Asphalt pavement repair material and asphalt pavement repair method

Abstract

To provide an asphalt pavement repair material which solves the problems of requiring fire such as a burner during construction, easily adhering to each other, reducing traveling performance due to a large thickness of the repair material immediately after construction, and causing a lot of waste due to cracks are not filled even when directly poured into the cracks.SOLUTION: An asphalt pavement repairing material comprises a water-absorbing fiber base material containing an asphalt emulsion, wherein the water-absorbing fiber base material has a water-absorbing ratio of 1.0 times or more a cation exchangeable group of 1.0 mmol / g or more.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to the repair of asphalt pavement cracks that have occurred on the surface of asphalt pavement, cracks that have occurred at the joint between newly laid asphalt pavement and existing asphalt pavement, cracks that have occurred at the joint between asphalt pavement on a bridge pier and the end of the pier, or potholes where the cracks have progressed and the surface asphalt pavement has peeled off. [Background technology]

[0002] A typical asphalt pavement is completed by laying a base layer of asphalt on top of the roadbed, and then laying a top layer of asphalt on top of that base layer. These construction steps require time and effort, including pressing and curing. However, the completed asphalt pavement will develop cracks over time due to thermal stress caused by repeated heating and cooling, and repeated stress caused by the weight of passing vehicles. If these cracks are left unattended, water will seep in through them and eventually reach the subgrade, causing deep damage. As a result, the entire road will eventually have to be repaired. Repairing this existing road requires nearly as much effort and time as constructing a new paved road.

[0003] For this reason, various repair materials and repair methods have been devised to quickly repair cracks in road surfaces. For example, Patent Document 1 discloses a string-shaped asphalt repair material in which asphalt is attached to a string-shaped member, and a repair method using the same. This method involves filling the cracks that have appeared in the pavement surface with the repair material, and then heating it to fill the cracks with asphalt.

[0004] Meanwhile, Patent Document 2 discloses an adhesive pavement repair material. This adhesive pavement repair material is in the form of a sheet containing petroleum asphalt as a constituent material and no aggregate. A primer is applied to the surface of the repair material to be repaired, and the repair material is then applied to the repair area. The asphalt that makes up this repair material does not have the durability to withstand the weight of passing vehicles, and as it wears down over time, some of it seeps into cracks, sealing them and preventing the intrusion of water and other substances, thereby preventing damage to the surface to be repaired.

[0005] Furthermore, Patent Document 3 discloses a cold application type hot asphalt mixture that is characterized in that it solidifies and develops strength when water is added after application at room temperature. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-53497 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-23949 [Patent Document 3] Patent No. 5583978 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the repair material of Patent Document 1 has a high viscosity of the applied asphalt in order to make the asphalt follow the cracks. As a result, the applied asphalt tends to adhere to itself or to other objects, reducing workability. In addition, applying the repair material to the repair area requires heating, which requires the use of open flames such as a burner, which is very dangerous. These work-related problems also apply to repair materials in shapes other than strings.

[0008] On the other hand, the repair material in Patent Document 2 does not require heating, but since it is assumed that the repair material applied to the surface to be repaired will penetrate into cracks and seal them due to the weight of vehicles passing over it, the repair material is thick, about 2 to 4 mm, and until it penetrates into the gaps, the repair material protrudes from the pavement surface, reducing road drivability. The repair material in Patent Document 3 does not require as much heating as conventional materials, but still requires application at about 60°C.

[0009] Furthermore, while the traditional asphalt emulsion can be applied at room temperature, its low concentration and viscosity mean that pouring it directly into cracks will not fill the cracks, and there is a lot of waste due to seepage into unnecessary areas. Furthermore, since it takes time for the emulsion to decompose, there is a risk that the emulsion will wash away if it rains after application. For this reason, it cannot be used as a repair material as is.

[0010] The present invention was devised in light of the current state of the prior art, and its purpose is to provide an asphalt pavement repair material that can be applied at room temperature without heating, and that does not require temperature control or pose the risk of burns or fires, etc. In addition, a further purpose of the present invention is to provide an asphalt pavement repair material that does not adhere to itself or to other objects, has good workability, can be used regardless of the size or shape of the area to be repaired, and does not impair vehicle drivability even immediately after repair. [Means for solving the problem]

[0011] As a result of extensive research into achieving the above-mentioned object, the inventors discovered that the above-mentioned problems could be solved by mixing a water-absorbent fibrous substrate with an asphalt emulsion and supporting the asphalt on the fibrous substrate, thereby arriving at the present invention.

[0012] That is, the present invention is achieved by the following means. (1) An asphalt pavement repair material comprising a water-absorbent fiber substrate containing an asphalt emulsion, wherein the asphalt emulsion is a cationic asphalt emulsion; The water-absorbent fibrous substrate contains water-absorbent fibers having cation-exchange groups, andAn asphalt pavement repair material characterized in that the water-absorbent fibrous base material has a water absorption ratio of 1.0 times or more or a cation exchange group of 1.0 mmol / g or more. ( 2 ) 200g / m 2 The asphalt pavement repair material according to (1), characterized in that it contains the above aggregate. ( 3 ) (1) or ( 2 ) A method for repairing asphalt pavement, comprising the steps of covering the area to be repaired with the asphalt pavement repair material described in (1) and drying the same. ( 4 ) A method for repairing asphalt pavement, comprising a coating step and a drying step of the area to be repaired, wherein the coating step comprises applying a cationic asphalt emulsion to the area to be repaired, and placing a water-absorbent fibrous substrate having a water absorption ratio of 1.0 times or more or a cation exchange group of 1.0 mmol / g or more on top of the applied cationic asphalt emulsion. ( 5 ) A method for repairing asphalt pavement, comprising a coating step and a drying step of the area to be repaired, characterized in that the coating step comprises placing a water-absorbent fibrous substrate having a water absorption ratio of 1.0 times or more or a cation exchange group of 1.0 mmol / g or more on the area to be repaired, and applying a cationic asphalt emulsion onto the placed fibrous substrate. ( 6 ) The coating step further includes adding aggregate. 4 )or( 5 ) A method for repairing asphalt pavement described in the above. [Effects of the Invention]

[0013] The repair material of the present invention is a mixture of a water-absorbent fibrous substrate and an asphalt emulsion. As the water-absorbent fibrous substrate absorbs the moisture from the asphalt emulsion, the asphalt emulsion decomposes, and the asphalt is supported on the fibrous substrate, forming an asphalt pavement repair material. By appropriately selecting the form of the water-absorbent fibrous substrate, it can be formed into any shape, including sheets, strings, and balls. As a result, it is possible to repair a wide variety of cracks, from large to small, radial cracks, and potholes. This reduces the risk of unevenness and adverse impacts on vehicle traffic after application. Additionally, because the repair material of the present invention uses an asphalt emulsion, it can be applied at room temperature without heating, reducing the need for temperature control and the risk of burns and fires. Furthermore, by coating the area to be repaired with the repair material of the present invention, it prevents water from entering cracks and potholes in the asphalt pavement surface and prevents damage below the pavement surface. The decomposition of asphalt emulsion refers to the separation (decomposition) of the asphalt emulsion into asphalt and water, resulting in caking properties. [Brief explanation of the drawings]

[0014] [Figure 1] 11 is a photograph showing the condition of the asphalt pavement repair material of Example 11 applied to a pothole after a durability test. [Figure 2] This is a photograph showing the condition of the asphalt pavement repair material of Example 12 applied to a linear crack after a durability test. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention is described in detail below. The repair material of the present invention is a water-absorbent fibrous substrate containing an asphalt emulsion. In such a repair material of the present invention, as the water-absorbent fibrous substrate absorbs the moisture from the asphalt emulsion, the asphalt emulsion decomposes, and asphalt is coated and supported on the fibrous substrate. This allows for a repair material with an asphalt layer that matches the shape of the fibrous substrate, such as a sheet, string, or ball. Therefore, the water-absorbent fibrous substrate used in the repair material of the present invention must have water absorption properties that are sufficient to cause the asphalt emulsion to decompose. In the present invention, the water-absorbent fibrous substrate refers to a fibrous substrate having water-absorbent properties.

[0016] The amount of asphalt emulsion to be incorporated into the water-absorbent fibrous substrate is preferably 5 to 100 times the weight of the water-absorbent fibrous substrate, although this depends on the water absorption ratio and composition of the water-absorbent fibrous substrate and the asphalt content of the asphalt emulsion. If the amount is less than 5 times, the asphalt emulsion may not spread throughout the fibrous substrate, resulting in areas that are not covered with asphalt. Even if the asphalt emulsion is evenly incorporated, the amount of asphalt supported by the water-absorbent fibrous substrate is small, often resulting in insufficient durability as an asphalt pavement repair material. On the other hand, if the amount of asphalt emulsion is more than 100 times, much of the asphalt emulsion will leak or drip from the water-absorbent fibrous substrate rather than being supported by the water-absorbent fibrous substrate, which can be disadvantageous in terms of workability and cost.

[0017] The water-absorbent fibrous substrate used in the present invention has a higher water absorption capacity, allowing for a greater amount of asphalt to be incorporated, making it possible to repair a wide variety of areas, such as cracks and potholes. The water absorption ratio is used as an indicator of water absorption. The water absorption ratio refers to the weight of ion-exchanged water that can be absorbed per weight of fibrous substrate. For the reasons mentioned above, the water absorption ratio of the water-absorbent fibrous substrate used in the present invention is preferably 1.0 or more, more preferably 10 or more. If the water absorption ratio is less than 1.0, depending on the area to be repaired, such as a pothole, where a relatively large amount of asphalt needs to be filled, the amount of asphalt incorporated may be insufficient, causing the fibrous substrate to appear on the surface, or the cracks may not be sufficiently covered with asphalt, resulting in insufficient effectiveness as a repair material. Furthermore, from the standpoint of workability, the upper limit of the water absorption ratio is preferably 100 or less. If the ratio exceeds 100 times, the high water absorption of the absorbent fiber substrate will cause the asphalt to aggregate locally at the point where the asphalt emulsion first comes into contact with the absorbent fiber substrate, and the asphalt emulsion may not be distributed throughout the entire absorbent fiber substrate.

[0018] Furthermore, the absorbent fibrous substrate used in the present invention preferably has 1.0 mmol / g or more, more preferably 2.0 mmol / g or more, of cation-exchange groups to impart high absorbency to the fibrous substrate and to promote the decomposition of commonly used cationic asphalt emulsions. If the amount of cation-exchange groups is less than 1.0 mmol / g, the amount of asphalt combined may be insufficient. Furthermore, the upper limit of the amount of cation-exchange groups is preferably 15 mmol / g or less. If the amount exceeds 15 mmol / g, the decomposition of the asphalt emulsion due to the action of the cation-exchange groups becomes too rapid, resulting in localized aggregation and support of the asphalt at the point where the asphalt emulsion first comes into contact with the absorbent fibrous substrate, which may prevent the asphalt emulsion from being distributed throughout the entire absorbent fibrous material.

[0019] Here, examples of the above-mentioned cationic exchange group include, but are not limited to, a sulfonic acid group, a carboxylic acid group, a phosphonic acid group, and salts thereof.

[0020] In the present invention, it is preferable to satisfy both the above-mentioned ranges of absorbency and amount of cation exchange groups, but the intended effect of the present invention can be obtained even if only one of them is satisfied.

[0021] The shape of the water-absorbent fiber substrate can be any shape, such as short fibers cut to an appropriate length, long fibers, spun yarn, twisted yarn, nonwoven fabric, woven fabric, knitted fabric, etc., and can be selected appropriately according to the shape of the part to be repaired. For example, if the part to be repaired has a small crack, it is preferable to select a sheet-like shape such as nonwoven fabric, woven fabric, knitted fabric, etc., as this will not interfere with the running performance of the vehicle. The basis weight of these is 20 g / m 2 More than 300g / m 2 The following is preferred: 20 g / m 2 If the density is less than 300 g / m, the water-absorbent fiber substrate may deform under the weight of the asphalt emulsion when impregnated with the asphalt emulsion, or even if it does not deform, the amount of asphalt compounded with the water-absorbent fiber substrate may be insufficient, resulting in a decrease in durability as an asphalt pavement repair material. 2 If the thickness of the repair material exceeds this, the thickness of the repair material will increase, which may worsen the running performance after repair. Furthermore, for repair areas that require filling with asphalt, such as wide cracks or potholes, it is preferable to select a string-like shape such as short fibers, spun yarn, or twisted yarn. Such a shape allows the repair material to be filled according to the shape of the area to be repaired.

[0022] The fibers constituting the water-absorbent fibrous substrate are not particularly limited as long as they can provide the above-mentioned water-absorbent properties to the fibrous substrate, and various fibers can be used, for example, polyester, polyamide, aromatic polyamide, polypropylene, vinylon, acrylic, polyvinyl chloride, rayon, cotton, wool, glass fiber, carbon fiber, metal fiber, etc. Water-absorbent fibers having cation-exchange groups are particularly preferred.

[0023] Such absorbent fibers having cation-exchange groups preferably have a core-sheath structure, with the cation-exchange groups in the sheath. Absorbent fibers with this structure have high absorbency in the sheath, while the core prevents deterioration of fiber properties. This not only provides the fiber substrate with the ability to incorporate a large amount of asphalt, but also allows the fiber to maintain its fiber shape even after absorbing water by mixing with asphalt emulsion. This allows them to be used while maintaining their short fiber form. Furthermore, they can be used as repair materials for spun yarns, twisted yarns, nonwoven fabrics, woven fabrics, knitted fabrics, and the like without losing their shape. As a result, they can be used for a wide variety of repair targets, making them highly suitable as fibers for constituting the absorbent fiber substrate used in the present invention. An example of such absorbent fibers is Lanseal (registered trademark) manufactured by Nippon Exlan Kogyo.

[0024] The asphalt emulsion used in the present invention is not particularly limited, and examples thereof include bitumen mixtures of one or more of natural asphalt such as lake asphalt, petroleum asphalt such as straight asphalt, blown asphalt, and semi-blown asphalt, heavy oil, tar, and pitch, emulsified in water using an appropriate emulsifying machine such as a colloid mill or homogenizer, with the use of an emulsifier such as various surfactants or clay (e.g., bentonite), and with the addition of alkali, acid, dispersant, protective colloid, and the like, as needed.

[0025] The emulsifier can be any of cationic, nonionic, and anionic types. In the present invention, the emulsifiers used are referred to as cationic asphalt emulsion, nonionic asphalt emulsion, and anionic asphalt emulsion, respectively, depending on the type of emulsifier used. Cationic asphalt emulsions are often used for road paving.

[0026] Cationic emulsifiers that can be used in the present invention include aliphatic or alicyclic monoamines, diamines, triamines, amidoamines, polyaminoethylimidazolines, long-chain alkyl groups, long-chain hydroxyalkyldiamines, rosin amines, ethylene oxide adducts of these amines, amine oxides, water-soluble or water-dispersible salts of these amine surfactants treated with acids such as hydrochloric acid, sulfamic acid, and acetic acid, as well as quaternary ammonium salts of these amine surfactants. These surfactants can also be used in combination with nonionic surfactants such as polyoxyethylene alkyl ethers and oxyethylene-oxypropylene block copolymers.

[0027] Examples of anionic emulsifiers that can be used in the present invention include higher alcohol sulfates, alkylarylsulfonates, alkylbenzenesulfonates, α-olefinsulfonates, higher alcohol ethoxylates, higher alcohol ethoxylate sulfates, soaps, naphthalenesulfonates and formalin-modified products, alkaline lignin salts, ligninsulfonates, alkaline casein salts, and polyacrylates.

[0028] Examples of nonionic emulsifiers that can be used in the present invention include alkylphenols, mono- and polyhydric alcohol acids, aliphatics, aliphatic amines, aliphatic amides, alkylene oxide adducts of ethanolamines, and the like.

[0029] Furthermore, examples of dispersants and protective colloids that can be used in the asphalt emulsion used in the present invention include sodium naphthalene sulfonate, casein, alginic acid, gelatin, carboxymethyl cellulose, ethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, sodium polyacrylate, lignin sulfonate, and nitrohumate.

[0030] In the asphalt emulsion used in this invention, natural rubber or various synthetic rubbers may be used alone or in combination as the emulsified and dispersed bitumen. Synthetic rubbers include chloroprene rubber, styrene-isoprene copolymer rubber, polyisoprene rubber, polybutadiene rubber, and styrene-butadiene copolymer rubber, and are used alone or in combination. Chloroprene rubber and styrene-isoprene copolymer rubber are particularly preferred, as they offer improved properties at both high and low temperatures.

[0031] The asphalt emulsion used in the present invention also includes modified asphalt prepared by adding the following polymers to bitumen in addition to rubber, and then emulsifying this modified asphalt to prepare an asphalt emulsion. Examples of polymers that can be added include synthetic polymers such as ethylene vinyl acetate copolymer, polyethyl acrylate, polymethyl acrylate, polyacrylic acid, and polyvinyl chloride; synthetic resins such as coumarone resin, phenolic resin, xylene resin, urea-formalin resin, and alkyd resin; and natural resins such as rosin and terpene resin.

[0032] Furthermore, ultraviolet absorbers, various additives, viscosity modifiers, etc. may be added to these asphalt emulsions for the purposes of improving heat resistance, preventing deterioration due to ultraviolet rays, etc., improving workability, and improving adhesiveness.

[0033] The solid content of the asphalt emulsion used in the present invention is preferably in the range of 30 to 80% by weight. If the solid content is less than 30% by weight, the asphalt cannot be efficiently compounded with the water-absorbent fibrous base material, while if it exceeds 80% by weight, the viscosity increases, making it difficult to mix the water-absorbent fibrous base material with the asphalt emulsion.

[0034] The repair material of the present invention may also contain aggregate, as in conventional asphalt repair. The inclusion of aggregate is believed to be effective in preventing asphalt adhesion when vehicles pass through areas to be repaired, such as linear or turtle-shell-shaped cracks, and in improving the durability of the repair material. Furthermore, when the area to be repaired is a pothole or a wide linear crack, the repair material is filled into the area to be repaired, improving hardness during this process. Aggregates commonly used in general asphalt pavements can be used. Examples include inorganic materials such as crushed stone, gravel, steel slag, emery, and crushed ceramic products, as well as granular resins such as hard rubber, thermosetting resins, and high-melting-point thermoplastic hard resins.

[0035] In addition, the amount of aggregate added is set at 1 / m² for repair material to provide abrasion resistance and hardness. 2 The amount is preferably 200 g or more, more preferably 300 g or more, and even more preferably 500 g or more per unit area. If the amount is less than 200 g, the function as a repair material will deteriorate quickly.

[0036] Furthermore, the particle size of the aggregate is appropriately selected taking into consideration the shape of the area to be repaired, such as cracks or potholes, and the shape of the repair material, such as sheet or ball shape.

[0037] Next, we will explain a method for repairing asphalt pavement using the asphalt pavement repair material of the present invention. One example of such a repair method is a construction method that includes the steps of coating the area to be repaired with a mixture of a water-absorbent fiber base material and an asphalt emulsion and drying the mixture.

[0038] Methods for mixing the water-absorbent fibrous base material with the asphalt emulsion include immersing the water-absorbent fibrous base material in the asphalt emulsion, or spraying, spraying, or applying the asphalt emulsion to the water-absorbent fibrous base material. The amount of asphalt emulsion mixed can be controlled by mixing more than a predetermined amount of asphalt emulsion in advance and then draining it off with a roller or by hanging it, or by mixing only a predetermined amount in advance.

[0039] The covering step can be carried out by applying or filling the repair material of the present invention, which is obtained by previously mixing the water-absorbent fiber base material with an asphalt emulsion by the above-mentioned method, to the area to be repaired.

[0040] In addition, in the covering process, a method of forming the repair material of the present invention on the repair target area during construction can also be used. Examples of such methods include attaching or filling a water-absorbent fibrous substrate to the repair target area, then adding and mixing an asphalt emulsion, or applying, spraying, injecting, or otherwise applying an asphalt emulsion to the repair target area, and then installing the water-absorbent fibrous substrate. These methods can be selected appropriately depending on the type and scale of the repair target area and the contractor's workability.

[0041] Here, the method for applying the asphalt emulsion to the area to be repaired is not particularly limited, and any conventional method can be used, such as coating, scattering, or spraying using a distributor, sprayer, brush, roller, etc., or pouring from a container, filling with a dropper, injection, etc.

[0042] The method for placing the water-absorbent fibrous substrate in the area to be repaired is not particularly limited, and conventionally known methods can be used. For example, when the water-absorbent fibrous substrate is in sheet form, the fibrous substrate can be wound in advance around a roller or the like and laid on the area to be repaired, and then cut, or a method in which a pre-cut fibrous substrate is laid on the area to be repaired. When the water-absorbent fibrous substrate is in string form, an example of a method is to cut it to a length that matches the area to be repaired, such as a crack, and embed it along the crack. Furthermore, when the water-absorbent fibrous substrate is in the form of short fibers, an example of a method is to fill the area to be repaired, such as a crack or pothole.

[0043] In the coating step, aggregate may be added to improve the durability and strength of the repair material of the present invention.

[0044] The drying step in the repair method of the present invention is carried out after the coating step described above, and is a step in which the repair material of the present invention that has coated the repair target area is dried to integrate the repair material with the repair target area. There are no particular restrictions on this drying step; the repair material may be left to dry naturally after coating the repair target area. If it is desired to shorten the usable time, drying may be performed using a drying device that generates hot air. [Example]

[0045] Examples are given below to facilitate understanding of the present invention, but these are merely illustrative and the gist of the present invention is not limited to these.

[0046] <Evaluation method> The evaluation method for the water-absorbent fibrous substrate will be described below.

[0047] 1) Water absorption capacity The weight (A [g]) of the absorbent fibrous substrate is measured. Next, the absorbent fibrous substrate is immersed in ion-exchanged water for 30 minutes, and then centrifuged at 160 G for 5 minutes. The weight (B [g]) after centrifugal dehydration is measured, and the absorbency is calculated using the following formula. Water absorption capacity (times) = (B / A)-1

[0048] 2) Amount of cation exchange groups The absorbent fibrous substrate is immersed in 0.1N hydrochloric acid, the pH is confirmed to be 2 or less, and the substrate is washed and dried, after which its weight (A [g]) is measured. Next, X [mL] of 0.1N sodium hydroxide is added to an amount of ion-exchanged water sufficient to fully immerse the absorbent fibrous substrate. The absorbent fibrous substrate after the weight measurement is immersed in the solution for 30 minutes, after which the absorbent fibrous substrate is removed and washed with ion-exchanged water. The wash water and the remaining ion-exchanged water are mixed and titrated with 0.1N hydrochloric acid. The amount of cation exchange groups is calculated using the following formula, with the amount of dripping required to reach the neutralization point being Y [mL]. Amount of cation exchange group (mmol / g) = {(0.1 × X) - (0.1 × Y)} / A

[0049] 3) Asphalt adhesion amount The weight (A [g]) of the water-absorbent fibrous substrate is measured. Next, the water-absorbent fibrous substrate and an excess amount of asphalt emulsion (as described in each example) are placed in a polyethylene bag with a zipper and sealed. After leaving the polyethylene bag at room temperature for one day, the water-absorbent fibrous substrate is removed and the excess asphalt emulsion is washed away with running water. After that, it is dried at room temperature for three days and its weight (B [g]) is measured. The amount of asphalt adhesion is calculated using the following formula. Asphalt adhesion amount (times) = (B / A) - 1 4) Ease of construction The ease of application of asphalt pavement repair materials to the area to be repaired (applying to or filling in cracks) is judged according to the following criteria. ○: Repair materials do not adhere easily even when they come into contact with each other. △: When repair materials come into contact with each other, they stick together. ×: It is difficult to separate and spread the repair materials from each other.

[0050] 5) Durability The asphalt pavement repair material was applied or filled into the area to be repaired on an asphalt pavement road with heavy vehicle traffic, and after drying, the condition was visually evaluated three months later using the following criteria. ○: No cracks or tears in the repair material △: There are some cracks or tears in the repair material. ×: Cracks or tears have occurred in the repair material, and the condition has returned to almost the same as before repair.

[0051] Example 1 The core is made of polyacrylonitrile, and the sheath is made of fiber with a water-absorbing part containing carboxyl groups (Lanseal (registered trademark) FK (fineness 5.6 dtex, fiber length 51 mm) manufactured by Nippon Exlan Kogyo Co., Ltd.). The fiber was needle-punched to a density of 100 g / m 2A nonwoven fabric of this formula was prepared and designated as water-absorbent fiber substrate 1. Next, the substrate was cut into 30 cm x 10 cm pieces and immersed in cationic asphalt emulsion (PK-3 manufactured by Maeda Road Co., Ltd.). Excess asphalt emulsion was then squeezed off with a roller to obtain sheet-shaped asphalt pavement repair material 1 containing 30 times the weight of asphalt emulsion relative to the weight of the substrate. The evaluation results of water-absorbent fiber substrate 1 and asphalt pavement repair material 1 are shown in Table 1.

[0052] <Examples 2 to 4> Instead of using only Lanseal®, the Lanseal® and polyester fiber (fineness 3.3 dtex, fiber length 51 mm) were used in a weight ratio of 50:50 (Example 2), the Lanseal® and polyester fiber were used in a weight ratio of 25:75 (Example 3), or only Moiscare® N38E (fineness 4.4 dtex, fiber length 50 mm) manufactured by Nippon Exlan Kogyo was used (Example 4). The amount of asphalt emulsion added was changed to 10 times (Example 2) or 6 times (Examples 3 and 4) the weight of the base material. Water-absorbent fiber substrates 2-4 and sheet-shaped asphalt pavement repair materials 2-4 were obtained in the same manner as in Example 1. The evaluation results are shown in Table 1. Note that Moiscare® N38E is a fiber that contains carboxyl groups, which are cation-exchange groups, on the surface and throughout the fiber.

[0053] <Examples 5 and 6> Asphalt pavement repair materials 5 and 6 were obtained in the same manner as in Example 1, except that cationic asphalt emulsion (PK-3, manufactured by Maeda Road Co., Ltd.) was replaced with cationic asphalt emulsion (RSK-4, manufactured by Toa Road Co., Ltd.) (Example 5) or cationic asphalt emulsion (Tackfine E, manufactured by Toa Road Co., Ltd.) (Example 6). The evaluation results are shown in Table 1.

[0054] <Examples 7 and 8> In Example 2, the basis weight of the nonwoven fabric was 100 g / m 2 from 40 g / m 2 (Example 7) or 150 g / m 2Water-absorbent fiber base materials 7 and 8 and asphalt pavement repair materials 7 and 8 were obtained in the same manner as in Example 8, except for the changes. The evaluation results are shown in Table 1.

[0055] Example 9 Asphalt pavement repair material 9 was obtained in the same manner as in Example 1, except that the weight of the asphalt emulsion to be contained was changed from 30 times to 20 times. The evaluation results are shown in Table 1.

[0056] Example 10 A sliver was prepared using Nippon Exlan Industries' Lanseal® FK (fineness 5.6 dtex, fiber length 51 mm) and polyester fiber (fineness 9 dtex, fiber length 51 mm). The sliver was then wrapped with 140 dtex polyester multifilament to produce a 10,000 dtex yarn containing 50% Lanseal®, which served as the water-absorbent fiber substrate 10. The yarn was then immersed in cationic asphalt emulsion (Maeda Road PK-3), and excess asphalt emulsion was squeezed off with a roller to obtain a string-shaped asphalt pavement repair material 10 containing 30 times the asphalt emulsion relative to the substrate weight. The evaluation results are shown in Table 1. Note that the yarn exhibited stronger fiber restraint than nonwoven fabric, resulting in a slightly lower water absorption ratio. To confirm workability, 10 rolls of asphalt pavement repair material 10 were filled along a 3 cm-wide linear crack. There was no strong adhesion between the repair materials, and workability was excellent.

[0057] Example 11 Lanseal (registered trademark) was cut into fibers with a fiber length of about 1 cm to prepare a water-absorbent fiber substrate 11. Next, a cationic asphalt emulsion (PK-3 manufactured by Maeda Road Co., Ltd.) was applied in an amount of 30 times the weight of the substrate and 2000 g / m2 was applied to the area of ​​the area to be repaired. 2 The amount of No. 4 aggregate was added and mixed to obtain aggregate-containing asphalt pavement repair material 11. The evaluation results are shown in Table 1. A photograph after the durability test is shown in Figure 1. The water absorption capacity was extremely high because there was no fiber restraint like in nonwoven fabric.

[0058] Example 12 The asphalt pavement repair material 1 prepared in Example 1 was applied to a linear crack 1 cm wide, and No. 4 aggregate was applied on top of it at a rate of 1000 g / m 2 The coating was applied so that the coating was uniformly dispersed, and after drying at room temperature, the durability was evaluated. The evaluation results are shown in Table 1. Figure 2 shows a photograph of the coating after the durability test.

[0059] Example 13 The water-absorbent fiber substrate 1 prepared in Example 1 was placed in a linear crack 1 cm wide, and a cationic asphalt emulsion (PK-3, manufactured by Maeda Road Co., Ltd.) was sprayed onto the substrate in an amount 30 times the weight of the substrate. In this application method, the water-absorbent fiber substrate was attached to the area to be repaired, and then the asphalt emulsion was directly applied. This prevented the asphalt emulsion from flowing out of the area to be repaired, and the repair materials did not stick together, resulting in good workability.

[0060] Example 14 The area to be repaired, which was a linear crack 1 cm wide, was surrounded by masking tape measuring 60 cm x 10 cm. Next, a cationic asphalt emulsion (PK-3 manufactured by Maeda Road Co., Ltd.) was sprayed evenly over the area to be repaired surrounded by the masking tape, in an amount 30 times the weight of the 60 cm x 10 cm water-absorbent fiber substrate 1. Next, the 60 cm x 10 cm water-absorbent fiber substrate 1 was attached to the area to be repaired. In this construction method, the asphalt emulsion was applied before the water-absorbent fiber substrate was attached, so the repair materials did not stick to each other, and workability was good.

[0061] <Comparative Example 1> Comparative fiber substrate 1 and comparative repair material 1 were obtained in the same manner as in Example 1, except that 100% by weight of polyester fiber was used instead of 100% by weight of Lanseal (registered trademark). The evaluation results are shown in Table 1.

[0062] [Table 1]

[0063] As shown in Table 1, the absorbent fibrous substrates of each Example have a higher water absorption capacity or a higher amount of cation exchange groups than the fibrous substrate of Comparative Example 1, and are therefore capable of adhering a larger amount of asphalt. It can also be seen that the asphalt pavement repair materials of each Example, which employ such absorbent fibrous substrates, are easy to apply and have good durability.

Claims

1. An asphalt pavement repair material comprising a water-absorbent fibrous base material containing an asphalt emulsion, wherein the asphalt emulsion is a cationic asphalt emulsion, the water-absorbent fibrous base material contains water-absorbent fibers having cation exchange groups, and the water-absorbent fibrous base material has a water absorption ratio of 1.0 times or more or cation exchange groups of 1.0 mmol / g or more.

2. 200 g / m ２ 2. The asphalt pavement repair material according to claim 1, characterized in that it contains the above aggregate.

3. 3. A method for repairing an asphalt pavement, comprising the steps of: coating an area to be repaired with the asphalt pavement repair material according to claim 1; and drying the coating.

4. A method for repairing asphalt pavement, comprising a coating step and a drying step of the area to be repaired, wherein the coating step comprises applying a cationic asphalt emulsion to the area to be repaired, and placing a water-absorbent fibrous substrate having a water absorption ratio of 1.0 times or more or a cation exchange group of 1.0 mmol / g or more on top of the applied cationic asphalt emulsion.

5. A method for repairing asphalt pavement, comprising a coating step and a drying step of the area to be repaired, characterized in that the coating step comprises placing a water-absorbent fibrous substrate having a water absorption ratio of 1.0 times or more or a cation exchange group of 1.0 mmol / g or more on the area to be repaired, and applying a cationic asphalt emulsion onto the placed fibrous substrate.

6. 6. The method for repairing an asphalt pavement according to claim 4 or 5, wherein the coating step further comprises adding aggregate.

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