CA2913839A1 - Method and composition for structural reinforcement - Google Patents
Method and composition for structural reinforcement Download PDFInfo
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- CA2913839A1 CA2913839A1 CA2913839A CA2913839A CA2913839A1 CA 2913839 A1 CA2913839 A1 CA 2913839A1 CA 2913839 A CA2913839 A CA 2913839A CA 2913839 A CA2913839 A CA 2913839A CA 2913839 A1 CA2913839 A1 CA 2913839A1
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/24—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs
- C08J5/241—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs using inorganic fibres
- C08J5/244—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs using inorganic fibres using glass fibres
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/24—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs
- C08J5/241—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs using inorganic fibres
- C08J5/243—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs using inorganic fibres using carbon fibres
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2363/00—Characterised by the use of epoxy resins; Derivatives of epoxy resins
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- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
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Abstract
A method and composition is provided for structural reinforcement using fiber-reinforced polymers. Saturated fiber mesh is prepared in advance and stored in a frozen state, to control the rate at which the epoxy cures. In some embodiments, at least one layer of removable film is used to contain the epoxy within the saturated mesh during storage or transport. Film layers are then removed as required during the application of the saturated mesh to the object or structure to be reinforced. One or more layers can be built up on the structure to form a reinforcing shell of composite material. The invention extends to method of preparing and using the frozen saturated mesh, as well as the frozen saturated mesh itself.
Description
METHOD AND COMPOSITION FOR STRUCTURAL REINFORCEMENT
TECHNICAL FIELD
[0001] The present invention relates generally to the field of structural reinforcement. More specifically, the present invention relates to the use of composite materials, such as fiber-reinforced polymers, to form a layer on the interior or exterior of a physical object to be reinforced.
BACKGROUND
TECHNICAL FIELD
[0001] The present invention relates generally to the field of structural reinforcement. More specifically, the present invention relates to the use of composite materials, such as fiber-reinforced polymers, to form a layer on the interior or exterior of a physical object to be reinforced.
BACKGROUND
[0002] Fiber-reinforced polymers are composite materials comprising a polymer reinforced with fibers. The fibers are usually a glass, carbon, or aramid matrix, although other fibers such as paper or wood are sometimes used. In many cases the polymer is a thermoset cured resin.
[0003] Fiber-reinforced polymers have a number of uses, including the reinforcement of the interior or exterior surfaces of structures. Surface reinforcement can be particularly useful when retrofitting or refurbishing structures, to avoid or delay the replacement of costly components.
[0004] For example, carbon fiber reinforced polymers ("CFRPs") and/or glass fiber reinforced polymers (GFRPs) are used in some applications to refurbish and/or strengthen portions of buildings or other types of civil and commercial infrastructure. Some examples include: reservoirs, cisterns, storage tanks, pipes, silos, bridges, dams, manholes, sewer lines, culverts, parapets, beams, slabs, walls, columns, floors, decks, vaults, and various other structural elements. A
number of material types can be reinforced using CFRPs and/or GFRPs, including concrete, steel, stone, and brickwork.
number of material types can be reinforced using CFRPs and/or GFRPs, including concrete, steel, stone, and brickwork.
[0005] A conventional approach for CFRP / GFRP reinforcement, particularly when dealing with interior surfaces, is the 'wet layup' technique. In the wet layup technique, alternating layers of epoxy and saturated fiber mesh are built up on the surface of the structure to be reinforced, with each layer at least partially curing before the next layer is applied, often using a roller.
[0006] Other methods include winding, which is particularly useful for the exterior surfaces of elongate structures. In the winding technique, the surface is first coated with a partially cured epoxy layer and then one or more layers of glass or carbon fiber mesh is then wound over the surface of the object, often in long strips.
[0007] In either case, the use of epoxies introduces timing requirements that can make the CFRP / GFRP reinforcement process difficult to execute and potentially quite wasteful. The need to saturate or otherwise impregnate the mesh layers with epoxy at the work site may also create undue mess during the installation process. Failure to properly adhere the impregnated fiber mesh layers to the surface being reinforced or an underlying layer of the fiber reinforced polymer, can also slow down the installation process.
[0008] For example, it is not uncommon using either technique for the fiber mesh to be saturated at the work site, wound into rolls, and transported to the installation site, These saturated rolls must then be used before the epoxy fully cures, with under-cured meshes having the tendency to delaminate from the surface and over-cured meshes being unusable and therefore wasted. To minimize waste, workers must saturate the mesh in relatively small batches and the resulting variation from batch to batch can negatively impact quality control. The saturation and use of epoxy-saturated meshes at the job site can also be messy, the cleanup of which can add to the installation time, Exposure of workers to uncured epoxy may also require protective equipment or clothing.
SU M MARY OF THE INVENTION:
SU M MARY OF THE INVENTION:
[0009] In one broad aspect, the present invention is directed to a method of structural reinforcement in which saturated fiber mesh is prepared in advance and stored in a frozen state, to control the rate at which the epoxy cures. In some embodiments, freezing permits the fiber mesh layers to be saturated off site in larger batches and transported to the work site in refrigerated carriers, to permit greater quality control. In some cases, this may involve a period of storage.
Freezing may also allow the epoxy to be maintained at or near a desired level of curing and/or increase the overall tackiness of the epoxy, either of which may increase the adherence of the fiber mesh to an underlying surface or layer, thereby reducing delamination. The invention extends to methods of preparing, storing, and using the frozen saturated mesh as well as the frozen saturated mesh itself.
Freezing may also allow the epoxy to be maintained at or near a desired level of curing and/or increase the overall tackiness of the epoxy, either of which may increase the adherence of the fiber mesh to an underlying surface or layer, thereby reducing delamination. The invention extends to methods of preparing, storing, and using the frozen saturated mesh as well as the frozen saturated mesh itself.
[0010] In another broad aspect, the present invention is directed to a saturated fiber mesh having at least one removable film layer to contain the epoxy within the saturated fiber mesh during storage or transport. In embodiments where only one film layer is used, the saturated fiber mesh may be wound into rolls, preferably with the film layer facing outward. In preferred embodiments the saturated fiber is sandwiched between opposing film layers, to permit easier winding of the rolls and provide greater control over exposure of the saturated mesh to the working environment. In either case, freezing in accordance with the present invention may permit storage of the wound rolls for later use and to control the rate at which the epoxy in the mesh is permitted to cure. Film layers are then removed as required during the application of the saturated mesh to the object or structure to be reinforced.
BRIEF DESCRIPTION OF THE DRAWINGS
10011] FIG 1 is an illustration of a manufacturing and installation method according to an embodiment of the present invention.
[0012] FIG 2A is a perspective view of a saturated fiber mesh according to one embodiment of the present invention.
[0013] FIG 2B is a perspective view of a saturated fiber mesh according to another embodiment of the present invention.
[0014] FIG 3A is a perspective view of a saturated fiber mesh roll according to an embodiment of the present invention.
[0015] FIG 3B is a perspective view of saturated fiber mesh sheets according to an embodiment of the present invention.
[0016] FIG 4A is a perspective view of a saturated fiber mesh according to the present invention being applied to an elongate structure using the winding technique.
[0017] FIG 4B is a perspective view of a saturated fiber mesh according to the present invention being applied to a concave structure using the wet layup technique.
DETAILED DESCRIPTION
[0018] With reference to the above drawings, various examples will be now be disclosed which illustrate, by way of example only, various embodiments of the invention contemplated herein.
[0019] FIG 1 depicts a method of manufacturing and installing a saturated fiber mesh 100 on the surface of a structure 10 according to an embodiment of the present invention.
(0020] Manufacture begins by saturating a fiber layer 120 (See FIG 2) with an epoxy resin. The fiber layer 120 may be of various types known in the art, the choice of which depends on the application in question. Common forms include glass fibers, carbon fibers, and aramid fibers.
[0021] In the example embodiments disclosed herein, the fiber layer 120 comprises glass or carbon fiber fabrics, with glass fiber fabrics being woven from HYBON 2022 direct roving fiber glass (PPG Industries, Inc.) having a weight of between 200 g/m2 and 1600 g/m2 and carbon fiber fabrics being woven from UTS50' F24 24K 1600tex D continuous carbon fiber (Toho Tenax America, Inc.) having a weight between 300 g/m2 and 8500 g/m2. Other carbon fiber and glass fiber fabrics may also be used as appropriate for the application in question.
Hybrid materials may also be used in some situations that combine different types of fiber in a single layer. Other suitable forms of fiber known in the art are also contemplated, depending on the specific application.
[0022] The fiber layer 120 is saturated with an epoxy that forms a polymer matrix when cured. In the example embodiments disclosed herein, the epoxy is TCI-300-B (Cridel Thermoset Resins, Inc.), a two-component room temperature cured thermoset resin, which in this case was mixed at a ratio of 100% resin to 33% hardener. Various other suitable epoxies are known in the art and so the choice of epoxy depends on the specific application in question.
[0023] The epoxy resin which saturates the fiber layer 120 is allowed to partially cure, preferably until the epoxy becomes tacky and adherent, but still pliable. In some embodiments, the partial curing time was less than 7 hours at room temperature and preferably between 2-4 hours. The precise curing time may depend at least in part on the epoxy used and the conditions under which the curing takes place.
[00241 Film 110, 130 is then applied to one or both sides of the fiber layer 120. FIG 2A shows a saturated fiber mesh 100 according to one embodiment in which a layer of film 110, 130 is applied to two opposing surfaces of the fiber layer 120. FIG 28 shows an alternative embodiment in which film 110 is applied to only one side of the fiber layer 120.
[0025] The film 110, 130 may be made of various materials, which may in some cases depend on the epoxy used. In the example embodiments described herein, the film comprises low density polyethylene film. Persons of skill in the art may identify other suitable films depending on the application in question.
[0026] In some embodiments, the resulting saturated mesh 100 is then either formed into sheets 150 or wound into roils 140. Examples are depicted in FIGS 3A and 3B. For example, sheets 150 may be formed by using pre-cut fiber layers 120 or by cutting the saturated mesh 100 into defined shapes. In either case, the formation of sheets 150 or rolls 140 may in some circumstances provide for easier storage and/or transportation of the saturated fiber mesh 100.
[0027] The saturated fiber mesh 100 is then frozen to substantially arrest the curing process. In the present examples, a room-temperature epoxy was used and temperatures of between -5 C and -34 C, preferably -18 C were used to freeze the saturated fiber mesh 100. The exact temperature used during freezing may depend on the curing temperature and freezing point of the epoxy used.
[0028] The fiber mesh 100 may be stored in a frozen state for future use and/or transported to the work site in refrigerated carriers. In some embodiments the frozen fiber mesh 100 may be stored at temperatures of between -5 C and 34 C for 3-5 days, preferably at least 10 days. The maximum shelf life of the saturated fiber mesh 100 may depend on storage conditions and the epoxy used.
[0029] The ability to store or transport the fiber mesh 100 in a frozen state may ease the timing requirements otherwise imposed by the curing of the epoxy resin. In particular, the ability to manufacture saturated fiber mesh 100 in large batches in a controlled environment off-site may permit greater quality control and consistency during the saturation process. This may in turn result in greater quality control for the final cured fiber-reinforced polymer, by reducing inconsistencies along the surface of the structure 10 or between layers of the fiber-reinforced polymer. The ability to transport saturated fiber mesh 100 across substantial differences may also be of particular use in some applications, such as where workers are reinforcing structures 10 located in areas that are difficult to access, such as underground.
[0030] At the work site, the frozen fiber mesh 100 may be allowed to partially thaw to improve the tackiness and adherence of the partially cured epoxy. In some embodiments, the frozen fiber mesh 100 may be allowed to partially thaw at room temperature for 15-30 mins. Where sheets 150 or rolls 140 are used, thawing may be done before or after separating the sheets 150 or unrolling the rolls 140, as appropriate for the application.
[0031] Once the saturated fiber mesh 100 has reached a working temperature, it can be applied to the surface of the structure 10 to be reinforced.
In the present examples, the working temperature is around 4 C to 40 C.
[0032] In the embodiment shown in FIG 2A, the second layer of film 130 is peeled from one side of the saturated mesh 100, to expose the partially cured epoxy. In the embodiment shown in FIG 2B, one side of the saturated mesh 100 is already exposed. The use of a second layer of film 130, although not essential, is preferable in applications where it is desirable to minimize mess and/or exposure of the environment or personnel to the partially cured epoxy. This in turn may reduce the need for special suits or other protective equipment. The exposed epoxy of the saturated mesh 100 is then applied to the surface of the structure 10.
[0033] FIGS 4A and 4B illustrate the application of saturated fiber meshes 100 according to embodiments of the present invention to exemplary structures 10. FIG 4A depicts a winding technique, whereas FIG 4B depicts a wet layup technique. Other techniques are also known in the art. In either example, the saturated fiber mesh 100 is applied to the surface of the structure 10 and the epoxy is allowed to at least partially cure.
[0034] In some applications, the saturated mesh 100 is applied to the surface of the structure 10 using tension (e.g. for the winding technique) and/or pressure from a trowel or roller (e.g. for the wet layup technique). The presence of the first layer of film 110 aids the application process by providing a clean surface upon which to apply [0035] Once applied, the first layer of film 110 is removed to expose the opposing surface of the saturated mesh 100 to permit any additional layers to be added to the fiber-reinforced polymer. In some applications, the film 110 is removed after the epoxy is allowed to partially cure. For example, in some embodiments, a partial curing time of 12-96 hours, preferably 72 hours may be used.
[0036] The use of a first film layer 110 provides a clean surface upon which an installer can apply force during the application process using a roller, trowel, or the like. In the wet layup technique, the first film layer 11.0 also provides a barrier between the epoxy and the worker or environment that can remain in place while the epoxy is partially cured.
[0037] In some applications the surface of the structure 10 may be sandblasted and/or primed with an epoxy primer before the saturated fiber mesh 100 is applied. Depending on the application, multiple layers (e.g. 2-20) of saturated fiber mesh 100 may be built up, depending on the thickness required.
Changing the orientation of the fiber mesh 100 in successive layers and/or using different types of fiber in the various layers may also be used to create a fiber-reinforced polymer having certain desired characteristics for the particular application. In some cases, thickened epoxy may be applied between layers as appropriate for the application. A top coat of epoxy may be applied if a finished surface is desired.
[0038] A wide variety of structures 10 may be reinforced by the present method. For example, the structure 10 may be a structural element of a building or other type of commercial or civil infrastructure of the type described above (see:
Background). Reinforcement of smaller scale structures 10 is also contemplated, including components of smaller objects in need of reinforcement.
Examples:
A layer of HYBON 2022 direct roving fiber glass having a weight of XXXX g/m2 was saturated with TCI-300-B resin [100 parts resin to 33 parts hardener, room temperature] and allowed to cure at 20C for 4 hours. Thereafter, the product was stored in a freezer at -20C for 10 days and then placed in ambient conditions [20C1 for a period of 30 minutes. One of the plastic layers was removed, and the side of the product thus exposed was then applied to a surface that had been previously primed in a conventional manner. After 72 hours, the remaining layer of plastic was removed, and the joint was tested according to AWWA ASTM standards, resulting in a pull strength in excess of the 300 psi minimum.
[0039] The embodiments of the present disclosure are intended to be examples only. Those of skill in the art may affect alterations, modifications and variations to the particular embodiments without departing from the intended scope of the present disclosure.
(00401 In particular, features from one or more of the above-described embodiments may be selected to create alternate embodiments comprised of a - 10 ¨
subcombination of features which may not be explicitly described above. In addition, features from one or more of the above-described embodiments may be selected and combined to create alternate embodiments comprised of a combination of features which may not be explicitly described above. Features suitable for such combinations and subcombinations would be apparent to persons skilled in the art upon review of the present application as a whole. The subject matter described herein and in the recited claims intends to cover and embrace all suitable changes in technology.
BRIEF DESCRIPTION OF THE DRAWINGS
10011] FIG 1 is an illustration of a manufacturing and installation method according to an embodiment of the present invention.
[0012] FIG 2A is a perspective view of a saturated fiber mesh according to one embodiment of the present invention.
[0013] FIG 2B is a perspective view of a saturated fiber mesh according to another embodiment of the present invention.
[0014] FIG 3A is a perspective view of a saturated fiber mesh roll according to an embodiment of the present invention.
[0015] FIG 3B is a perspective view of saturated fiber mesh sheets according to an embodiment of the present invention.
[0016] FIG 4A is a perspective view of a saturated fiber mesh according to the present invention being applied to an elongate structure using the winding technique.
[0017] FIG 4B is a perspective view of a saturated fiber mesh according to the present invention being applied to a concave structure using the wet layup technique.
DETAILED DESCRIPTION
[0018] With reference to the above drawings, various examples will be now be disclosed which illustrate, by way of example only, various embodiments of the invention contemplated herein.
[0019] FIG 1 depicts a method of manufacturing and installing a saturated fiber mesh 100 on the surface of a structure 10 according to an embodiment of the present invention.
(0020] Manufacture begins by saturating a fiber layer 120 (See FIG 2) with an epoxy resin. The fiber layer 120 may be of various types known in the art, the choice of which depends on the application in question. Common forms include glass fibers, carbon fibers, and aramid fibers.
[0021] In the example embodiments disclosed herein, the fiber layer 120 comprises glass or carbon fiber fabrics, with glass fiber fabrics being woven from HYBON 2022 direct roving fiber glass (PPG Industries, Inc.) having a weight of between 200 g/m2 and 1600 g/m2 and carbon fiber fabrics being woven from UTS50' F24 24K 1600tex D continuous carbon fiber (Toho Tenax America, Inc.) having a weight between 300 g/m2 and 8500 g/m2. Other carbon fiber and glass fiber fabrics may also be used as appropriate for the application in question.
Hybrid materials may also be used in some situations that combine different types of fiber in a single layer. Other suitable forms of fiber known in the art are also contemplated, depending on the specific application.
[0022] The fiber layer 120 is saturated with an epoxy that forms a polymer matrix when cured. In the example embodiments disclosed herein, the epoxy is TCI-300-B (Cridel Thermoset Resins, Inc.), a two-component room temperature cured thermoset resin, which in this case was mixed at a ratio of 100% resin to 33% hardener. Various other suitable epoxies are known in the art and so the choice of epoxy depends on the specific application in question.
[0023] The epoxy resin which saturates the fiber layer 120 is allowed to partially cure, preferably until the epoxy becomes tacky and adherent, but still pliable. In some embodiments, the partial curing time was less than 7 hours at room temperature and preferably between 2-4 hours. The precise curing time may depend at least in part on the epoxy used and the conditions under which the curing takes place.
[00241 Film 110, 130 is then applied to one or both sides of the fiber layer 120. FIG 2A shows a saturated fiber mesh 100 according to one embodiment in which a layer of film 110, 130 is applied to two opposing surfaces of the fiber layer 120. FIG 28 shows an alternative embodiment in which film 110 is applied to only one side of the fiber layer 120.
[0025] The film 110, 130 may be made of various materials, which may in some cases depend on the epoxy used. In the example embodiments described herein, the film comprises low density polyethylene film. Persons of skill in the art may identify other suitable films depending on the application in question.
[0026] In some embodiments, the resulting saturated mesh 100 is then either formed into sheets 150 or wound into roils 140. Examples are depicted in FIGS 3A and 3B. For example, sheets 150 may be formed by using pre-cut fiber layers 120 or by cutting the saturated mesh 100 into defined shapes. In either case, the formation of sheets 150 or rolls 140 may in some circumstances provide for easier storage and/or transportation of the saturated fiber mesh 100.
[0027] The saturated fiber mesh 100 is then frozen to substantially arrest the curing process. In the present examples, a room-temperature epoxy was used and temperatures of between -5 C and -34 C, preferably -18 C were used to freeze the saturated fiber mesh 100. The exact temperature used during freezing may depend on the curing temperature and freezing point of the epoxy used.
[0028] The fiber mesh 100 may be stored in a frozen state for future use and/or transported to the work site in refrigerated carriers. In some embodiments the frozen fiber mesh 100 may be stored at temperatures of between -5 C and 34 C for 3-5 days, preferably at least 10 days. The maximum shelf life of the saturated fiber mesh 100 may depend on storage conditions and the epoxy used.
[0029] The ability to store or transport the fiber mesh 100 in a frozen state may ease the timing requirements otherwise imposed by the curing of the epoxy resin. In particular, the ability to manufacture saturated fiber mesh 100 in large batches in a controlled environment off-site may permit greater quality control and consistency during the saturation process. This may in turn result in greater quality control for the final cured fiber-reinforced polymer, by reducing inconsistencies along the surface of the structure 10 or between layers of the fiber-reinforced polymer. The ability to transport saturated fiber mesh 100 across substantial differences may also be of particular use in some applications, such as where workers are reinforcing structures 10 located in areas that are difficult to access, such as underground.
[0030] At the work site, the frozen fiber mesh 100 may be allowed to partially thaw to improve the tackiness and adherence of the partially cured epoxy. In some embodiments, the frozen fiber mesh 100 may be allowed to partially thaw at room temperature for 15-30 mins. Where sheets 150 or rolls 140 are used, thawing may be done before or after separating the sheets 150 or unrolling the rolls 140, as appropriate for the application.
[0031] Once the saturated fiber mesh 100 has reached a working temperature, it can be applied to the surface of the structure 10 to be reinforced.
In the present examples, the working temperature is around 4 C to 40 C.
[0032] In the embodiment shown in FIG 2A, the second layer of film 130 is peeled from one side of the saturated mesh 100, to expose the partially cured epoxy. In the embodiment shown in FIG 2B, one side of the saturated mesh 100 is already exposed. The use of a second layer of film 130, although not essential, is preferable in applications where it is desirable to minimize mess and/or exposure of the environment or personnel to the partially cured epoxy. This in turn may reduce the need for special suits or other protective equipment. The exposed epoxy of the saturated mesh 100 is then applied to the surface of the structure 10.
[0033] FIGS 4A and 4B illustrate the application of saturated fiber meshes 100 according to embodiments of the present invention to exemplary structures 10. FIG 4A depicts a winding technique, whereas FIG 4B depicts a wet layup technique. Other techniques are also known in the art. In either example, the saturated fiber mesh 100 is applied to the surface of the structure 10 and the epoxy is allowed to at least partially cure.
[0034] In some applications, the saturated mesh 100 is applied to the surface of the structure 10 using tension (e.g. for the winding technique) and/or pressure from a trowel or roller (e.g. for the wet layup technique). The presence of the first layer of film 110 aids the application process by providing a clean surface upon which to apply [0035] Once applied, the first layer of film 110 is removed to expose the opposing surface of the saturated mesh 100 to permit any additional layers to be added to the fiber-reinforced polymer. In some applications, the film 110 is removed after the epoxy is allowed to partially cure. For example, in some embodiments, a partial curing time of 12-96 hours, preferably 72 hours may be used.
[0036] The use of a first film layer 110 provides a clean surface upon which an installer can apply force during the application process using a roller, trowel, or the like. In the wet layup technique, the first film layer 11.0 also provides a barrier between the epoxy and the worker or environment that can remain in place while the epoxy is partially cured.
[0037] In some applications the surface of the structure 10 may be sandblasted and/or primed with an epoxy primer before the saturated fiber mesh 100 is applied. Depending on the application, multiple layers (e.g. 2-20) of saturated fiber mesh 100 may be built up, depending on the thickness required.
Changing the orientation of the fiber mesh 100 in successive layers and/or using different types of fiber in the various layers may also be used to create a fiber-reinforced polymer having certain desired characteristics for the particular application. In some cases, thickened epoxy may be applied between layers as appropriate for the application. A top coat of epoxy may be applied if a finished surface is desired.
[0038] A wide variety of structures 10 may be reinforced by the present method. For example, the structure 10 may be a structural element of a building or other type of commercial or civil infrastructure of the type described above (see:
Background). Reinforcement of smaller scale structures 10 is also contemplated, including components of smaller objects in need of reinforcement.
Examples:
A layer of HYBON 2022 direct roving fiber glass having a weight of XXXX g/m2 was saturated with TCI-300-B resin [100 parts resin to 33 parts hardener, room temperature] and allowed to cure at 20C for 4 hours. Thereafter, the product was stored in a freezer at -20C for 10 days and then placed in ambient conditions [20C1 for a period of 30 minutes. One of the plastic layers was removed, and the side of the product thus exposed was then applied to a surface that had been previously primed in a conventional manner. After 72 hours, the remaining layer of plastic was removed, and the joint was tested according to AWWA ASTM standards, resulting in a pull strength in excess of the 300 psi minimum.
[0039] The embodiments of the present disclosure are intended to be examples only. Those of skill in the art may affect alterations, modifications and variations to the particular embodiments without departing from the intended scope of the present disclosure.
(00401 In particular, features from one or more of the above-described embodiments may be selected to create alternate embodiments comprised of a - 10 ¨
subcombination of features which may not be explicitly described above. In addition, features from one or more of the above-described embodiments may be selected and combined to create alternate embodiments comprised of a combination of features which may not be explicitly described above. Features suitable for such combinations and subcombinations would be apparent to persons skilled in the art upon review of the present application as a whole. The subject matter described herein and in the recited claims intends to cover and embrace all suitable changes in technology.
Claims (34)
1. A method of reinforcing a surface of a structure using fiber-reinforced polymers, the method comprising:
saturating a fiber mesh in epoxy;
partially curing the epoxy;
applying a first layer of film to a first surface of the saturated fiber mesh;
freezing the saturated mesh to slow and/or stop the curing of the epoxy;
storing or transporting the frozen saturated mesh;
warming the frozen saturated mesh to reactivate the epoxy;
applying the saturated mesh to the surface of the structure;
substantially curing the epoxy;
removing the first layer of film; and applying the saturated fiber mesh to the surface of the structure.
saturating a fiber mesh in epoxy;
partially curing the epoxy;
applying a first layer of film to a first surface of the saturated fiber mesh;
freezing the saturated mesh to slow and/or stop the curing of the epoxy;
storing or transporting the frozen saturated mesh;
warming the frozen saturated mesh to reactivate the epoxy;
applying the saturated mesh to the surface of the structure;
substantially curing the epoxy;
removing the first layer of film; and applying the saturated fiber mesh to the surface of the structure.
2. The method of claim 1, further comprising applying a second layer of film to a second surface of the saturated fiber mesh, opposing the first surface of the saturated fiber mesh, prior to freezing.
3. The method of claim 1 or claim 2, wherein the film is low density polyethylene film or polyvinyl chloride.
4. The method of any one of claims 1 to 3, wherein the epoxy is a two-component room-temperature cured thermoset resin.
5. The method of any one of claims 1 to 4, wherein the step of partially curing the epoxy is carried out in less than 7 hours and preferably between 2-4 hours.
6. The method of any one of claims 1 to 5, wherein the fiber mesh is a glass fiber fabric.
7. The method of claim 6, wherein the glass fiber fabric has a minimum weight of 200 g/m2 and a maximum weight of 1600 g/m2.
8. The method of claim 6 or claim 7, wherein the glass fiber fabric is applied to the surface of the structure in 1-2 layers.
9. The method of any one of claims 1 to 8, wherein the fiber mesh is a carbon fiber fabric.
10. The method of claim 9, wherein the carbon fiber fabric has a minimum weight of 300 g/m2 and a maximum weight of 8500 g/m2.
11. The method of claim 9 or claim 10, wherein the carbon fiber fabric is applied to the surface of the structure in 1-10 layers.
12. The method of any one of claims 1 to 11, further comprising winding the saturated fiber mesh into a roll, prior to freezing.
13. The method of any one of claims 1 to 12, further comprising forming the fiber mesh into sheets, prior to freezing.
14. The method of any one of claims 1 to 13, wherein the freezing is to a temperature between -5°C and -34°C, preferably -18°C.
15. The method of any one of claims 1 to 14, wherein the freezing substantially arrests curing of the epoxy.
16. The method of any one of claims 1 to 15, wherein the storing or transporting is at a temperature between -5°C and -34°C.
17. The method of any one of claims 1 to 16, wherein the frozen saturated mesh is stored for at least 3-5 days, preferably at least 10 days.
18. The method of any one of claims 1 to 17, wherein the step of warming is carried out at room temperature for 15-30 minutes.
19. The method of any one of claims 1 to 18, further comprising applying an epoxy primer to the surface of the structure and at least partially curing the primer, prior to applying the saturated mesh to the surface of the structure.
20. The method of any one of claims 1 to 19, further comprising allowing the saturated mesh to further cure for 12-96 hours, preferably 72 hours, after applying the saturated mesh to the surface.
21. The method of any one of claims 1 to 20, further comprising applying a thickened epoxy coating to the saturated mesh, after applying the saturated mesh to the surface.
22. The method of claim 21, wherein a further layer of partially frozen saturated mesh is applied to the thickened epoxy coating,
23. The method of claim 22, wherein the further layer of partially frozen saturated mesh comprises a different type of fiber mesh.
24. A method of manufacturing epoxy-saturated fiber mesh for use in fiber-reinforced polymers, the method comprising:
saturating a fiber mesh in epoxy;
partially curing the epoxy for 2-4 hours; and freezing the saturated mesh to slow and/or stop the curing of the epoxy.
saturating a fiber mesh in epoxy;
partially curing the epoxy for 2-4 hours; and freezing the saturated mesh to slow and/or stop the curing of the epoxy.
25. The method according to claim 24, further comprising applying a first layer of film to a first surface of the saturated fiber mesh, prior to freezing.
26. The method of claim 24 or claim 25, wherein, after freezing, the frozen epoxy-saturated fiber mesh is stored or transported.
27. A method of reinforcing a surface of a structure using a fiber-reinforced polymer, the method comprising:
providing a fiber mesh saturated in epoxy, the saturated fiber mesh being stored or transported in a frozen state;
warming the frozen saturated mesh to reactivate the epoxy;
applying the saturated mesh to the surface of the structure;
substantially curing the epoxy;
removing the first layer of film; and applying the saturated fiber mesh to the surface of the structure.
providing a fiber mesh saturated in epoxy, the saturated fiber mesh being stored or transported in a frozen state;
warming the frozen saturated mesh to reactivate the epoxy;
applying the saturated mesh to the surface of the structure;
substantially curing the epoxy;
removing the first layer of film; and applying the saturated fiber mesh to the surface of the structure.
28. An epoxy-saturated fiber mesh for use in fiber-reinforced polymers, the saturated mesh comprising:
a fiber mesh;
an epoxy impregnated in the fiber mesh;
a first layer of film applied to a first surface of the fiber mesh;
wherein the expoy-saturated fiber mesh is stored or transported in a frozen state.
a fiber mesh;
an epoxy impregnated in the fiber mesh;
a first layer of film applied to a first surface of the fiber mesh;
wherein the expoy-saturated fiber mesh is stored or transported in a frozen state.
29. The saturated fiber mesh of claim 28, further comprising a second layer of film applied to a second opposing surface of the fiber mesh.
30. A product comprising:
a web;
an epoxy impregnated in the web, the epoxy being in a temperature condition at which curing is inhibited or arrested; and a layer of film applied to one of the sides of the web.
a web;
an epoxy impregnated in the web, the epoxy being in a temperature condition at which curing is inhibited or arrested; and a layer of film applied to one of the sides of the web.
31. A product according to claim 30, wherein the epoxy is partially cured.
32. A product according to claim 30 or 31, further comprising a layer of film applied to the other of the sides of the web.
33. A method, for use of the product of any one of claims 30 to 32, for reinforcing a surface of a structure, the method comprising:
removing the temperature condition which inhibited or arrested curing of the epoxy;
pressing the web against the surface of the structure;
allowing the epoxy to cure; and removing the layer of film.
removing the temperature condition which inhibited or arrested curing of the epoxy;
pressing the web against the surface of the structure;
allowing the epoxy to cure; and removing the layer of film.
34. A method for use of the product of claim 33 for reinforcing a surface of a structure, the method comprising:
removing the temperature condition which inhibited or arrested curing of the epoxy;
removing one of the layers of film;
pressing the surface from which the one layer of film has been removed against the surface of the structure;
allowing the epoxy to cure; and removing the other layer of film.
removing the temperature condition which inhibited or arrested curing of the epoxy;
removing one of the layers of film;
pressing the surface from which the one layer of film has been removed against the surface of the structure;
allowing the epoxy to cure; and removing the other layer of film.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA2913839A CA2913839A1 (en) | 2015-12-03 | 2015-12-03 | Method and composition for structural reinforcement |
| PCT/CA2016/051418 WO2017091904A1 (en) | 2015-12-03 | 2016-12-02 | Methods and composition for structural reinforcement |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA2913839A CA2913839A1 (en) | 2015-12-03 | 2015-12-03 | Method and composition for structural reinforcement |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2913839A1 true CA2913839A1 (en) | 2017-06-03 |
Family
ID=58794281
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2913839A Abandoned CA2913839A1 (en) | 2015-12-03 | 2015-12-03 | Method and composition for structural reinforcement |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA2913839A1 (en) |
| WO (1) | WO2017091904A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11014327B2 (en) * | 2017-12-20 | 2021-05-25 | Palo Alto Research Center Incorporated | Materials and method for joining fiber reinforced pipeline |
| EP3590690B1 (en) | 2018-07-04 | 2020-12-23 | ABB Power Grids Switzerland AG | Fibre reinforced polymer tube |
| WO2023064552A1 (en) * | 2021-10-15 | 2023-04-20 | Pipeline Coatings System Llc | Pipeline repair epoxy composites, methods, and applications |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102011082192B4 (en) * | 2011-09-06 | 2022-10-06 | Bayerische Motoren Werke Aktiengesellschaft | Process and device for producing prepregs from winding processes |
| ES2738178T3 (en) * | 2013-08-22 | 2020-01-20 | Cytec Ind Inc | Union of composite materials |
-
2015
- 2015-12-03 CA CA2913839A patent/CA2913839A1/en not_active Abandoned
-
2016
- 2016-12-02 WO PCT/CA2016/051418 patent/WO2017091904A1/en active Application Filing
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| Publication number | Publication date |
|---|---|
| WO2017091904A1 (en) | 2017-06-08 |
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| FZDE | Discontinued |
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