Asphalt fiber reinforcing material having hot melt adhesive coating layer

Abstract

The present invention relates to an asphalt fiber reinforcing material having a hot melt adhesive coating layer Specifically, the present invention relates to an asphalt fiber reinforcing material having a hot melt adhesive coating layer, which melts at a medium temperature asphalt pavement temperature and exhibits adhesive strength, thereby improving adhesive strength between an intermediate layer of pavement and asphalt to improve durability of an asphalt pavement road and prevent early damage, and accordingly, can reduce social costs caused by asphalt re-pavement, reduce carbon emissions, and reduce costs due to civil complaint treatment costs, compensation costs, and re-pavement costs due to road damage.

Description

Asphalt fiber reinforcement with hot melt adhesive coating layer

[0001] The present invention relates to an asphalt fiber reinforcing material having a hot melt adhesive coating layer.

[0002] Specifically, it can improve the durability of asphalt pavement and prevent premature damage by improving the adhesion between the middle layer of the pavement and the asphalt by melting and exerting adhesive force at medium-temperature asphalt pavement temperatures.

[0003] Accordingly, the present invention relates to an asphalt fiber reinforcing material having a hot melt adhesive coating layer that can solve the problem of social costs arising from asphalt resurfacing, reduce carbon emissions, and reduce costs such as the cost of handling complaints due to road damage, compensation costs, and resurfacing costs.

[0004] Asphalt is a complex mixture of thousands of polymeric hydrocarbons with organic compounds and trace amounts of inorganic compounds, also called asphalt concrete or asphalt.

[0005] When mixed with 5 to 6% asphalt and crushed stone, sand, or stone powder, it becomes hard and sticky, so it can be used as a floor material for road paving and asphalt tiles.

[0006] However, over time, asphalt pavement surfaces can experience vertical or horizontal deformation, cracks, and potholes due to long-term use, traffic loads, ground movement, and the intrusion of freezing, thawing, and deicing agents like chloride. This leads to significant maintenance costs.

[0007] To overcome these problems, a method of installing asphalt reinforcement made of reinforcing fibers such as carbon fiber, glass fiber, aramid fiber, and polyester fiber is being applied to prevent reflection cracking and suppress plastic deformation during asphalt construction.

[0008] Because reinforcing fibers have both elasticity and ductility, they play a role in extending the life of asphalt when applied to asphalt construction.

[0009]

[0010] As a prior art using such reinforcing fibers, Patent Publication No. 10-1336333 discloses a reinforcing material in which a non-woven fabric is attached to a grid-shaped glass fiber and a pavement reinforcing method for preventing early damage to a special section road using the reinforcing material.

[0011] Reinforcing materials based on these prior technologies had the problem of being unsuitable for medium-temperature asphalt construction, which is being implemented as part of the government's recent carbon reduction policy.

[0012] Specifically, the existing asphalt construction process involved heating the asphalt, which resulted in the emission of harmful gases, the use of fossil fuels, and chemical exposure of on-site construction workers. As part of a carbon reduction policy to address these issues, the government introduced a medium-temperature asphalt construction technology that allows construction at temperatures 20 to 55℃ lower than the existing heated asphalt mixture.

[0013] This method of road paving using medium-temperature asphalt lowers the heating temperature of the asphalt, enabling road paving construction even at low temperatures, thereby reducing harmful gas emissions, reducing the use of fossil fuels, and reducing chemical exposure of field workers.

[0014] However, the reinforcing material according to the prior art does not melt at the asphalt laying temperature, so there is a problem that the worker must melt the reinforcing material or film with a separate device (torch). In addition, there is a problem that the reinforcing material coating layer and film layer do not melt at the medium-temperature asphalt laying temperature, so the adhesive strength cannot be extracted during construction, which can cause premature damage such as peeling.

[0015]

[0016] In addition, Patent Publication No. 10-1719615 describes a heat-responsive adhesive-reinforced film-attached asphalt fiber reinforcing material and a pavement reinforcement method using the same.

[0017] The above technology relates to an asphalt fiber reinforcement material having a heat-responsive adhesive reinforcing film attached thereto, which can enhance the interlayer adhesive strength of asphalt, improve workability, and enhance the quality of construction, and a pavement reinforcement method using the same, wherein the adhesive reinforcing film melts when reacting with the heat of the asphalt mixture heating temperature (110 to 180°C) during the installation process of a fiber grid for crack prevention of road pavement, and acts as a release film that does not stick to each other during the installation process of fiber reinforcement material and during the storage and handling of materials, and is easily separated from the grid-shaped reinforcing fiber impregnated with an asphalt compound during construction in winter, and quickly melts when reacting with the heat of the heated asphalt after the installation of the fiber grid, and acts as an enhanced adhesive function, and the asphalt fiber reinforcement material and a pavement reinforcement method using the same, wherein the asphalt fiber reinforcement material is formed by adding 10 to 20 wt% of polyolefin and ethylene-vinyl acetate copolymer (EVA: Ethylene-Vinyl) to the upper side of the grid-shaped reinforcing fiber impregnated with an asphalt compound, so that the adhesive can melt at a temperature of 80 to 90°C and serve as an adhesive while normally serving as a release material. By using an asphalt fiber reinforcement material including a heat-responsive adhesive-reinforced film composed of 50 to 60 wt% of an acetate copolymer, 10 to 15 wt% of an adhesive reinforcing agent, and 10 to 15 wt% of an anti-blocking agent, the film performs the role of a release film, and when constructing an asphalt pavement layer, the film, which acts as a release material, is quickly melted by the heat generated from the asphalt without a separate combustion operation, and acts as an adhesive that bonds the asphalt fiber reinforcement layer and asphalt concrete, thereby enhancing the adhesion between asphalt layers, improving workability, and enhancing the quality of construction, and a pavement reinforcement method using the same are provided.

[0018]

[0019] These prior arts also describe low softening point bonding that can melt at temperatures of 80 to 90°C and function as an adhesive, but there is a need for improvement in temperatures lower than this softening point.

[0020] The purpose of the present invention is to improve the durability of asphalt pavement and prevent premature damage by improving the adhesive strength between the middle layer of the pavement and the asphalt by melting and exhibiting adhesive strength at a medium-temperature asphalt pavement temperature.

[0021] Accordingly, the purpose of the present invention is to provide an asphalt fiber reinforcing material having a hot melt adhesive coating layer that can solve the problem of social cost arising from asphalt resurfacing, reduce carbon emissions, and reduce costs such as civil complaint handling costs, compensation costs, and resurfacing costs due to road damage.

[0022] In order to achieve the above-described purpose, the asphalt fiber reinforcing material having a hot melt adhesive coating layer according to the present invention is an asphalt fiber reinforcing material having a hot melt adhesive coating layer that melts at the paving temperature of medium-temperature asphalt and exerts adhesive force, thereby improving the adhesive force between the middle layer of the pavement and the asphalt.

[0023] It is characterized in that an adhesive coating layer having a low softening point of 50 to 90°C is formed on a fiber of a lattice structure.

[0024]

[0025] At this time, the adhesive coating layer,

[0026] Paraffin wax as a hardener;

[0027] Hydrogenated hydrocarbons (C6-20) polymer as a catalyst;

[0028] Petroleum hydrocarbon and polyisobutylene (Polyisobutene, 2-Methyl-1-propene, Homopolymer) as adhesives;

[0029] 2,4-Bis(1,1-dimethylethyl)phenol phosphite (3:1) and Tris(2,4-ditertbutylphenyl)phosphite as stabilizers;

[0030] It is formed by coating the fiber with a low softening point adhesive made of an ethylene-vinyl copolymer, which is a thermoplastic resin of the EVA series.

[0031]

[0032] As an example, the low softening point adhesive is

[0033] Paraffin wax as a hardener;

[0034] Hydrogenated hydrocarbons (C6-20) polymer as a catalyst;

[0035] Petroleum hydrocarbon as an adhesive;

[0036] 2,4-Bis(1,1-dimethylethyl)phenol phosphite (3:1) and Tris(2,4-ditertbutylphenyl)phosphite as stabilizers;

[0037] It may also be made of ethylene-vinyl copolymer, a thermoplastic resin of the EVA series.

[0038]

[0039] As another example, in the present invention, the low softening point adhesive,

[0040] Consisting of paraffin wax as a hardener, hydrogenated hydrocarbons (C6-20) polymer as a catalyst, petroleum hydrocarbon and polyisobutylene (Polyisobutene, 2-Methyl-1-propene, Homopolymer) as an adhesive, 2,4-bis(1,1-dimethylethyl)phenol phosphite (3:1) and tris(2,4-ditertbutylphenyl)phosphite as stabilizers, and ethylene-vinyl copolymer, which is an EVA series resin, as a thermoplastic resin;

[0041] A composition comprising paraffin wax as a hardener, hydrogenated hydrocarbons (C6-20) polymer as a catalyst, petroleum hydrocarbon as an adhesive, 2,4-bis(1,1-dimethylethyl)phenol phosphite (3:1) and tris(2,4-ditertbutylphenyl)phosphite as stabilizers, and ethylene-vinyl copolymer, which is an EVA series resin, as a thermoplastic resin;

[0042] It is characterized by using a mixture in a certain ratio.

[0043]

[0044] In addition, the fiber on which the adhesive coating layer is formed is characterized in that a film (30) is adhered to at least one selected surface of the fiber.

[0045]

[0046] Meanwhile, as a method for manufacturing an asphalt fiber reinforcement having the above-described hot melt adhesive coating layer,

[0047] A first melting step (S1) of creating a first mixture by mixing a curing agent, a catalyst, an adhesive, and a stabilizer while melting them at a temperature of 140 to 160°C;

[0048] A second melting step (S2) of producing a low softening point adhesive by adding a thermoplastic resin that serves as a backbone resin of the low softening point adhesive to the first mixture melted and mixed through the first melting step (S1) and mixing while melting;

[0049] An adhesive coating layer forming step (S3) of forming a low softening point adhesive layer (24) by coating the low softening point adhesive mixed and melted by the above-mentioned second melting step (S2) on the longitudinal fiber (22A) and transverse fiber (22B) surfaces of the fiber (22) at 80 to 200 g / ㎡; and

[0050] It is characterized by comprising a film attachment step (S4) in which a fiber (22) on which a low softening point adhesive coating layer (24) is formed through the adhesive coating layer formation step (S3) and a film (30) formed by melting a thermoplastic resin and a dispersant are passed between a pair of heating rollers and then cooled to attach a film (30) to the fiber (22).

[0051] According to the asphalt fiber reinforcement having a hot melt adhesive coating layer according to the present invention, firstly, in order to solve the problem that the performance of the asphalt fiber reinforcement is not properly performed and a peeling phenomenon occurs due to insufficient adhesive strength, a low softening point adhesive coating layer having a softening point of 50 to 90℃ that melts at a compaction temperature (laying temperature) or higher of medium-temperature asphalt is laminated to form a uniform adhesive coating layer on the asphalt fiber reinforcement to improve the adhesive strength, thereby preventing the premature peeling phenomenon that occurs due to insufficient adhesive strength when the low softening point adhesive coating layer melts at the medium-temperature asphalt pavement temperature, thereby having the effect of allowing the asphalt fiber reinforcement to properly perform its performance.

[0052] Second, as a low softening point adhesive coating layer is formed on the fiber reinforcement, it has the effect of enhancing the inherent performance of the fiber reinforcement, such as crack resistance and resistance to asphalt deformation.

[0053] Third, by forming a film layer that melts below the compaction temperature (laying temperature) of medium-temperature asphalt on the asphalt fiber reinforcement material having a low softening point adhesive coating layer formed thereon, the film layer protects the tack coating (asphalt adhesive) and has the effect of increasing adhesive strength by melting at the medium-temperature asphalt laying temperature.

[0054] Fourth, by increasing the resistance of asphalt pavement to cracking and deformation, it is possible to extend the life cycle of roads, thereby reducing carbon emissions resulting from asphalt resurfacing. In addition, it is possible to realize the effect of reducing social costs, such as reducing the cost of handling complaints and compensation arising from road damage and reducing the cost of resurfacing.

[0055] FIG. 1 is a drawing illustrating an asphalt fiber reinforcing material having a low softening point hot melt adhesive coating layer according to the present invention.

[0056] FIG. 2 is a partially enlarged cross-sectional view showing a state in which a film is attached to an asphalt fiber reinforcing material having a low softening point hot melt adhesive coating layer according to the present invention illustrated in FIG. 1.

[0057] Figure 3 is a flow chart for explaining a method for manufacturing an asphalt fiber reinforcing material having a low softening point hot melt adhesive coating layer according to the present invention.

[0058] Figure 4 is a graph showing the results of an experiment on a 5cm regular dense asphalt mixture + RSC4 + 5cm regular dense asphalt mixture as test specimen 1.

[0059] Figure 5 is a graph showing the results of an experiment on a 5cm regular dense asphalt mixture + RSC4 + asphalt fiber reinforcement + 5cm regular dense asphalt mixture as test specimen 2.

[0060] Figure 6 is a graph showing the results of an experiment on a 5cm regular dense asphalt mixture + RSC4 + asphalt fiber reinforcement + 5cm medium-temperature dense asphalt mixture as test specimen 3.

[0061] Figure 7 is a graph showing the results of an experiment on a 5cm regular dense asphalt mixture + RSC4 + 5cm regular dense asphalt mixture as test specimen 4.

[0062] Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the term to best explain his or her own invention.

[0063]

[0064] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0065]

[0066] Hereinafter, before explaining with reference to the drawings, it is to be noted that matters that are not necessary to reveal the gist of the present invention, that is, known configurations that can be obviously added by a person skilled in the art with ordinary knowledge, are not illustrated or specifically described.

[0067]

[0068] The present invention relates to an asphalt fiber reinforcing material having a hot melt adhesive coating layer.

[0069] Specifically, it can improve the durability of asphalt pavement and prevent premature damage by improving the adhesion between the middle layer of the pavement and the asphalt by melting and exerting adhesive force at medium-temperature asphalt pavement temperatures.

[0070] Accordingly, the present invention relates to an asphalt fiber reinforcing material having a hot melt adhesive coating layer that can solve the problem of social costs arising from asphalt resurfacing, reduce carbon emissions, and reduce costs such as the cost of handling complaints due to road damage, compensation costs, and resurfacing costs.

[0071]

[0072] Among the attached drawings, FIG. 1 is a drawing illustrating an asphalt fiber reinforcing material having a low softening point hot melt adhesive coating layer according to the present invention.

[0073]

[0074] *As shown in Fig. 1 of the attached drawing, the asphalt fiber reinforcing material (20) having a low softening point hot melt adhesive coating layer according to the present invention has a structure in which a low softening point adhesive coating layer (24) that melts below the compaction temperature of medium-temperature asphalt is formed on the surface of the fiber (22) to a predetermined thickness.

[0075] To elaborate more specifically, the fibers (22) constituting the fiber reinforcement (20) are lattice-shaped reinforcing fibers formed by crossing multiple longitudinal fibers (22A) and multiple transverse fibers (22B) upward and downward, as shown in Fig. 1 of the attached drawing. The longitudinal fibers (22A) and transverse fibers (22B) may be composed of the same material or different materials, and may be formed of various materials such as carbon fiber, glass fiber, aramid fiber, basalt fiber, polyethylene, and polypropylene fiber.

[0076]

[0077] The low softening point adhesive coating layer (24) melts at the laying temperature of medium-temperature asphalt to generate adhesive force and adhere fibers (22) to the asphalt, and is composed of a hardener, a catalyst, an adhesive, a stabilizer, and a thermoplastic resin.

[0078] The above hardener has the function of adjusting the hardening time during the application process after melting in the low softening point adhesive and affects the viscosity during melting. As an example, 20 to 30 parts by weight of paraffin wax is added as the hardener.

[0079] If the hardener is added in an amount less than 20 parts by weight, the curing time of the low softening point adhesive will be delayed, preventing it from solidifying within an appropriate time. If the hardener is added in an amount exceeding 30 parts by weight, the curing time will be too rapid, causing the adhesive to harden before the adherend is bonded, resulting in weak adhesive strength. Therefore, 25 parts by weight is preferably added.

[0080] Additionally, a wax mixture consisting of paraffin waxes and hydrocarbon waxes can be used as a hardener.

[0081]

[0082] The above catalyst plays a role in increasing the chemical reaction rate in a low softening point adhesive or creating conditions for a reaction to occur and exhibiting adhesive strength. In the present invention, 15 to 45 parts by weight of a hydrogenated hydrocarbons (C6-20) polymer is added.

[0083] Hydrogenated hydrocarbon C6-20 polymer is a hydrogenated carbon resin that plays a role in developing adhesive strength in low softening point adhesives, and by being hydrogenated, the heat stability of the low softening point adhesive is improved.

[0084] If the catalyst is added in an amount less than 15 parts by weight or more than 45 parts by weight, the adhesive strength and thermal stability may deteriorate. Preferably, 30 parts by weight is added.

[0085]

[0086] In addition, the adhesive exerts adhesive force in a low softening point adhesive and affects initial adhesive force and viscosity, and particularly improves adhesive strength and heat resistance.

[0087] In the present invention, 5 to 20 parts by weight of petroleum hydrocarbon is used as an adhesive.

[0088] Alternatively, as an example, 5 to 20 parts by weight of petroleum hydrocarbon and 1 to 15 parts by weight of polyisobutylene (Polyisobutene, 2-Methyl-1-propene, Homopolymer) are used as the adhesive.

[0089] Petroleum hydrocarbons are a mixture of various hydrocarbons in which carbon (C) and hydrogen (H) are combined in different sizes and arrangements, including paraffin, naphthene, and aromatic hydrocarbons.

[0090]

[0091] When petroleum hydrocarbons are added in amounts less than 5 parts by weight or more than 20 parts by weight, the adhesive strength and viscosity may decrease, and heat resistance may decrease. Therefore, 12 parts by weight is preferably added.

[0092] Additionally, if polybutene is added in amounts less than 1 part by weight or more than 15 parts by weight, adhesive strength and heat resistance may decrease. Therefore, 7 parts by weight is preferably added.

[0093]

[0094] In addition, a stabilizer used to further stabilize the stability of heating maintains the thermal stability of a low softening point adhesive working at high temperatures and further plays a role in preventing oxidation. In the present invention, 0.1 to 1 part by weight of 2,4-bis(1,1-dimethylethyl)phenol phosphite (3:1) and tris(2,4-ditertbutylphenyl)phosphite are added.

[0095] If such stabilizers are added in an amount of less than 0.1 part by weight, thermal stability may deteriorate and oxidation prevention may be difficult. If they are added in an amount exceeding 1 part by weight, the viscosity of the low softening point adhesive may increase, reducing adhesiveness, or the melting point may decrease, causing the low softening point adhesive to melt more quickly, increasing fluidity and reducing adhesiveness. In addition, the color of the low softening point adhesive may change. Therefore, the stabilizer may be added in an amount of preferably less than 1 part by weight, more preferably 0.5 to 1 part by weight.

[0096]

[0097] Thermoplastic resin is an EVA series resin, which serves as the main base and skeletal resin in low softening point adhesives, and affects the adhesive strength and cohesiveness after application of the low softening point adhesive and the solidification process. In the present invention, 15 to 40 parts by weight of ethylene-vinyl copolymer, which is an EVA series resin, can be added.

[0098]

[0099] At this time, the present invention, as another example, for the low softening point adhesive coating layer (24),

[0100] Consisting of paraffin wax as a hardener, hydrogenated hydrocarbons (C6-20) polymer as a catalyst, petroleum hydrocarbon and polyisobutylene (Polyisobutene, 2-Methyl-1-propene, Homopolymer) as an adhesive, 2,4-bis(1,1-dimethylethyl)phenol phosphite (3:1) and tris(2,4-ditertbutylphenyl)phosphite as stabilizers, and ethylene-vinyl copolymer, which is an EVA series resin, as a thermoplastic resin;

[0101] It may also be used by mixing paraffin wax as a hardener, hydrogenated hydrocarbons (C6-20) polymer as a catalyst, petroleum hydrocarbon as an adhesive, 2,4-bis(1,1-dimethylethyl)phenol phosphite (3:1) and tris(2,4-ditertbutylphenyl)phosphite as stabilizers, and ethylene-vinyl copolymer, a thermoplastic resin of the EVA series; in a certain ratio.

[0102] At this time, the ratio is not particularly limited.

[0103]

[0104] Structure of asphalt fiber reinforcement

[0105]

[0106] A low softening point adhesive, which is a mixture of a hardener, catalyst, adhesive, stabilizer, and thermoplastic resin melted at a temperature of 140 to 160°C, is coated on the surface of a lattice-structured fiber (22) at 80 to 200 g / ㎡ to form a low softening point adhesive coating layer (24).

[0107] That is, the coating is performed so that the weight per square meter of the fiber reinforcement (20) is 20 to 200 g. At this time, if the low softening point adhesive is coated at less than 80 g / ㎡, the shear bonding strength is not properly exhibited, and if the coating exceeds 200 g / ㎡, the shear bonding strength is not significantly improved compared to the increase in the unit cost of product production. Therefore, it is preferable to coat at 160 g / ㎡.

[0108]

[0109] Meanwhile, as illustrated in FIG. 2, a film (30) composed of 99 wt% of an ethylene-vinyl copolymer of the EVA series as a thermoplastic resin and 1 wt% (based on weight ratio) of a dispersant can be further adhered to one or both sides of the asphalt fiber reinforcement (20) on which a low softening point adhesive coating layer (24) is formed, i.e., one or both sides of the fiber (22).

[0110] The film (30) is intended to prevent the asphalt emulsion applied to the base surface from being damaged by work vehicles or workers, and to improve the adhesion to the base layer through the asphalt emulsion.

[0111] The film (30) is a thermoplastic resin having a melting point of 50 to 110°C, made of an ethylene-vinyl copolymer or an EVA series hot melt that melts under the heat of medium-temperature asphalt, and is attached to one side of a fiber (22) on which a low-softening-point contact coating layer (24) is formed. At this time, the melting point of the film (30) may preferably be 81.8°C.

[0112] The basis weight of this film (30) is 10 to 100 g / ㎡, and is attached to one side of the grid (20) by heat welding while passing between a pair of rollers heated to a predetermined temperature together with the fiber (22) on which the low softening point adhesive coating layer (24) is formed.

[0113]

[0114] Method for manufacturing asphalt fiber reinforcement

[0115]

[0116] Hereinafter, a method for manufacturing an asphalt fiber reinforcement (20) having a low softening point adhesive coating layer configured as described above is described.

[0117]

[0118] a) 1st melting stage (S1)

[0119] This is a step of creating a primary mixture by mixing the curing agent, catalyst, adhesive, and stabilizer constituting the low softening point adhesive coating layer (24) while melting them at a temperature of 140 to 160°C, preferably 150°C.

[0120] 25 parts by weight of paraffin wax is added as a hardener to form the primary mixture. Paraffin wax plays a role in adjusting the hardening time during the application process after melting of the low softening point adhesive and affects the viscosity when melted.

[0121] 30 parts by weight of hydrogenated hydrocarbons (C6-20) polymer is added as a catalyst constituting the primary mixture. The catalyst plays a role in increasing the chemical reaction rate in low softening point adhesives, creating conditions for reaction to occur, and developing adhesive strength.

[0122] As an adhesive constituting the primary mixture, 12 parts by weight of petroleum hydrocarbon and 7 parts by weight of polyisobutylene (Polyisobutene, 2-Methyl-1-propene, Homopolymer) are added. This adhesive exhibits adhesive strength in a low softening point adhesive and affects the initial adhesive strength and softening point.

[0123] As stabilizers constituting the primary mixture, 0.1 to 1 part by weight of 2,4-bis(1,1-dimethylethyl)phenol phosphite (3:1) and tris(2,4-ditertbutylphenyl)phosphite are added. These stabilizers maintain the thermal stability of low softening point adhesives used at high temperatures and prevent oxidation.

[0124] In this way, 25 parts by weight of a hardener; 30 parts by weight of a catalyst; 7 parts by weight of an adhesive; and 0.1 to 1 part by weight of a stabilizer are placed in a container and mixed while heating to melt.

[0125]

[0126] b) Second melting stage (S2)

[0127] By performing the first melting step (S1) described above, 30 parts by weight of an ethylene-vinyl copolymer as a thermoplastic resin that serves as a backbone resin of a low softening point adhesive is added to the melted and mixed first mixture, and the mixture is melted and mixed to manufacture a low softening point adhesive.

[0128] At this time, the thermoplastic resin is added and melted when the curing agent, catalyst, adhesive, and stabilizer added to the primary mixture are more than two-thirds melted. This is to improve adhesive and cohesive strength. Furthermore, the melting temperature is maintained at 150°C when adding and melting the thermoplastic resin.

[0129]

[0130] c) Adhesive coating layer formation step (S3)

[0131] A low softening point adhesive mixed and melted by the aforementioned second melting step (S2) is coated on the longitudinal fiber (22A) and transverse fiber (22B) surfaces of the fiber (22) at 80 to 200 g / ㎡ to form a low softening point adhesive coating layer (24).

[0132] The method for forming a low softening point adhesive coating layer (24) on a fiber (22) is as follows.

[0133] First, a molten low softening point adhesive in a molten state is supplied to a pair of heating rollers, and the fiber (22) is passed between the heating rollers and then cooled so that a low softening point adhesive coating layer is formed on the longitudinal fiber (22A) and the transverse fiber (22B) of the fiber (22).

[0134] In this way, by passing the fiber (22) between each heating roller supplied with the low softening point adhesive and then cooling it to room temperature, a low softening point adhesive coating layer of a predetermined thickness can be formed on the surfaces of the longitudinal fiber (22A) and the transverse fiber (22B) of the fiber (22).

[0135] Second, after impregnating the fiber (22) with a low softening point adhesive in a molten state and passing it between a pair of heating rollers as described above, the fiber (22) is cooled to room temperature so that a low softening point adhesive coating layer of a predetermined thickness can be formed on the surfaces of the longitudinal fiber (22A) and the transverse fiber (22B) of the fiber (22).

[0136] In this way, by passing the fiber (22) and the low softening point adhesive between a pair of heating rollers or by passing the fiber (22) impregnated with the low softening point adhesive between a pair of heating rollers, the longitudinal fibers (22A) and transverse fibers (22B) of the fiber (22) can be flattened, and the low softening point adhesive coating layer (24) can be evenly formed.

[0137] In particular, by passing fibers (22) containing a low softening point adhesive between heating rollers and applying pressure, the low softening point adhesive can penetrate between each strand of longitudinal fibers (22A) and transverse fibers (22B), thereby forming a stable and thick low softening point adhesive coating layer.

[0138]

[0139] Meanwhile, the adhesive coating layer forming step (S3) may further include a film attachment step (S4) of attaching a film (30) to the surface, back, or both sides of the fiber (22).

[0140] Preferably, the film attachment step (S4) preferably attaches the film (30) to both sides. This is because, after applying the asphalt fiber reinforcement having the hot melt adhesive coating layer according to the present invention, the temperature of the surface of the reinforcement becomes 55°C or higher due to direct sunlight incident on the asphalt, and the coating layer of the fiber reinforcement according to the present invention can melt even at the above-described temperature.

[0141] Therefore, it may be preferable to attach the film to both sides rather than to just one side.

[0142]

[0143] d) Film attachment stage (S4)

[0144] The film attachment step (S4) passes a fiber (22) having a low softening point adhesive coating layer (24) formed thereon and a film (30) formed by melting a thermoplastic resin and a dispersant between a pair of heating rollers and then cools the film (30) to attach the film (30) to the fiber (22).

[0145] Asphalt fiber reinforcing material (20) having a low softening point adhesive coating layer according to the present invention manufactured in this manner melts at a medium asphalt pavement temperature and exhibits adhesive strength, thereby improving the adhesive strength between the middle layer of the pavement and the asphalt, thereby improving the durability of the asphalt pavement and preventing premature damage, etc., and thereby realizing reduction of social costs and carbon generated by asphalt resurfacing.

[0146]

[0147] [Experimental Example 1]

[0148] Reflective cracking of asphalt fiber reinforcement (20) having a low softening point contact coating layer according to the present invention was tested.

[0149]

[0150] a. Production of public test specimens

[0151] A test specimen was manufactured using an asphalt fiber reinforcing material (20) according to the present invention, which is a basic asphalt mixture (general, medium temperature) and has a low softening point adhesive coating (24) formed by coating a low softening point adhesive at 80 to 200 g / ㎡.

[0152] The mixing temperature of the asphalt was 135℃, and the compaction temperature was 120℃.

[0153] o Test specimen 1: 5cm regular dense asphalt mixture + RSC4 + 5cm regular dense asphalt mixture

[0154] o Test specimen 2: 5cm regular dense asphalt mixture + RSC4 + asphalt fiber reinforcement + 5cm regular dense asphalt mixture

[0155] o Specimen 3: 5cm regular dense asphalt mixture + RSC4 + asphalt fiber reinforcement + 5cm medium temperature dense asphalt mixture

[0156] o Test specimen 4: 5cm regular dense asphalt mixture + RSC4 + 5cm medium-temperature dense asphalt mixture

[0157]

[0158] For the general dense asphalt mixture, the mixing temperature was 150℃, and the compaction temperature was 140℃. For the medium-temperature dense asphalt mixture, the mixing temperature was 135℃, and the compaction temperature was 120℃. After compacting the lower layer, RSC4 coating was applied at 0.3L / m 2 After performing the process, a curing period of 24 hours was allowed, and then the fibers with the adhesive coating layer were placed and the upper layer was compacted.

[0159]

[0160] b. Preparation of the public test specimen

[0161] The compacted test specimen was cut to a width of 76 mm and a length of 150 mm with fibers placed between the lower and upper layers, and a 12.5 mm notch was made to simulate the joints on site.

[0162] The temperature of the specimen was maintained at 25±0.52℃ during the experiment.

[0163] This experiment was conducted under strain-controlled conditions, with the triangular model repeatedly loaded. A strain of 0.635 mm was applied, and the experiment was conducted until the initial load was reduced by 85%.

[0164]

[0165] c. Experimental method

[0166] To evaluate the reflection cracking resistance of asphalt mixtures, a cyclic loading (R-OT: dynamic cyclic test with cyclic loading) test method was used.

[0167] The experimental method is as shown in [Table 1] below.

[0168]

[0169] ITEMR-OT (cyclic load) Experimental form: Repeated pulling load applied with a uniform load on both sides based on the notch. Repeated (dynamic) tensile (displacement control) experimental parameters: Frequency = 10 sce / cycle (0.1 Hz) (5 s loading + 5 s rest period) Loading speed = 0.635 mm / cycle) Temperature: 25℃ (≥12 hours specimen drying) Experimental time: ≤ 180 minutes (3 hours) Experimental end: 85% maximum load deformation Test results: Load cycle for cracking failure Number of specimens: 4 or more

[0170]

[0171] c. Experimental results

[0172] As confirmed in the attached drawings, Figs. 4 to 7 and [Table 2], in the reflection cracking test results, specimen 1 showed the lowest reflection cracking resistance with an average of 232 cycles, specimen 2 showed the highest reflection cracking resistance with an average of 643 cycles, and specimen 3 showed high reflection cracking resistance with an average of 574 cycles. In addition, specimen 4 showed the lowest reflection cracking resistance with an average of 222 cycles.

[0173] As a result of the experiment, it was found that the asphalt fiber reinforcement (asphalt fiber reinforcement having a low softening point adhesive coating layer) according to the present invention had higher reflection crack resistance in the pulled-out heated asphalt mixture than in the medium-temperature asphalt mixture under the same conditions.

[0174] In the absence of asphalt fiber reinforcement, the difference between the normal asphalt mixture and the medium-temperature asphalt mixture was not significant.

[0175] Therefore, it was found that when applying a medium-temperature asphalt mixture, it is preferable to reinforce with an asphalt fiber reinforcement material (asphalt fiber reinforcement material having a low softening point adhesive coating layer) according to the present invention.

[0176]

[0177] Classification 1st 2nd 3rd Average Standard Deviation COV (%) No. 1216235246232157 No. 2648623657643183 No. 357158356857481 No. 4205223237222167

[0178]

[0179] The results of the Tukey-Kramer statistical analysis, as shown in [Table 3], showed that there were differences between the specimens reinforced with asphalt fiber reinforcement (No. 2 and No. 3) and the specimens without asphalt fiber reinforcement (No. 1 and No. 4), but there was no significant difference between the specimens in which the upper layer was composed of a general dense-grained asphalt mixture and a medium-temperature dense-grained asphalt mixture without asphalt fiber reinforcement.

[0180]

[0181] Item 1Item 2p-value ConclusionNO. 1NO. 30.001Significantly differentNO. 1NO. 30.001Significantly differentNO. 2NO. 40.792Not significantly differentNO. 3NO. 30.002Significantly differentNO. 3NO. 40.001Significantly differentNO. 3NO. 40.001Significantly different

[0182]

[0183] [Experimental Example 2]

[0184] The shear bond strength of an asphalt fiber reinforcing material (20) having a low softening point adhesive coating layer according to the present invention was tested.

[0185] Shear bond strength is one of the important indicators for resisting stress applied by the passing load of vehicles on the road. If the shear bond strength is insufficient, it can cause premature damage such as potholes and peeling in the newly constructed pavement layer.

[0186] Since this shear bond strength, like the tensile bond strength, can be affected by the type of mixture, type of tack coating, degree of construction, and curing conditions, this experiment evaluated the shear bond strength according to the surface mixture and the presence or absence of fiber.

[0187] Additionally, in the present invention, experiments were conducted on the assumption that there was no tack coating.

[0188] This is because, in actual field conditions, the tack coating layer is often damaged, and even in these cases, a certain level of adhesive strength must be maintained. Therefore, the experiments below were deliberately conducted without tack coating to evaluate adhesive strength in a more harsh environment.

[0189]

[0190] a. Psalm production

[0191] The specimen was made by heating an asphalt mixture and compacting the lower portion to produce a lower asphalt specimen, placing an asphalt fiber reinforcing material (20) according to the present invention having a low softening point adhesive coating layer (24) on the upper surface, then laying the upper asphalt, allowing it to harden, and then cutting it. At this time, the compaction temperature is 140±5°C.

[0192]

[0193] b. Experimental method

[0194] The lower layer consisting of lower asphalt was fixed to a fixed jig for shear bond strength testing, and the upper layer consisting of upper asphalt was fixed to a jig of a testing machine. The jig of the testing machine was lowered downward to measure the shear bond strength of the lower layer and the upper layer.

[0195] The shear bond strength was measured by substituting the measured maximum load and the cross-sectional area of ​​the tack coat into the mathematical equation 1 below.

[0196]

[0197] [Mathematical Formula 1]

[0198]

[0199]

[0200] c. Experimental results

[0201] The results of the shear bond strength test are shown in [Table 4] below.

[0202] Here, specimens No. 1 and 3 are applied with asphalt fiber reinforcement (20) having a low softening point adhesive coating layer according to the present invention, and the amount used per square meter was adjusted to 158 g and 168 g, respectively, and specimen No. 2 is applied with "asphalt fiber reinforcement having a low melting point hot melt adhesive coating layer" described in application number 10-2024-0035125 filed by the present applicant. In this case, the amount used for specimen No. 2 was set to 166 g per square meter.

[0203] As a result of the experiment, specimens 1 and 3 according to the present invention were 0.40 MPa and 0.50 MPa, respectively. This is confirmed by the increase in shear bond strength due to the increase in usage.

[0204] However, in specimen 2, the shear bond strength was 0.45 Mpa, which was confirmed to be a higher increase rate in shear bond strength per amount of use compared to specimen 3 with a similar amount of use.

[0205]

[0206] Meanwhile, according to the Road Traffic Research Institute, when a standard truck load (96kN) is driven at 80km / h and the brakes are applied, the shear stress generated on a paved road with a surface thickness of 5cm is 0.35Mpa, while the bond strength (shear) value of the grid pavement method is typically only about 0.2Mpa, raising the issue of not ensuring the safety of the paved road for driving vehicles.

[0207] That is, the shear strength on the paved road must meet at least 0.35Mpa, and for this purpose, tack coating is sometimes performed in the field, but

[0208] Since the present invention has a shear bonding strength of 0.4 Mpa or more even without tack coating, it has the effect of overcoming the conventional problem.

[0209]

[0210] Shear bond strength test (compaction temperature 140±5)℃, no milling, no tack coating, unit Mpa Sample name 1st 2nd 3rd average 1. General WC-2, no tack coating, no milling, grid (158), shear specimen 0.39 0.41 0.40 0.40 2. General WC-2, no tack coating, no milling, grid (166), shear specimen 0.46 0.46 0.42 0.45 3. General WC-2, no tack coating, no milling, grid (168), shear specimen 0.49 0.48 0.52 0.50

[0211] o General WC-2: Heated asphalt o Asphalt fiber reinforcement: Asphalt fiber reinforcement having a low softening point adhesive coating layer according to the present invention

[0212] o Unit: Mpa (mega pascal)

[0213]

[0214] [Experimental Example 3]

[0215] In this experiment, the shear bond strength of an asphalt fiber reinforcement (20) having a low softening point adhesive coating layer according to the present invention with a film (30) attached to one side was tested.

[0216] The film (30) is composed of 99 wt% of an ethylene-vinyl copolymer of the EVA series and 1 wt% of a dispersant, and the basis weight of the film (30) is 10 to 100 g / ㎡.

[0217] The film (30) is passed between a pair of rollers heated to a predetermined temperature together with a fiber (22) having a low softening point adhesive coating layer (24) formed thereon, and is attached to the grid (20) by thermal bonding.

[0218]

[0219] a. The sample production and experimental method are the same as Experimental Example 2.

[0220] b. Experimental results

[0221] As shown in [Table 5], the experimental results showed that, under the conditions of general heated asphalt and no tack coating, the average shear bond strength of specimen 1, a commercially available product, was 0.24 Mpa, and in comparison, the average shear bond strength of specimen 2, to which the fiber reinforcement according to the present invention was applied, was 0.50 Mpa, indicating that the shear bond strength of the asphalt fiber reinforcement (20) having the adhesive coating layer according to the present invention was excellent.

[0222]

[0223] Sample name 1st 2nd 3rd 4th 1. General WC-2, tack coating (none), fiber (asphalt fiber reinforcement) shear specimen 0.220.250.250.24 2. General WC-2, tack coating (none), fiber (asphalt fiber reinforcement + thermoplastic resin film) shear specimen 0.490.480.520.50

[0224] o General WC-2: Heated asphalt o Asphalt fiber reinforcement: Asphalt fiber reinforcement having a low softening point adhesive coating layer according to the present invention

[0225] o Unit: Mpa (mega pascal)

[0226]

[0227] As described above, according to the asphalt fiber reinforcement having a low softening point hot melt adhesive coating layer according to the present invention, firstly, in order to solve the problem of the asphalt fiber reinforcement not performing properly and the occurrence of peeling due to insufficient adhesive strength, a low softening point adhesive coating layer having a softening point of 50 to 90℃ that melts at a compaction temperature (laying temperature) or higher of medium-temperature asphalt is laminated to form a uniform adhesive coating layer to enhance adhesive strength, thereby preventing the phenomenon of premature peeling caused by insufficient adhesive strength when the low softening point adhesive coating layer melts at the medium-temperature asphalt pavement temperature, thereby having the effect of allowing the asphalt fiber reinforcement to properly exhibit its performance.

[0228] Second, as a low softening point adhesive coating layer is formed on the fiber reinforcement, it has the effect of enhancing the inherent performance of the fiber reinforcement, such as crack resistance and resistance to asphalt deformation.

[0229] Third, by forming a film layer that melts below the compaction temperature (laying temperature) of medium-temperature asphalt on the asphalt fiber reinforcement material having a low softening point adhesive coating layer formed thereon, the film layer protects the tack coating (asphalt adhesive) and has the effect of increasing adhesive strength by melting at the medium-temperature asphalt laying temperature.

[0230] Fourth, by increasing the resistance of asphalt pavement to cracking and deformation, it is possible to extend the life cycle of roads, thereby reducing carbon emissions resulting from asphalt resurfacing. In addition, it is possible to realize the effect of reducing social costs, such as reducing the cost of handling complaints and compensation arising from road damage and reducing the cost of resurfacing.

[0231]

[0232] The description using the drawings above only describes the main aspects of the present invention, and it is obvious that the present invention is not limited to the configuration of the drawings, as various designs are possible within the technical scope.

Claims

1. An asphalt fiber reinforcing material having a hot melt adhesive coating layer that melts at the paving temperature of medium-temperature asphalt and exerts adhesive force, thereby improving the adhesive force between the middle layer of the pavement and the asphalt. An adhesive coating layer having a low softening point of 50 to 90°C is formed on the fibers of the lattice structure, The above adhesive coating layer is, Paraffin wax as a hardener; Hydrogenated hydrocarbons (C6-20) polymer as a catalyst; As an adhesive 'Petroleum Hydrocarbon' or, 'A mixture of petroleum hydrocarbon and polyisobutylene (Polyisobutene, 2-Methyl-1-propene, Homopolymer)' or, Among the mixtures of 'petroleum hydrocarbon' and 'petroleum hydrocarbon and polyisobutylene (Polyisobutene, 2-Methyl-1-propene, Homopolymer)', Any one of the selected ones; With stabilizers; A low softening point adhesive made of ethylene-vinyl copolymer, a thermoplastic resin of the EVA series; Asphalt fiber reinforcing material having a hot melt adhesive coating layer, characterized in that it is formed by coating the above fibers.

2. In claim 1, The above stabilizer is, An asphalt fiber reinforcing material having a hot melt adhesive coating layer, characterized in that the hot melt adhesive coating layer is at least one selected from among 2,4-bis(1,1-dimethylethyl)phenol phosphite (3:1) and tris(2,4-ditertbutylphenyl)phosphite.

3. In claim 2, The above low softening point adhesive is, 20 to 30 parts by weight of paraffin wax as a hardener; 15 to 40 parts by weight of hydrogenated hydrocarbons (C6-20) polymer as a catalyst; 5 to 20 parts by weight of petroleum hydrocarbon as an adhesive; and 1 to 15 parts by weight of polyisobutylene (Polyisobutene, 2-Methyl-1-propene, Homopolymer); 0.1 to 1 part by weight of at least one selected from among 2,4-bis(1,1-dimethylethyl)phenol phosphite (3:1) and tris(2,4-ditertbutylphenyl)phosphite as a stabilizer; An asphalt fiber reinforcing material having a hot melt adhesive coating layer, characterized in that it is composed of 15 to 40 parts by weight of an ethylene-vinyl copolymer, which is a thermoplastic resin of the EVA series.

4. In claim 2, The above low softening point adhesive is, 20 to 30 parts by weight of paraffin wax as a hardener; 20 to 45 parts by weight of hydrogenated hydrocarbons (C6-20) polymer as a catalyst; 5 to 20 parts by weight of petroleum hydrocarbon as an adhesive; 0.1 to 1 part by weight of at least one selected from among 2,4-bis(1,1-dimethylethyl)phenol phosphite (3:1) and tris(2,4-ditertbutylphenyl)phosphite as a stabilizer; An asphalt fiber reinforcing material having a hot melt adhesive coating layer, characterized in that it is composed of 15 to 40 parts by weight of an ethylene-vinyl copolymer, which is a thermoplastic resin of the EVA series.

5. In claim 1, Fibers with an adhesive coating layer formed, An asphalt fiber reinforcing material having a hot melt adhesive coating layer, characterized in that a film (30) is adhered to at least one selected surface of the fiber.

6. In any one of claims 1 to 5, A first melting step (S1) of creating a first mixture by mixing a curing agent, a catalyst, an adhesive, and a stabilizer while melting them at a temperature of 140 to 160°C; A second melting step (S2) of producing a low softening point adhesive by adding a thermoplastic resin that serves as a backbone resin of the low softening point adhesive to the first mixture melted and mixed through the first melting step (S1) and mixing while melting; An adhesive coating layer forming step (S3) of forming a low softening point adhesive layer (24) by coating the low softening point adhesive mixed and melted by the above-mentioned second melting step (S2) on the longitudinal fiber (22A) and transverse fiber (22B) surfaces of the fiber (22) at 80 to 200 g / ㎡; and An asphalt fiber reinforcing material having a hot melt adhesive coating layer, characterized in that it is manufactured by a film attachment step (S4) in which a fiber (22) having a low softening point adhesive coating layer (24) formed through the adhesive coating layer forming step (S3) and a film (30) formed by melting a thermoplastic resin and a dispersant are passed between a pair of heating rollers and then cooled to attach a film (30) to the fiber (22).

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