple interior radii, each independently of the same or different distance, depending on the shape of the flexible glass fiber sleeve, the position on the axis B each interior radius extends from, the position on the interior surface each interior radius extends to, or combinations thereof. It is also to be appreciated that the difference between interior and exterior radii extending from a same position on the axis B may be referred to as a thickness of the flexible glass fiber sleeve. In other words, the flexible glass fiber sleeve may further define a thickness comprising a distance equal to the difference between the exterior radius and the interior radius extending from the same position on the axis B. The thickness of the flexible glass fiber sleeve may be any distance in accordance with the description of the interior and exterior radii above. Additionally, the flexible glass fiber sleeve may comprise multiple thicknesses, each independently a distance depending on the shape of the structural element, the position on the axis B each radius extends from, the position on the interior or exterior surface each radius extends to, or combinations thereof. Furthermore, due to the flexibility of the flexible glass fiber sleeve, a thickness of the flexible glass fiber sleeve may be different in a natural state than in an expanded state. Typically, the thickness of the flexible glass fiber sleeve is between from about 0.005 to about 12 inches. In particular embodiments, the thickness of the flexible glass fiber sleeve is from about 0.01 to about 11 , about 0.05 to about 10, about 0.1 to about 9, about 0.1 to about 8, about 0.5 to about 7, or about 1 to about 6 inches. [0029] The flexible glass fiber sleeve comprises a resin and glass fiber(s). The resin may be any resin known in the art. Typically, thermosetting and/or thermoplastic resins are utilized. Examples of suitable thermosetting and/or thermoplastic resins typically include epoxy resins, polyester resins, phenolic resins (e.g. resol type), urea resins (e.g. melamine type), polyamide resins, polyimide resins, polyvinyl resins, polyvinyl ester resins, polyurethane resins, and the like, as well as copolymers, modifications, and combinations thereof. Additionally, elastomer or rubber can be added to or compounded with the thermosetting and/or thermoplastic resin to improve certain properties such as impact strength.

[0030] In some embodiments the resin is an epoxy resin, which may be a thermosetting and/or thermoplastic resin. The term "epoxy" represents a compound comprising a cross- linked reaction product of a typically polymeric compound having one or more epoxide groups (i.e., an epoxide) and a curing agent. Thus, suitable epoxy resins include those formed by reacting an epoxide with a curing agent. The term "epoxy" is conventionally used to refer to an uncured resin that contains epoxide groups. With such usage, once cured, the epoxy resin is no longer an epoxy, or no longer includes epoxide groups, but for any unreacted or residual epoxide groups or reactive sites, which may remain after curing, as understood in the art. However, unless description to the contrary is provided, reference to epoxy herein in the context of an epoxy resin shall be understood to refer to a cured epoxy resin. The term "cured epoxy" shall be understood to mean the reaction product of an epoxide as defined herein and a curing agent as defined herein.

[0031] It is to be understood that the terms "curing agent" and "cross-linking agent" can be used interchangeably. Curing agents suitable for use in forming suitable epoxy resins are typically at least difunctional molecules that are reactive with epoxide groups (i.e., comprise two or more epoxide-reactive functional groups). The term "cured" refers to a composition that has undergone cross-linking at an amount of from about 50% to about 100% of available cure sites. Additionally, the term "uncured" refers to the composition when it has undergone little or no cross-linking. However, it is to be understood that some of the available cure sites in an uncured composition may be cross-linked. Likewise, some of the available cure sites in a cured composition may remain uncross-linked. Thus, the terms "cured" and "uncured" may be understood to be functional terms. Accordingly, an uncured composition is typically characterized by a solubility in organic solvents and an ability to undergo plastic flow. In contrast, a cured composition suitable for the practice of the present invention is typically characterized by an insolubility in organic solvents and an absence of plastic flow under ambient conditions. [0032] Examples of suitable epoxides include aliphatic, aromatic, cyclic, acyclic, and polycyclic epoxides, and modifications and combinations thereof. The epoxide may be substituted or unsubstituted, and hydrophilic or hydrophobic. The epoxide may have an epoxy value (equiv./kg) of about 2 or greater, such as from about 2 to about 10, about 2 to about 8, about 2.5 to about 6.5, about 5 to about 10, about 2 to about 7, or about 4 to about 8.

[0033] Specific examples of suitable epoxides include glyidyl ethers of biphenol A and bisphenol F, epoxy novolacs (such as epoxidized phenol formaldehydes), naphthalene epoxies, trigylcidyl adducts of p-aminophenol, tetraglycidyl amines of methylenedianiline, triglycidyl isocyanurates, hexahydro-o-phthalic acid-bis-glycidyl ester, hexahydro-m- phthalic acid-bis-glycidyl ester, hexahydro-p-phthalicacid-bis-glycidyl ester, and modifications and combinations thereof.

[0034] Examples of suitable curing agents include polyols, such as glycols and phenols. Particular examples of phenols include biphenol, bisphenol A, bisphenol F, tetrabromobisphenol A, dihydroxydiphenyl sulfone, phenolic oligomers obtained by the reaction of above mentioned phenols with formaldehyde, and combinations thereof. Additional examples of suitable curing agents include anhydride curing agents such as nadic methyl anhydride, methyl tetrahydrophthalic anhydride, and aromatic anhydrides such pyromellitic dianhydride, biphenyltetracarboxylic acid dianhydride, benzophenonetetracarboxylic acid dianhydride, oxydiphthalic acid dianhydride, 4,4'- (hexafluoroisopropylidene) diphthalic acid dianhydride, naphthalene tetracarboxylic acid dianhydrides, thiophene tetracarboxylic acid dianhydrides, 3,4,9, 10-perylenetetracarboxylic acid dianhydrides, pyrazine tetracarboxylic acid dianhydrides, 3,4,7,8-anthraquinone tetracarboxylic acid dianhydrides, oligomers or polymers obtained by the copolymerization of maleic anhydride with ethylene, isobutylene, vinyl methyl ether, and styrene, and combinations thereof. Further examples of suitable curing agents include maleic anhydride- grafted polybutadiene.

[0035] Other specific examples of suitable thermosetting and/or thermoplastic resins include polyamides (PA); polyesters such as polyethylene terephthalates (PET), polybutylene terephthalates (PET), polytrimethylene terephthalates (PTT), polyethylene naphthalates (PEN), liquid crystalline polyesters, and the like; polyolefins such as polyethylenes (PE), polypropylenes (PP), polybutylenes, and the like; styrenic resins; polyoxymethylenes (POM); polycarbonates (PC); polymethylenemethacrylates (PMMA); polyvinyl chlorides (PVC); polyphenylene sulfides (PPS); polyphenylene ethers (PPE); polyimides (PI); polyamideimides (PAI); polyetherimides (PEI); polysulfones (PSU); polyethersulfones; polyketones (PK); polyetherketones (PEK); polyetheretherketones (PEEK); polyetherketoneketones (PEKK); polyarylates (PAR); polyethernitriles (PEN); phenolic resins; phenoxy resins; fluorinated resins, such as polytetrafluoroethylenes; thermoplastic elastomers, such as polystyrene types, polyolefin types, polyurethane types, polyester types, polyamide types, polybutadiene types, polyisoprene types, fluoro types, and the like; and copolymers, modifications, and combinations thereof.

[0036] In some embodiments the resin is a polyamide resin, which may be a thermosetting and/or thermoplastic resin. Examples of suitable polyamides include polycaproamide (Nylon 6), polyhexamethyleneadipamide (Nylon 66), polytetramethyleneadipamide (Nylon 46), poly hexamethylenesebacamide (Nylon 610), polyhexamethyl enedodecamide (Nylon 612), polyundecaneamide, poly dodecaneamide, hexamethyleneadipamide/caproamide copolymer (Nylon 66/6), caproamide/hexamethyleneterephthalamide copolymer (Nylon 6/6T), hexamethyleneadipamide/hexamethyleneterephthalamide copolymer (Nylon 66/6T) hexamethyleneadipamide/hexamethyleneisophthalamide copolymer (Nylon 66/61), hexamethyleneadipamide/ hexamethyleneisophthalamide/caproamide copolymer (Nylon 66/6I/6), hexamethyleneadipamide/hexamethylene terephthalamid/carpoamide copolymer (Nylon 66/6T/6), hexamethyleneterephthalamide/hexamethyleneisophthala mide copolymer (Nylon 6T/6I), hexamethyleneterephthalamide/dodecanamide copolymer (Nylon 6T/12), hexamethyleneadipamide/hexamethyleneterephthalamide/hexameth yleneisophthalamide copolymer (Nylon 66/6T/6I), polyxylyleneadipamide, hexamethyleneterephthalamide/2- methyl pentamethyleneterephthalamide copolymer, polymetaxylylenediamineadipamide (Nylon MXD6), polynonamethyleneterephthalamide (Nylon 9T), and combinations thereof.

[0037] In certain embodiments the resin is a phenol resin, which may be a thermosetting and/or thermoplastic resin. Examples of suitable phenol resins include resins prepared by homopolymerizing or copolymerizing components containing at least a phenolic hydroxyl group. Specific examples of suitable phenol resins include phenolic resins such as phenolnovolaks, cresolnovolaks, octylphenols, phenylphenols, naphtholnovolaks, phenolaralkyls, naphtholaralkyls, phenolresols, and the like, as well as modified phenolic resins such as alkylbenzene modified (especially, xylene modified) phenolic resins, cashew modified phenolic resins, terpene modified phenolic resins, and the like. Further examples of suitable phenol resins include 2,2-bis(4-hydroxyphenyl)propane (generally referred to as bisphenol A), 2,2-bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 1,1- bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2- bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2-bis(hydroxy-3-methylphenyl)propane, bis(4- hydroxyphenyl)sulfide, bis(4-hydroxy-phenyl)sulfone, hydroquinone, resorcinol, 4,6- dimethyl-2,4,6-tri(4-hydroxyphenyl)heptene, 2,4,6-dimethyl-2,4,6-tri(4- hydroxyphenyl)heptane, 2,6-dimethyl-2,4,6-tri(4-hydroxyphenyl)heptene, 1 ,3,5-tri(4- hydroxyphneyl)benzene, 1,1 ,1-tri(4-hydroxyphenyl) ethane, 3,3-bis(4- hydroxyaryl)oxyindole, 5-chloro-3,3-bis(4-hydroxyaryl)oxyindole, 5,7-dichloro-3,3-bis(4- hydroxyaryl) oxyindole, 5-brome-3,3-bis(4-hydroxyaryl) oxyindole, and combinations thereof.

[0038] In particular embodiments the resin is a polyester resin, which may be a thermosetting and/or thermoplastic resin. Examples of suitable polyester resins include polycondensation products of a polycarboxylic acid and a polyol, ring-opened polymers of a cyclic lactone, polycondensation products of a hydroxycarboxylic acid, and polycondensation products of a dibasic acid and a polyol. It is to be appreciated that the term "polyol" as used herein is meant to describe a molecule with at least two -OH functional groups (e.g. alcohol, hydroxy and/or hydroxyl functional groups). Particular examples of suitable polyols include polyetherpolyols, diols such as glycols, triols such as glycerine, 1,2,6-hexanetriol, trimethoxypropane (TMP), and triethoxypropane (TEP), sugar alcohols such as erythtitol, lactitol, maltitol, mannitol, sorbitol, and xylitol, and the like, as well as combinations and modifications thereof. Other suitable polyols include biopolyols such as castor oil, hydroxylated fatty esters (e.g. hydroxylated glycerides), hydroxylated fatty acids, and the like, as well as modifications and/or combinations thereof. Specific examples of suitable polyester resins include polyethylene terephthalate resins, polypropylene terephthalate resins, polytrimethylene terephthalate resins, polybutylene terephthalate resins, polyethylene naphthalate resins, polybutylene naphthalate resins, polycyclohexanedimethylene terephthalate resins, polyethylene-1 ,2-bis(phenoxy) ethane- 4,4'-dicarboxylate resins, polyethylene-1, 2-bis(phenoxy)ethane-4,4'-dicarboxylate resins, as well as copolymer polyesters such as polyethylene isophthalate/terephthalate resins, polybutylene terephthalate/isophthalate resins, polybutylene terephthalate/ decanedicarboxyate resins, and polycyclohexanedimethylene terephthalate/isophthalate resins, and combinations thereof.

[0039] In some embodiments the resin is a polyvinyl resin, which may be a thermosetting and/or thermoplastic resin. Examples of suitable polyvinyl resins include polymerization products of molecules comprising vinyl, vinylidene, and/or vinylene functional groups. Specific examples of polyvinyl resins include those formed from vinylhalides such as vinyl chloride, vinylarenes such as styrene, vinyl esters, and the like, as well as combinations and/or modifications thereof. Specific examples of suitable polyvinyl resins include polyvinyl ester resins, such as homopolymer, copolymer, and di-, tri-, and/or poly-block polymer products of vinyl esters. Examples of suitable vinyl esters include vinyl alkanoates such as vinyl acetates, vinyl stearates, vinyl decanoates, vinyl valerates, vinyl pivalate, and the like, vinyl benzoates, vinyl formates, vinyl cinnamates, and the like, as well as combinations and/or modifications thereof.

[0040] In certain embodiments, the resin is a polyurethane resin, which may be a thermosetting and/or thermoplastic resin. Examples of suitable polyurethanes include condensation products of a polyisocyanate and a polyol, such as those polyols described herein. Examples of suitable polyisocyanates include diisocyanates such as aromatic diisocyanates (e.g. toluene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI), and naphthalene diisocyanate (NDI)), alkylisocyanates (e.g. hexamethylene diisocyanate (HDI) and methylene bis-cyclohexylisocyanate (HMDI)), and aliphatic diisocyanates (e.g., isophorone diisocyanate (IPDI)), and the like, as well as combinations, modifications, and self-polymerization products thereof.

[0041] It is to be appreciated that the term "glass fiber(s)" can denote a single fiber of glass and/or a plurality of glass fibers. Herein, use of the term "glass fiber(s)" denotes one or more individual fibers of glass, which can be independently selected based on composition, size, length, and the like, or combinations thereof. For clarity and consistency, reference to "the glass fiber(s)" is made herein, which is not intended to refer to but one fiber of glass, but to any one fiber of glass, which may be independently selected. The description below may relate to a single fiber of glass, or all of the fibers of glass, utilized. The term "glass fiber(s)" also encompasses particles and particulates, i.e., the fibers of glass need not have an elongated form or shape.

[0042] The glass fiber(s) of the flexible glass fiber sleeve comprises a fibrous material comprising, consisting essentially of, or consisting of, glass. The flexible glass fiber sleeve typically comprises a combination of the resin and glass fiber(s), i.e., a fiberglass. As described above, the fiberglass comprises a combination of both glass fiber(s) (i.e., fibers of glass) and resin. Accordingly, as used herein, the term "fiberglass" is meant to denote such a combination. The fiberglass may be present in the flexible glass fiber sleeve in the form of strings, webs, sheets, wires, fabrics, tubes, cables, strands, monofilaments, or combinations thereof. Additionally, the fiberglass may be woven or nonwoven. In some embodiments, the fiberglass is present in the flexible glass fiber sleeve in the form of a filament product. Filament products include spun yarns such as woven fabrics, knits, and braids, webs such as papers and mats, and copped and milled fibers. In certain embodiments, the fiberglass is a staple product. Staple products include spun stable yarns, fabrics, knits, and braids of staple yarn, webs of staple including felts, mats, and papers, and chopped or milled stable fibers.

[0043] In some embodiments, the fiberglass is present in the flexible glass fiber sleeve in the form of strings, strands, and/or cables. In such some embodiments, the strings, strands, and/or cables within the flexible glass fiber sleeve may be randomly oriented or selectively oriented, such as aligned in one direction, oriented in cross directions, oriented in curved sections, and combinations thereof. In certain embodiments, the flexible glass fiber sleeve comprises braided fiberglass.

[0044] It is to be appreciated that the orientation of strings, strands, and/or cables may be selected to provide various mechanical properties to the flexible glass fiber sleeve such as flexibility, tearing tendency, differential tensile strength along different directions, and the like. It is also to be appreciated that the terms "flexible" and "flexibility" are used herein to describe an ability to readily undergo expansion, contraction, bending, flexure, twisting, and the like. As will be apparent from the description herein, the flexibility of the flexible glass fiber sleeve may comprise an ability to undergo expansion in response to force applied to the interior surface, such as in the radial direction, to result in an increase in the exterior and interior radii, as well as an increase in the circumference of the flexible glass fiber sleeve. Likewise, the flexibility of the flexible glass fiber sleeve may comprise an ability to contract when force is applied to the flexible glass fiber sleeve, such as upon tension or twisting in the longitudinal direction, to result in a decrease in the circumference of the flexible glass fiber sleeve. Accordingly, in some embodiments, the flexible glass fiber sleeve expands in response to force applied to the interior surface.

[0045] In some embodiments, the flexible glass fiber sleeve further comprises an additional fibrous material, such as carbon fiber, basalt fiber, natural fiber, metal fiber, polymer-based fibers, such as aramid (e.g. Kevlar, Nomex, Technora), and the like, or combinations thereof.

[0046] In some embodiments, the flexible glass fiber sleeve further comprises additional components. Examples of additional components include: fillers, such as mica, talc, kaoline, sericite, bentonite, xonotlite, sepiolite, smectite, montmoril lonite, wollastonite, silica, calcium carbonate, glass bead, glass flake, glass micro balloon, clay, molybdenum disulphide, titanium oxide, zinc oxide, antimony oxide, calcium polyphosphate, graphite, barium sulfate, magnesium sulfate, zinc borate, calcium borate, aluminum borate whisker, potassium titanate whisker, polymer, and the like; flame retardants and flame retardant aids; pigments; dyes; lubricants; releasing agents; compatibilizers; dispersants; crystallizing agents such as mica, talc, kaoline, and the like; plasticizers such as phosphate esters and the like; thermal stabilizers; antioxidants; anticoloring agents; UV absorbers; flowability modifiers; foaming agents; antimicrobial and/or antifouling agents; dust controlling agents; deodorants; sliding modifiers; antistatic agents such as polyetheresteramide and the like; and combinations thereof. In certain embodiments, the flexible glass fiber sleeve further comprises two or more additional components. [0047] In some embodiments, the dimensions, components, compositions, and/or structures of the flexible glass fiber sleeve, as described above, may be selected to reduce, inhibit, and/or prevent galvanic corrosion. Accordingly, in certain embodiments, the flexible glass fiber sleeve may act as a galvanic corrosion protection layer. In some such particular embodiments, the flexible glass fiber sleeve may prevent electrolyte and/or ion migration between the exterior and interior surfaces of the flexible glass fiber sleeve, thereby also preventing galvanic coupling across the thickness of the flexible glass fiber sleeve.

[0048] Typically, disposing the flexible glass fiber sleeve comprises inserting the flexible glass fiber sleeve into the interior cavity of the structural element. However, it is to be appreciated that the flexible glass fiber sleeve may positioned, placed, slid, dropped, unfurled, or rolled in the interior cavity of the structural element. Similarly, the flexible glass fiber sleeve may be formed or partially formed in the interior cavity of the structural element. Alternatively, the flexible glass fiber sleeve may be pre-formed outside of the structural element and then inserted into the interior cavity of the structural element. In particular embodiments, the flexible glass fiber sleeve is pre-formed prior to disposing the flexible glass fiber sleeve into the interior cavity of the structural element. In some embodiments, once disposed in the interior cavity of the structural element, at least a portion of the interior surface of the structural element is disposed about and adjacent to the exterior surface of the flexible glass fiber sleeve. In certain embodiments, once disposed in the interior cavity of the structural element, at least a portion of the interior surface of the structural element is disposed about and spaced apart from the exterior surface of the flexible glass fiber sleeve. Furthermore, the flexible glass fiber sleeve may be disposed in the interior cavity of the structural element by any method, such as manually, mechanically, pneumatically, hydraulically, gravitationally, and the like, or combinations thereof.

[0049] In some embodiments, disposing the flexible glass fiber sleeve further comprises wetting or saturating the flexible glass fiber sleeve prior to, concurrently with, or subsequent to disposing the flexible glass fiber sleeve into the interior cavity of the structural element. It is to be understood that the term "wetting" as used herein describes any contacting, moistening, or covering of at least a portion of the flexible glass fiber sleeve with a flowable substance. Likewise, it is also to be understood that the term "saturating" as used herein is meant to describe contacting, moistening, or covering all of the flexible glass fiber sleeve with the flowable substance. Wetting is distinguished from saturating by virtue of the amount of flowable substance utilized and whether the flexible glass fiber sleeve is capable of absorbing or directly contacting any additional amount of the flowable substance. Furthermore, any method suitable for contacting, moistening, or covering a portion or all of the flexible glass fiber sleeve with the flowable substance can be used to wet or saturate the flexible glass fiber sleeve. In certain embodiments, the method includes dip coating, roll coating, spray coating, flow coating, spin coating, or drop coating the flexible glass fiber sleeve with the flowable substance. In some embodiments, the method includes wetting or saturating the flexible glass fiber sleeve via wet/hand lay-up, spray lay- up, saturating machine, vacuum infusion, and the like. In specific embodiments, the method includes combining the flexible glass fiber sleeve in the flowable substance. The flowable substance may be disposed on the flexible glass fiber sleeve with the flowable substance or the flexible glass fiber sleeve may be disposed in the flowable substance, e.g. in a vessel. In particular embodiments, the flowable substance comprises a resin, such that disposing the flexible glass fiber sleeve comprises wetting or saturating the flexible glass fiber sleeve with the resin. The resin may be the same as or different from any resin utilized to form the flexible glass fiber sleeve, and may be selected from but is not limited to any of those resins described above. In certain embodiments, the flexible glass fiber sleeve is wetted or saturated with an epoxy resin, such as one of the epoxy resins described above. In some embodiments, the flexible glass fiber sleeve is wetted or saturated with a polyester resin, such as one of the polyester resins described above. In further embodiments, the flexible glass fiber sleeve is wetted or saturated with a vinyl resin, such as one of the vinyl resins described above. In particular embodiments, the flexible glass fiber sleeve is wetted or saturated with a polyurethane resin, such as one of the polyurethane resins described above. The flexible glass fiber sleeve may be wetted or saturated with different types of resins or combinations of resins. In addition, when the resins are formed via a reaction between two or more components, the flexible glass fiber sleeve may be wetted or saturated with the components, a reaction intermediary thereof, the reaction product thereof, etc. Typically, the resin is not fully cured or otherwise has a viscosity such that the resin is flowable. Forming the resin in situ when in contact with the flexible glass fiber sleeve is within the scope of contacting the flexible glass fiber sleeve with the resin. The components may react prior to being applied to the flexible glass fiber sleeve, as they are being applied to the flexible glass fiber sleeve, and/or upon being applied to the flexible glass fiber sleeve. The components may be separately metered and applied, and may be applied in a manner such that the components are combined during application to the flexible glass fiber sleeve.

[0050] The method also includes (ii) disposing a flexible carbon fiber sleeve in the first cavity of the flexible glass fiber sleeve to give a composite sleeve. In general, the flexible carbon fiber sleeve comprises a first end and a second end, and a height extending for a distance between the first and second ends. In certain embodiments, the height of the flexible carbon fiber sleeve extends between the first and second ends for a distance along an axis C. The height of the flexible carbon fiber sleeve can be any distance, such as a distance of from about 1/24 to about 10,000 feet. Typically, the height of the flexible carbon fiber sleeve is a distance of from about 1/24 to about 200, about 1/16 to about 175, about 1/8 to about 150, about 1/4 to about 125, about 1/2 to about 100, about 2/3 to about 75, about 3/4 to about 50, about 5/6 to about 25, or about 1 to about 10 feet.

[0051] It is to be appreciated that the flexible carbon fiber sleeve need not be linear. Rather, the flexible carbon fiber sleeve is flexible, and may thus be curved, arcuate, bent, folded, rolled, and the like, or combinations thereof. Furthermore, because the flexible carbon fiber sleeve is flexible, it may take any shape and the shape may be dynamic. Moreover, the shape of the flexible carbon fiber sleeve may be complimentary to a container in which the flexible carbon fiber sleeve is disposed and expanded. Therefore, it is also to be appreciated that the dimensions and ranges used herein to describe the flexible carbon fiber sleeve may apply to the flexible carbon fiber sleeve in any state of expansion or nonexpansion, such as in a natural state or an expanded state.

[0052] Typically, the flexible carbon fiber sleeve is in the form of a balloon or bladder. The flexible carbon fiber sleeve also presents at least an exterior surface and an interior surface. The exterior and interior surfaces of the flexible carbon fiber sleeve may be, independently, of any shape, texture, and/or contour, such as smooth, rough, textured, and the like, or combinations thereof. Accordingly, it is to be appreciated that the exterior and interior surfaces of the flexible carbon fiber sleeve may be the same or different. In some embodiments, the exterior and/or interior surface of the flexible carbon fiber sleeve is substantially smooth. In certain embodiments, the exterior and/or interior surface of the flexible carbon fiber sleeve is textured.

[0053] The exterior surface of the flexible carbon fiber sleeve has a perimeter extending for a distance around a plane lying perpendicular to the axis C (i.e., a cross-section). The exterior surface presents a shape of flexible carbon fiber sleeve. The shape of the flexible carbon fiber sleeve may be any shape, such as cubic, cylindrical, pyramidal, conical, prismatic, and the like, and combinations thereof. In specific embodiments, the shape of the flexible carbon fiber sleeve is a concentric cylinder, such that the perimeter of the exterior surface of the flexible carbon fiber sleeve is a circumference. The flexible carbon fiber sleeve further includes an exterior radius extending radially from a position on the axis C to a position on the exterior surface. The exterior radius of the flexible carbon fiber sleeve can be any distance, such as a distance of from about 1/12 to about 100 feet, although distances outside of this range are also contemplated. Typically, the exterior radius of the flexible carbon fiber sleeve will be a distance of from about 1/6 to about 75, about 1/5 to about 50, about 1/4 to about 25, or about 1/3 to about 10 feet.

[0054] It is to be appreciated that the flexible carbon fiber sleeve may comprise multiple exterior radii, each independently of the same or different distance, depending on the shape of the flexible carbon fiber sleeve, the position on the axis C the exterior radius extends from, the position on the exterior surface of the flexible carbon fiber sleeve each exterior radius extends to, or combinations thereof.

[0055] The interior surface of the flexible carbon fiber sleeve defines a second cavity, and comprises an interior radius extending radially from the axis C to the interior surface of the flexible carbon fiber sleeve. The second cavity extends along the axis C for at least a portion of the distance between the second and second ends of the flexible carbon fiber sleeve. The second cavity may have any shape, such as cubic, cylindrical, pyramidal, conical, prismatic, trapezoidal, spherical, and the like, and combinations thereof. Accordingly, the second cavity may have any cross-sectional shape, such as circular, square, rectangular, triangular, trapezoidal, star, and the like. Additionally, the shape and/or cross-sectional shape of the second cavity may be the same or different than the shape and/or cross-sectional shape of the flexible carbon fiber sleeve. In some embodiments, the second cavity has a uniform cross-sectional shape. In other embodiments, the second cavity has multiple cross-sectional shapes, each independently the same or different as one another. Typically, the shape of the second cavity is cylindrical such that the cross-sectional shape of the second cavity is circular. Furthermore, the second cavity can be concentric or eccentric to the flexible carbon fiber sleeve. The second cavity can also be centered around the axis C, or off-centered with respect to the axis C. In some embodiments, the second cavity is centered around the axis C. In certain embodiments, the second cavity is concentric with the flexible carbon fiber sleeve and both the second cavity and the flexible carbon fiber sleeve are centered around the axis C. It is to be appreciated that the shape, cross-sectional shape, and dimensions of the second cavity described herein may apply to the second cavity of the flexible carbon fiber sleeve upon expansion or in a natural state. Furthermore, the second cavity may have the same or different shape and/or cross-sectional shape upon expansion compared to the natural state.

[0056] The interior radius can be any distance less than the distance of an exterior radius extending radially from the same position on the axis C to a position on the exterior surface in the same plane. The interior radius can be any distance, such as a distance of from about 1/24 to about 99 feet, although distances outside of this range are also contemplated. Typically, the interior radius will be a distance of from about 1/24 to about 95, about 1/16 to about 85, about 1/12 to about 75, about 1/8 to about 50, about 1/6 to about 25, or about 1/5 to about 10 feet. In some embodiments, the interior radius is a distance of from about 10 to about 99, about 15 to about 95, or about 20 to about 90 percent of the distance of the exterior radius extending radially from the same point on axis C.

[0057] It is to be appreciated that the flexible carbon fiber sleeve may comprise multiple interior radii, each independently of the same or different distance, depending on the shape of the flexible carbon fiber sleeve, the position on the axis C each interior radius extends from, the position on the interior surface each interior radius extends to, or combinations thereof. It is also to be appreciated that the difference between interior and exterior radii extending from a same position on the axis C may be referred to as a thickness of the flexible carbon fiber sleeve. In other words, the flexible carbon fiber sleeve may further define a thickness comprising a distance equal to the difference between the exterior radius and the interior radius extending from the same position on the axis C. The thickness of the flexible carbon fiber sleeve may be any distance in accordance with the description of the interior and exterior radii above. Additionally, the flexible carbon fiber sleeve may comprise multiple thicknesses, each independently a distance depending on the shape of the structural element, the position on the axis C each radius extends from, the position on the interior or exterior surface each radius extends to, or combinations thereof. Furthermore, due to the flexibility of the flexible carbon fiber sleeve, a thickness of the flexible carbon fiber sleeve may be different in a natural state than in an expanded state. Typically, the thickness of the flexible carbon fiber sleeve is between from about 0.005 to about 12 inches. In particular embodiments, the thickness of the flexible carbon fiber sleeve is from about 0.01 to about 11 , about 0.05 to about 10, about 0.1 to about 9, about 0.1 to about 8, about 0.5 to about 7, or about 1 to about 6 inches.

[0058] The flexible carbon fiber sleeve comprises a resin and carbon fiber(s). The resin may be any resin known in the art, such as one or more of the thermosetting and/or thermoplastic resins described above, including epoxy resins, polyester resins, vinyl ester resins, polyamide resins, and the like, as well as copolymers, modifications, and combinations thereof. Additionally, elastomer or rubber can be added to or compounded with the thermosetting and/or thermoplastic resin to improve certain properties such as impact strength. Accordingly, in some embodiments, the resin is a thermosetting and/or a thermoplastic resin. In specific embodiments, the resin is an epoxy resin.

[0059] It is to be appreciated that the term "carbon fiber(s)" can denote a single fiber of carbon and/or a plurality of carbon fibers. Herein, use of the term "carbon fiber(s)" denotes one or more individual fibers of carbon, which can be independently selected based on composition, size, length, and the like, or combinations thereof. For clarity and consistency, reference to "the carbon fiber(s)" is made herein, which is not intended to refer to but one fiber of carbon, but to any one fiber of carbon, which may be independently selected. The description below may relate to a single fiber of carbon, or all of the fibers of carbon, utilized. The term "carbon fiber(s)" also encompasses particles and particulates, i.e., the fibers of carbon need not have an elongated form or shape.

[0060] The carbon fiber(s) of the flexible carbon fiber sleeve comprises a fibrous material comprising, consisting of, or consisting essentially of, graphene, graphite, and/or combinations thereof. The carbon fiber(s) may be or include polyacrylonitrile (PAN)-type, pitch type, or Rayon type carbon, or combinations thereof. The carbon fiber(s) may be in any form, such as single layer fibers, multilayer fibers, nanotubes, linked-particles, and combinations thereof.

[0061] The flexible carbon fiber sleeve typically comprises a combination of the resin and the carbon fiber(s), i.e., a carbon fiber. As described above, the carbon fiber comprises a combination of both carbon fiber(s) (i.e., fibers of carbon) and resin. Accordingly, as used herein, the term "carbon fiber" is meant to denote such a combination. The carbon fiber may be present in the flexible carbon fiber sleeve in the form of strings, webs, sheets, wires, fabrics, tubes, cables, strands, monofilaments, or combinations thereof. Additionally, the carbon fiber may be woven or nonwoven. In some embodiments, the carbon fiber is present in the flexible carbon fiber sleeve in the form of a filament product. Filament products include spun yarns such as woven fabrics, knits, and braids, webs such as papers and mats, and copped and milled fibers. In certain embodiments, the carbon fiber is a staple product. Staple products include spun stable yarns, fabrics, knits, and braids of staple yarn, webs of staple including felts, mats, and papers, and chopped or milled stable fibers.

[0062] In some embodiments, the carbon fiber is present in the flexible carbon fiber sleeve in the form of strings, strands, and/or cables. In such some embodiments, the strings, strands, and/or cables within the flexible carbon fiber sleeve may be randomly oriented or selectively oriented, such as aligned in one direction, oriented in cross directions, oriented in curved sections, and combinations thereof. In certain embodiments, the flexible carbon fiber sleeve comprises braided carbon fiber.

[0063] The carbon fiber within the flexible carbon fiber sleeve may be randomly oriented or selectively oriented, such as aligned in one direction, oriented in cross directions, oriented in curved sections, and combinations thereof. The orientation of the carbon fiber may be selected to provide various mechanical properties to the flexible carbon fiber sleeve such as flexibility, tearing tendency, differential tensile strength along different directions, and the like.

[0064] It is to be appreciated that the orientation of strings, strands, and/or cables may be selected to provide various mechanical properties to the flexible carbon fiber sleeve such as flexibility, tearing tendency, differential tensile strength along different directions, and the like. It is also to be appreciated that the flexibility of the flexible carbon fiber sleeve may be the same or different as the flexibility of the flexible glass fiber sleeve. Accordingly, the flexibility of the flexible carbon fiber sleeve may be described as an ability to readily undergo expansion, contraction, bending, flexure, twisting, and the like. Likewise, as will be apparent from the description of the flexible carbon fiber sleeve and the method herein, the flexibility may comprise an ability to undergo expansion in response to force applied to the interior surface, such as in the radial direction, to result in an increase in the exterior and interior radii, as well as an increase in the circumference of the flexible carbon fiber sleeve. Likewise, the flexibility of the flexible carbon fiber sleeve may comprise an ability to contract when force is applied to the flexible carbon fiber sleeve, such as upon tension or twisting in the longitudinal direction, to result in a decrease in the circumference of the flexible carbon fiber sleeve. Accordingly, in some embodiments, the flexible carbon fiber sleeve expands in response to force applied to the interior surface.

[0065] In some embodiments, the flexible carbon fiber sleeve further comprises an additional fibrous material, such as glass fiber, basalt fiber, natural fiber, metal fiber, polymer-based fiber such as aramid (e.g. Kevlar, Nomex, Technora), and the like, or combinations thereof.

[0066] In certain embodiments, the flexible carbon fiber sleeve further comprises additional components. Examples of additional components include: fillers, such as mica, talc, kaoline, sericite, bentonite, xonotlite, sepiolite, smectite, montmoril lonite, wollastonite, silica, calcium carbonate, carbon bead, carbon flake, carbon micro balloon, clay, molybdenum disulphide, titanium oxide, zinc oxide, antimony oxide, calcium polyphosphate, graphite, barium sulfate, magnesium sulfate, zinc borate, calcium borate, aluminum borate whisker, potassium titanate whisker, polymer, and the like; flame retardants and flame retardant aids; pigments; dyes; lubricants; releasing agents; compatibilizers; dispersants; crystallizing agents such as mica, talc, kaoline, and the like; plasticizers such as phosphate esters and the like; thermal stabilizers; antioxidants; anticoloring agents; UV absorbers; flowability modifiers; foaming agents; antimicrobial and/or antifouling agents; dust controlling agents; deodorants; sliding modifiers; antistatic agents such as polyetheresteramide and the like; and combinations thereof. In certain embodiments, the flexible carbon fiber sleeve further comprises two or more additional components.

[0067] Typically, disposing the flexible carbon fiber sleeve comprises inserting the flexible carbon fiber sleeve into the first cavity of the flexible glass fiber sleeve. However, it is to be appreciated that the flexible carbon fiber sleeve may positioned, placed, slid, dropped, unfurled, or rolled in the first cavity of the flexible glass fiber sleeve. Similarly, the flexible carbon fiber sleeve may be formed or partially formed in the first cavity of the flexible glass fiber sleeve. Alternatively, the flexible carbon fiber sleeve may be pre-formed outside of the flexible glass fiber sleeve and then inserted into the first cavity of the flexible glass fiber sleeve. In particular embodiments, the flexible carbon fiber sleeve is pre-formed prior to disposing the flexible carbon fiber sleeve into the first cavity of the flexible glass fiber sleeve. Furthermore, the flexible glass fiber sleeve may be disposed in the interior cavity of the structural element by any method, such as manually, mechanically, gravitationally, pneumatically, hydraulically, and the like, or combinations thereof. In some embodiments, disposing the flexible carbon fiber sleeve further comprises wetting or saturating the flexible carbon fiber sleeve prior to, concurrently with, or subsequent to disposing the flexible carbon fiber sleeve into the first cavity of the flexible glass fiber sleeve. In some such embodiments, disposing the flexible carbon fiber sleeve comprises wetting or saturating the flexible carbon fiber sleeve with a flowable substance. It is to be appreciated that wetting or saturating the flexible carbon fiber sleeve with the flowable substance may comprise any suitable method, such as those methods described above. Furthermore, wetting or saturating the flexible carbon fiber sleeve may comprise the same or different method as wetting or saturating the flexible glass fiber sleeve (if optionally done). Likewise, the flowable substance may be the same as or different from the flowable substance utilized to wet or saturate the flexible glass fiber sleeve (if optionally done). In particular embodiments, the flowable substance comprises a resin. The resin may be the same as or different from the resin utilized to wet or saturate the flexible glass fiber sleeve (if optionally done), the resin utilized to form the flexible glass fiber sleeve, and/or the resin utilized to form the flexible carbon fiber sleeve. Examples of suitable resins are set forth above. In certain embodiments, the flexible carbon fiber sleeve is wetted or saturated with an epoxy resin, such as one of the epoxy resins described above. In some embodiments, the flexible carbon fiber sleeve is wetted or saturated with a polyester resin, such as one of the polyester resins described above. In further embodiments, the flexible carbon fiber sleeve is wetted or saturated with a vinyl resin, such as one of the vinyl resins described above. In particular embodiments, the flexible carbon fiber sleeve is wetted or saturated with a polyurethane resin, such as one of the polyurethane resins described above. [0068] The flexible carbon fiber sleeve may be wetted or saturated with different types of resins or combinations of resins. In addition, when the resins are formed via a reaction between two or more components, the flexible carbon fiber sleeve may be wetted or saturated with the components, a reaction intermediary thereof, the reaction product thereof, etc. Typically, the resin is not fully cured or otherwise has a viscosity such that the resin is flowable. Forming the resin in situ when in contact with the flexible carbon fiber sleeve is within the scope of contacting the flexible carbon fiber sleeve with the resin. The components may react prior to being applied to the flexible carbon fiber sleeve, as they are being applied to the flexible carbon fiber sleeve, and/or upon being applied to the carbon glass fiber sleeve. The components may be separately metered and applied, and may be applied in a manner such that the components are combined during application to the flexible glass fiber sleeve.

[0069] As described above, the composite sleeve comprises the flexible glass fiber sleeve disposed about the flexible carbon fiber sleeve. Accordingly, the composite sleeve also defines at least the second cavity. In some embodiments, the composite sleeve comprises at least a portion of the interior surface of the flexible glass fiber sleeve disposed about and adjacent to the exterior surface of the flexible carbon fiber sleeve. In certain embodiments, the composite sleeve further comprises at least a portion of the interior surface of the flexible glass fiber sleeve disposed about and spaced apart from the exterior surface of the flexible carbon fiber sleeve. Furthermore, the flexible glass fiber sleeve and flexible carbon fiber sleeve of the composite sleeve may each independently move, flex, expand, and/or contract. In some embodiments, the flexible glass fiber sleeve and the flexible carbon fiber sleeve of the composite sleeve expand in unison when force is applied radially to a portion of the interior surface defining the second cavity. In some such embodiments, the expansion of the flexible carbon fiber sleeve of the composite sleeve may be described in terms of an expansion of the composite sleeve. Accordingly, in certain embodiments, the composite sleeve may expand such that the second cavity increases in volume by from 0.001 to 10%. For example, in some embodiments, the composite sleeve may expand such that the second cavity increases in volume by from about 0.001 to about 10, about 0.005 to about 10, about 0.01 to about 10, about 0.05 to about 10, about 0.1 to about 10, about 0.5 to about 10, or about 1 to about 10%, based on an initial volume and an expanded volume of the composite sleeve.

[0070] In certain embodiments, the method includes wetting or saturating the composite sleeve with a flowable substance. It is to be appreciated that wetting or saturating the composite sleeve with the flowable substance may comprise any suitable method, such as those methods described above. Typically, the flowable substance comprises a resin. The resin may be the same as or different from the resin utilized to form the flexible glass fiber sleeve, and/or the resin utilized to form the flexible carbon fiber sleeve. Examples of suitable resins are set forth above. In certain embodiments, the composite sleeve is wetted or saturated with an epoxy resin, such as one of the epoxy resins described above. Wetting or saturating the composite sleeve may comprise individually wetting or saturating the glass fiber sleeve and/or the carbon fiber sleeve prior to forming the composite sleeve such that the composite sleeve is wetted or saturated upon its formation, or the composite sleeve may be wetted or saturated during and/or after its formation.

[0071] The method further includes (iii) disposing a filler composition into the second cavity to form the composite structural element. The filler composition is typically selected to form a core of the structural element. Accordingly, the filler composition typically comprises a matrix-forming material, such as material capable of forming an inorganic and/or organic matrix. The filler composition is typically a concrete, cement, grout, resin, aggregate, sand, packing, geopolymer, ceramic, and the like, or combinations thereof. Furthermore, it is to be appreciated that the filler composition may comprise an expanding- type filler composition, a non-shrinking-type filler composition, a shrinking-type filler composition, or combinations thereof. It is also to be appreciated that the filler composition may be a wet-mixed filler composition, a dry-mixed filler composition, or combinations thereof.

[0072] In some embodiments, the filler composition comprises a geopolymer. Examples of suitable geopolymers include inorganic geopolymers, organic containing geopolymers, and ceramics. Specific examples of suitable geopolymers include minerals comprising repeating units such as silico-oxide (-Si-O-Si-O-), silico-aluminate (-Si-O-AI-O-), ferro-silico- aluminate (-Fe-O-Si-O-AI-O-), alumino-phosphate (-ΑΙ-0-Ρ-0-), and the like, and combinations thereof. In certain embodiments, the filler composition comprises a geopolymer cement such as a slag-based geopolymer cement, a rock-based geopolymer cement, a fly ash-based geopolymer cement, a ferro-sialate-based geopolymer cement, and the like, or combinations and/or modifications thereof.

[0073] In certain embodiments, the filler composition comprises a resin. Examples of suitable resins include the thermosetting and/or thermoplastic resins described above, including epoxy resins, polyester resins, vinyl ester resins, polyamide resins, and the like, as well as copolymers, modifications, and combinations thereof. Accordingly, in some embodiments the filler composition comprises a thermosetting and/or thermoplastic resin.

[0074] In some embodiments, the filler composition comprises a grout. Examples of suitable grouts include ANSI category A118.3 epoxy grouts, ANSI category A118.5 furan grouts, ANSI category A118.6 cement grouts, ANSI category A118.7 polymer-modified cement grouts, ANSI category A118.8 modified epoxy emulsion grouts, and the like, and combinations thereof. Particular examples of suitable grouts include CarbonBond™ epoxy grout systems, commercially available from DowAksa USA of Marietta, GA. Specific examples of suitable CarbonBond™ epoxy grout systems include DowAksa CarbonBond™ 600 Underwater Epoxy Grout Systems. In specific embodiments, the filler composition comprises an epoxy grout. In particular embodiments, the filler composition comprises an expanding-type, a non-shrinking-type, or a shrinking-type epoxy grout.

[0075] In specific embodiments, the filler composition comprises an epoxy grout. It is to be appreciated that the filler composition may comprise an expanding-type filler composition, a non-shrinking-type filler composition, a shrinking-type filler composition, or combinations thereof. In specific embodiments, the filler composition comprises an expanding-type filler composition. In certain embodiments, the filler composition comprises a non-shrinking-type filler composition. In some embodiments, the filler composition comprises a shrinking-type filler composition. In particular embodiments, the filler composition comprises an expanding-type, a non-shrinking-type, or a shrinking-type epoxy grout.

[0076] In certain embodiments, the filler composition comprises a concrete. In some such certain embodiments, the filler composition comprises an expanding-type, a non- shrinking-type, or a shrinking-type concrete. The term "concrete" as used herein is meant to describe a combination of a binder phase and a filler phase. Typically, the binder phase comprises an inorganic matrix-forming material. Combinations of materials may be utilized.

[0077] In specific embodiments, the inorganic matrix-forming material is a cement. It is to be appreciated that the cement may be a dry cement powder, a wet cement paste, or a hardened cement. The cement may also comprise a geopolymer cement such as those described herein. Examples of suitable cements include Portland cements such as those having an American Society of Testing Materials (ASTM) category l-V designation, rapid hardening cements, quick setting cements, low heat cements, slag cements, alumina cements, white cements, colored cements, pozzolanic cements, air entraining cements, hydrographic cements, sulfates resisting cement, and the like, or combinations thereof. In particular embodiments, the cement is a calcium silicate cement. The filler phase may be any material that can react with the binder phase to form the concrete. Typically, the filler phase comprises aggregate. Examples of suitable aggregates include sand, soil, gravel, rocks, waste byproducts, recycled materials, minerals, and the like, or combinations thereof. Specific examples of suitable aggregate include granite aggregates, scabbled stone aggregates, gravel aggregates, limestone aggregates, secondary aggregates such as crushed concrete, bricks, asphalt and the like, slag aggregates, and combinations thereof.

[0078] Typically, the concrete comprises water. It is to be appreciated that water may be added to the binder phase and/or the filler phase separately or in combination to form the concrete. In specific embodiments, water is added to a combination of the binder phase and the filler phase. In certain embodiments, the binder phase and the filler phase are combined in the presence of water.

[0079] The concrete may further comprise an additive such as an air entrainer, a colorant, a pigment, a fiber, a hydration accelerator, a hydration retarder, a water reducer, a plasticizer, a non-shrinking additive, a shrink reducer, a fast-set additive, an anti- corrosion additive, a set-retarder, an accelerator, a plasticizer, and the like, or combinations thereof. In specific embodiments, the concrete comprises a grout, such as a grout selected from or comprising one or more of the grouts described above.

[0080] Typically, disposing the filler composition comprises pumping the filler composition into the second cavity. However, it is to be appreciated that any method can be used to dispose the filler composition into the second cavity, such as dumping, spraying, pouring, and the like. Accordingly, the filler composition may be disposed into the second cavity manually, mechanically, pneumatically, hydraulically, and the like, or combination thereof. Furthermore, when the filler composition comprises concrete, the binder phase, the filler phase, and the water may be disposed into the second cavity separately or in any combination with one another.

[0081] In some embodiments, disposing the filler composition in the second cavity expands the flexible carbon fiber sleeve to fill the first cavity of the flexible glass fiber sleeve. In such some embodiments, upon expansion, the exterior surface of the flexible carbon fiber sleeve contacts the interior surface of the flexible glass fiber sleeve. Accordingly, in certain embodiments the flexible carbon fiber sleeve and the flexible glass fiber sleeve are sized generally complimentary to one another upon expansion. In such certain embodiments, upon expansion, the exterior surface of the flexible carbon fiber sleeve contacts the interior surface of the flexible glass fiber sleeve.

[0082] In specific embodiments, disposing the filler composition in the second cavity also expands the flexible glass fiber sleeve to fill the interior cavity of the structural element. In such specific embodiments, upon expansion, the exterior surface of the flexible glass fiber sleeve contacts a portion of the structural element defining the interior cavity. Accordingly, in some embodiments, upon expansion the flexible glass fiber sleeve is sized complimentary to the portion of the structural element defining the interior cavity. In such some embodiments, upon expansion, the exterior surface of the flexible glass fiber sleeve contacts the portion of the structural element defining the interior cavity. It is to be appreciated that, upon expansion, the flexible glass fiber sleeve and/or flexible carbon fiber sleeve may become locked in place by the filler composition, such that flexible glass fiber sleeve and/or flexible carbon fiber sleeve no longer exhibit flexibility.

[0083] In further embodiments, disposing the filler composition in the second cavity causes the composite sleeve to expand and fill in interior cavity of the structural element. In some such further embodiments, upon expansion, the composite sleeve may be sized complementary to at least a portion of the structural element defining the interior cavity.

[0084] In particular embodiments, the filler composition is disposed into the second cavity after the flexible glass fiber sleeve, the flexible carbon fiber sleeve, and/or the composite sleeve has been wetted or saturated with a resin, as introduced above. In some such particular embodiments, the filler composition is disposed into the second cavity after the flexible glass fiber sleeve, the flexible carbon fiber sleeve, and/or the composite sleeve has been wetted or saturated with an epoxy resin, such as any of the epoxy resins set forth above.

[0085] In certain embodiments, the method further comprises curing the filler composition. Suitable methods for curing the filler composition include setting, hardening, cross-linking, polymerizing, gelatinizing, vulcanizing, and the like, or combinations thereof. However, it is to be appreciated that any method can be used to cure the filler composition. Typically, curing the filler composition comprises reacting one or more component of the filler composition together to form an inorganic and/or organic matric. Accordingly, curing the filler composition may comprise physical, chemical, or electronic curing methods, such as curing methods initiated by exposing the filler composition to heat, moisture, pressure, chemical additives such as catalysts and/or cross-linkers, electron beams such as infrared and/or ultraviolet (UV) radiation, and the like, or combinations thereof, contingent on a selection of the filler composition and any relevant curing technique. Additionally, the filler composition may be cured before, during, and/or after disposing the filler composition in the second cavity. In some embodiments, curing the filler composition comprises procuring and/or partially curing the filler composition prior to disposing the filler composition in the second cavity. In such some embodiments, the filler composition may be pre-cured and/or partially cured by any of the methods for curing the filler composition described herein.

[0086] In particular embodiments, curing the filler composition comprises heating the filler composition. In such particular embodiments, heating the filler composition may comprise heating the filler composition, or any component thereof, via conduction and/or radiation from any vessel used for storing, holding, and/or disposing the filler composition. In such particular embodiments, the term "vessel" is used refer to any article in contact with, or near, a portion of the filler composition, or any component thereof, such as a heating element, tank, tube, bucket, hose, pipe, vat, nozzle, port, and the like. Accordingly, heating the filler composition may comprise contacting the filler composition, or any component thereof, with a vessel used for storing, holding, mixing, pumping, dumping, spraying, or pouring the filler composition. In particular embodiments, the filler composition is heated via conduction and/or radiation from the structural element. In some embodiments, the filler composition is heated via in situ exothermic reactions during curing.

[0087] In certain embodiments, curing the filler composition comprises cooling the filler composition. In such certain embodiments, the filler composition may be cooled after heating the filler composition.

[0088] In specific embodiments, the filler composition comprises two or more components, such as those described above, and the method comprises combining the two or more components together to give a pre-mixed filler composition, and disposing the pre-mixed filler composition into the second cavity. Alternatively, the two or more components, and thus the filler composition, may be mixed in situ while disposing into the second cavity. In such specific embodiments, the two or more components of the filler composition may react together before, during, and/or after the pre-mixed filler composition is disposed into the second cavity to give a cured filler composition and form the composite structural element. In some embodiments, the cured filler composition is further defined as a core.

[0089] In some embodiments, the method includes cleaning the inside surface of the structural element prior to disposing the flexible glass fiber sleeve in the interior cavity of the structural element. In such some embodiments, cleaning the inside surface may comprise washing, scrubbing, spraying, blasting, sanding, rinsing, brushing, and the like, or combinations thereof. In certain embodiments, the inside surface of the structural element is cleaned with high pressure water prior to disposing the flexible glass fiber sleeve in the interior cavity of the structural element.

[0090] In certain embodiments, the structural element is hollow and the interior cavity is completely encapsulated by the structural element. In such certain embodiments, the method further includes defining an access point through a portion of the structural element into the interior cavity. The access point may be defined by any method, such as drilling, cutting, blasting, disassembling, and the like. Accordingly, in some embodiments, the flexible glass fiber sleeve is disposed in the interior cavity of the structural element via the access point. Additionally, in certain embodiments, the flexible carbon fiber sleeve is disposed in the first cavity of the flexible glass fiber sleeve via the access point of the structural element. Furthermore, in particular embodiments, the filler composition is disposed in the second cavity of the flexible carbon fiber sleeve via the access point of the structural element. Likewise, in some embodiments, the method further comprises closing the access point. The access point may be closed by any method, such as welding, capping, plugging, sealing, and the like.

[0091] It is to be appreciated that the method described above can be repeated any number of times on any number of portions of the structural element. Likewise, the method can be used to reinforce the entire structural element, or only a portion of the structural element. Accordingly, in some embodiments the method is used to reinforce only a portion of the structural element. In certain embodiments, the method is used to reinforce the entire structural element. In particular embodiments, the method is used to reinforce multiple portions of the structural element.

[0092] The invention also provides a composite structural element formed in accordance with the method described above. Specifically, the method may be used to form a composite structural element comprising a core; a carbon fiber sleeve disposed about and adjacent the core; a glass fiber sleeve disposed about and adjacent the carbon fiber sleeve; and a structural element disposed about and adjacent the glass fiber sleeve. Typically, the composite structural element has different physical properties than the structural element, such as an improved (e.g. an increased) loading capacity, structural efficiency, stiffness, compression strength, and/or shear strength, compared to the structural element. Accordingly, it is to be appreciated that the composite structural element may comprise multiple reinforced sections, which are each independently formed by the method described above.

[0093] The invention further provides a composite structural element. Specifically, the invention provides a composite structural element comprising a core; a carbon fiber sleeve disposed about and adjacent the core; a glass fiber sleeve disposed about and adjacent the carbon fiber sleeve; and a structural element disposed about and adjacent the glass fiber sleeve. Typically, the core of the composite structural element is formed from a filler composition, such as one of the filler compositions described above. In some embodiments, the core of the composite structural element is formed from curing the filler composition, as described above.

[0094] With reference to the specific embodiment of the Figures, wherein like numerals generally indicate like parts throughout the several views, a structural element is shown generally at 10. The structural element 10 extends along an axis A. The structural element 10 comprises an access point 16, and is disposed about a flexible glass fiber sleeve 12. [0095] Figure 2 shows the structural element 10 disposed about the flexible glass fiber sleeve 12. Figure 2 also shows the flexible glass fiber sleeve 12 disposed about a flexible carbon fiber sleeve 14.

[0096] Figure 3 shows the structural element 10 disposed about the flexible glass fiber sleeve 12, and the flexible glass fiber sleeve 12 disposed about the flexible carbon fiber sleeve 14. Figure 3 also shows the flexible carbon fiber sleeve 14 disposed about a filler composition 18.

[0097] Figure 4 shows a composite structural element 20 formed in accordance with the method exemplified in Figures 1-3. In particular, the composite structural element 20 comprises the structural element 10, a glass fiber sleeve 112, a carbon fiber sleeve 114, and the filler composition 118. Figure 4 also shows the structural element 10 disposed about the glass fiber sleeve 112, the glass fiber sleeve 112 disposed about the carbon fiber sleeve 114, and the carbon fiber sleeve 114 disposed about a core 118 formed from filler composition 18 (not shown). Figure 4 further shows the structural element 10, the glass fiber sleeve 112, and the carbon fiber sleeve 114 each in a concentric configuration such that axes A, B, and C are aligned in the same direction.

[0098] Figure 5 shows a cross-sectional view of the composite structural element 20 exemplified in Figure 4. In particular, Figure 5 shows the structural element 10 disposed about the glass fiber sleeve 112, the glass fiber sleeve 112 disposed about the carbon fiber sleeve 114, and the carbon fiber sleeve 114 disposed about the core 118.

[0099] The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the present invention are possible in light of the above teachings. The invention may be practiced otherwise than as specifically described.

[00100] Likewise, it is also to be understood that the appended claims are not limited to express and particular compounds, compositions, or methods described in the detailed description, which may vary between particular embodiments that fall within the scope of the appended claims. With respect to any Markush groups relied upon herein for describing particular features or aspects of various embodiments, different, special, and/or unexpected results may be obtained from each member of the respective Markush group independent from all other Markush members. Each member of a Markush group may be relied upon individually and or in combination and provides adequate support for specific embodiments within the scope of the appended claims.

[00101] Further, any ranges and subranges relied upon in describing various embodiments of the present invention independently and collectively fall within the scope of the appended claims, and are understood to describe and contemplate all ranges including whole and/or fractional values therein, even if such values are not expressly written herein. One of skill in the art readily recognizes that the enumerated ranges and subranges sufficiently describe and enable various embodiments of the present invention, and such ranges and subranges may be further delineated into relevant halves, thirds, quarters, fifths, and so on. As just one example, a range "of from 0.1 to 0.9" may be further delineated into a lower third, i.e., from 0.1 to 0.3, a middle third, i.e., from 0.4 to 0.6, and an upper third, i.e., from 0.7 to 0.9, which individually and collectively are within the scope of the appended claims, and may be relied upon individually and/or collectively and provide adequate support for specific embodiments within the scope of the appended claims. In addition, with respect to the language which defines or modifies a range, such as "at least," "greater than," "less than," "no more than," and the like, it is to be understood that such language includes subranges and/or an upper or lower limit. As another example, a range of "at least 10" inherently includes a subrange of from at least 10 to 35, a subrange of from at least 10 to 25, a subrange of from 25 to 35, and so on, and each subrange may be relied upon individually and/or collectively and provides adequate support for specific embodiments within the scope of the appended claims. Finally, an individual number within a disclosed range may be relied upon and provides adequate support for specific embodiments within the scope of the appended claims. For example, a range "of from 1 to 9" includes various individual integers, such as 3, as well as individual numbers including a decimal point (or fraction), such as 4.1, which may be relied upon and provide adequate support for specific embodiments within the scope of the appended claims.