JP7691064B2 - Waterproof sheet, waterproof structure, waterproofing method, and method for manufacturing waterproof sheet - Google Patents

Description

The present invention relates to a waterproof sheet that covers the inner surface of a concrete structure that forms an underground space, a waterproof structure, a waterproofing method, and a method for manufacturing a waterproof sheet.

There are two methods for waterproofing underground concrete structures: the post-applying method and the pre-applying method. The post-applying method is a method in which a waterproof layer is applied directly to the outer surface of the underground structure after pouring. The pre-applying method is a method in which, when an earth retaining wall and an underground structure are close to each other, a waterproof layer is applied to the earth retaining wall surface before pouring the underground structure, using the earth retaining wall as a form before pouring the underground structure, and then the underground structure is poured, thereby adhering the underground structure and the waterproof layer to each other. For example, Patent Document 1 discloses a method in which a waterproof layer is formed using a waterproof sheet fixed to the construction target with rock bolts and a waterproof material such as mortar that covers the waterproof sheet.

JP 2000-80894 A

However, with the post-applying method, reliable construction is difficult due to the special underground environment and the influence of groundwater. Furthermore, with the pre-applying method, after construction of the waterproof layer, the waterproof layer may be damaged by the installation of rebar and formwork for the underground structure. In this way, when constructing a waterproof layer on the outside of the underground structure, it is difficult to build a complete waterproof layer, and water leakage is likely to occur. On the other hand, there is also a method in which a waterproof layer is constructed on the inner surface of the underground structure with consideration given to construction ease. Even if the method of Patent Document 1 is applied to this, it does not provide a fundamental solution, as it is not intended to prevent water leakage from the underground structure.

The waterproof sheet that solves the above problem is a waterproof sheet that is adhered to a concrete structure via an adhesive layer, and is made of a sheet-like synthetic polymer and includes a resin sheet having a first surface that is arranged on the adhesive layer side and a second surface that is arranged on the opposite side of the adhesive layer, and a fibrous material having a base fiber that is attached to the first surface and a nap-like fiber that is raised from the base fiber to the opposite side of the resin sheet, and parts of the first surface are exposed in a scattered manner.

According to the present invention, the waterproof sheet has good watertightness against the underground structure, so water leakage is less likely to occur, and the waterproof layer can withstand the pressure of groundwater present on the outside of the underground structure attempting to infiltrate into the underground structure.

1 is a cross-sectional view showing a schematic configuration of an embodiment of a waterproof structure. FIG. 1A is a schematic diagram showing how waterproof sheets are attached to each other; FIG. 1B is a schematic diagram showing the waterproof sheets attached to each other; (a) A schematic diagram showing waterproof sheets butted together, and (b) A schematic diagram showing the boundary portions of the waterproof sheets covered with boundary covering sheets. FIG. 2 is a diagram showing a schematic configuration of a base fiber. FIG. 2 is a diagram showing a schematic configuration of a loop-shaped napped fiber. FIG. 2A is a schematic diagram showing the general configuration of a mushroom-shaped brushed fiber; FIG. 2B is a schematic diagram showing the general configuration of a hook-shaped brushed fiber; and FIG. 2C is a schematic diagram showing the general configuration of a matchstick-shaped brushed fiber. FIG. 2A is a diagram showing a schematic diagram of a thermal lamination process when the pile height is greater than the mesh size, and FIG. 2B is a diagram showing a schematic diagram of a thermal lamination process when the pile height is smaller than the mesh size. (a) A schematic diagram showing the test specimen before the through passage is formed, (b) A schematic diagram showing the state after the through passage has been formed, and (c) A schematic diagram showing the supply of pressurized water to the through passage.

An embodiment of a waterproof sheet, a waterproof structure, a waterproofing method, and a method for manufacturing a waterproof sheet will be described with reference to Figs. 1 to 8 .
(Summary of waterproof structure)
As shown in FIG. 1 , the waterproof structure 10 covers an inner surface 12 a of an underground structure 12 installed in the ground 11 , thereby suppressing water leakage into the underground space formed by the underground structure 12 .

The underground structure 12 is a hardened first cementitious hydraulic material. The first cementitious hydraulic material is a fluid made by mixing at least cement and water. The first cementitious hydraulic material is, for example, concrete made by mixing water with a cement mixture in which cement is mixed with aggregates such as gravel or sand.

The waterproof structure 10 has an adhesive layer 13 that covers the inner surface 12a of the underground structure 12, and a waterproof sheet 15 that covers the inner surface 12a of the underground structure 12 via the adhesive layer 13. In the following, the pressure that water leaking from the underground structure 12 exerts on the waterproof structure 10 is referred to as back water pressure.

The adhesive layer 13 is formed by hardening an adhesive applied to the inner surface 12a of the underground structure 12. Examples of adhesives include second cement-based hydraulic materials such as cement paste, mortar, and concrete using one or more types of cement selected from the following: ordinary Portland cement, high-early-strength cement, moderate-heat Portland cement, low-heat cement, fly ash cement, blast-furnace cement, silica cement, sulfate-resistant Portland cement, ultra-fast-hardening cement, alumina cement, and ecocement.

The second cement-based hydraulic material is preferably fly ash cement or silica cement. Fly ash cement is a cement-based hydraulic material containing fly ash. Silica cement is a cement-based hydraulic material containing silica fume. Fly ash and silica fume do not themselves undergo hydration reactions, but are porazon-reactive substances that undergo a porazon reaction with calcium hydroxide contained in cement to produce a hardened body. By using fly ash cement or silica cement as the second cement-based hydraulic material, even if a crack occurs in the adhesive layer 13, a hardened body will be produced in the crack. As a result, water leakage into the underground space can be further suppressed.

The second cement-based hydraulic material may be a mixture of admixtures such as water-reducing agents, air-entraining agents, air-entraining water-reducing agents, high-performance water-reducing agents, high-performance air-entraining water-reducing agents, superplasticizers, hardening accelerators, retarders, and defoamers, or short fibers such as polypropylene, vinylon, and nylon, either alone or in combination.

In addition, resin-based materials such as epoxy resin, urethane resin, acrylic resin, and polyester can also be used as adhesives. Furthermore, resin mortars using these resin-based materials, and mixtures of these resin-based materials with a second cement-based hydraulic material can also be used.

Other adhesives that can be used include ethylene vinyl acetate resin, acrylic resin, resin asphalt, SBR, latex, and mixtures of polymer dispersions for cement admixture or re-emulsifiable powdered resins that meet the standards of the Japanese Industrial Standard JIS A6203:2015 "Polymer dispersions for cement admixture and re-emulsifiable powdered resins" and a second cement-based hydraulic material.

Because underground spaces tend to be humid environments, the adhesive is preferably a second cement-based hydraulic material that exhibits good adhesion to the underground structure 12 even in humid environments. From the standpoint of watertightness and adhesion, it is even more preferable that the adhesive be a cement paste mixed with a polymer dispersion for cement mixing, which is made of either ethylene vinyl acetate resin, acrylic resin, or epoxy resin.

The waterproof sheet 15 is attached to the uncured adhesive layer 13, and then fixed to the inner surface 12a of the underground structure 12 as the adhesive layer 13 hardens. Considering the application of the waterproof sheet 15 to the entire inner surface 12a and the ease of handling the waterproof sheet 15, it is preferable to overlap waterproof sheets 15 of appropriate size with an appropriate width. Multiple waterproof sheets 15 are attached to the adhesive layer 13 so that parts of their outer peripheries overlap.

Specifically, as shown in FIG. 2(a), when a second waterproof sheet 17 is applied after a first waterproof sheet 16, adhesive is applied to a first overlapping area 16A, which is part of the outer periphery of the first waterproof sheet 16. Then, as shown in FIG. 2(b), a second overlapping area 17A of the second waterproof sheet 17 is overlapped so that part of the outer periphery overlaps the first overlapping area 16A.

As shown in FIG. 3(a), the first waterproof sheet 16 and the second waterproof sheet 17 may be butted together without overlapping. In that case, as shown in FIG. 3(b), it is preferable to attach a boundary covering sheet 18 of an appropriate width so as to cover the boundary portion. The boundary covering sheet 18 may be a sheet similar to the waterproof sheet 15. By covering the boundary portion with the boundary covering sheet 18 in this way, the boundary portion of the waterproof sheet 15 can be reinforced. As a result, the waterproof sheet 15 is less likely to bulge even if a leak occurs from the underground structure 12.

(About waterproof sheets)
As shown in FIG. 1 , the waterproof sheet 15 is a two-layer sheet having a resin sheet 21 and a fibrous material 22 .
The resin sheet 21 is made of a sheet-shaped synthetic polymer. The resin sheet 21 is formed of one or more resin materials, such as ethylene vinyl acetate resin, vulcanized rubber, non-vulcanized rubber, vinyl chloride resin, thermoplastic elastomer, modified asphalt, high density polyethylene, low density polyethylene, polyester, polypropylene, polystyrene, ABS resin, epoxy resin, polyurethane resin, acrylic resin, polyamide, and polycarbonate. The resin sheet 21 may be a single layer of a single resin or a mixture of multiple resins, or a layer of multiple waterproof layers. The resin sheet 21 is preferably an ethylene vinyl acetate resin or a polyethylene resin from the viewpoints of handling, water impermeability, and corrosion resistance.

The resin sheet 21 has a first surface 21a and a second surface 21b. The first surface 21a is the surface that is disposed on the adhesive layer 13 side. The first surface 21a is the surface to which the fiber material 22 is attached as the first fiber material. The second surface 21b is the surface that is disposed on the opposite side of the adhesive layer 13.

In this embodiment, the second surface 21b is an uneven surface. The second surface 21b is formed into an uneven surface by a plurality of protrusions 23. The shapes of the protrusions 23 include linear, pyramidal, ridgeline, sea-island, embossed, mushroom, hook, and matchstick shapes. The width of the plurality of protrusions 23 is preferably 0.01 to 10 mm, and the height is preferably 0.01 to 1 mm. These protrusions 23 are formed during the manufacture of the resin sheet 21. The protrusions 23 create an anchor effect in the overlapping portions of the waterproof sheets 15, improving the adhesion between the waterproof sheets 15. Furthermore, the resin portions at the tips of the protrusions may be physically raised to improve adhesion.

The fibrous material 22 has base fibers 25 and raised fibers (pile) 26 .
The material of the fiber material 22 may be any of organic synthetic fibers, natural fibers, semi-synthetic fibers, and inorganic fibers, and specifically, may be selected from one or more of the following: polyethylene, ultra-high molecular weight polyethylene, polypropylene, polyester, nylon, acrylic resin, vinylon, polyurethane resin, polyvinyl chloride resin, rayon, aramid fiber, alkali-resistant glass fiber, basalt fiber, PAN-based carbon fiber, pitch-based carbon fiber, liquid crystal polymer, cotton, and hemp. Among these, polypropylene, polyester, nylon, and vinylon are preferable.

As shown in FIG. 4, the base fiber 25 has a mesh shape. Examples of the base fiber 25 include woven fabric, knitted fabric, net-like fabric, and nonwoven fabric. The base fiber 25 is the part that is attached to the resin sheet 21. When the base fiber 25 is attached to the resin sheet 21, the napped fibers 26 are present in a dense state and the first surface 21a of the resin sheet 21 is exposed in a scattered manner. This allows the adhesive layer 13 to be well filled around the fiber material 22, thereby increasing the watertightness between the adhesive layer 13 and the waterproof sheet 15 and suppressing the lateral movement of water. The fiber material 22 may be attached to the second surface 21b of the resin sheet 21 as a second fiber material.

The mesh size E of the mesh-like base fibers 25 is related to the density of the napped fibers 26. The mesh size E is the maximum width of the mesh portion. It is preferable that the mesh size E is greater than 0.1 mm. In addition, the mesh size E is less than 10 mm, preferably less than 5.0 mm, and more preferably less than 3.0 mm.

The napped fibers 26 have a three-dimensional shape that naps on the opposite side of the resin sheet 21 from the base fibers 25. The fiber diameter of the napped fibers 26 is preferably 0.1 to 500 μm. The napped fibers 26 are fixed to the base fibers 25 by a method such as weaving, knitting, entangling, embedding, or gluing so that they do not easily come off or fall out of the base fibers 25. The napped fibers 26 create an anchor effect between the waterproof sheet 15 and the adhesive layer 13. This can improve the adhesion between the underground structure 12 and the waterproof sheet 15 via the adhesive layer 13. Examples of the shape of the napped fibers 26 include loop fibers and cut fibers, as well as spiral fibers and non-directional fibers.

As shown in FIG. 5, the loop-like raised fibers 26 are formed by joining a portion of a circular fiber to the base fiber 25. In the raised fibers 26, the length of the raised fibers 26 itself is called the pile length L, and the height (raised height) from the base fiber 25 in a free-standing state is called the pile height H. The pile height H is equal to or less than the pile length L. It is preferable that the pile length L is equal to or less than 10 mm. It is also preferable that the pile length L is greater than the mesh size E of the base fiber 25.

As shown in Figures 6(a) to 6(c), the cut fiber-like brushed fibers 26 have a base end joined to the base fiber 25 and a tip end separated from the base fiber 25. With respect to the cut fiber-like brushed fibers 26, Figure 6(a) shows mushroom-shaped brushed fibers. Figure 6(b) shows hook-shaped brushed fibers. Figure 6(c) shows matchstick-shaped brushed fibers. The cut fiber-like brushed fibers 26 have, for example, a pile body 28 extending from the base fiber 25 and a pile tip portion 29 integrally provided at the tip of the pile body 28. The pile tip portion 29 has a portion extending laterally from the tip of the pile body 28 with respect to the central axis 30 of the pile body 28.

The basis weight of the fibrous material 22 is preferably 30 to 200 g/ ^m2 . When the basis weight is 30 g/ ^m2 or more, wrinkles are less likely to occur in the fibrous material 22 before and after bonding with the adhesive layer 13. When the basis weight is 200 g/ ^m2 or less, the waterproof sheet 15 can be made to have an appropriate thickness, making the waterproof sheet 15 easier to handle. The fibrous material 22 may be attached to the second surface 21b of the resin sheet 21. This can improve the adhesion between the waterproof sheets 15.

The waterproof sheet 15 is also subjected to a hydrophilic treatment to impart hydrophilicity to its surface. The hydrophilic treatment is preferably performed after the fiber material 22 is bonded to the resin sheet 21. The hydrophilic treatment is a treatment that imparts functional groups such as hydroxyl groups, carboxyl groups, and amino groups to the surface of the waterproof sheet 15. By imparting hydrophilicity to the waterproof sheet 15, the adhesion between the waterproof sheet 15 and the adhesive layer 13, specifically, the adhesion between the exposed portion of the first surface 21a of the resin sheet 21 and the adhesive layer 13, and the adhesion between the fiber material 22 and the adhesive layer 13 are improved.

Since the functional group is a carboxyl group, a complex is formed between the calcium ion (Ca ²⁺ ) and the carboxylate ion (COO ⁻ ) of the cement, and thus chemical bonding with the cement can be obtained, thereby improving the adhesion of the waterproof sheet 15 to the cement-based hydraulic material.

(Method of manufacturing waterproof sheet)
An example of a method for manufacturing the waterproof sheet 15 will now be described.
As shown in FIG. 7(a), the waterproof sheet 15 is manufactured by bonding a fiber material 22 to a resin sheet 21 by a thermal lamination process, and then cutting the resulting sheet to an appropriate size.

The lamination method involves extruding heated and molten resin from a sheet molding machine into a sheet, which is then rolled by roll 33 to form the resin sheet 21 through extrusion molding. At the same time, fibrous material 22 is fed into roll 33. The fibrous material 22 is supplied so that the base fibers 25 abut against the first surface 21a of the resin sheet 21, in other words, so that the napped fibers 26 are napped on the opposite side of the resin sheet 21. This causes the resin sheet 21 and the fibrous material 22 to be laminated together.

As shown in FIG. 7(b), if the pile length L of the brushed fibers 26 is smaller than the mesh size E of the base fibers 25, the proportion of brushed fibers 26 that are embedded in the exposed portion of the first surface 21a of the resin sheet 21 and stuck together will be high. On the other hand, if the pile length L of the brushed fibers 26 is larger than the mesh size E of the base fibers 25, a portion of the brushed fibers 26 will get caught on the base fibers 25, and the proportion of brushed fibers 26 that are embedded in the exposed portion of the first surface 21a of the resin sheet 21 and stuck together will be low. For this reason, it is preferable that the pile length L is larger than the mesh size E.

(Examples of waterproof sheets)
In a specific example of the waterproof sheet 15 of this embodiment, "San-A Sheet" (registered trademark) manufactured by Hasegawa Chemical Industry Co., Ltd. was used as the resin sheet 21. As shown in Table 1, this resin sheet 21 is a sheet made of ethylene vinyl acetate resin and has a thickness of 1.1 mm. At this time, the tensile strength was 1800 N/cm ² and the elongation rate was 600%. In addition, protrusions 23 having a width of 0.24 mm and a height of 0.13 mm were formed on the entire second surface 21b of the resin sheet 21.

As the fiber material 22, fiber material 1, fiber material 2, and fiber material 3 with the physical properties shown in Table 2 were prepared. Then, they were attached to the first surface 21a of the resin sheet 21 by a thermal lamination process.

As shown in Table 2, fiber material 1 used nylon having a fiber diameter of 28 μm for the base fiber 25 and the raised fiber 26, and was prepared by weaving loop-shaped raised fiber 26 into base fiber 25 having a mesh size E of 0.24 mm. In fiber material 1, the pile height H of the raised fiber 26 in a free-standing state before the thermal lamination treatment was 2.37 mm, and the basis weight was 73 g/ ^m2 .

The fiber material 2 used polyester having a fiber diameter of 32 μm for the base fiber 25 and vinylon having a fiber diameter of 32 μm for the napped fiber 26, and was obtained by entangling the random loop-shaped napped fiber 26 with the base fiber 25 having an aperture E of 1.82 mm. In the fiber material 2, the pile height H of the napped fiber 26 in a free-standing state before the thermal lamination process was 2.47 mm and the basis weight was 72 g/ ^m2 .

The fiber material 3 was made by using polypropylene and nylon with a fiber diameter of 220 μm for the base fiber 25 and the napped fiber 26, and knitting the loop-shaped napped fiber 26 into the base fiber 25 with a mesh size E of 11.1 mm. In the fiber material 3, the pile height H of the napped fiber 26 in a free-standing state before the thermal lamination treatment was 3.01 mm, and the basis weight was 118 g/ ^m2 .

In the waterproof sheet 15 in which the fiber material 1 was bonded to the resin sheet 21, the pile height H after bonding was 1.9 mm. It also had a moderate thickness and was easy to handle. In the waterproof sheet 15 in which the fiber material 2 was bonded to the resin sheet 21, the pile height H after bonding was 0.95 mm. It also had a moderate thickness and was easy to handle.

On the other hand, the waterproof sheet 15 in which the fiber material 3 is bonded to the resin sheet 21 has a basis weight of 118 g/ ^m2 , which makes the waterproof sheet 15 thick and difficult to handle. In addition, since the pile height H of the napped fibers 26 in the fiber material 3 in a free-standing state is smaller than the mesh size E, a high proportion of the napped fibers 26 are embedded in the exposed portion of the first surface 21a of the resin sheet 21 after lamination. This confirms that it is preferable that the pile height H of the napped fibers 26 in a free-standing state is larger than the mesh size E.

(Specific examples of waterproof structures)
A concrete example of a waterproof structure using a waterproof sheet 15 in which the fiber material 1 or the fiber material 2 is laminated, as well as experiments conducted on the waterproof structure and the results thereof will be described.

(Specific examples of adhesives)
First, specific examples of adhesive materials that form the adhesive layer 13 will be described.
In this embodiment, three adhesive materials will be described: adhesive 1, adhesive 2, and adhesive 3. Table 3 shows the specifications of each adhesive.

Adhesive 1 is made using ordinary Portland cement, "Sanae Polymer E" (registered trademark), an ethylene vinyl acetate resin-based polymer dispersion for mixing with cement manufactured by Hasegawa Chemical Industry Co., Ltd., and tap water, with a water-cement ratio (W/C) of 30% by mass and a polymer-cement ratio (P/C) of 4% by mass.

Adhesive 2 is made using ordinary Portland cement, ethylene vinyl acetate resin-based polymer dispersion for mixing with cement "Sanae Polymer E" (manufactured by Hasegawa Chemical Industry Co., Ltd.), and tap water, with a water-cement ratio (W/C) of 30% by mass and a polymer-cement ratio (P/C) of 8% by mass.

Adhesive 3 is made from ordinary Portland cement, silica fume, ethylene vinyl acetate resin-based polymer dispersion for cement mixing "Sanae Polymer E" (manufactured by Hasegawa Chemical Industry Co., Ltd.), tap water, and a polycarboxylic acid-based high-performance water-reducing agent. The binder is the sum of ordinary Portland cement and silica fume, with a silica fume substitution rate (SF/B) of 10%, a water-to-binder ratio (W/B) of 20%, a polymer binder ratio (P/B) of 8%, and an amount of polycarboxylic acid-based high-performance water-reducing agent added (Ad/B) of 0.6%.

(An experimental example of waterproof structure)
Next, a test specimen of a waterproof structure constructed using the above-mentioned resin sheet 21, fiber materials 1 and 2, and specific examples of adhesives 1 to 3, as well as an experiment on backside water pressure conducted on the test specimen and the results thereof will be described.

As shown in Figures 8(a) and 8(b), the test specimen 40 was made by attaching a waterproof sheet 15 to the surface 41a of two adjacent concrete plates 41 (15 cm long x 30 cm wide x 4 cm thick) via an adhesive layer 13.

Specifically, as shown in FIG. 8(a), first, a waterproof sheet 15 was attached to the surface 41a of two abutting concrete plates 41 via an adhesive layer 13. Next, as shown in FIG. 8(b), the two concrete plates 41 were separated to form a through passage 42 with a width of 0.1 mm that reached the waterproof sheet 15 from the back surface 41b side of the concrete plate 41. Thereafter, the periphery of the through passage 42 was sealed with an epoxy resin-based adhesive, and the specimen was cured for 28 days or more after the waterproof sheet 15 was attached to prepare the test specimen 40.

As shown in Figure 8 (c), pressurized water of 0.2 MPa was supplied from the back surface 41b side of the concrete plate 41 toward the passage 42, and the swelling of the waterproof sheet 15 after one hour of testing and the degree of penetration of the pressurized water between the waterproof sheet 15 and the adhesive layer 13 were checked. The degree of penetration was measured by measuring the horizontal length of the spread of the pressurized water in the waterproof sheet 15.

As shown in Table 4, in Example 1, the waterproof sheet 15 in which the fiber material 1 was attached to the resin sheet 21 was adhered to the concrete plate 41 using adhesive 1. In Example 2, the waterproof sheet 15 in which the fiber material 1 was attached to the resin sheet 21 was adhered to the concrete plate 41 using adhesive 2. In Example 3, the waterproof sheet 15 in which the fiber material 1 was attached to the resin sheet 21 was adhered to the concrete plate 41 using adhesive 3. In Example 4, the waterproof sheet 15 in which the fiber material 2 was attached to the resin sheet 21 was adhered to the concrete plate 41 using adhesive 3. In Comparative Example 1, the first surface 21a of the resin sheet 21 had protrusions 23 similar to those on the second surface 21b, and the resin sheet 21 was adhered to the concrete plate 41 using adhesive 1. In Examples 1 to 4 and Comparative Example 1, the second surface 21b of the resin sheet 21 had protrusions 23 formed thereon.

The experimental results are shown in Table 5.

As shown in Table 5, in Examples 1 to 4, no swelling occurred in the waterproof sheet 15. On the other hand, in Comparative Example 1, swelling occurred in the waterproof sheet 15. In addition, the lateral run length was 75 mm in Example 1, 20 mm in Example 2, 3 mm in Experimental Example 3, 3 mm in Example 4, and 95 mm in Comparative Example 1. Thus, in Examples 1 to 4, more useful results were obtained in terms of both swelling and lateral run length than in Comparative Example 1. In other words, it was confirmed that good watertightness was obtained by attaching the waterproof sheet 15 to the concrete plate 41 via the adhesive layer 13.

The effects of this embodiment will be described.
(1) By attaching the waterproof sheet 15 to the inner surface 12a of the underground structure 12 via the above-mentioned adhesive layer 13, good watertightness can be obtained between the underground structure 12 and the waterproof sheet 15. In addition, the stretchability of the waterproof sheet 15 and the anchor effect of the fiber material 22 make it difficult for the waterproof sheet 15 to break or swell due to back water pressure. Furthermore, a series of operations can be performed in the underground space formed by the underground structure 12.

(2) In the fiber material 22 that constitutes the waterproof sheet 15, the pile length L is greater than the mesh size E of the resin sheet 21. This makes it easier for the napped fibers 26 to remain self-supporting even after the resin sheet 21 and the fiber material 22 are bonded together.

(3) In the fiber material 22 before lamination, the pile height H of the napped fibers 26 in a free-standing state is 10.0 mm or less. This allows the thickness of the adhesive layer 13 to be reduced. As a result, the workability of applying the adhesive is improved.

(4) Since the waterproof sheet 15 is hydrophilic, the adhesion between the adhesive layer 13 and the waterproof sheet 15, and ultimately the adhesion between the underground structure 12 and the waterproof sheet 15, can be improved.
(5) The second surface 21b of the resin sheet 21 is formed into an uneven surface by the protrusions 23. This can improve the adhesion between the waterproof sheets 15.

(6) The pile height H of the brushed fibers 26 is greater than the mesh size E of the base fibers 25, which reduces the proportion of brushed fibers 26 that are embedded in and bonded to the exposed portion of the first surface 21a of the resin sheet 21.

(7) By bonding the fiber material 22 to the second surface 21b of the resin sheet 21, the adhesion between the waterproof sheets 15 is improved.
(8) Since the napped fibers 26 are loop-shaped, the adhesive layer 13 and the fibrous material 22 can be more firmly attached to each other.

(9) The raised fibers 26 are cut pile, and the cut pile is a pile tip 29 that extends laterally from the pile body 28, which strengthens the grip between the adhesive layer 13 and the fiber material 22.

(10) By setting the pile height H after bonding to the resin sheet 21 to 10 mm or less, it becomes easier to apply pressure to the adhesive to ensure watertightness, and the amount of adhesive layer applied in underground spaces where workability is poor can be minimized, reducing the variation in resistance to back water pressure. These effects become more pronounced when the pile height H is set to 5.0 mm or less, or even 3.0 mm or less.

(11) The boundary portion of the waterproof sheet 15 is covered by the boundary covering sheet 18, so that the boundary portion can be reinforced. This makes it less likely for the waterproof sheet 15 to bulge.

(12) The waterproof sheet 15 is manufactured by thermal lamination of the resin sheet 21 and the fiber material 22. This allows the waterproof sheet 15 to be manufactured by a simple method and with simple equipment.

This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.
The boundary portion of the waterproof sheet 15 does not have to be covered by the boundary covering portion 18 .

The second surface 21b of the resin sheet 21 does not have to be an uneven surface, and may be a flat surface.
The technical ideas that can be understood from the above-described embodiment and modified examples will be described.
(Appendix 1)
The raised fibers are loop pile.

(Appendix 2)
The brushed fibers are cut piles, and the cut piles have a pile body extending from the base fibers and a pile tip integrally formed at the tip of the pile body, and the pile tip has a portion extending laterally from the tip of the pile body.

(Appendix 3)
The second surface of the waterproof sheet is a textured surface.
(Appendix 4)
The adhesive layer contains Portland cement as a main component, and a polymer dispersion for mixing with cement or a re-emulsifiable powdered resin.

(Appendix 5)
The adhesive layer contains a material that has pozzolanic reaction.
(Appendix 6)
The adhesive layer contains at least one of an epoxy resin, a urethane resin, an acrylic resin, and a polyester resin.

(Appendix 7)
The waterproof sheets are arranged so as to cover the concrete structure, and adjacent waterproof sheets have overlapping portions, and the overlapping portions are bonded together via an adhesive layer.

(Appendix 8)
When the waterproof sheet is attached by butting, a boundary covering portion is provided for covering the boundary portion from the outside.

10...waterproof structure, 11...underground, 12...underground structure, 12a...inner surface, 13...adhesive layer, 15...waterproof sheet, 16...first waterproof sheet, 16A...first overlapping area, 17...second waterproof sheet, 17A...second overlapping area, 18...boundary covering sheet, 21...resin sheet, 21a...first surface, 21b...second surface, 22...fiber material, 23...projection, 25...base fiber, 26...brushed fiber, 28...pile body, 29...pile tip, 30...center axis, 33...roll, 40...test specimen, 41...concrete plate, 41a...surface, 41b...back surface, 42...passageway.

Claims (8)

A waterproof sheet that is adhered to a concrete structure via an adhesive layer,
a resin sheet made of a sheet-like synthetic polymer and having a first surface disposed on the adhesive layer side and a second surface disposed on the opposite side to the adhesive layer;
A fibrous material having a base fiber bonded to the first surface and a nap-like fiber raised from the base fiber to an opposite side of the resin sheet,
A portion of the first surface is exposed in a scattered manner,
The second surface is hydrophilic and has a concave-convex surface formed by a plurality of protrusions.
Waterproof sheet. The waterproof sheet according to claim 1 , wherein the napped fibers have a length greater than an aperture of the base fibers. The waterproof sheet according to claim 1 or 2, wherein the nap height of the napped fibers is 10.0 mm or less when the fibers are self-supporting. The waterproof sheet according to any one of claims 1 to 3, wherein the first surface of the resin sheet and the napped fibers of the fibrous material are hydrophilic. the fibrous material is a first fibrous material;
A second fiber material having a base fiber bonded to the second surface of the resin sheet and a brushed fiber brushed from the base fiber to an opposite side of the resin sheet,
The waterproof sheet according to any one of claims 1 to 4, wherein parts of the second surface are exposed in a scattered manner. The concrete structure is provided with an adhesive layer that covers the concrete structure, and a waterproof sheet that covers the concrete structure via the adhesive layer,
A waterproof structure, wherein the waterproof sheet is the waterproof sheet according to any one of claims 1 to 5. A method for waterproofing a concrete structure, comprising the steps of:
applying an adhesive layer to cover the concrete structure;
and attaching a waterproof sheet to the applied adhesive layer to cover the concrete structure with the waterproof sheet via the adhesive layer.
In the step of covering with the waterproof sheets, the waterproof sheets are overlapped with each other at portions of their outer peripheries and bonded with an adhesive to cover the concrete structure with a plurality of the waterproof sheets,
The waterproof sheet is
a resin sheet made of a sheet-like synthetic polymer and having a first surface disposed on the adhesive layer side and a second surface disposed on the opposite side to the adhesive layer;
A fibrous material having a base fiber bonded to the first surface and a nap-like fiber raised from the base fiber to an opposite side of the resin sheet,
A portion of the first surface is exposed in a scattered manner,
The second surface is hydrophilic and has a concave-convex surface formed by a plurality of protrusions.
Waterproofing method. A method for manufacturing a waterproof sheet that covers a concrete structure via an adhesive layer that covers the concrete structure, comprising:
The waterproof sheet is
a resin sheet made of a sheet-like synthetic polymer and having a first surface disposed on the adhesive layer side and a second surface disposed on the opposite side to the adhesive layer;
The present invention is characterized in that the sheet has a base fiber bonded to the first surface and a fiber material having napped fibers that are raised from the base fiber to an opposite side of the resin sheet, and a portion of the first surface is exposed in a scattered manner , and the second surface is formed into an uneven surface by a plurality of protrusions ,
The resin sheet is formed by extrusion molding of a thermoplastic resin,
the fiber material is thermally laminated to the resin sheet during extrusion molding of the resin sheet ;
After the extrusion molding, a hydrophilic treatment is performed on the second surface of the resin sheet.
How waterproof sheets are manufactured.

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