Pavement repairing material

Abstract

To provide a pavement repairing material capable of repairing a pavement surface with a simple work in a short time and at a low cost, and having excellent durability.SOLUTION: A repairing material 1 is provided with a butyl rubber layer 5 which contains butyl rubber which can be adhered to a pavement surface and is molded in layers, and a rubber chip layer 6 which contains a rubber chip mixture 11 obtained by mixing a rubber chip material 8, an aggregate 9, and a binder 10, is molded in layers, and is stacked on the upper surface 5b of the butyl rubber layer 5, wherein the mixing ratio of the rubber chip material 8 to the aggregate 9 is in the range of 60:40-90:10 by weight, and the mixing ratio of the rubber chip material 8 to the binder 10 is in the range of 70:30-90:10 by weight.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pavement repair material, and more particularly to a pavement repair material for repairing areas such as cracks that have occurred on the pavement surface of a road. [Background technology]

[0002] It has been known that road surfaces, such as asphalt and concrete pavements, deteriorate due to various factors, such as long-term use, resulting in damage such as cracks, irregularities, and fissures. If this damage is left unattended, the surface layer of the asphalt or other pavement surface may peel off or the road may collapse, causing larger irregularities and unevenness, making safe vehicle travel difficult and potentially leading to traffic accidents. Furthermore, the resulting unevenness poses a risk of pedestrians tripping and falling.

[0003] Therefore, when damage to the pavement surface as described above is confirmed, the road administrator or the like must promptly repair the damaged area. For example, repairs are carried out using the overlay method, in which the damaged area and the surrounding pavement surface are removed and a new pavement surface is formed. Alternatively, as an emergency repair for the damaged area, a common process is to fill the damaged area with an asphalt-based cold mix, which is a pre-mix of asphalt and aggregate, and then apply pressure from above to compact the asphalt-based cold mix, filling any voids in the damaged area.

[0004] However, with the overlay method, it is necessary to remove a large area of ​​the damaged area and its surroundings, which makes the repair work itself large-scale, requiring heavy machinery, etc. This requires a large number of workers, takes a long time for the repair work, and increases the work costs. Therefore, when the damaged area is limited to a small area, it is difficult to implement the overlay method.

[0005] On the other hand, repairs using asphalt-based cold mixtures can be carried out with relatively simple work, and the number of workers, work time, and work costs can be reduced compared to the overlay method. Therefore, it can be used to adequately repair even small areas of damage.

[0006] However, because the repairs simply involved filling the damaged area with cold asphalt and compacting it from above, there was a possibility that the repairs would not be durable enough. As a result, further vehicle traffic or pedestrian traffic over the repaired area could cause further damage to the pavement surface in a relatively short period of time, and there was a risk that repair work would have to be carried out repeatedly in the same area.

[0007] As explained above, both the overlay method and emergency repair using asphalt-based cold mixes have their advantages and disadvantages. Therefore, proposals have been made for pavement repair materials that can be used to repair road pavement surfaces relatively easily, without increasing work costs, and with excellent durability.

[0008] For example, a pavement repair method has been proposed in which a cement composition containing cement and other ingredients and an accelerator for rapidly setting the cement composition are used to cover the damaged area, and then the accelerator is poured on top (see Patent Document 1).This repair method allows for pavement repair that is easy to work with and has excellent early strength development and durability.

[0009] On the other hand, repair materials and repair methods using such repair materials have been proposed, including a mat-type asphalt mixture pavement repair material (see Patent Document 2), in which an asphalt mixture made by heating and kneading asphalt, fine aggregate, and coarse aggregate is formed into a mat of a predetermined size, and a mat-type repair material (see Patent Document 3), in which an asphalt mixture is formed into a mat, a mat-type repair material body, and an adhesive layer provided on the underside of the mat-type repair material body and capable of self-adhering to the repair surface (adhesive surface), and a release sheet attached to the underside of the adhesive layer.

[0010] In the case of the mat-type asphalt mixture pavement repair material shown in Patent Document 2, by further scattering aggregate on the surface of the heated and kneaded asphalt mixture, the material has flexibility and elasticity that prevents it from breaking or rupturing even when subjected to the load applied when a vehicle runs over it. The scattered aggregate prevents deformation of the repair material itself and generates appropriate friction with the vehicle tires, allowing the tires to grip even when rainwater accumulates on the repair material during rainy weather, enabling stable vehicle travel.

[0011] On the other hand, in the case of the mat-type repair material shown in Patent Document 3, the adhesive layer provided on the underside of the mat-type repair material body can strengthen the adhesive force (bonding force) between the mat-type repair material and the road pavement surface, and further, the mat-type repair material body containing the asphalt mixture has the advantage of generating an appropriate friction force against the vehicle tires.

[0012] Furthermore, as another repair material, an elastic pavement has been proposed (see Patent Document 4) that has an adhesive layer containing polyisobutylene rubber and an aggregate layer made of powdered granular material laid on the adhesive layer. By adopting such a configuration, it can be easily laid on the paved road surface, it can simplify the repair work, and it also has the effect of suppressing the road surface from freezing. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Japanese Patent Application Publication No. 2013-209822 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-019483 [Patent Document 3] Japanese Patent Publication No. 2020-084720 [Patent Document 4] Utility Model Registration No. 3198448 Summary of the Invention [Problem to be solved by the invention]

[0014] However, the above-mentioned pavement repair materials and repair methods have sometimes caused the following problems. For example, in the repair method of Patent Document 1, an accelerator is poured over the cement composition and then compressed. Although this can accelerate the hardening of the cement composition, the adhesion between the cement composition and the pavement surface can still be low. As a result, the hardened cement composition does not adhere firmly to the pavement surface, and durability may be insufficient.

[0015] On the other hand, in the case of the mat-type asphalt mixture pavement repair material disclosed in Patent Document 2, a pretreatment step was required before carrying out the repair work, such as heating the pavement surface to be repaired with a gas burner or applying an organic solvent-based primer in advance. As a result, there were problems such as an increase in the number of work steps and a long work time.

[0016] In the case of the types disclosed in Patent Documents 3 and 4 that have an adhesive layer in the lower layer, the pretreatment process was unnecessary or could be simplified as described above. However, since it was necessary to firmly fix it to the road pavement surface, the adhesive layer had to have strong adhesive strength. As a result, if the thickness of the mat-type repair material itself or the aggregate layer on top of the adhesive layer was thin or the density was low, such as there being large gaps between the aggregates, and if a strong force was applied from above after construction, there was a risk that the adhesive components, such as butyl rubber, contained in the adhesive layer would seep out to the surface of the upper layer (aggregate layer, etc.).

[0017] As a result, the adhesive strength of the repair material and the elastic pavement itself to the pavement surface may decrease, causing durability problems. Furthermore, the adhesive component may seep into the upper layer, causing problems such as the adhesive component adhering to tires or pedestrian shoes, or the adhesive strength of the adhesive component may cause pedestrians to trip.

[0018] In view of the above, the present invention aims to provide a pavement repair material with a two-layer structure having an adhesive layer as a lower layer, which can repair pavement surfaces relatively easily, in a short time, and at low cost without requiring any pretreatment process before repair work, and which is highly durable. In addition, the present invention aims to provide a pavement repair material that can prevent the adhesive components of the adhesive layer from seeping out to the surface of the upper layer, thereby ensuring the safety of pedestrians, and is particularly suitable for repairing sidewalk pavements. [Means for solving the problem]

[0019] As a result of extensive research, the inventors of the present application discovered that the above-mentioned problems could be solved by optimizing the configuration of the rubber chip layer containing rubber chip material, etc., on the adhesive layer, and thus completed the present invention described below.

[0020] [1] A pavement repair material comprising: an adhesive layer containing an adhesive component that can adhere to a pavement surface and formed into a layer; and a rubber chip layer containing a rubber chip mixture that is a mixture of rubber chip material, aggregate, and binder, formed into a layer, and stacked on top of the adhesive layer, wherein the mixing ratio of the rubber chip material to the aggregate is in the range of 60:40 to 90:10 by weight, and the mixing ratio of the rubber chip material to the binder is in the range of 70:30 to 90:10 by weight.

[0021] [2] A pavement repair material as described in [1], wherein the chip diameter of the rubber chip material is set to less than 2 mm, and the particle size ratio of the chip diameter of the rubber chip material to the aggregate particle size of the aggregate is in the range of 2:1 to 1:2.

[0022] [3] A pavement repair material as described in [1] or [2], wherein the layer thickness ratio of the adhesive layer thickness to the rubber chip layer thickness is in the range of 2.5:1 to 4:1, and the sum of the adhesive layer thickness and the rubber chip layer thickness is set to 4 mm or less.

[0023] [4] A pavement repair material as described in [1] or [2], wherein the side end surface of the repair material formed by the adhesive layer and the rubber chip layer has a tapered portion that slopes diagonally upward from the lower surface end of the adhesive layer toward the center of the rubber chip layer.

[0024] [5] The pavement repair material according to [1] or [2], wherein the adhesive component is butyl rubber.

[0025] [6] The pavement repair material according to [1] or [2] above, used to repair the pavement surface of a sidewalk. [Effects of the Invention]

[0026] The pavement repair material of the present invention eliminates the need for pre-treatment processes such as heat treatment and primer application to the area to be repaired, and allows repairs to be carried out simply by placing the material on the area to be repaired. This reduces work time, simplifies the work process, and reduces work costs.

[0027] Furthermore, the adhesive strength of the adhesive layer allows the pavement repair material to be stably fixed to the repair area, resulting in excellent durability after repair.The rubber chip layer on top of the adhesive layer exerts frictional force and provides moderate elasticity, thereby reducing impact and noise when vehicles are passing by and allowing pedestrians to walk steadily.

[0028] Furthermore, by more specifically specifying the mixing ratio of rubber chip material, aggregate, and binder in the rubber chip layer, adjusting the particle size ratio of the chip diameter of the rubber chip material and the aggregate particle size of the aggregate, as well as the layer thickness ratio and overall layer thickness of the adhesive layer and rubber chip layer, it is possible to prevent adhesive components such as butyl rubber from seeping out onto the top surface of the rubber chip layer, and by minimizing the step from the pavement surface as much as possible, it is possible to prevent pedestrians from falling, etc. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is an explanatory diagram showing a schematic configuration of a pavement repair material according to one embodiment of the present invention. [Figure 2] FIG. 1 is a reference cross-sectional view showing a schematic example of repair using a pavement repair material. [Figure 3] FIG. 2 is a reference cross-sectional view showing an example of a pavement repair material having a tapered portion. [Figure 4] FIG. 1 is an explanatory diagram showing the application positions of the repair material to be evaluated and a commercially available product. [Figure 5] 1 is a graph showing a comparison of the skid resistance values ​​immediately after construction and after one month has passed. [Figure 6] 1 is a graph showing a comparison of the GB coefficient and SB coefficient values ​​immediately after construction and after one month has passed. DETAILED DESCRIPTION OF THE INVENTION

[0030] The following describes embodiments of the pavement repair material of the present invention. Note that the pavement repair material of the present invention is not limited to the following embodiments, and changes, modifications, improvements, etc. can be made without departing from the gist of the present invention.

[0031] 1. Pavement repair materials One embodiment of the present invention, a pavement repair material 1 (hereinafter simply referred to as "repair material 1"), is used to repair a repair area 3 such as a crack that has occurred on a pavement surface 2 of a road such as asphalt pavement.The repair material 1 is placed so as to cover the repair area 3 from above, and its adhesive power is used to secure the repair material 1 on top of the repair area 3, thereby enabling vehicles, pedestrians, etc. to drive or walk stably.

[0032] The repair material 1 of this embodiment is used to repair a repair spot 3 that has occurred on a paved surface 2 of a road such as a "roadway (including paved surfaces such as parking lots)" where vehicles pass and a "sidewalk" where pedestrians pass, and is not particularly limited. However, some examples suitable for "sidewalks" will be shown.

[0033] Here, Figure 1 is an explanatory diagram showing the general configuration of the repair material 1 of this embodiment, Figure 2 is a reference cross-sectional view showing a schematic example of repair using the repair material 1, Figure 3 is a reference cross-sectional view showing an example of a repair material 1a having a tapered portion 13, Figure 4 is an explanatory diagram showing the application positions of the repair material P1 to be evaluated and the commercially available product P2, Figure 5 is a graph showing the comparison of the values ​​of skid resistance immediately after application and one month after, and Figure 6 is a graph showing the comparison of the values ​​of the GB coefficient and the SB coefficient immediately after application and one month after.

[0034] The repair material 1 of this embodiment basically has a two-layer structure comprising a lower butyl rubber layer 5 that contacts the paved portion of the pavement surface, and an upper rubber chip layer 6 that is stacked on the butyl rubber layer 5. Here, the butyl rubber layer 5 corresponds to the "adhesive layer" in the present invention.

[0035] The butyl rubber layer 5 is made primarily from well-known butyl rubber, which provides strong adhesive properties that enable adhesion to the pavement surface 2. Here, the butyl rubber is layered on the "adhesive component" of the present invention, and is thinly stretched to a predetermined adhesive layer thickness t1 and molded into a layer (sheet). The butyl rubber layer 5 may be a commercially available butyl rubber sheet that is reused as is.

[0036] Here, as described above, the butyl rubber layer 5 not only exhibits adhesiveness for firmly fixing the repair material 1 to the pavement surface 2 (repair area 3), but also has a water-stopping function that prevents rainwater and the like that has accumulated on the pavement surface 2 from reaching the rubber chip layer 6 above the butyl rubber layer 5. In other words, it prevents rainwater and the like from reaching the rubber chip layer 6 and reducing the frictional force.

[0037] Furthermore, the butyl rubber layer 5 always exhibits its adhesiveness, and if the butyl rubber layer 5 is left exposed during the production of the repair material 1, during storage after production is completed, and during transport to the pavement surface 2 having the repair area 3, it would be inconvenient to store or transport the repair material in a stacked state.

[0038] 1, a release paper 7 coated with a release agent is attached to the underside 5a of the butyl rubber layer 5. This allows multiple repair materials 1 to be stacked during storage and transportation after production, facilitating storage and transportation, and also allows the adhesive strength of the butyl rubber layer 5 to be quickly exerted by peeling off the release paper 7 during repair work.

[0039] On the other hand, the rubber chip layer 6 is formed from a rubber chip mixture 11 obtained by mixing rubber chip material 8, aggregate 9, and binder 10 in a predetermined mixing ratio, and the rubber chip mixture 11 is thinly spread on the butyl rubber layer 5 so as to have a predetermined rubber chip layer thickness t2, and then molded into a layer (sheet).

[0040] As a result, a repair material 1 having a two-layer structure is formed in which the laminar rubber chip layer 6 is stacked on the upper surface 5b of the laminar butyl rubber layer 5.

[0041] 1 and 2, the repair material 1 of this embodiment has a generally square shape when viewed from above and is formed with a predetermined repair material thickness t3. More specifically, in the case of the repair material 1 of this embodiment, the length L1 of one side and the length L2 of the other side perpendicular to the first side are each set to "500 mm," and the repair material thickness t3, which is the sum of the adhesive layer thickness t1 of the butyl rubber layer 5 and the rubber chip layer thickness t2 of the rubber chip layer 6, is set to "4 mm." In other words, it is configured as a two-layered thin plate-like member measuring 500 mm long, 500 mm wide, and 4 mm thick.

[0042] The pavement repair material of the present invention is not limited to the shapes and sizes described above, and may be formed into an appropriate shape (rectangular, circular, elliptical, etc.) and size depending on the size, shape, or position of the repair area 3. However, when multiple repair materials 1 are used side by side depending on the size of the repair area 3 or the transportation to the repair area 3, it is particularly preferable to use repair materials standardized to the shapes and sizes described above.

[0043] There are no particular restrictions on the material of the rubber chip material 8 used in the rubber chip layer 6 of the repair material 1. In other words, any material that exhibits the functions of friction and shock absorption described below can be used for the rubber chip layer 6. For example, waste rubber materials such as EPDM and urethane rubber generated during the manufacturing process of automotive rubber products such as vehicle door seals and wipers can be reused. This allows for effective use of waste rubber materials that would otherwise have been discarded.

[0044] These waste rubber materials can be crushed into chips of a predetermined size using a well-known cutting machine such as a chopper, and can be used. Of course, the use of waste rubber materials is not limited to waste rubber materials, and new rubber chips can also be produced from existing rubber products, etc., for use in the pavement repair material of the present invention.

[0045] In the repair material 1 of this embodiment, the chip diameter of the rubber chip material 8 used is preferably adjusted to be at least less than 2 mm, and more preferably 1.5 mm or less. Here, the rubber chip layer 6 containing the rubber chip material 8 has the function of preventing the butyl rubber, which is the adhesive component of the butyl rubber layer 5 located below it, from adhering to tires, shoes, etc. passing over the repair material 1. Furthermore, the elastic repulsive force of the rubber chip material 8 has the function of suppressing impact and noise when passing over it.

[0046] As described above, by making the chip diameter of the rubber chip material 8 less than 2 mm, preferably 1.5 mm or less, it is possible to improve the dispersibility of the rubber chip material 8 when it is stirred and mixed with the aggregate 9 (details of which will be described later). In other words, if the chip diameter of the rubber chip material 8 is 2 mm or more, it is likely to accumulate at the bottom of the stirring vessel when it is stirred and mixed, and the rubber chip material 8 and the aggregate may not be mixed uniformly in the rubber chip mixture 11.

[0047] Therefore, as described above, by setting the chip diameter to at least less than 2 mm, uniform dispersion and mixing are possible. Furthermore, by enabling uniform dispersion and mixing in the rubber chip mixture 11, the density of the rubber chip mixture 11 and the rubber chip layer 6 formed therefrom becomes uniform. As a result, the density becomes constant, which makes it possible to improve the strength of the rubber chip layer 6 itself and the repair material 1, thereby enhancing durability.

[0048] On the other hand, the aggregate 9 used in the rubber chip layer 6 is a well-known material that has been conventionally used in the production of concrete compositions, cement compositions, asphalt compositions, etc., and known examples include sand and gravel such as river sand, sea sand, and mountain sand, pumice, volcanic ejecta, etc., or blast furnace slag aggregate.

[0049] The repair material 1 of this embodiment uses colored ceramic artificial aggregate, which is a type of ceramic aggregate. By including this aggregate 9 in the rubber chip layer 6, it is possible to impart frictional force to the rubber chip layer 6. In other words, when a vehicle or pedestrian passes over the repair material 1, a strong frictional force is generated between the upper surface 6a of the rubber chip layer 6 and the tire or shoe, thereby preventing the tire or shoe from slipping. This ensures the safety of vehicles and pedestrians.

[0050] Additionally, in the repair material 1 of this embodiment, it is preferable that the particle size ratio between the chip diameter of the rubber chip material 8 and the aggregate particle size of the aggregate 9 is in the range of 2:1 to 1:2, and more preferably 1:1. In other words, if the chip diameter of the rubber chip material 8 is limited to less than 2 mm, it is preferable that the aggregate particle size of the aggregate 9 is also less than 2 mm.

[0051] By setting the particle size ratio of the rubber chip material 8 to the aggregate 9 within a certain range, preferably 1:1, as already explained, the dispersibility of the rubber chip material 8 and the aggregate 9 during stirring and mixing is improved, and the density of the rubber chip layer 6 is made uniform. As a result, the strength of the rubber chip layer 6 and the repair material 1 can be improved. Note that if the particle size ratio of the rubber chip material 8 and the aggregate 9 deviates from the above-specified numerical limit range, unevenness will occur during stirring and mixing, making uniform dispersion difficult and making the behavior during stirring unstable, increasing the likelihood of uneven stirring.

[0052] On the other hand, the binder 10 functions as a kind of adhesive for forming and processing the rubber chip material 8 and aggregate 9 into layers while keeping them uniformly dispersed. For example, a urethane binder whose main ingredient is a conventionally well-known urethane resin material, or various other binders whose main ingredient is a resin material, can be used.

[0053] In the repair material 1 of this embodiment, the above-mentioned urethane binder is used as the binder 10, taking into consideration ease of availability and ease of handling. The urethane binder has thermoplastic properties and can become fluid when heated to a predetermined temperature. After becoming fluid, the heating is stopped and the binder hardens and loses its fluidity when cooled.

[0054] The three components, rubber chip material 8, aggregate 9, and binder 10, are mixed in the mixing ratio shown below using a well-known mixer or the like while being heated so that the binder 10 has fluidity, to prepare a rubber chip mixture 11 in which the three components are uniformly mixed. The rubber chip mixture 11 is then spread evenly on the butyl rubber layer 5 to a predetermined rubber chip layer thickness t2, and is then molded into a layer to form the rubber chip layer 6.

[0055] In the repair material 1 of this embodiment, the mixing ratio of the rubber chip material 8, aggregate 9, and binder 10 can be in the range of 60:40 to 90:10 by weight. A mixing ratio of 75:25 is more preferable. By keeping the mixing ratio within this range, uniform dispersion of the rubber chip material 8 and aggregate 9 can be maintained, and uniform density and high strength can be maintained when molded into the rubber chip layer 6.

[0056] If the mixing ratio of the rubber chip material 8 and the aggregate 9 deviates from the above-specified numerical limit range, it becomes difficult to maintain uniform density and strong strength, and the butyl rubber of the butyl rubber layer 5 located below the rubber chip layer 6 may seep out from the upper surface 6a of the rubber chip layer 6, or the strength of the rubber chip layer 6 may be reduced due to uneven density, which may affect the durability of the repair material 1 itself.

[0057] The mixing ratio of the rubber chip material 8 to the binder 10 can be in the range of 70:30 to 90:10 by weight, and is preferably 80:20. By using such a mixing ratio, it is possible to prepare a rubber chip mixture 11 containing the rubber chip material 8 and the aggregate 9 that is suitable for molding into layers.

[0058] Here, if the weight ratio of the rubber chip material 8 to the aggregate 9 is set to the above-mentioned preferred mixing ratio (75:25), and the weight ratio of the rubber chip material 8 to the binder 10 is set to the above-mentioned preferred mixing ratio (20:5), the mixing ratio of the rubber chip material 8:aggregate 9:binder 10 will be 75:25:18.75 by weight. For example, if 75 kg of rubber chip material 8 is used, 25 kg of aggregate 9 and an additional 18.75 kg of binder 10 are used, the final rubber chip mixture 11 will be 118.75 kg.

[0059] In the repair material 1 of this embodiment, the layer thickness ratio of the adhesive layer thickness t1 of the butyl rubber layer 5 to the rubber chip layer thickness t2 of the rubber chip layer 6 is in the range of 2.5:1 to 4:1, and preferably 3:1. Furthermore, the repair material thickness t3, which is the sum of the adhesive layer thickness t1 and the rubber chip layer thickness t2, is desirably 4 mm or less.

[0060] That is, if the repair material thickness t3 of the repair material 1 is set to 4 mm as already explained, the adhesive layer thickness t1 of the butyl rubber layer 5 will be 1 mm, while the rubber chip layer thickness t2 of the rubber chip layer 6 will be 3 mm.

[0061] By setting the rubber chip layer thickness t2 of the rubber chip layer 6 to 2 to 4 times the adhesive layer thickness t1 of the butyl rubber layer 5, it is possible to prevent the butyl rubber from seeping out from the upper surface 6a of the rubber chip layer 6 and adhering to tires, shoes, etc.

[0062] That is, by forming the rubber chip layer 6 with a rubber chip layer thickness t2 equal to or greater than a certain value relative to the adhesive layer thickness t1 of the butyl rubber layer 5, it is possible to prevent the butyl rubber from seeping out from the upper surface 6a of the rubber chip layer 6. If the rubber chip layer thickness t2 is less than 2.5 times the adhesive layer thickness t1 of the butyl rubber layer 5, it is not possible to prevent the seeping out from the upper surface 6a. On the other hand, if the rubber chip layer thickness t2 is more than four times the adhesive layer thickness t1, the repair material thickness t3 of the repair material 1 will be large, which will increase the difference in level from the pavement surface 2 (described below), potentially causing problems. Therefore, the rubber chip layer thickness t2 is set to be within the above range relative to the adhesive layer thickness t1.

[0063] The seepage of butyl rubber from the upper surface 6a of the rubber chip layer 6 is not determined solely by the relationship between the adhesive layer thickness t1 and the rubber chip layer thickness t2, but is also affected by the dispersibility and density, which are determined by adjusting the mixing ratio of the rubber chip material 8, aggregate 9, and binder 10, and the particle size ratio between the chip diameter of the rubber chip material 8 and the aggregate particle size of the aggregate 9, as already explained. Therefore, it is necessary to manufacture the repair material 1 by adjusting these factors appropriately.

[0064] The seepage from the upper surface 6a of the butyl rubber layer not only causes adhesion to tires, shoes, etc., but also has the potential to reduce the adhesive strength of the butyl rubber layer 5 that is bonded to the pavement surface 2. This reduces the adhesive strength of the repair material 1, which may result in reduced durability, such as the repair material 1 peeling off from the repair area 3. Therefore, it is necessary to prevent such seepage.

[0065] In addition, by setting the repair material thickness t3 of the repair material 1 to 4 mm or less, it is possible to minimize the difference in level with the pavement surface 2. This reduces the occurrence of problems such as pedestrians tripping and falling over the difference in level caused by the repair material 1, and also reduces the impact and noise caused by vehicles driving over the difference in level.

[0066] Furthermore, the pavement repair material of the present invention may have a characteristic configuration as shown in Fig. 3. That is, in the repair material 1a of another configuration, the repair material side end surface 4 layered on the ends of the butyl rubber layer 5 and the rubber chip layer 6 may be provided with a tapered portion 13 that is inclined obliquely upward from the lower surface end 12 of the butyl rubber layer 5 toward the center of the rubber chip layer 6 (corresponding to the right side of the paper in Fig. 3).

[0067] By providing such a tapered portion 13, the step between the pavement surface 2 and the repair material 1a can be made gentler. As a result, the occurrence of problems such as pedestrians tripping and falling can be reduced, allowing them to walk stably. This ensures the safety of pedestrians. In addition, it has the advantage of mitigating the impact of vehicles going over steps and suppressing noise when passing over steps.

[0068] As explained above, the repair material 1 of this embodiment can complete repair work through a relatively simple process of simply placing it on the repair area 3 of the pavement surface 2, eliminating the need for pre-treatment processes such as heating, allowing the work to be completed in a short time and reducing the labor costs required for repair work.

[0069] Furthermore, the adhesive strength of the butyl rubber layer 5 (adhesive layer) allows it to be easily and firmly fixed to the pavement surface, and the frictional force generated by the rubber chip layer 6 and the appropriate elasticity provide driving stability and walking stability when vehicles and pedestrians pass over it.

[0070] In addition, the bleeding of the adhesive component (butyl rubber) on the lower layer to the upper surface 6a of the rubber chip layer 6 can be suppressed by adjusting the compounding ratio and particle size ratio of the rubber chip layer 6, the thickness t2 of the rubber chip layer, etc., which reduces the occurrence of inconvenience to pedestrians and improves the durability of the repair material 1. In addition, the tapered portion 13 can prevent pedestrians from tripping over steps. [Example]

[0071] The present invention will be specifically described below based on examples, but it goes without saying that the present invention is not limited to these examples and can be implemented in various forms as long as they fall within the technical scope of the present invention.

[0072] 1. Formation of Repair Materials of Examples 1 to 4 and Comparative Examples 1 to 4 (1) Example 1 (Example 3) Waste rubber containing EPDM (ethylene propylene diene rubber) was crushed into chips and passed through a 1.6 mm nominal mesh metal sieve to produce chips of 1.6 mm or less. 0.6 kg of the resulting rubber chips, 0.2 kg of a ceramic aggregate (colored ceramic artificial aggregate) (Aggregate A: SaraSand HW-C, manufactured by Bishu Kosan Co., Ltd., 0.15–0.5 mm), and 0.15 kg of a urethane binder (Thinkbond S, manufactured by Think Chemical Industry Co., Ltd.), a thermoplastic urethane resin that becomes fluid upon heating, were mixed and stirred while heating to uniformly disperse the rubber chips and aggregate, producing a rubber chip mixture. At this point, the rubber chip mixture was fluid. The rubber chip, aggregate, and urethane binder ratio in the rubber chip mixture was set to 60:20:15 by weight. The above-mentioned rubber chip material, aggregate, and urethane binder indicate the amounts required to manufacture one repair material sheet measuring 500 mm long x 500 mm wide.

[0073] The resulting rubber chip mixture was molded using a square mold measuring 500 mm long x 500 mm wide so that the rubber chip layer was 3 mm thick. The mixture was then laminated to a commercially available butyl rubber sheet (SR Bumper, manufactured by Saitama Rubber Industry Co., Ltd., 1 mm thick) pre-cut to 500 mm x 500 mm, yielding a repair material of Example 1 with a two-layer structure having a butyl rubber layer (butyl rubber sheet) and a rubber chip layer, with a thickness of 4 mm. Example 3 was formed under the same conditions as Example 1, with only the test conditions described below differing. Because the butyl rubber sheet itself is adhesive, the rubber chip layer and the butyl rubber layer can be easily laminated together.

[0074] (2) Example 2 (Example 4) Using the same rubber chip material and binder as in Example 1 and in the same amounts, 0.2 kg of aggregate B (Sarasand HW-B, manufactured by Bishu Kosan Co., Ltd., 0.5-1.0 mm) was used instead of aggregate A to obtain a rubber chip mixture. Other conditions were the same as in Example 1, and a repair material of Example 2 with a two-layer structure and a repair material thickness of 4 mm was obtained. Example 4 was formed under the same conditions as Example 2, with only the test conditions described below differing.

[0075] (3) Comparative Example 1 (Comparative Example 3) Waste rubber material containing EPDM (ethylene propylene diene rubber) was crushed into chips and passed through a metal mesh sieve with a screen diameter (nominal mesh size) of 3.0 mm. Using the rubber chip material adjusted to a chip diameter of 3.0 mm or less, a rubber chip mixture was obtained using aggregate A under the same conditions as in Example 1.

[0076] The obtained rubber chip mixture was molded using a square mold frame measuring 500 mm long x 500 mm wide so that the rubber chip layer was 2 mm thick, and then laminated to the same commercially available butyl rubber sheet as used in Example 1, which had been pre-cut to 500 mm x 500 mm, to obtain Comparative Example 2, a two-layer repair material with a thickness of 3 mm. Note that Comparative Example 3 was formed under the same conditions as Comparative Example 1, with only the test conditions described below being different.

[0077] (4) Comparative Example 2 (Comparative Example 4) Waste rubber material containing EPDM (ethylene propylene diene rubber) was crushed into chips and passed through a metal mesh sieve with a screen diameter (nominal mesh size) of 1.6 mm. Using the rubber chip material adjusted to a chip diameter of 1.6 mm or less, a rubber chip mixture containing aggregate B was obtained under the same conditions as in Example 1.

[0078] The obtained rubber chip mixture was molded using a square molding mold measuring 500 mm long x 500 mm wide so that the rubber chip layer was 2 mm thick, and then laminated to the same commercially available butyl rubber sheet as used in Example 2, which had been pre-cut to 500 mm x 500 mm, to obtain Comparative Example 2, a two-layer repair material with a thickness of 2 mm. Note that Comparative Example 4 was formed under the same conditions as Comparative Example 2, with only the test conditions described below being different.

[0079] 2. Butyl rubber bleeding evaluation The repair materials of Examples 1 to 4 and Comparative Examples 1 to 4 prepared as described above were placed on the surface of the asphalt pavement, and pressure was applied from above by stepping on the rubber chip layer side with a foot or the like, thereby adhering and fixing the repair materials of the Examples and Comparative Examples to the pavement surface.

[0080] Here, for the repair materials of Examples 1 and 2 and Comparative Examples 1 and 2, the test conditions were as follows: a 40 kg load heated to 50°C was placed on the rubber chip layer, and the 40 kg load and heating at 50°C were maintained for 60 minutes. After 60 minutes, the load was removed from the rubber chip layer, and the condition of the surface (top surface) of the rubber chip layer where the load was placed was visually confirmed to determine whether or not the butyl rubber had bled from the butyl rubber layer. The presence or absence of bleed of the butyl rubber was determined by the difference in color from the surface of the surrounding rubber chip layer where the load was placed.

[0081] On the other hand, for the repair materials of Examples 3 and 4 and Comparative Examples 3 and 4, test conditions were different from those described above. A 40 kg load heated to 40°C was placed on the rubber chip layer, and the 40 kg load and heating at 40°C were maintained for 60 minutes. After 60 minutes had elapsed, the load was removed from the rubber chip layer, and the condition of the surface (upper surface) of the rubber chip layer where the load had been placed was visually confirmed to determine whether or not butyl rubber had bled from the butyl rubber layer. The rest of the test was the same as Example 1, etc. The conditions for forming the repair materials of Examples 1 to 4 and Comparative Examples 1 to 4, and the results of the butyl rubber bleed evaluation, are shown in Table 1 below.

[0082] [Table 1]

[0083] 3. Butyl rubber bleeding evaluation results As shown in Table 1 above, when the rubber chip material passed through a metal mesh sieve with a screen diameter of 3 mm, i.e., when the rubber chip material contained chips with a diameter of 2 mm or more (Comparative Examples 1 and 3), bleeding of butyl rubber was confirmed. Furthermore, bleeding of butyl rubber was also confirmed when the rubber chip layer thickness was 2 mm (Comparative Examples 1 to 4). Therefore, it was shown that when the repair materials of Comparative Examples 1 to 4 are used on paved surfaces, there is a possibility that butyl rubber will adhere to tires, shoes, etc.

[0084] On the other hand, for the repair materials of Examples 1 to 4, which satisfy both the chip diameter and rubber chip layer thickness of the repair material of the present invention, as already explained, the dispersion and uniform mixing of the rubber chip material and aggregate are improved, and it is presumed that the density of the formed rubber chip layer is high. As a result, no bleeding of butyl rubber from the upper surface of the rubber chip layer was observed. It was also confirmed that in the repair materials of Examples 1 to 4, the rubber chip layer thickness needs to be set to at least 3 mm or more.

[0085] 4. Performance evaluation of repair materials immediately after application and after application Furthermore, various performance evaluations were carried out to examine the practicality of the pavement repair material of the present invention. Here, the repair material P1 to be subjected to the performance evaluation was formed under the same conditions as in Example 1 in the above-mentioned bleeding evaluation.

[0086] Additionally, to evaluate practicality, a similar performance evaluation was also conducted on a commercially available pavement repair material, a "stick-on crack repair material" (PMR99+, manufactured by Kajima Road Co., Ltd.) (hereafter referred to as "commercial product P2"). Commercial product P2 is a square 500mm x 500mm thick repair material with a two-layer structure, with a butyl rubber layer underneath.

[0087] (1) Construction conditions The repair material P1 to be evaluated and the commercially available product P2 were applied under the following application conditions: application location, application quantity, and application position. Construction location: Parking lot within the applicant's factory (asphalt pavement, Higashimatsuyama City, Saitama Prefecture) Construction quantity: 2m 2 (Repair material P1), 1m 2 (Commercially available product P2) Construction location: Parking lot vehicle run areas and pedestrian walkways

[0088] More specifically, debris such as trash and dust is removed from the pavement surface 2 of the road R to be repaired using a broom or similar tool, and the butyl rubber layers of the repair material P1 and commercial product P2 are placed so that they come into contact with the pavement surface 2. Then, the repair material P1 and commercial product P2 are stepped on with a foot or similar tool to apply pressure from above, firmly adhering and fixing them to the pavement surface 2 (see Figure 4). This completes the application of the repair material P1 and commercial product P2. Note that neither the repair material P1 nor the commercial product P2 undergoes any pretreatment process, such as preheating the pavement surface 2 or applying a primer or similar.

[0089] As shown in Figure 4, on the pavement surface 2 in the vehicle run area of ​​the parking lot, repair material P1 was placed at the center position CL and a position LP to the left of the center line C of the road R (see the dashed line in Figure 4), while commercially available product P2 was placed at the center position CR and a position RP to the right of the center line C. Note that construction was carried out on the pedestrian walkway in the area where pedestrians pass, and a detailed explanation will be omitted.

[0090] (2) Evaluation of slip resistance (friction) Using a pendulum-type skid resistance tester (manufactured by Stanley London), the slip resistance of the surface of the pavement material (top surface of the rubber chip layer) was evaluated immediately after application to the pavement surface and one month after application.

[0091] The pendulum skid resistance tester swings a rubber slider at the end of the pendulum down from a predetermined position to measure the damping caused by friction between the slider and the sample, which is expressed in BPN (British Pundulum Number). The evaluation of skid resistance was conducted in accordance with ASTM E303 and the Interlocking Block Pavement Design and Construction Guidelines. According to the Interlocking Block Pavement Design and Construction Guidelines, a "40 BPN or greater in wet conditions" is desirable.

[0092] The results are shown in Figure 5. Figure 5 shows the results of measuring the slip resistance in a wet state immediately after application and one month after application at a vehicle travel location in a parking lot. It was confirmed that the repair material P1 under evaluation exhibited values ​​of 65 BPN or higher in all cases. Furthermore, it was shown that the slip resistance was not impaired even after one month had passed. Although not shown in Figure 5, measurements in a dry state showed that the slip resistance of repair material P1 was 100 BPN or higher. This suggests that the repair material P1 of the present invention has practical value in terms of slip resistance.

[0093] (3) SB / GB Test The SB / GB test is often used to evaluate the resilience of sidewalks and other surfaces used by pedestrians. A steel ball (SB) and a golf ball (GB) are dropped from a certain height onto the applied repair material P1 and the commercially available product P2, and the restitution coefficients (SB coefficient and GB coefficient) are calculated for each. The SB / GB test was conducted in accordance with the "Test Method for Resilience of Pavement Surfaces" in the "Pavement Survey and Test Methods Handbook S026-1," and a detailed explanation will be omitted here.

[0094] The results are shown in Figure 6. Figure 6 shows the measured and calculated restitution coefficients of a steel ball (SB) and a golf ball (GB) immediately after application to a pedestrian walkway and one month later. The results demonstrate that repair material P1 has good elasticity, and the SB coefficient in particular is higher than that of commercially available product P2. Taking into consideration the measured and calculated SB and GB coefficients, the repair material (the rubber chip layer) of the present invention is comparable to artificial turf and other surfaces. Therefore, areas repaired with the repair material of the present invention, like artificial turf and other surfaces, possess excellent elasticity and shock absorption that do not impose excessive strain on pedestrians, allowing for stable walking. As a result, as already explained, the repair material of the present invention can be used effectively to repair paved surfaces on pedestrian walkways, while of course not interfering with vehicle traffic. [Industrial Applicability]

[0095] The pavement repair material of the present invention has industrial applicability in repairing damage to pavement surfaces of roads such as roadways and sidewalks. Furthermore, because it has a particularly excellent restitution coefficient, it is useful in repairing sidewalks where pedestrians pass. [Explanation of symbols]

[0096] 1, 1a, P1: repair material (pavement repair material), 2: pavement surface, 3: repair area, 4: repair material side edge, 5: butyl rubber layer (adhesive layer), 5a: underside of layer, 5b, 6a: upper surface of layer, 6: rubber chip layer, 7: release paper, 8: rubber chip material, 9: aggregate, 10: binder, 11: rubber chip mixture, 12: end of underside of layer, 13: tapered section, C: center line, CL: center position on the left side, CR: center position on the right side, L1: length of one side, L2: length of the other side, LP: left position, P2: commercially available product, R: road, RP: right position, t1: adhesive layer thickness, t2: rubber chip layer thickness, t3: repair material thickness.

Claims

1. an adhesive layer containing an adhesive component that can adhere to a pavement surface and that is formed into a layer; a rubber chip layer containing a rubber chip mixture obtained by mixing rubber chip material, aggregate, and binder, which is formed into a layer, and stacked on the adhesive layer; Equipped with The mixing ratio of the rubber chip material and the aggregate is: The weight ratio is in the range of 60:40 to 90:10, The mixing ratio of the rubber chip material and the binder is: A pavement repair material having a weight ratio ranging from 70:30 to 90:

10.

2. The tip diameter of the rubber tip material is: Set to less than 2 mm, and The particle size ratio of the chip diameter of the rubber chip material to the aggregate particle size of the aggregate is 2. The pavement repair material according to claim 1, wherein the ratio is in the range of 2:1 to 1:

2.

3. The thickness ratio of the adhesive layer thickness to the rubber chip layer thickness is in the range of 2.5:1 to 4:1, and 3. The pavement repair material according to claim 1, wherein the sum of the thickness of the adhesive layer and the thickness of the rubber chip layer is set to 4 mm or less.

4. The repair material side end surface formed by the adhesive layer and the rubber chip layer is 3. A pavement repair material according to claim 1, further comprising a tapered portion that slopes obliquely upward from the edge of the lower surface of the adhesive layer toward the center of the rubber chip layer.

5. The adhesive component is 3. The pavement repair material according to claim 1, which is made of butyl rubber.

6. 3. The pavement repair material according to claim 1, which is used to repair the paved surface of a sidewalk.

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