Waterproof sheet and waterproof structure

Abstract

To provide a waterproof sheet and a waterproof structure that can improve the water pressure resistance of the waterproof sheet for concrete structures.SOLUTION: A waterproof sheet 10 to be adhered to an underground framework 22, which is an example of a concrete structure, includes a resin sheet 11 made of a synthetic polymer and a fibrous material 12. The fibrous material 12 has base fibers 14 attached to a first surface 11A of the resin sheet 11 and raised fibers 15 that rise from the base fibers 14 to the opposite side of the resin sheet 11. The first surface 11A is exposed in a dispersed manner through gaps in the base fibers 14. The bonded area of the first surface 11A, where the base fibers 14 are bonded, is larger than the non-bonded area of the first surface 11A, where the base fibers 14 are not bonded.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a waterproof sheet and a waterproof structure. [Background technology]

[0002] Known methods for waterproofing underground concrete structures include a pre-applied method and a post-applied method. In the pre-applied method, a waterproofing layer is applied to the surface of an earth retaining wall, using the wall as a formwork, before the underground structure is poured, and then the underground structure is poured so that it is in close contact with the waterproofing layer. In the post-applied method, a waterproofing layer is applied directly to the outer surface of the underground structure after pouring. Patent Document 1, for example, discloses an example of a waterproofing layer, a waterproof sheet that is adhered to a concrete structure via an adhesive layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-19026 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned waterproof sheets, further improvement in the water pressure resistance of the waterproof sheets for concrete structures is desired in order to more reliably waterproof the underground structure. Note that the above-mentioned problem is not limited to waterproof sheets that are adhered to concrete structures via an adhesive layer, but is also common to waterproof sheets that are adhered directly to concrete structures without an adhesive layer. [Means for solving the problem]

[0005] A waterproof sheet that solves the above problem is a waterproof sheet that is adhered to a concrete structure, and comprises a resin sheet made of a synthetic polymer and a fibrous material, wherein the fibrous material has base fibers that are attached to a first side of the resin sheet and brushed fibers that brush from the base fibers to the opposite side of the resin sheet, the first side being exposed in a dispersed manner through gaps in the base fibers, and the adhesive area on the first side where the base fibers are adhered is larger than the non-adhesive area on the first side where the base fibers are not adhered. [Effects of the Invention]

[0006] According to the present invention, the water pressure resistance of a waterproof sheet for a concrete structure can be improved. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view of a waterproof sheet. [Figure 2] FIG. 2 is a plan view of the base fiber of the fibrous material provided in the waterproof sheet. [Figure 3] FIG. 3 is a schematic diagram of a napped fiber in the form of a looped fiber. [Figure 4] FIG. 4 is a schematic diagram of mushroom-shaped hairy fibers. [Figure 5] FIG. 5 is a schematic diagram of a hook-shaped napped fiber. [Figure 6] FIG. 6 is a schematic diagram of matchstick-shaped napped fibers. [Figure 7] FIG. 7 is a cross-sectional view of a first waterproof structure including a waterproof sheet and an adhesive layer. [Figure 8] FIG. 8 is a schematic diagram showing how waterproof sheets are attached together. [Figure 9] FIG. 9 is a schematic diagram showing how the boundary between the butted waterproof sheets is covered with a boundary covering sheet. [Figure 10] FIG. 10 is a cross-sectional view of a second waterproof structure that includes a waterproof sheet but does not include an adhesive layer. [Figure 11] FIG. 11 is a table showing the configurations of the resin sheets used in the test examples. [Figure 12] FIG. 12 is a table showing the composition of the fiber materials used in the test examples. [Figure 13] FIG. 13 is an image showing the fiber material used in the test example. [Figure 14] FIG. 14 is a table showing the configurations of the waterproof sheets used in the test examples. [Figure 15] FIG. 15 is an image showing the waterproof sheet used in the test example. [Figure 16] FIG. 16 is a table showing the compositions of the adhesives used in the test examples. [Figure 17] FIG. 17 is a table showing the configurations of the waterproof structures of the test examples and the comparative examples. [Figure 18] FIG. 18 is a table showing the results of the peel adhesion test of the waterproof sheet of Test Example 1. [Figure 19] FIG. 19 is a table showing the composition of the concrete used in Test Example 2. [Figure 20] FIG. 20 is a table showing the physical properties of the components shown in FIG. [Figure 21] FIG. 21 is a table showing the results of the peel adhesion test of the waterproof structure of Test Example 2. [Figure 22] FIG. 22 is a table showing the results of the backside water pressure test of Test Example 3. [Figure 23] FIG. 23 is an image showing the appearance of Example 1 in the backside water pressure test of Test Example 3. [Figure 24] FIG. 24 is an image of the cross section of the adhesive layer of Example 1 after the back water pressure test of Test Example 3, taken with a scanning electron microscope. [Figure 25] FIG. 25 is a table showing the test results of the water cross-flow resistance test of Test Example 4. [Figure 26] FIG. 26 is a table showing the test results of the warp resistance test of Test Example 5. [Figure 27] FIG. 27 is a table summarizing the test results of Test Examples 2 to 5. [Figure 28] FIG. 28 is a cross-sectional view showing a modified waterproof structure. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of a waterproof sheet and a waterproof structure will be described with reference to FIGS. [Tarp 10] As shown in Figure 1, the waterproof sheet 10 is a two-layer sheet comprising a resin sheet 11 and a fiber material 12. The waterproof sheet 10 is manufactured by bonding the fiber material 12 to the resin sheet 11 by thermal lamination, and then cutting the sheet to an appropriate size.

[0009] The resin sheet 11 is formed from a sheet-like synthetic polymer. The resin sheet 11 is formed from one or more resin materials selected from the group consisting of, for example, 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, nylon, and polycarbonate. The resin sheet 11 may be a single layer of a single resin or a mixture of multiple resins, or may be a laminate having multiple layers. From the viewpoints of handling, water barrier properties, and corrosion resistance, the resin sheet 11 is preferably an ethylene vinyl acetate resin or a polyethylene resin.

[0010] The resin sheet 11 has a first surface 11A and a second surface 11B. A fibrous material 12 is bonded to the first surface 11A. The second surface 11B faces the opposite side of the first surface 11A. In this embodiment, the second surface 11B is an uneven surface having a plurality of protrusions 13. Examples of the shape of the protrusions 13 include linear, pyramidal, ridgeline, sea-island, embossed, mushroom, hook, and matchstick shapes. The protrusions 13 create an anchor effect in the overlapping portions of the waterproof sheets 10, improving the adhesion between the waterproof sheets 10.

[0011] The fibrous material 12 includes base fibers 14 and pile fibers (pile) 15. The base fibers 14 are bonded to the first surface 11A of the resin sheet 11. The pile fibers 15 are raised on the opposite side of the resin sheet 11 from the base fibers 14.

[0012] The material of the fiber material 12 may be, for example, any of organic synthetic fibers, natural fibers, semi-synthetic fibers, and inorganic fibers, and specifically, it is formed from one or more fiber materials selected from the group consisting of 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 preferred.

[0013] 2, the base fibers 14 are shown by dots when the waterproof sheet 10 is viewed from the side of the fiber material 12. Note that in FIG. 2, the napped fibers 15 of the fiber material 12 are omitted. As shown in FIG. 2 , the base fibers 14 have a mesh-like shape, for example. Examples of the base fibers 14 include woven fabric, knitted fabric, net-like fabric, and nonwoven fabric. When the base fibers 14 are bonded to the resin sheet 11, the napped fibers 15 are densely packed, and portions of the first surface 11A of the resin sheet 11 are exposed from the base fibers 14 in a scattered manner. That is, the first surface 11A of the resin sheet 11 is exposed in a dispersed manner through gaps in the base fibers 14. The mesh portions of the mesh-like base fibers 14 are an example of gaps in the base fibers 14.

[0014] The mesh-shaped base fiber 14 has a mesh size E1. The mesh size E1 is the maximum width of the mesh portion. The mesh size E1 is the maximum width of the mesh portion. The mesh size E1 is preferably greater than 0.1 mm. The mesh size E1 is preferably less than 10 mm, more preferably less than 5.0 mm, and even more preferably less than 3.0 mm.

[0015] The first surface 11A has bonded regions where the base fibers 14 are bonded and non-bonded regions where the base fibers 14 are not bonded. The bonded regions are portions of the first surface 11A that are in contact with the base fibers 14. The non-bonded regions are portions of the first surface 11A that are exposed from the base fibers 14. On the first surface 11A, the area of the bonded regions is larger than the area of the non-bonded regions.

[0016] The area of the adhesive region may be, for example, a value obtained by measuring the area of the portion of the base fiber 14 of the fiber material 12 that is in contact with the first surface 11A of the resin sheet 11 before the resin sheet 11 is bonded. The area of the non-adhesive region may be a value obtained by subtracting the area of the adhesive region from the area of the first surface 11A.

[0017] Furthermore, the ratio of the area of the bonded region and the area of the non-bonded region to the total area of the first surface 11A may be measured, for example, from a cross section obtained by cutting the waterproof sheet 10, which is made by laminating the resin sheet 11 and the fibrous material 12. When measuring the area ratios of the bonded region and the non-bonded region within a cross section obtained by cutting the waterproof sheet 10, the average value of the area ratios measured within cross sections obtained by cutting the waterproof sheet 10 from multiple directions may be used.

[0018] For example, the area of the bonded region being larger than the area of the non-bonded region means that the area of the portion of the base fiber 14 that contacts the first side 11A of the resin sheet 11 is larger than 50% of the entire area of the first side 11A of the resin sheet 11. Also, for example, assume that the entire area of the first side 11A of the resin sheet 11 is equal to the area of the entire outer shape of the base fiber 14, including gaps. The ratio of the area of the portion of the base fiber 14 that contacts the first side 11A of the resin sheet 11 to the area of the entire outer shape of the base fiber 14 is defined as the bonded area ratio. The area of the bonded region being larger than the area of the non-bonded region means that the bonded area ratio is larger than 50%.

[0019] The area of the adhesive region is preferably 60% or more of the entire area of the first surface 11A of the resin sheet 11, and more preferably 70% or more of the entire area of the first surface 11A. Such an area ratio of the adhesive region can more suitably increase the peel strength between the resin sheet 11 and the fibrous material 12. Furthermore, since the base fibers 14 are densely arranged, the breaking strength of the base fibers 14 is also improved.

[0020] The area of the adhesive region is preferably 90% or less of the total area of first side 11A, and more preferably 80% or less of the total area of first side 11A. With this ratio of the adhesive region area, the adhesive for adhering waterproof sheet 10 or unhardened concrete can be suitably filled into the gaps in base fibers 14.

[0021] 3, the raised fibers 15 have a three-dimensional shape raised from the base fibers 14. The fiber diameter of the raised fibers 15 is, for example, 0.1 μm or more and 500 μm or less. The raised fibers 15 are fixed to the base fibers 14 by a method such as weaving, knitting, entangling, embedding, or bonding so that they do not easily come off or detach from the base fibers 14.

[0022] The shape of the napped fibers 15 includes, for example, one or more selected from loop fibers, cut fibers, spiral fibers, and non-directional fibers. The napped fibers 15 have, for example, a loop fiber shape. The looped napped fibers 15 are circular napped fibers 15 partially bonded to the base fibers 14.

[0023] The pile length L1 is the length of the piled fibers 15 itself, and the pile height H1 is the height of the pile from the base fibers 14 in a free-standing state. The pile height H1 is equal to or less than the pile length L1. The pile length L1 is preferably equal to or less than 10 mm.

[0024] In order to prevent the napped fibers 15 from being buried in the portion where the first surface 11A of the resin sheet 11 is exposed from the base fibers 14, the pile length L1 is preferably greater than the mesh size E1 of the base fibers 14.

[0025] 4 to 6 show cut fiber-like napped fibers 15. Cut fiber-like napped fibers 15 have a base end joined to base fibers 14 and a tip end separated from base fibers 14.

[0026] The cut-fiber-like napped fibers 15 shown in Fig. 4 have a mushroom shape. The cut-fiber-like napped fibers 15 shown in Fig. 5 have a hook shape. The cut-fiber-like napped fibers 15 shown in Fig. 6 have a matchstick shape. These cut-fiber-like napped fibers 15 have, for example, a pile body 16 extending from the base fibers 14 and a pile tip portion 17 integrally formed at the tip of the pile body 16. The pile tip portion 17 has a portion that extends laterally from the tip of the pile body 16 or a portion that bulges laterally, based on the central axis CL1 of the pile body 16.

[0027] The waterproof sheet 10 is also subjected to a hydrophilic treatment to impart hydrophilic properties to the second surface 11B of the resin sheet 11. The hydrophilic treatment may be performed before or after the fiber material 12 is bonded to the resin sheet 11. The hydrophilic treatment is a treatment that imparts functional groups such as hydroxyl groups, carboxyl groups, and amino groups to the second surface 11B of the resin sheet 11 of the waterproof sheet 10.

[0028] The fibrous material 12 may also be subjected to a water-absorption prevention treatment to prevent water absorption into the fibrous material 12. One example of such a treatment is a surface treatment in which the fibrous material 12 is coated with a surface treatment agent. The surface treatment may be performed before or after bonding the fibrous material 12 to the resin sheet 11. The surface treatment agent may be at least one selected from the group consisting of fluororesin, paraffin resin, melamine resin, epoxy resin, acrylic resin, vinyl acetate resin, polyester resin, silicone resin, zirconium-wax emulsion, fatty acid amide derivative, alkyl ethylene urea, alkyl ketene dimer, and Werner complex salt. The water-absorption prevention treatment may also be a measure to impart a finely textured cross-sectional shape, such as a lotus leaf shape, to the fibrous material 12. Applying a water-absorption prevention treatment to the fibrous material 12 suppresses water absorption by the fibrous material 12. This prevents dimensional changes and warping of the waterproof sheet 10 due to water absorption by the fibrous material 12.

[0029] [Waterproof structure] 7, a first waterproof structure 20A, which is an example of a waterproof structure, includes a waterproof sheet 10 and an adhesive layer 23. In the first waterproof structure 20A, the waterproof sheet 10 is adhered to an inner surface 22A of an underground structure 22 installed in the ground 21 via the adhesive layer 23. In the first waterproof structure 20A, by covering the inner surface 22A of the underground structure 22 with the waterproof sheet 10 and the adhesive layer 23, water leakage into the underground space formed by the underground structure 22 is suppressed.

[0030] In the first waterproof structure 20A, the napped fibers 15 of the waterproof sheet 10 are embedded in the adhesive layer 23. The napped fibers 15 create an anchor effect between the waterproof sheet 10 and the adhesive layer 23, thereby improving the adhesion between the underground structure 22 and the waterproof sheet 10 via the adhesive layer 23.

[0031] The underground structure 22 is an example of a concrete structure. The underground structure 22 is a hardened body of a first cementitious hydraulic material. The first cementitious hydraulic material is a fluid obtained by mixing at least cement and water. The first cementitious hydraulic material is, for example, concrete obtained by mixing water with a cement mixture in which cement is mixed with aggregates such as gravel and sand.

[0032] The adhesive layer 23 is a hardened adhesive applied to the inner surface 22A of the underground skeleton 22. The adhesive is, for example, a second cementitious hydraulic material. The second cementitious hydraulic material is a cement paste, mortar, concrete, or the like containing one or more cements selected from the group consisting of 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-rapid-hardening cement, alumina cement, and ecocement.

[0033] The second cementitious hydraulic material may contain, in addition to the above cement, one or more admixtures such as a water reducing agent, an air-entraining agent, an air-entraining water reducing agent, a high-performance water reducing agent, a high-performance air-entraining water reducing agent, a superplasticizer, a hardening accelerator, a setting retarder, or an antifoaming agent, or one or more short fibers such as polypropylene, vinylon, or nylon.

[0034] Instead of the second cement-based hydraulic material, the adhesive may be a resin-based material such as epoxy resin, urethane resin, acrylic resin, polyester, etc. Furthermore, the adhesive may be a resin mortar using such a resin-based material, or a mixture of such a resin-based material and the second cement-based hydraulic material.

[0035] The adhesive may be a mixture of the second cementitious hydraulic material with a polymer dispersion for cement admixture or a re-emulsifiable powdered resin. Examples of the polymer dispersion and re-emulsifiable powdered resin for cement admixture include ethylene vinyl acetate resin, acrylic resin, resin asphalt, SBR, and latex. The polymer dispersion and re-emulsifiable powdered resin for cement admixture may be any polymer that satisfies the Japanese Industrial Standard JISA6203:2015 "Polymer dispersions and re-emulsifiable powdered resins for cement admixture."

[0036] Since underground spaces tend to be humid environments, the second cementitious hydraulic material of the adhesive is preferably a material that exhibits good adhesion to the underground structure 22 even in humid environments. From the viewpoint of watertightness and adhesiveness, it is even more preferable that the adhesive be a cement paste mixed with a polymer dispersion for cement admixture, which is made of either ethylene vinyl acetate resin, acrylic resin, or epoxy resin.

[0037] In particular, the adhesive is preferably a cement paste obtained by mixing the second cementitious hydraulic material with epoxy resin and acrylic resin, which are polymers for cement admixture. That is, the adhesive layer 23 is preferably a hardened cement paste obtained by mixing the second cementitious hydraulic material with epoxy resin and acrylic resin.

[0038] The moisture that has penetrated into the adhesive layer 23 is consumed by rehydration when it comes into contact with the cement that makes up the adhesive layer 23. Therefore, even if water penetrates into the adhesive layer 23 temporarily, the watertightness will increase in the long term.

[0039] In the first waterproof structure 20A, the waterproof sheet 10 is attached to the uncured adhesive layer 23, and then fixed to the inner surface 22A of the underground structure 22 as the adhesive layer 23 cures. Considering the application of the waterproof sheet 10 to the entire inner surface 22A and the ease of handling the waterproof sheet 10, it is preferable to overlap waterproof sheets 10 of appropriate size with an appropriate width. Multiple waterproof sheets 10 are attached to the adhesive layer 23 so that parts of their outer peripheries overlap.

[0040] 8, when two waterproof sheets 10A and 10B are attached, an adhesive is applied to a first overlapping region 10C, which is part of the outer periphery of waterproof sheet 10A, which is first adhered to inner surface 22A. Then, waterproof sheet 10B is adhered to inner surface 22A so that a second overlapping region 10D, which is part of the outer periphery of waterproof sheet 10B, which is then adhered to inner surface 22A, overlaps with first overlapping region 10C.

[0041] As shown in Figure 9, the two waterproof sheets 10A, 10B may be butted together without overlapping, leaving no gaps. In this case, it is preferable to attach a boundary covering sheet 10E of an appropriate width to cover the boundary. The boundary covering sheet 10E may be a sheet similar to the waterproof sheet 10. By covering the boundary with the boundary covering sheet 10E in this way, the boundary of the waterproof sheet 10 can be reinforced. As a result, the waterproof sheet 10 is less likely to bulge even if water leaks from the underground structure 22.

[0042] 10 , a second waterproof structure 20B, which is an example of a waterproof structure, includes a waterproof sheet 10. In the second waterproof structure 20B, the waterproof sheet 10 is placed between the ground 21 and an outer surface 22B of an underground structure 22. In the second waterproof structure 20B, by covering the outer surface 22B of the underground structure 22 with the waterproof sheet 10, leakage of water into the underground space formed by the underground structure 22 is suppressed.

[0043] In the second waterproof structure 20B, the napped fibers 15 of the waterproof sheet 10 are embedded in the underground structure 22. The napped fibers 15 create an anchor effect between the waterproof sheet 10 and the underground structure 22, thereby improving the adhesion between the underground structure 22 and the waterproof sheet 10.

[0044] For example, in the second waterproofing structure 20B, an earth retaining wall may be placed underground 21. Then, the second surface 11B of the waterproofing sheet 10 is faced toward the underground 21, and the waterproofing sheet 10 is attached to the earth retaining wall side using any adhesive or the like. Then, unhardened concrete for forming the underground structure 22 is poured so that it adheres closely to the napped fibers 15 of the waterproofing sheet 10. This allows the waterproofing sheet 10 to be adhered to the outer surface 22B of the underground structure 22 without an adhesive layer 23. Note that, as with the first waterproofing structure 20A, it is preferable to overlap waterproofing sheets 10 of appropriate size with an appropriate width.

[0045] In the first waterproof structure 20A and the second waterproof structure 20B, a carboxyl group is introduced to the second surface 11B of the resin sheet 11 by a hydrophilic treatment, so that calcium ions (Ca 2+ ) and carboxylate ion (COO - ) forms a complex. This allows chemical bonding between the second surface 11B of the resin sheet 11 of the waterproof sheet 10 and the cement. As a result, the adhesiveness of the waterproof sheet 10 to the cement-based hydraulic material can be improved.

[0046] That is, in the first waterproof structure 20A and the second waterproof structure 20B, the second surface 11B of the resin sheet 11 of the waterproof sheet 10 is made hydrophilic, thereby improving adhesion to the first surface 11A of the resin sheet 11 when two waterproof sheets 10 are stacked and attached together. Also, in the second waterproof structure 20B, the second surface 11B of the resin sheet 11 of the waterproof sheet 10 is made hydrophilic, thereby improving adhesion of the waterproof sheet 10 to the ground 21 (which may include an earth retaining wall, etc.).

[0047] [Test example: Composition of waterproof sheet 10] As shown in FIG. 11, in the test example of this embodiment, a sheet made of ethylene vinyl acetate resin having a thickness of 1.1 mm was prepared as the resin sheet 11. "Sanae Sheet" (registered trademark) manufactured by Hasegawa Sheet Co., Ltd. was used as this resin sheet 11. The resin sheet 11 had a tensile strength of 1800 N / cm 2 The elongation was 600%. Furthermore, protrusions 13 each having a width of 0.46 mm and a height of 0.25 mm were formed on the entire second surface 11B of the resin sheet 11.

[0048] As shown in Fig. 12, in the test example of this embodiment, a first fiber material was prepared as the fiber material 12. In the first fiber material, nylon having a fiber diameter of 29 µm was used for the base fiber 14 and the napped fiber 15. The first fiber material was prepared by weaving loop-shaped napped fibers 15 into base fiber 14 having a mesh size E1 of 0.44 mm. In the first fiber material, the pile height H1 of the napped fibers 15 in a free-standing state before thermal lamination treatment was 1.57 mm, and the basis weight was 55 g / m 2 The adhesive area ratio of the base fiber 14 was 78.6%.

[0049] In the test example of this embodiment, a second fiber material was used in addition to the first fiber material. For the second fiber material, nylon with a fiber diameter of 28 μm was prepared for the base fiber 14 and the napped fiber 15. For the second fiber material, loop-shaped napped fibers 15 were woven into the base fiber 14 with a mesh size E1 of 0.53 mm. For the second fiber material, the pile height H1 of the napped fibers 15 in a free-standing state before the thermal lamination treatment was 2.37 mm and the basis weight was 46 g / m. 2 The adhesive area ratio of the base fiber 14 was 48.9%.

[0050] FIG. 13 shows images of the first and second fiber materials. The image on the left side of FIG. 13 is an image of the first fiber material. The image on the right side of FIG. 13 is an image of the second fiber material. The images in the upper row of FIG. 13 are images of the first and second fiber materials taken from the side of the napped fiber 15. The images in the middle row of FIG. 13 are images of the first and second fiber materials taken from the side of the base fiber 14. The image in the lower row of FIG. 13 is a binarized image of the image in the middle row, which extracts the portion of the base fiber 14 that contacts the first surface 11A of the resin sheet 11 when the first and second fiber materials are bonded to the resin sheet 11. In the image in the lower row of FIG. 13, the white portion represents the portion of the base fiber 14 that contacts the first surface 11A of the resin sheet 11. The adhesive area ratio shown in FIG. 12 refers to the ratio of the area of the white portion to the area of the entire image in the image in the lower row of FIG. 13.

[0051] As shown in the middle and bottom images of FIG. 13, in the base fibers 14 of the first and second fiber materials, the portions woven in the left-right direction of the paper correspond to the portions of the base fibers 14 that come into contact with the first surface 11A of the resin sheet 11. As shown in the middle image of FIG. 13, in the base fibers 14, there is a portion woven in the up-down direction of the paper closer to the brushed fibers 15 than the portion woven in the left-right direction of the paper. In this embodiment, the portion woven in the up-down direction of the paper is not included in the portion that comes into contact with the first surface 11A of the resin sheet 11. The mesh size E1 can be measured from the middle image of FIG. 13.

[0052] As shown in FIG. 14, in a test example of this embodiment, a first waterproof sheet was prepared as the waterproof sheet 10 used in the test. The first waterproof sheet was constructed by bonding the first fiber material shown in FIG. 12 as the fiber material 12 to the first surface 11A of the resin sheet 11 shown in FIG. 11 using a thermal lamination process. In the first waterproof sheet, the pile height H1 after bonding was 0.82 mm. The ratio of the area of the adhesive region to the entire area of the first surface 11A of the resin sheet 11 in the first waterproof sheet was 63.4% in a cross section cut along a predetermined first direction, and 77.8% in a cross section cut along a second direction perpendicular to the first direction.

[0053] In a test example of this embodiment, a second waterproof sheet was prepared in addition to the first waterproof sheet. The second waterproof sheet was constructed by bonding the second fiber material shown in FIG. 12 to the first surface 11A of the resin sheet 11 shown in FIG. 11 using a thermal lamination process. The pile height H1 of the second waterproof sheet after bonding was 1.06 mm. The ratio of the area of the adhesive region to the total area of the first surface 11A of the resin sheet 11 in the second waterproof sheet was 40.6% in a cross section cut in a predetermined first direction, and 47.4% in a cross section cut along the second direction, which is perpendicular to the first direction.

[0054] In the test example of this embodiment, in addition to the first and second waterproof sheets, a third waterproof sheet was prepared as the waterproof sheet 10 for testing. Like the first waterproof sheet, the third waterproof sheet was constructed by attaching a first fiber material to the first surface 11A of a resin sheet 11 using a thermal lamination process. For the third waterproof sheet, a water-absorption-preventing treatment was applied to the first fiber material. For the water-absorption-preventing treatment, a solution of "Hi-SAT Polymer" manufactured by Hasegawa Sheet Co., Ltd. and tap water in a mass ratio of 1:9 was used as a surface treatment agent. Note that "Hi-SAT Polymer" is an example of a polymer for cement admixtures containing epoxy resin and acrylic resin, but is used as a surface treatment agent here. For comparison, a resin sheet 11 without any fiber material 12 attached was also tested in the test example of this embodiment.

[0055] Figure 15 shows images of the cross sections of the first waterproof sheet and the second waterproof sheet. The image on the left side of Figure 15 is an image of the cross section of the first waterproof sheet. The image on the right side of Figure 15 is an image of the cross section of the second waterproof sheet. The images in the top row of Figure 15 are images of the cross sections of the first waterproof sheet and the second waterproof sheet cut along a predetermined first direction. The images in the bottom row of Figure 15 are images of the cross sections of the first waterproof sheet and the second waterproof sheet cut along a second direction perpendicular to the first direction. The pile height H1 of the first waterproof sheet and the second waterproof sheet can be measured from the images in the top row or bottom row of Figure 15.

[0056] Furthermore, in each of the first direction and the second direction, the ratio of the area of the adhesive region to the entire area of the first surface 11A of the resin sheet 11 can be measured from the upper and lower images in Fig. 15. For example, in each image in Fig. 15, the entire length of the first surface 11A of the resin sheet 11 and the length of the portion where the first surface 11A and the base fibers 14 contact each other are measured. Then, the ratio of the length of the portion where the first surface 11A and the base fibers 14 contact each other to the entire length of the first surface 11A can be used as the ratio of the area of the adhesive region to the entire area of the first surface 11A.

[0057] [Test example: adhesive composition] As shown in Fig. 16, a first adhesive and a second adhesive were prepared as adhesives for forming the adhesive layer 23 of the first waterproof structure 20A. The first adhesive was made by mixing ordinary Portland cement with "Hi-SAT Polymer" manufactured by Hasegawa Sheet Co., Ltd. The water-cement ratio (W / C) of the first adhesive was 32% by mass, and the polymer-cement ratio (P / C) was 13% by mass.

[0058] The second adhesive was made by mixing ordinary Portland cement, San-A Polymer E (registered trademark), an ethylene vinyl acetate resin-based polymer dispersion for cement mixing manufactured by Hasegawa Sheet Co., Ltd., and tap water. The water-to-cement ratio (W / C) of the second adhesive was 30% by mass, and the polymer-to-cement ratio (P / C) was 4% by mass.

[0059] [Test Examples: Examples and Comparative Examples of Waterproof Structures] As shown in Fig. 17, in the test examples of this embodiment, test specimens were prepared for the waterproof structures of Examples 1 to 3 and Comparative Examples 1 to 5. In Examples 1 and 3 and Comparative Examples 1 to 4, the test specimens had a first waterproof structure 20A in which the waterproof sheet 10 (resin sheet 11 in Comparative Example 4) was adhered to a base board via an adhesive layer 23. In Example 2 and Comparative Example 5, the test specimens had a second waterproof structure 20B in which the waterproof sheet 10 (resin sheet 11 in Comparative Example 5) was adhered to a concrete board without an adhesive layer 23.

[0060] Example 1 includes a first waterproof sheet as the waterproof sheet 10 and an adhesive layer 23 formed by a first adhesive. Example 2 includes a first waterproof sheet directly adhered to a concrete slab without an adhesive layer 23. Example 3 includes a third waterproof sheet as the waterproof sheet 10 and an adhesive layer 23 formed by a first adhesive. Comparative Example 1 includes a first waterproof sheet and an adhesive layer 23 formed by a second adhesive. Comparative Example 2 includes a second waterproof sheet and an adhesive layer 23 formed by the first adhesive. Comparative Example 3 includes a second waterproof sheet and an adhesive layer 23 formed by a second adhesive. Comparative Example 4 includes a resin sheet 11 instead of the waterproof sheet 10 and an adhesive layer 23 formed by a second adhesive. Comparative Example 5 includes a resin sheet 11 adhered directly to a concrete slab without an adhesive layer 23.

[0061] [Test Example 1: Peel adhesion test of waterproof sheet 10] In Test Example 1, the first and second waterproof sheets 10 were bonded to a 150 x 110 x 6 mm flexible board substrate using an epoxy resin adhesive, with the napped fiber 15 side facing the substrate. This was then cured in air (23°C, 65% RH) for 7 days. The waterproof sheet 10 was then cut into 25 mm widths down to the substrate. The interface between the resin sheet 11 and the fibrous material 12 in the waterproof sheet 10 was partially peeled off, and the edge of the resin sheet 11 was grasped and peeled off at a 90° angle at 200 mm / min. The peel strength was determined by averaging the peel load at five points 15 mm apart from the 25 mm peel length, in accordance with the method for determining 90° peel strength in JIS A 5536:2007 "Floor Finishing Adhesives." Three tests were conducted for each of the first and second waterproof sheets. The evaluation results are shown in Figure 18.

[0062] In the peel adhesion test, the load required of the waterproofing structure when subjected to water pressure from cracks that have appeared in the underground concrete structure was set as the standard value. First, the width of the crack is assumed to be W = 0.5 mm, which is the allowable value for shrinkage cracks in reinforced concrete structures. The length of the crack (total length of the crack) is then set to L. Furthermore, since underground concrete structures are often installed at locations shallower than 40 m underground, the water pressure from the crack is set to P = 0.4 MPa, which corresponds to a water head of 40 m. In this case, the force applied to the waterproofing structure covering the crack is W (mm) × L (mm) × P (N / mm 2 ) is given as

[0063] The waterproofing structure supports this force from both sides of the crack along its extension. Therefore, the force per unit length on one side of the waterproofing structure supporting the water pressure from the crack is expressed as WLP (N) / 2L (mm) = WP / 2 (N / mm). Considering the width of the specimen (25 mm) in the peel adhesion test, the force exerted by the above water pressure on a waterproofing structure with a width of 25 mm can be expressed as WP / 2 (N / mm) x 25 = 12.5WP (N / 25 mm). Substituting W = 0.5 mm and P = 0.4 MPa into this formula, the result is 12.5 x 0.5 x 0.4 = 2.5 (N / 25 mm). Furthermore, setting a safety factor of S = 10 to the above value, a reference value of 25 (N / 25 mm) is derived. If the measurement result of the peel adhesion test is equal to or greater than the standard value, it means that the peel strength of the measurement point is equal to or greater than the load when a water pressure of 0.4 MPa is applied through a crack with a width of 0.5 mm.

[0064] As shown in Figure 18, the first waterproof sheet using a first fiber material with a base fiber 14 adhesion area ratio of 78.6% had a peel strength of approximately 75.5 (N / 25mm). The second waterproof sheet using a second fiber material with a base fiber 14 adhesion area ratio of 48.9% had a peel strength of approximately 50.2 (N / 25mm). This indicates that a base fiber 14 adhesion area ratio of 50% or more improves the peel strength between the resin sheet 11 and the fiber material 12 compared to a case where the peel strength is less than 50%. It was also confirmed that the average peel strength minus three times the standard deviation (σ) (=3σ) was equal to or greater than the reference value for both the first waterproof sheet and the second waterproof sheet.

[0065] [Test Example 2: Peel adhesion test of waterproof structure] In Test Example 2, using the configurations of Example 1 and Comparative Examples 1 to 4, a test waterproof sheet 10 or resin sheet 11 was adhered to a 150 x 110 x 6 mm (t) flexible board as a substrate with the napped fiber 15 side facing the substrate via an adhesive. When only the resin sheet 11 was used as the test sheet, it was adhered with the first surface 11A side facing the substrate. After that, the test specimen was cured in air (23°C, 65% RH) for 7 days to obtain a test specimen.

[0066] In Test Example 2, using the configurations of Example 2 and Comparative Example 5, a waterproof sheet 10 was laid on the bottom of a 30 cm x 30 cm x 5 cm steel formwork with the napped fiber 15 side (first surface 11A side in Comparative Example 5) facing up, and fresh concrete was poured into the formwork to form an integrated structure. The concrete was then cured in air (23°C, 65% RH) for 28 days and then demolded to form a test specimen. The compositions of the fresh concrete used in Example 2 and Comparative Example 5 are shown in Figures 19 and 20.

[0067] For each test specimen, the waterproof sheet 10 or resin sheet 11 was cut to a width of 25 mm down to the substrate, and the edge was gripped and peeled at a 90-degree angle at 200 mm / min. The peel strength was determined by averaging the peel load at five points 15 mm apart from the 25 mm peel length, in accordance with the method for determining 90-degree peel adhesion strength in JIS A 5536:2007 "Floor Finishing Adhesives." Three specimens (n=3) were tested per test specification. The evaluation results are shown in Figure 21. The peel adhesion test for the waterproof structure of Test Example 2 also used a standard value of 25 (N / 25 mm), as in Test Example 1.

[0068] As shown in Figure 21, the peel adhesion strength (N / 25 mm) for each specification was 126.4 for Example 1, 83.6 for Example 2, 67.7 for Comparative Example 1, 51.6 for Comparative Example 2, 49.9 for Comparative Example 3, 7.5 for Comparative Example 4, and 13.1 for Comparative Example 5.

[0069] Furthermore, it was confirmed that in Examples 1 and 2 and Comparative Examples 1 to 3, the value obtained by subtracting three times the standard deviation (σ) (=3σ) from the average adhesive peel strength was equal to or greater than the reference value. Therefore, it was confirmed that Examples 1 and 2 and Comparative Examples 1 to 3 had sufficient performance to suppress swelling of the waterproof sheet 10 when water pressure was applied to the waterproof structure. In particular, particularly excellent peel adhesion strength was confirmed in Examples 1 and 2, demonstrating high resistance to water pressure.

[0070] [Test Example 3: Rear Water Pressure Test of First Waterproof Structure 20A] In Test Example 3, a 30 cm × 30 cm × 4 cm concrete slab with a 10 mm diameter through-hole drilled in the center was used as the base for Examples 1 and 3 and Comparative Examples 1 to 4. An adhesive was applied to the base, avoiding the through-hole. The test waterproof sheet 10 or resin sheet 11 was then adhered to the base with the napped fiber 15 side facing the base via adhesive. When only the resin sheet 11 was used as the test sheet, the first surface 11A side was adhered facing the base. The test specimens were then cured in air (23°C, 65% RH) for 7 days to prepare test specimens. A backwater pressure test was then conducted by applying a water pressure of 0.2 MPa, equivalent to a head of water of 20 m, through the through-hole from the concrete slab side for 7 days. The backwater pressure test confirmed the presence or absence of water leakage. One test specimen (n=1) was used for each specification. The evaluation results are shown in Figure 22.

[0071] In Examples 1 and 3, no water leakage occurred due to backside water pressure. Therefore, it was confirmed that the waterproof structures of Examples 1 and 3 exhibit excellent resistance to backside water pressure. On the other hand, in Comparative Example 1, water leakage due to lateral water flow caused by backside water pressure was confirmed. Furthermore, in Comparative Examples 2 to 4, water leakage due to swelling of the waterproof sheet 10 (resin sheet 11 in Comparative Example 4) caused by backside water pressure was confirmed.

[0072] As shown in Figure 23, in Example 1, no swelling or peeling of the waterproof sheet 10 was observed, but water temporarily ran horizontally, but not to the extent that leakage did occur. The running of water was confirmed as a wet color on the waterproof sheet 10 side. When pressure was continued to be applied in Example 1 from that point on, it was confirmed that the wet color caused by the running of water had disappeared in some areas 36 days after the start of pressure application.

[0073] Further, in the test specimens where pressure was continued for up to 168 days, portions of the adhesive layer 23 were sampled from non-water-wetted areas where no wet color due to lateral water flow had occurred, and from wet color-disappeared areas where wet color had occurred but had disappeared due to continued pressure.

[0074] The collected sample was observed with a scanning electron microscope (SEM), as shown in Figure 24. As a result, the SEM image confirmed that the adhesive layer 23 was densified by crystals of calcium hydroxide and calcium silicate hydrate (CSH). Furthermore, when the same sample was subjected to powder X-ray diffraction, it was confirmed that the proportion of calcium hydroxide, a hydration product of cement, was higher in the wet color-disappeared area than in the non-water-wetted area.

[0075] Therefore, in Example 1, even if water wetting occurs, a hydration reaction between the cement of the adhesive layer 23 and the infiltrating water generates cement hydrate, and the infiltrating water is consumed by the hydration reaction, and the cement hydrate densifies the structure of the adhesive layer 23. As a result, in Example 1, it is thought that the densified structure in the adhesive layer 23 blocks the flow path of the infiltrating water, thereby maintaining high watertightness for a long period of time.

[0076] [Test Example 4: Test of resistance to lateral water movement in second waterproof structure 20B] In Test Example 4, using the configurations of Example 2 and Comparative Example 5, the first waterproof sheet or resin sheet 11 was laid on the bottom of a 30 cm x 30 cm x 5 cm steel formwork with the napped fiber 15 side (first surface 11A side in Comparative Example 5) facing up. A hole with a diameter of 10 mm was pre-formed in the center of the first waterproof sheet and resin sheet 11. Fresh concrete with the composition shown in Figures 19 and 20 was then poured into the steel formwork and integrated. The concrete was then cured in air (23°C, 65% RH) for 28 days, and then demolded to prepare a test specimen.

[0077] Then, water pressure was applied from the first waterproof sheet and resin sheet 11 side through the hole located in the center. The water pressure was 0.5 MPa, equivalent to a water head of 50 m. The pressurization time was 6 hours. The number of tests was one for each specification (n=1).

[0078] As shown in FIG. 25, in Test Example 4, in both Example 2 and Comparative Example 5, no lateral movement of water was observed between the first waterproof sheet and the concrete (between the resin sheet 11 and the concrete in Comparative Example 5).

[0079] [Test Example 5: Warp Resistance Test of Waterproof Sheet 10] In Test Example 5, a test specimen was prepared using the same configurations as in Examples 1 and 3, with a 1 m x 1 m first waterproof sheet or a 1 m x 1 m third waterproof sheet attached with a first adhesive to a 1 m x 1 m plywood base placed vertically. After one hour had passed, the first waterproof sheet or the third waterproof sheet was visually inspected for out-of-plane warping.

[0080] As shown in Figure 26, in Example 1, warping was confirmed within one hour of application of the first waterproof sheet. The warping was such that the first waterproof sheet could be applied by pressing it down so that it remained within the plane. In Example 3, visual inspection of the condition one hour after application of the third waterproof sheet revealed no out-of-plane deformation due to warping of the third waterproof sheet. Therefore, it was confirmed that in Example 3, in which the fiber material 12 was treated to prevent water absorption, warping of the waterproof sheet 10 was suppressed, allowing for more optimal installation.

[0081] [Summary of test results for test examples 2 to 5] 27, Example 1 having adhesive layer 23 exhibited a particularly excellent value equal to or greater than the standard value in the peel adhesion strength test in Test Example 2, and was confirmed to have been able to prevent water leakage in the back water pressure test in Test Example 3. Furthermore, Example 3 was confirmed to have been able to prevent water leakage in the back water pressure test in Test Example 3, and was confirmed to be more suitable for construction than Example 1 in Test Example 5.

[0082] On the other hand, Comparative Examples 1 to 3, which have adhesive layer 23, showed values equal to or greater than the standard value in the peel adhesion strength test in Test Example 2, but did not reach the value of Example 1, and water leakage was confirmed in the back water pressure test in Test Example 3. Comparative Example 4, which has adhesive layer 23, showed a value less than the standard value in the peel adhesion strength test in Test Example 2, and water leakage was confirmed in the back water pressure test in Test Example 3.

[0083] It was confirmed that Example 2, which does not have adhesive layer 23, exhibited an excellent value equal to or greater than the standard value in the peel adhesion strength test in Test Example 2, and was able to prevent lateral water migration in the lateral migration resistance test in Test Example 4. On the other hand, Comparative Example 5, which does not have adhesive layer 23, was able to prevent lateral water migration in the lateral migration resistance test in Test Example 4, but exhibited a value below the standard value in the peel adhesion strength test in Test Example 2.

[0084] [Effects of the embodiment] (1) On the first surface 11A, the bonded area is larger than the non-bonded area, which increases the peel strength between the resin sheet 11 and the fibrous material 12. This can suppress peeling between the resin sheet 11 and the fibrous material 12. In addition, the base fibers 14 are densely arranged, which also improves the breaking strength of the base fibers 14. This can improve the water pressure resistance of the waterproof sheet 10.

[0085] (2) In the waterproof sheet 10, the first surface 11A of the resin sheet 11 is dispersed and exposed through the gaps in the base fibers 14. This allows the adhesive constituting the adhesive layer 23 and the unhardened concrete constituting the underground structure 22 to be suitably filled around the fiber material 12, thereby improving the watertightness between the adhesive layer 23 and the waterproof sheet 10, or between the underground structure 22 and the waterproof sheet 10.

[0086] (3) According to the configuration of the first waterproof structure 20A, the waterproof sheet 10 can be adhered to the underground structure 22, which is an example of a concrete structure, via the adhesive layer 23. This configuration improves the watertightness between both the adhesive layer 23 and the waterproof sheet 10 and between the resin sheet 11 and the fiber material 12. Therefore, it is possible to construct a first waterproof structure 20A that exhibits high watertightness overall.

[0087] (4) By using a cement-mixable polymer containing epoxy resin and acrylic resin as the adhesive material constituting the adhesive layer 23, the waterproof sheet 10 can be adhered with high adhesive strength to the underground structure 22. With this configuration, the adhesive strength of the adhesive layer 23 can be increased compared to when an adhesive containing an ethylene vinyl acetate resin-based material is used, for example.

[0088] (5) The fiber material 12 is densely arranged on the first surface 11A so that the bonded area is larger than the non-bonded area, and is subjected to a water absorption prevention treatment, thereby preventing dimensional changes and warping in the waterproof sheet 10 due to water absorption by the fiber material 12.

[0089] (6) By using a cement-based hydraulic material as the adhesive material that constitutes the adhesive layer 23, even if the fibrous material 12 absorbs water, rehydration occurs when the cement that constitutes the adhesive layer 23 comes into contact with water. Then, in the adhesive layer 23, the structure formed by the hydration reaction blocks the flow path of water, thereby improving watertightness in the long term.

[0090] (7) According to the configuration of the second waterproof structure 20B, the waterproof sheet 10 can be adhered to the underground structure 22, which is an example of a concrete structure, without using the adhesive layer 23. This configuration improves the watertightness between both the underground structure 22 and the waterproof sheet 10, and between the resin sheet 11 and the fiber material 12. Therefore, the second waterproof structure 20B can be constructed with high watertightness overall.

[0091] [Example of change] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0092] The second surface 11B of the resin sheet 11 is not limited to an uneven surface, but may be a flat surface. The fiber material 12 or other fiber materials may be attached to the second surface 11B of the resin sheet 11. This can improve the adhesion between the waterproof sheets 10.

[0093] The water absorption prevention treatment of the fiber material 12 may be omitted. The second surface 11B of the resin sheet 11 may be coated with a resin material. This improves the corrosion resistance of the waterproof sheet 10. The resin material to be coated is, for example, at least one selected from the group consisting of epoxy resin, acrylic resin, polyurethane resin, vinyl acetate resin, polyester resin, silicone resin, polyethylene, ultra-high molecular weight polyethylene, polypropylene, polyester, nylon, acrylic resin, vinylon, polyvinyl chloride resin, fluororesin, and melamine resin. The coating may be performed on-site or during the manufacturing stage. Multiple coats of paint may also be applied.

[0094] 28, in the third waterproof structure 20C, the waterproof sheet 10 may be adhered to the inner surface 22A of the underground structure 22 without the adhesive layer 23. In this case, the waterproof sheet 10 may be installed in a position facing the portion corresponding to the inner surface 22A of the underground structure 22 in a formwork for pouring unhardened concrete when constructing the underground structure 22. In the third waterproof structure 20C, the second surface 11B of the resin sheet 11 faces away from the ground 21.

[0095] [Note] According to the above embodiment and its modifications, the following technical ideas can be further derived. (Appendix 1) A waterproof sheet is provided to cover the concrete structure, The waterproof sheet includes a resin sheet made of a synthetic polymer and a fiber material, the fibrous material has a base fiber bonded to the first surface of the resin sheet and a raised fiber raised from the base fiber to the opposite side of the resin sheet, The first surface is dispersed and exposed through gaps in the base fibers, a bonded region on the first surface to which the base fibers are bonded is larger than a non-bonded region on the first surface to which the base fibers are not bonded; The waterproof sheet is disposed so that the brushed fibers are embedded in the concrete structure with a second surface of the resin sheet facing the opposite side of the first surface facing underground. Waterproof construction.

[0096] (Appendix 2) A waterproof sheet to be adhered to a concrete structure, The device includes a resin sheet made of a synthetic polymer and a fiber material, the fibrous material has a base fiber bonded to the first surface of the resin sheet and a raised fiber raised from the base fiber to the opposite side of the resin sheet, The first surface is dispersed and exposed through gaps in the base fibers, a bonded region on the first surface to which the base fibers are bonded is larger than a non-bonded region on the first surface to which the base fibers are not bonded; The fiber material has been treated to prevent water absorption. Waterproof sheet. [Explanation of symbols]

[0097] CL1...central axis, H1...pile height, L1...pile length, 10, 10A, 10B...waterproof sheet, 10C...first overlapping region, 10D...second overlapping region, 10E...boundary covering sheet, 11...resin sheet, 11A...first surface, 11B...second surface, 12...fiber material, 13...projection, 14...base fiber, 15...brushed fiber, 16...pile body, 17...pile tip, 20A...first waterproof structure, 20B...second waterproof structure, 20C...third waterproof structure, 21...underground, 22...underground body, 22A...inner surface, 22B...outer surface, 23...adhesive layer.

Claims

1. A waterproof sheet to be adhered to a concrete structure, The device includes a resin sheet made of a synthetic polymer and a fiber material, the fibrous material has a base fiber bonded to the first surface of the resin sheet and a raised fiber raised from the base fiber to the opposite side of the resin sheet, The first surface is dispersed and exposed through gaps in the base fibers, A bonded area on the first surface where the base fibers are bonded is larger than a non-bonded area on the first surface where the base fibers are not bonded. Waterproof sheet.

2. A waterproof sheet according to claim 1, which comprises an adhesive layer that covers a concrete structure and the waterproof sheet according to claim 1 that covers the concrete structure via the adhesive layer, The adhesive layer has brushed fibers embedded therein, the adhesive layer is a hardened cement paste obtained by mixing a cement-based hydraulic material and a polymer for cement admixture; The polymer for cement admixture includes an epoxy resin and an acrylic resin. Waterproof construction.

3. A waterproof sheet according to claim 1 for covering a concrete structure, The raised fibers of the waterproof sheet are embedded in the concrete structure. Waterproof construction.

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