The present invention is directed to surface reinforcement systems, more particularly to road surface reinforcement systems, and even more particularly to road surface reinforcement systems that include the use of a reinforced fiber mat. The present invention is particularly applicable for use with paved surfaces such as, but not limited to, roads, parking lots, sidewalks, jogging and bike paths, etc. The present invention includes the use of reinforced fiber mats to provide increased benefit to the asphalt paved surface.
Asphalt paved surfaces are typically constructed of one or more layers of asphalt paving material placed over a graded stone sub base. The strength and durability of the paved surface is extremely dependent on the stability of the sub base material as the asphalt paving does not have the rigidity and stiffness to span over very large areas of softness or voids. This inherent flexibility, while at times a positive, is most of the time a detriment. Slight amounts of movement in the sub base allow for cracks to form in the asphalt paving surface.
Due to the effects of weather, traffic and other environmental issues, the paved surface begins to flex more than it can withstand and cracks begin to develop in the asphalt surface. These cracks then allow water to penetrate the asphalt paving and cause further deterioration through freeze thaw and the development of hydraulic pressure as vehicular traffic passes over it. These mechanisms result in a shortened life time of the asphalt paving.
The fact that the asphalt paving is typically placed over either an existing concrete or previously paved surface results in another mode of failure due to lack of adhesion to the substrate. Typically a “tack coat” of a hot or cold applied asphaltic emulsion is sprayed onto the existing layer. The hot asphalt is then laid down over this sticky liquid layer. The result is a bond between the new asphalt layer and the existing substrate that is generally very weak. Traffic, thermal expansion and contraction as well as differential bending of the layers induce significant shear loads at the bond line. These bond line failures exacerbate the cracking failures and further shorten the paving life span of the asphalt paving.
The typical way of repairing this damaged asphalt is to apply an additional layer of asphalt paving over the existing asphalt layer that is cracking or failing. Alternatively, a “pot hole” is often just filled in with a new layer of asphalt paving. Since neither of these methodologies fixes the underlying cause of the failure, the pavement often fails directly over the existing cracks or bad area. Over the years, many ways have been tried to address these inadequacies in asphalt paving.
One method attempted is to reinforce the pavement itself This method has been done through various combinations of chemical additives and alternate filler materials. The use of fibers added directly to the asphalt paving matrix has been tried both as fibers and as woven glass fabric as far back as 1938 as described in U.S. Pat. No. 2,115,667, which is incorporated herein by reference. This method for reinforcing the asphalt paving did not prove very successful as the woven mat trapped the water in the paving. In general, due to the physical properties of the asphalt paving, the ability to reinforce the asphalt paving has been of limited commercial success.
Another method that has been used to reinforce asphalt paving involves the use of a geo-textile material that is placed between the asphalt paving and the subsurface material (stone, soil or existing asphalt paving). These geo-textiles are comprised of various layers of woven and nonwoven polypropylene. The polypropylene is very efficient at wicking water away from the layer of asphalt paving and provides some reinforcement and limited crack bridging abilities. The Mirapave 400 material described in U.S. Pat. No. 7,207,744 embodies this approach. Because the asphalt paving is applied at temperatures above 300° F., the polypropylene melts and bonds to the asphalt as it cools. Unfortunately, the polypropylene mat tends to melt and/or shrink when it is exposed to the hot paving material, which detracts from its ability to provide reinforcement and waterproofing. This problem has been overcome by some manufacturers by adding a layer of glass reinforcing to the polypropylene mat. The glass reinforcing has been utilized in various configurations including mats, fabrics and individual strands both alone and in combination with the polypropylene mat. U.S. Pat. No. 6,648,547, which is incorporated by reference, illustrates and discloses one example of these reinforcement mats. The material used in the reinforcement mat is still susceptible to shrinkage upon cooling and slippage during application. Additionally, these fiber reinforced polypropylene mats add no structural capacity to the asphalt paving.
U.S. Pat. No. 6,235,136, which is incorporated by reference, discloses a water-resistant mastic membrane. The membrane comprises a carrier layer and a grid of glass fibers, both embedded in molten mastic material which then cools and forms a solid membrane. The membrane is bulky, having a thickness of 50 mm to 150 mm, and consists primarily of mastic material. The mastic becomes molten from the heat of the asphalt and melts away during application of the asphalt and helps bond the mat to the asphalt paving. The mat in this instance still is flexible and does not offer significant support after installation.
What becomes clear to one versed in the art is the need for a mat that can be used to reinforce asphalt pavement that encompasses all of the best attributes of the current art.
The present invention relates to a reinforcement mat that can be used with a paved surface to provide structural support to the paved surface, which can facilitate in forming a strong bond between the paved surface and the sub base, and which wicks water from the paved surface.
In one non-limiting aspect of the present invention, the reinforcement mat of the present invention includes a grid of fibers. Many different types of materials that can be used to form the fibers can be used to form the reinforcement mat. The reinforcement mat can be formed of the same or different compositional type of fibers. The fibers in the reinforcement mat can have the same or differently sized and/or shaped cross-sectional area. The fibers in the reinforcement mat can have the same or different color. In one non-limiting embodiment of the invention, the fibers can include materials such as, but not limited to, glass fibers (e.g., silica glass, aramid glass, etc.), carbon fibers, quartz fibers, Kevlar® fibers, boron fibers, polyethylene fibers, polyamide fibers, polypropylene fibers, etc. The fibers can be formed of a single material or be a hybrid of one or more materials. In another and/or additional non-limiting embodiment of the invention, a majority of the fibers in the reinforcement mat are non-woven fibers. In still another and/or additional non-limiting embodiment of the invention, a majority of the fibers in the reinforcement mat are woven fibers such as, but not limited to a roving of fibers. In yet another and/or additional non-limiting embodiment of the invention, several sets of fibers are oriented together and then at least partially secured in position relative to one another to form the reinforcement mat. In one non-limiting aspect of this embodiment, the reinforcement mat if formed of at least two layers of fiber material. Each layer of fiber material is formed of a plurality of fibers or a plurality of sets of fibers. The shape, size, color and/or composition of the fibers or the fibers in each set of fibers of each layer of fiber material can be the same or different. In one non-limiting design, the shape, size and composition of a majority of the fibers or the fibers in each set of fibers of each layer of fiber material are substantially the same. In another and/or additional non-limiting design, a majority of the fibers or the fibers in each set of fibers of each layer of fiber material are non-woven fibers (e.g., laid fibers, etc.). In still another and/or additional non-limiting design, a majority of the fibers or the fibers in each set of fibers of each layer of fiber material are woven fibers. In yet another and/or additional non-limiting design, at least a portion of the fibers or the fibers in each set of fibers of each layer of fiber material are non-woven fibers and at least a portion of the fibers are non-woven fibers. For instance, the core of a set of fibers could be woven or non-woven fibers and the outer region of the set of fibers could be formed of non-woven or woven fibers.
The reinforcement mat includes at least two layers of fiber material wherein at least one layer of fiber material includes a plurality of fibers or a plurality of fiber sets that are laid in a generally parallel relationship to one another. The at least one layer of fiber material can be formed from a plurality of fibers or fiber sets wherein the plurality of fiber or fibers sets are spaced next to one another, overlap one another, or are spaced apart from one another. When the at least one layer of fiber material is formed by a plurality of fiber sets, each fiber set generally has the same number of fibers; however, this is not required. The number of fibers in a fiber set generally is about 2-500000, and typically about 5-10000, and more typically about 10-1000; however, other numbers of fibers in a fiber set can be used. Typically the fiber set includes a plurality of layers of fibers; however, this is not required. The thickness of at least one fiber set is generally at least about 0.05 mm, and typically at least about 0.1 mm; however, other thicknesses can be used. The width of a fiber set is generally greater than the thickness of the fiber set; however, this is not required. Typically the width of at least one fiber set is at least about 0.5 mm, and more typically at least about 1 mm; however, other widths can be used. As can be appreciated, when one or more of the layers of fiber material are formed of fibers, the fibers can have the same or difference sizes as the fabric sets as described above. When a plurality of fibers or fiber sets are spaced apart from one another, the fibers or fiber sets are spaced at generally the same distance apart from one another; however, this is not required. Each fiber or set of fibers is generally formed of the same material; however, this is not required. As can be appreciated, each fiber or set of fibers can be formed of the same type of material or the same mixture of materials, however, this is not required.
The reinforcement mat includes at least layers of fiber material. At least two of the layers of fiber material are laid in a non-parallel relationship to one another. The fibers in each layers of fiber material can be the same or different material. Each layer of fiber material can have the same number of fibers or fiber sets; however, this is not required. When two or more layers of fiber material are positioned in a non-parallel relationship to one another, one layer of fiber material has an angular orientation to another layer of fiber material of about 10-90°. In one non-limiting design of this aspect, the one layer of fiber material is laid at least partially on another layer of fiber material so as to form an angular orientation that is generally perpendicular. As can be appreciated, more than two layers of fiber material can be used to form the reinforced fabric. These layers of fiber material can be positioned parallel or non-parallel to one another. For instance, when the reinforcement mat is formed of three layers of fiber material, none of the layers of fiber material are positioned parallel to one another. In one non limiting orientation of three layers of fiber material, the first and second layers of fiber material are oriented 70-90° to one another and the third layers of fiber material is oriented at about 20-60° relative to the first and second layers of fiber material. As can be appreciated, many other orientations of the three layers of fiber material can be used. As can also be appreciated, more than three layers of fiber material can be used to form the reinforcement mat.
The reinforcement mat is formed by a plurality of fiber or fiber sets that are at least partially held together and at least partially held in position by one or more stitched or knitted threads, woven together, and/or by a melted bond. As defined hereinafter, any reference to “stitch”, “stitching” or “stitched” will broadly refer to any type of stitching, knitting, knotting, and/or crocheting technique. The one or more threads, when used, are used to at least partially maintain the relative position of the fiber sets in one or more layers of fiber material and are looped about one or more fiber sets such that a portion of the thread forms a substantially closed loop about one or more fiber sets. The intersecting portion of the thread can be least partially fused together by radiation and/or heat; however, this is not required. In one non-limiting embodiment, the fibers or fibers sets of a layer of fabric material are at least partially held together by stitching and/or by being woven together. In another non-limiting embodiment, a plurality of layers of fiber material are at least partially held together by stitching, adhesive, melted bond and/or by being woven together.
In another non-limiting aspect of the present invention, the reinforcement mat can be partially or fully impregnated with one or more coatings of a polymer material to form a reinforced composite material. Many types of polymer coatings can be used to at least partially impregnate the reinforcement mat. Such polymer coatings include, but are not limited to, bitumen, asphalt, tar, various types of resins, various types of resin epoxies, polyester, polypropylene, polyethylene, polyurethane, polyacrylate, and copolymers thereof. The one or more polymer coatings can be used to partially or fully impregnate all or only a portion of the reinforcement mat. The one or more polymer coatings are typically applied to the reinforcement mat by a dipping process and/or a spray coating process; however, other or additional coating processes can be used. In one non-limiting embodiment of the present invention, the reinforcement mat is partially or fully saturated or pre-impregnated with a coating that is fully or partially formed of a catalyzed resin (e.g., epoxy resin, etc.). The fibers or fiber sets used in the reinforced mat generally include glass fibers, carbon fibers, aramid fibers and some combination thereof. As can be appreciated, other or additional fibers can be used. The resin impregnated mat is generally flexible and can easily be rolled for storage and transport and then unrolled and applied to a substrate such as existing paving. The coating on the reinforcement mat can be limited to the fibers or can for a continuous layer on the reinforcement mat. In one non-limiting design, the coating on the reinforcement mat is limited to the fibers on the reinforcement mat such that a continuous layer of coating is included on the reinforcement mat after the coating is applied to the fibers of the reinforcement mat. The application of the coated reinforcement mat of the present invention to existing paving can be easier than other types of mats in that the reinforcement mat of the present invention is less prone to bunching up and blowing around when being applied to the existing paving. Additionally, the pre-impregnated reinforcement mat has an inherent tackiness to it which allows it to adhere to existing substrates without the use of liquid mastic, thus resulting in less mess and manpower during the initial laying of the reinforcement mat onto a pavement.
In still another non-limiting aspect of the present invention, the coating that can be applied to the fibers in the reinforcement mat generally includes a resin (e.g., epoxy resin, etc.) that typically has a cure temperature in excess of about 140° F. and up to about 400° F. When the reinforcement mat of the present invention is applied over an existing sub base, the reinforcement mat is generally flexible and provides reinforcement to the asphalt or bitumen material paving that is subsequently applied to the top of the reinforcement mat. Once the reinforcement mat is applied to a sub base, a layer of hot asphalt or bitumen material paving is then applied over the reinforcement mat. The manner in which the asphalt or bitumen material paving is applied over the reinforcement mat of the present invention can be the same or similar as the manner in which the asphalt paving is applied over prior art mats. The combination of the heat of the asphalt or bitumen material paving and the pressure from the rollers as the asphalt or bitumen material is applied to the top of the reinforcement mat causes the pre-impregnated resin (e.g., epoxy resin, etc.) to a) become less viscous and flow into the asphalt, bitumen material, bitumen material-concrete matrix, or asphalt-concrete matrix to facilitate in the bonding of the reinforcement mat to the asphalt, bitumen material, bitumen material-concrete matrix, or asphalt-concrete matrix that is being applied to the top of the reinforcement mat, b) saturate the fibers of the fiber reinforcement mat and/or c) facilitate in the bonding of the reinforcement mat to the sub base. At the same time that heat and pressure is being applied to the reinforcement mat of the present invention, the cure cycle of the epoxy is initiated and thereafter is quickly completed. The result of the flowing and curing of the resin in the reinforcement mat of the present invention creates a structural reinforcement that is fully bonded to the asphalt or bitumen material paving and the sub base. The use of the reinforcement mat of the present invention can add significant structural and life cycle properties to the asphalt or bitumen material paving.
In yet another non-limiting aspect of the present invention, the thickness of the coating on the fibers or fiber sets of the reinforcement mat is generally at least about 0.05 mm thick and up to about 50 mm; however, other thicknesses can be used. The ratio of the thickness of the coating (e.g., resin, etc.) to the thickness of the fibers or fiber sets of the reinforcement mat is generally about 0.1-50:1, typically about 0.2-25:1, more typically about 0.25-10:1, and yet more typically about 0.3-5:1. In one non-limiting design the thickness of the resin is greater than the thickness of the fibers or fiber sets of the reinforcement mat. In another non-limiting design the thickness of the resin is less than the thickness of the fibers or fiber sets of the reinforcement mat.
In still yet another non-limiting aspect of the present invention, the fibers or the fibers that form the fiber sets that can be used in the reinforcement mat of the present invention include carbon, aramid or basalt, glass, etc.
In another non-limiting aspect of the present invention, the reinforcement mat of the present invention can be fabricated using any methodology including weaving or adhesive bonding and/or stitching.
In still another non-limiting aspect of the present invention, the spacing of the tows in the reinforcement mat of the present invention can be any distance. Generally the spacing is about 0.2 inches to about 4 inches, depending on the final application.
In yet another non-limiting aspect of the present invention, the reinforcement mat of the present invention can be fabricated with the fiber tows (i.e., fibers or fiber sets) oriented in the 0°, the 90° direction, any angle from 0° to 180° or any combination of those angles. In one non-limiting embodiment, the reinforcement mat of the present invention has fiber tows oriented 90° relative to adjacently positioned tows.
In still yet another non-limiting aspect of the present invention, the reinforcement mat of the present invention can include one or more layers of nonwoven material that is applied as a backing. The layer of nonwoven material can have a generally uniform thickness along the longitudinal length of the nonwoven material; however, this is not required. The layer of nonwoven material can be connected to the fibers or fibers sets of the reinforcement mat by stitching, adhesive bonding, melted or fused connection, use of one or more coatings, etc. The nonwoven material can have a melting point that is less than the melting point of the fibers or fibers set; however, this is not required. In one non-limiting aspect of this embodiment, the nonwoven material is formed of a polymer material that includes a material such as, but not limited to, nylon, polyester, polypropylene, polyethylene, polyurethane, poly(meth)acrylate, etc. In another and/or additional non-limiting embodiment of the invention, the nonwoven material is formed of a plurality of materials.
In another non-limiting aspect of the present invention, the resin can be any thermo-set or thermoplastic including epoxy, polyester, vinyl ester and PEET. In one non-limiting embodiment, the resin is an epoxy resin.
In still another non-limiting aspect of the present invention, the resin can be pre-applied to the fibers or fibers sets of the reinforcement mat prior to construction of the complete alignment and connection of the fibers or fibers sets or after the complete alignment and connection of the fibers or fibers sets. In one non-limiting embodiment, the resin is applied after complete alignment and connection of the fibers or fibers sets. The resin can be applied to the fibers or fibers sets in liquid and/or powder form. In one non-limiting embodiment, the resin is applied to the fibers or fibers sets in liquid form. The resin can be applied to the fibers or fibers sets either un-catalyzed or catalyzed. In one non-limiting embodiment, the resin is a pre-catalyzed resin when applied to the fibers or fibers sets.
It is one non-limiting object of the present invention to provide an improved reinforcement mat for the repair of pavement.
It is another non-limiting object of the present invention to provide an improved reinforcement mat that includes a fiber mat and a resin coating.
It is still another non-limiting object of the present invention to provide an improved reinforcement mat that includes a fiber mat and a pre-catalyzed resin coating.
It is yet another non-limiting object of the present invention to provide an improved reinforcement mat that includes a fiber mat and a resin coating and a non-woven backing.
These and other advantages will become apparent to those skilled in the art upon the reading and following of this description taken together with the accompanying drawings.
Reference may now be made to the drawings, which illustrates non-limiting embodiments that the invention may take in physical form and in certain parts and arrangements of parts wherein:
Referring now to the drawings wherein the showing is for the purpose of illustrating a non-limiting embodiment of the invention only and not for the purpose of limiting the same,
Referring now to
A first fiber layer 20 includes a plurality of fibers or fiber sets 22 that are spaced apart a distance W1. The spacing of the plurality of fibers or fiber sets 22 can be constant or vary over the width of the first fiber layer 20. Generally the spacing of the plurality of fibers or fiber sets 22 is generally constant over the width of the first fiber layer 20. Distance W1 is generally about 0.1-10 inches, typically 0.25-6 inches, and more typically about 0.4-4 inches; however, other distances can be used. The total width of which is generally the width of the reinforcement mat, and such width can be about 0.1-100 ft., typically 0.5-50 ft., and more typically about 2-20 ft.; however, other total widths of the reinforcement mat can be used. The plurality of fibers or fiber sets 22 is generally arranged parallel to one another; however, this is not required. The plurality of fibers or fiber sets 22 run along the longitudinal length of the reinforcement mat and are generally equal to the longitudinal length of the reinforcement mat. The longitudinal length of the reinforcement mat is non-limiting, (e.g., 1-5000 ft., etc.). The first fiber layer 20 can be formed of a plurality of fibers and/or a plurality of fiber sets 22. For instance, fiber 22 can be formed of a single fiber. Alternatively, the fiber set can be formed of a plurality of fibers. Generally, the fibers that form the fiber set are connected together by stitching, adhesive, twisting together, etc.; however, this is not required. The fibers and/or the fibers in the fibers sets that are used in the first fiber layer 20 can be formed of the same or different material. The number of fibers that form a plurality of fiber sets can be the same or different. The number of fibers that form a plurality of fiber sets is non-limiting. The thickness of the fibers or the fibers included in a fiber set or a plurality of fiber sets can be the same or different. The thickness of a plurality of fibers sets can be the same or different. The thickness of the fibers or the fibers that form a fiber set is non-limiting. The shape of the fibers or the fibers included in a fiber set or a plurality of fiber sets can be the same or different. The color of fibers or the fibers included in a fiber set or a plurality of fiber sets can be the same or different. The strength and/or other physical properties (e.g., melting temperature, flexibility, etc.) of the fibers or the fibers included in a fiber set or a plurality of fiber sets can be the same or different. Generally, the plurality of fibers or fiber sets 22 are formed from glass fibers, carbon fibers, basalt fibers and/or aramid fibers.
A second fiber layer 30 includes a plurality of fibers or fiber sets 32 that are spaced apart a distance W2. The spacing of the plurality of fibers or fiber sets 32 can be constant or vary over the width of the second fiber layer 30. Generally the spacing of the plurality of fibers or fiber sets 32 is generally constant over the width of the second fiber layer 30. Distance W2 is generally about 0.1-10 inches, typically 0.25-6 inches, and more typically about 0.4-4 inches; however, other distances can be used. The total width is generally the longitudinal length of the reinforcement mat, and such width is non-limiting. The plurality of fibers or fiber sets 32 is generally arranged parallel to one another; however, this is not required. The plurality of fibers or fiber sets 32 run along the width of the reinforcement mat and are generally equal to the width of the reinforcement mat. The second fiber layer 30 can be formed of a plurality of fibers and/or a plurality of fiber sets 32. For instance, fiber 32 can be formed of a single fiber. Alternatively, the fiber set can be formed of a plurality of fibers. Generally, the fibers that form the fiber set are connected together by stitching, adhesive, twisting together, etc.; however, this is not required. The fibers and/or the fibers in the fibers sets that are used to the for the second fiber layer 30 can be formed of the same or different material. The number of fibers that form a plurality of fiber sets can be the same or different. The number of fibers that form a plurality of fiber sets is non-limiting. The thickness of the fibers or the fibers included in a fiber set or a plurality of fiber sets can be the same or different. The thickness of a plurality of fibers sets can be the same or different. The thickness of the fibers or the fibers that form a fiber set is non-limiting. The shape of the fibers or the fibers included in a fiber set or a plurality of fiber sets can be the same or different. The color of fibers or the fibers included in a fiber set or a plurality of fiber sets can be the same or different. The strength and/or other physical properties (e.g., melting temperature, flexibility, etc.) of the fibers or the fibers included in a fiber set or a plurality of fiber sets can be the same or different. Generally, the plurality of fibers or fiber sets 32 are formed from glass fibers, carbon fibers, basalt fibers and/or aramid fibers. The spacing W1 and W2 can be the same or different. Generally, spacing W1 and W2 is the same. The orientation of fibers or fiber sets 22 to fibers or fiber sets 32 is a non-parallel relationship. Generally, the angular relationship of fibers or fiber sets 22 to fibers or fiber sets 32 is 10-90°; typically 45-90°, and more typically about 80-90°. As illustrated in
Referring now to
The fabric layers illustrated in
As illustrated in
Referring now to
Referring again to
The reinforcement mat of the present invention is designed to form a stronger bond with the asphalt or bitumen top layer and a sub-base as compared with prior art repair systems. Referring now to
As illustrated in
After the reinforcement mat is laid on the sub-base, a layer of asphalt or bitumen 100 or some other type of surface material (composite surface, bituminous surface, etc.) is applied to the top surface of the reinforcement mat as illustrated in
When the reinforcement mat includes a backing material 70, the backing material can be used to further facilitate in the connection of the reinforcement mat to layer 100 and/or sub-base 90.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and since certain changes may be made in the constructions set forth without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. The invention has been described with reference to preferred and alternate embodiments. Modifications and alterations will become apparent to those skilled in the art upon reading and understanding the detailed discussion of the invention provided herein. This invention is intended to include all such modifications and alterations insofar as they come within the scope of the present invention. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention, which, as a matter of language, might be said to fall therebetween. The invention has been described with reference to the preferred embodiments. These and other modifications of the preferred embodiments as well as other embodiments of the invention will be obvious from the disclosure herein, whereby the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims.
The present invention claims priority on U.S. Provisional Patent Application Ser. No. 61/576,484 filed Dec. 16, 2011, which is incorporated herein by reference.
Number | Date | Country | |
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61576484 | Dec 2011 | US |