JP2006037440A - Water cut-off material for underground structure outer wall - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water cut-off material for an underground structure outer wall having high the reliability of a water cut-off effect, and also having self-repair performance by providing sufficient strength endurable against the construction by a pre-performing construction method, improving workability, eliminating reduction in water cut-off performance by pre-water absorption, and integrating a water swelling agent layer even in a joining part. <P>SOLUTION: This water cut-off material for an underground structure has a stacked structure. In the water cut-off material for the underground structure, water swelling agent layers having stickiness and water absorbing swelling performance are formed on both sides of an impervious sheet by arranging the impervious sheet as an inner layer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a water-stopping material that has an effect of preventing moisture such as groundwater from entering the underground joint surface of the underground structure from the outside, and more specifically, the underground structure. When trying to build, it is installed in advance in places where groundwater intrusion is expected, such as concrete joints and joints in the outer periphery of the underground, especially with high waterproof effect and good work efficiency. The present invention relates to a waterproofing material for the outer wall of underground structures that is useful for the construction method.

  Conventionally, when constructing a structure having at least a part of the underground burial, that is, an underground structure, a facility for draining groundwater or the like entering from the ground is provided or moisture enters. In order to prevent this, waterproofing is generally performed. When wastewater treatment is performed, methods such as double walls are taken so that intrusion water is not visible to the public. The water that has entered the water is collected in the water collection pit, and the water collected in the water collection pit is Although it is discharged and removed by a timely pump, etc., the adoption is decreasing due to the narrowing of the basement space by the double wall installation space and the running cost of pumping and draining.

  On the other hand, when waterproofing is applied, the “retroductory construction method” is applied to the outer surface of the underground outer wall after constructing the structure underground outer wall, and the waterproof layer is applied to the retaining wall or concrete formwork before the structure underground outer wall is constructed. Then, it can be divided into “advanced construction method” in which the underground outer wall is constructed so as to be in close contact with the waterproof layer. In the case of the retrofitting method, a work space for waterproofing is required on the outside of the underground outer wall, so that the prepaid method is almost always performed.

  As for the advance waterproofing method for the underground outer wall of such a structure, (1) a method of pasting a butyl rubber waterproofing material or asphalt waterproofing material to a retaining wall embedded in the ground, (2) epoxy resin (2) A method of attaching a bentonite water-stopping material filled with bentonite inside a mat or panel to a retaining wall, etc. Is used. Of these methods, the method (1) requires the work of joining the water-stopping material, and requires reliable construction management to obtain a reliable waterproof effect, resulting in a defect in the waterproof layer. In some cases, the waterproof effect cannot be obtained. The method (2) has the advantage that it forms a seamless waterproof layer and can follow even complex ground shapes, but it takes time to install the foundation nonwoven fabric, etc., and two-component weighing errors and mixing. Insufficient or the like causes variations in waterproof performance, and, similarly to the method (1), there is a disadvantage that a waterproof effect cannot be obtained when a defective portion occurs in the waterproof layer.

  On the other hand, in the method (3), the bentonite absorbs the surrounding water and swells to form a waterproof layer, and performs water shielding. Even when a defect portion occurs in the waterproof layer, the bentonite In recent years, it has been frequently used because it can be expected to have a self-healing effect that swells and closes the defect. However, the existing bentonite water-stopping material is a powdered or granular bentonite filled into a woven fabric, nonwoven fabric or craft panel. There was a problem with waterproof reliability such as the nonwoven fabric becoming a water channel. Also, powder and granular bentonite absorb and swell quickly, so if the bentonite waterproof material comes into contact with rain or groundwater before building the underground outer wall of the structure, it will immediately swell and reduce its self-healing function In addition, it is necessary to perform a pretreatment water stop and a curing treatment on the laying ground surface, which requires a long construction period and is complicated.

As a means of solving the disadvantages of the existing bentonite water-stopping material, that is, water stoppage due to contact with water during construction or curing, and the problem of reduced self-healing properties, bentonite is bonded to asphalt, butyl rubber, polypropene, polybutene, etc. Patent Document 1 or Patent Document 2 discloses mixing with an organic pressure-sensitive adhesive having adhesiveness to obtain a water-swelling agent having adhesiveness. These water-swelling agents having adhesive properties do not have sufficient strength when formed as a water-stopping material alone, so they need to be embedded in concrete or impervious to polyethylene. When it is applied to one side of a sheet to form a laminated water-stopping material, its use has been limited, such as being limited to the post-processing method. In addition, in the waterproofing material in a state where the water swelling agent layer is applied to one side of the water-impermeable sheet, when the waterproofing material is overlapped and joined, the sheet becomes a blocking layer. The agent layer could not be made into a continuous integration, which was a weak point in water stoppage.
JP 10-338812 A JP-A-6-340017

  The present invention has been made in view of the prior art as described above, has sufficient strength to withstand the construction of the advance construction method, has excellent workability, and reduces water stoppage due to prior water absorption. An object of the present invention is to provide a water-stopping material for an outer wall of an underground structure that has a high water-reliability effect and has a self-repairing property because a water-swelling agent layer can be integrated even at a joint. It is what.

The above technical problem has been achieved by the following means.
(1) A waterproofing material for underground structures having a laminated structure, in which a water shielding sheet is disposed as an inner layer, and a water swelling agent layer having adhesiveness and water absorption swelling is provided on both sides of the water shielding sheet. A water-stopping material for underground structures,
(2) The waterproofing material for underground structures according to (1), wherein a protective layer is provided on the outer surface of one of the water swelling agent layers, and a release layer is provided on the outer surface of the other water swelling agent layer. ,
(3) The structure for an underground structure according to (1) or (2), wherein the water-swelling agent layer is composed of a composition containing a water-swellable mineral and a sticky organic pressure-sensitive adhesive. Water material,
(4) The waterstop material for underground structures according to (3), wherein the mineral having water swellability is at least one selected from bentonite, smectite, and swellable mica,
(5) The structure for underground structure according to (3), wherein the organic pressure-sensitive adhesive is one or a mixture of two or more selected from asphalt, gelled oil, liquid resin, and rubber-like substance. Water material,
(6) The ground according to any one of (1) to (5), wherein the water shielding sheet is at least one selected from a polyester resin sheet, a polyvinyl resin sheet, a polyethylene resin sheet, and an asphalt-impregnated nonwoven fabric. Water-stopping material for intermediate structures,
(7) The water-stopping material for underground structures according to any one of (1) to (6), which has a protective layer of an alkali-decomposable resin film or a water-soluble resin film,
(8) In the underground structure of underground water attached to the outer wall or earth retaining wall of the underground structure in which the water-stopping material according to any one of (1) to (7) is erected by concrete placement Construction method to prevent flooding,
(9) The construction method according to (8), in which the protective layer of the water-stopping material according to any one of (1) to (7) having a protective layer is attached so as to contact a concrete surface on which the protective layer is placed.

  Since the waterproofing material of the present invention is effective for the advance construction method, the construction is simple, it is possible to easily obtain a waterproof layer having excellent water pressure resistance and self-repairing property. In addition, in the situation where the waterproofing material is severely uneven in the retaining wall that temporarily stops the waterproofing material by interposing a water shielding sheet represented by, for example, polyester resin in the inner layer of the laminated structure. Also, it has good follow-up adhesion to the wall surface, and can prevent excessive deformation and breakage of the installed water-stopping material, and by appropriately suppressing the swelling deformation limit of the water swelling agent layer, Maintains adhesion between the water swelling agent layer and the outer wall of the underground structure over a long period of time, thereby providing a highly reliable water-stopping effect. Furthermore, even at the joint between the water-stopping materials, the presence of the water swelling agent layer on both surfaces of the water shielding sheet represented by the polyester resin located at the center of the laminated structure makes it possible to The adhesive allows continuous integration of the swelling agent layer, and does not make the joint between the water-stopping materials a weak point in water-stopping.

  A preferred embodiment of the present invention is based on a laminated structure, with a water shielding sheet represented by a polyester resin in the center, and a water swelling agent layer represented by a bentonite clay-containing composition on both sides thereof. A water-stopping material characterized in that a protective layer represented by an alkali-decomposable resin film is attached to the surface on one side and a release layer is attached to the surface on the other side. This water-stopping material is nailed so that the protective layer side faces the structure housing side on the surface that corresponds to the outer wall of the underground structure housing such as the prefabricated mountain retaining wall (hereinafter also referred to as “earth retaining wall”). It is possible to construct the underground outer wall of the structure by placing it continuously by hammering, etc., and then placing concrete so that it is in close contact with the water stop material, forming a waterproof layer by easy construction work, The formed waterproof layer has the advantage of self-healing. The position at which the water blocking material is temporarily fixed is preferably a position that covers a portion where there is a possibility of water leakage, such as a joint portion or a joint portion of the outer wall of the underground structure erected by the concrete to be placed.

The present invention is described in further detail below.
A preferred embodiment of the waterstop material of the present invention will be described with reference to FIG. As shown in FIG. 1, the waterstop material of the present invention is preferably provided with a water-impervious sheet layer 12 as an inner layer, and water swelling agent layers 11A and 11B are provided on both sides thereof. A laminated structure in which a protective layer 13 and a release layer 14 are provided on the outer surfaces of 11A and 11B, respectively, is more preferable. The water-impervious sheet 12 gives the strength necessary for the construction of the water-stopping material of the present invention to the entire water-stopping material, and the water-swelling agent layers 11A and 11B absorb and swell when they come into contact with groundwater and swell. It has the important purpose of moderately suppressing deformation and maintaining water stoppage performance.
The waterstop material of the present invention is not limited to the embodiment of FIG. 1, and other layers may be inserted between each layer, and other layers are added outside the protective layer 13 or the release layer 14. It may be pasted.

  In constructing the outer wall of the underground structure, the mountain retaining wall is constructed in advance for the purpose of preventing the collapse of the ground after underground excavation. As a method for constructing this mountain retaining wall, there are known a pile pile sheet pile method, a sheet pile method, a column array method, an underground continuous wall method, etc., which are appropriately selected depending on the soil and other construction environment and conditions. The mountain retaining wall constructed in this way exposes the inner surface of the retaining wall by excavating and removing the ground soil. In many cases, concrete is placed so that the structure frame is in direct contact with the exposed retaining wall surface, but the surface of the mountain retaining wall is very uneven as it is excavated.

  In the case of the advance construction method, the waterstop material is temporarily fixed to the mountain wall surface in a state where the unevenness is severe in this way, but it is often fixed to the mountain wall by nailing as this temporary fixing method, The construction of a series of temporary fixing processes requires a strength that can maintain the shape of the water stop material in the water stop material body. In addition, it is impossible to cause the water-stopping material to completely follow the mountain wall surface with severe irregularities, and therefore, a gap is generated on a part of the back surface of the water-stopping material viewed from the housing side. In this way, concrete is placed with a gap on the back surface of the water-stopping material, but the water-stopping material is pressed and deformed by the pressure of the concrete in the direction of the mountain retaining wall. Tensile strength that can withstand deformation is required.

  During operation, the water-stopping material is present between the mountain retaining wall and the underground structural frame, but there is still a gap between the water-stopping material and the mountain retaining wall, and the water-swelling material of the water-stopping material is present. The agent swells and deforms freely in the gap portion, and cannot maintain sufficient self-healing properties, but the water-stopping material of the present invention has a water-impervious sheet having a tensile strength at the center thereof. The water swelling agent layer on the surface sandwiched between the water-impervious sheet and the surface of the underground structure enclosure is free-swelled by the water-impervious sheet and can form a waterproof layer having self-healing properties.

(Water shielding sheet)
The water-impervious sheet used for the water-stopping material of the present invention is not particularly limited as long as it is a sheet having a water-impervious property and having a tensile strength that can withstand the pressure of concrete to be placed. Polyethylene terephthalate (PET) resin sheet), polyvinyl resin sheet (for example, polyvinyl chloride (PVC) resin sheet), polyethylene resin sheet (for example, ethylene vinyl acetate copolymer (EVA) resin sheet), and asphalt impregnation A water shielding sheet such as a non-permeable nonwoven fabric is preferred.
In the water blocking material of the present invention, the water shielding sheet may be one layer or two or more layers. In the case of two or more layers, they may be the same sheet or different sheets. Further, in the water blocking material of the present invention, the thickness of the water shielding sheet can be appropriately set depending on the shape of the wall surface of the mountain retaining wall, the pressure of the concrete to be placed, etc. mm to 5.0 mm are preferable, and those of 0.1 mm to 3.0 mm are more preferable. The physical properties of the water shielding sheet are also set as appropriate according to the conditions used in the same manner as above, but the modulus at 50% elongation is preferably 1 MPa or more, the modulus at 100% elongation is more preferably 2 MPa or more, and 100% The modulus at the time of extension is particularly preferably 5 MPa or more.

(Protective layer)
In the waterstop material of the present invention, the water swelling agent layer has a surface (hereinafter also referred to as “A surface”) positioned on the side of the underground outer wall, and a surface positioned on the mountain retaining wall or the formwork side (hereinafter referred to as “B”). 1), the protective layer 13 in FIG. 1 is preferably affixed to the A side for the purpose of protecting the water swelling agent layer. This protective layer prevents adhesion of foreign matter to the surface of the water swelling agent layer during storage and transportation of the adhesive water swelling agent layer during construction and suppresses the adhesiveness of the water swelling agent layer, The handleability of the water stop material of the present invention is improved. The protective layer used in the water-stopping material of the present invention is preferably an alkali-decomposable resin film, but may be a water-soluble resin film (for example, a polyvinyl alcohol resin film). When using an alkali-degradable film, the water swelling agent layer is protected from water and foreign matter until the concrete is placed. After the concrete is placed, it is decomposed by the alkali content of the concrete, so it is peeled off. Without inconvenience, the water swelling agent layer of the water-stopping material and the housing of the underground structure can be in close contact during use. Even when a water-soluble film is used, if the water-stopping material is not wetted during the period until the water-stopping material is applied, the prevention and handling of foreign matter on the water-swelling agent layer of the water-stopping material The effect of improving the property can be obtained.

(Peeling layer)
In the water blocking material of the present invention, a release layer is attached to the B surface of the water swelling agent layer. This release layer prevents adhesion of foreign matter to the surface of the water swelling agent layer during storage, transportation, and construction during the construction of the water swelling agent layer as well as the protective layer described above. By suppressing the tackiness, the handleability of the waterstop material of the present invention is improved. As the release layer used in the waterstop material of the present invention, any release layer can be used as long as it has a release effect, and generally a release film (or release paper) is commercially available. Can be used. The release layer used in the water-stopping material of the present invention may be used without being peeled off or used at the time of construction of the water-stopping material, but at least the overlapping range at the joint between the water-stopping materials is peeled off. However, it is necessary to expose the water swelling agent layer B surface of the waterstop material.
The thickness of the release layer can be appropriately adopted from the viewpoints of physical properties and handleability, and suppression of waste after peeling, but is usually preferably 0.001 mm to 1 mm, more preferably 0.01 mm to 0.1 mm. As a method for forming the release layer on the water swelling agent layer, a fixed product is attached to the water swelling agent layer, or dissolved in an organic solvent capable of dissolving the resin and coated (coating). Can be formed.

  In the water-stopping material of the present invention, the overlapping surface at the joint between the water-stopping materials is such that the A surface and the B surface of the water swelling agent layer face each other with the protective layer interposed therebetween. At the time of service after placing, since it is decomposed or dissolved as described above, the A surface and B surface of the water swelling agent layer will be in close contact, and the water swelling agent layer can be continuously integrated. The joint part of the water stop material does not become a weak point on the water stop.

  The water-stop material in the present invention is temporarily fixed to the inner surface of the mountain retaining wall, and then a concrete is cast to form a waterproof layer having a self-repairing property by being in close contact with the wall surface of the underground structure. The position where the material is temporarily fixed to the inner surface of the retaining wall is preferably designed and determined in advance so as to completely cover at least a portion having a possibility of water leakage, such as a joint portion or a joint portion of the frame wall of the underground structure. .

(Water swelling agent)
Examples of the water-swelling agent having adhesiveness used in the water-stopping material of the present invention include clay having water-swelling properties such as bentonite (hereinafter also referred to as component (A)), asphalt and gelled oil. A composition in which at least one selected from adhesives such as liquid resins and unvulcanized rubber (hereinafter, also referred to as component (B)) is preferable, and a composition in which uniform mixing is more preferable. preferable. The water-swelling agent can be adhered and integrated at the time of joining the water-stopping materials due to the tackiness of the water-swelling agent and forms a waterproof layer having water-swelling properties. The formed waterproof layer is self-repairing. Have advantages.

  For example, the compositions disclosed in Japanese Patent Application No. 7-345902 and Japanese Patent Application No. 10-99078 are preferably used for the water swelling agent used in the waterstop material of the present invention. As described above, the component (A) is preferably a water-swelling clay, more preferably at least one clay selected from natural or synthetic water-swelling clays. Such clay may be unmodified or modified, but is more preferably at least one selected from smectite clays such as bentonite and hectorite, and swelling mica. Among these, bentonite is a particularly preferred clay because it is a naturally occurring clay and is excellent in safety, stable in the long term, can maintain a high water-stopping effect, and is inexpensive. In the water swelling agent, one kind of clay selected from the clays is used alone, or two or more kinds of clays are used. The water swelling agent preferably contains the water-swellable clay, preferably 20 to 95% by mass, more preferably 30 to 90% by mass, when the total amount with the component (A) is 100% by mass. Use. If the amount of clay having water swellability is too small, the swellability of the water-stopping material of the present invention is deteriorated, and sufficient self-repairing and water-stopping effects are difficult to obtain. The physical properties such as properties are impaired, and workability and adhesiveness are deteriorated.

  As the component (B), at least one selected from adhesive organic adhesives such as asphalt, gelled oil, liquid resin, and unvulcanized rubber-like substance is preferable. Examples of asphalt include straight asphalt, blown asphalt, and modified asphalt. Gelling oils include base oils selected from mineral oils, natural or synthetic aromatic hydrocarbon oils, natural or synthetic aliphatic hydrocarbon oils, oils, waxes, fatty acids and metal salts thereof, and organic bentonite. And oils that have been gelled into a semi-solid or solid form by dispersing a thickener selected from polyurea and the like. Liquid resins include liquid polybutene, polypropylene, polyisobutylene, polybutadiene, etc., and unvulcanized rubber-like materials include unvulcanized natural rubber, isoprene rubber, butadiene rubber, butyl rubber, chloroprene rubber, and ethylene-propylene rubber. And thermoplastic elastomers such as urethane rubber, nitrile rubber, styrene-butadiene rubber, silicone rubber, acrylic rubber, epichlorohydrin rubber, and styrene-isoprene block copolymer. These components (B) can be used individually or in mixture of 2 or more types. Component (B) is a component that imparts tackiness and shape retention to the water swelling agent used in the waterstop material of the present invention, and prevents the component (A) clay having water swelling property from being unevenly distributed or missing. And is a component as a swelling speed adjusting agent for suppressing the water swelling agent from swelling more quickly than necessary, and preferably 5% when the total amount with the component (A) is 100% by mass. -80 mass%, More preferably, 10-70 mass% is used.

Moreover, the said water swelling agent can mix | blend various additive components as an arbitrary component as needed in the range which does not impair the objective of this invention other than the said component (A) and component (B). Examples of the additive component include softeners (for example, oils such as mineral oils, synthetic oils, fatty oils, and plasticizers such as phthalic acid esters, aliphatic basic acid esters, and polyether esters), and stabilizers (for example, Anionic and nonionic surfactants, metal soaps such as lead, zinc, and calcium), water conductivity imparting agents (eg, inorganic water-absorbing substances, anionic water-absorbing resins, nonionic water-absorbing agents) Resin, etc.), fillers, tackifiers, anti-aging agents, lubricants, colorants and the like. In producing the water swelling agent used for the waterstop material of the present invention, there is no particular limitation on the order and method for adding and mixing the components. Moreover, the said water swelling agent can be manufactured in a composite with a fibrous substance as needed in the range which does not impair the objective of this invention. Examples of the fibrous material include glass fiber, carbon fiber, synthetic fiber (for example, nylon, vinylon, polypropylene, polyethylene, polyester, polyamide, etc.), cotton, silk, pulp fiber, steel fiber, and the like. It is mixed for the purpose of improving the shear strength and stiffness of the swelling agent layer. The thickness of the water swelling agent layer is determined by the balance between the unevenness of the retaining wall surface to be temporarily fixed, the required performance from the environment during operation, such as the working groundwater pressure, and the economy, but usually 0.1 mm -20 mm is preferable, and 0.5 mm-10 mm is more preferable.
As a method of forming the water swelling agent layer on the water-impervious sheet, for example, it may be formed into a sheet shape by a roll molding machine and attached to the water-impervious sheet, so that the concentration is appropriate for the soluble organic solvent. It may be dissolved and applied (coated) to be molded, or may be molded by co-pressing a water swelling agent and a water shielding sheet with an extrusion molding machine.

(Alkali-degradable resin film)
When the preferred embodiment of the present invention is illustrated in FIG. 1, a laminated structure in which the protective layer 13 is attached to the A surface of the water swelling agent layer and the release layer 14 is attached to the B surface is preferable. From when the water-stopping material of the present invention is temporarily secured to the retaining wall until the underground outer wall of the structure is constructed by placing concrete, when the water-stopping material is in contact with water for a long time due to rain, etc. The swelling rate of the water swelling agent layer is suppressed by the action of the organic pressure-sensitive adhesive, but there is a risk that the self-healing function may be deteriorated by starting swelling and exceeding the limit. In such a case, if the protective layer 13 is made of an alkali-decomposable resin film, the surface A of the water swelling agent layer 11A blocks contact with water during the period up to the placement of the concrete, thereby preventing the water swelling agent layer. The deterioration of the self-healing function can be prevented, and then the concrete of the outer wall of the underground wall is placed in contact with the inner side surface of the alkali-decomposable resin film, so that the alkali-decomposable resin film is caused by the alkali component of the concrete. Since it will be decomposed soon, it is possible to construct a waterproof layer in which the surface of the water swelling agent layer and the underground outer wall housing are in close contact with each other without taking the trouble of removing the alkali-decomposable resin film.

  Examples of the alkali-decomposable resin film that serves as a protective layer include aliphatic polyester resins such as polylactic acid resin, polyvinylphenol resin, cellulose acetate phthalate, hydroxypropylmethylcellulose phthalate, polyvinyl alcohol phthalate, isobutylene / maleic anhydride copolymer, Examples thereof include an ethylene / maleic anhydride copolymer or a styrene / maleic anhydride copolymer. As for substances other than these, any substances can be used as long as they are water-impervious to acidic or neutral water and are decomposed by a strong alkali having a pH of 11 to 14. Further, the thickness of the protective layer (for example, alkali-decomposable resin film) is preferably about 5 μm to 100 μm, and if it is less than 5 μm, there is a high possibility of breakage until the construction of the underground outer wall by concrete placement, and 100 μm If it exceeds, it takes a long time until it is decomposed by alkali, and an undecomposed portion may remain, which is not preferable.

  As a method of forming this alkali-decomposable resin film on the A-side of the water-swelling agent layer, a fixed product of the alkali-decomposable resin film is attached to the A-side of the water-swelling-agent layer, or an alkali-decomposable resin is used. It can be formed by dissolving an alkali-decomposable resin in a soluble organic solvent so as to have an appropriate concentration, and applying (coating) this alkali-decomposable resin solution on the surface A of the water swelling agent layer. .

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

Example 1
Modified asphalt prepared by adding 7 parts by weight of styrene butadiene styrene block copolymer (SBS) resin to 100 parts by weight of straight asphalt with a penetration of 60/80 in bentonite (Kunimine Industries, Ltd .; trade name Kunigel VA) , And mineral oil process oil (manufactured by Cosmo Oil Co., Ltd .; trade name Cosmo Process 100) is blended at a ratio of 60 parts by weight of modified asphalt and 10 parts by weight of mineral oil process oil to 100 parts by weight of bentonite. The resulting mixture was thoroughly mixed while being heated to 160 ° C. using an attached disper to obtain a water-swelling agent having adhesiveness. This composition 1 had adhesiveness and swollen at an appropriate swelling speed when immersed in water.
Next, the water stop material shown in FIG. 1 was formed by the following procedure. As the release layer 14, the composition 1 is continuously poured in a heated and melted state on the surface of the release paper wound in a roll shape, and a water swelling agent layer 11B having a thickness of 1 mm is formed. After the preparation, a polyethylene terephthalate (PET) resin sheet (thickness: 0.75 mm) wound in a roll shape is pasted as a central water-impervious sheet 12 having a laminated structure, and the composition 1 is further formed thereon. Is continuously poured in a heated and melted state, and after adjusting the water swelling agent layer 11A having a thickness of 1.5 mm, a polylactic acid resin film (thickness 40 μm) wound in a roll shape is applied as the protective layer 13 Then, a water-stop material having a laminated structure was obtained, and a strip-type water-stop material cut into a width of 200 mm was used as Sample 1.

Comparative Example 1
Next, the water stop material shown in FIG. 2 was formed by the following procedure. In the manufacturing process of the strip-shaped water-stopping material described in Example 1, the same treatment was performed except that the step of providing the one composition 11B and the release layer 14 in FIG. 1 was omitted. Explaining in FIG. 2, a belt-like water-stopping material obtained by cutting the width of a water-stopping material having a laminated structure in which the water swelling agent layer 21 exists only on one side of a polyethylene terephthalate (PET) resin sheet to 200 mm is obtained. It was.

Example 2
90 parts by weight of 100 parts by weight of machine oil (manufactured by Cosmo Oil; product name Cosmo Machine 46), 50 parts by weight of lauric acid (manufactured by Kao; product name LUNAC L-98) and 10 parts by weight of slaked lime (model number SA149 manufactured by Chichibu Lime Industry) To obtain a gelled base oil. This gelled base oil, bentonite (Kunimine Kogyo Co., Ltd .; trade name Kunigel V1), butyl rubber (JSR; model Butyl065), and polybutene (Shin Nippon Petrochemical Co., Ltd .; model HV-100) were added to 100 parts by weight of bentonite. On the other hand, 50 parts by weight of gelled base oil, 10 parts by weight of butyl rubber, and 2 parts by weight of polybutene were mixed well while heating to 150 ° C. using a heating kneader, and a water swelling agent having adhesiveness This was designated as composition 2. This composition 2 had adhesiveness and swelled at an appropriate swelling rate when immersed in water.
Next, the water stop material shown in FIG. 1 was formed by the following procedure. The composition 2 is formed into a sheet shape having a thickness of 2 mm and 3 mm by a roll molding machine, and the water shielding sheet 12 is formed on both surfaces of an ethylene vinyl acetate copolymer (EVA) resin water shielding sheet (thickness 1 mm). It is pasted so as to be interposed in the center of the laminated structure, and further a polyvinyl alcohol resin film as a protective layer 13 on one surface of each composition 2 and a polyethylene film (thickness as a release layer 14 on the other surface). 45 μm) was applied to obtain a water-stop material having a laminated structure, and a strip-type water-stop material cut into a width of 200 mm was used as Sample 3.

Comparative Example 2
Next, the water stop material shown in FIG. 3 was formed by the following procedure. In the production process of the strip-shaped water-stopping material described in Example 2, composition 2 was obtained by the same method, formed into a sheet having a thickness of 5 mm by a roll molding machine, and protected on one surface of composition 2 A film made of polyvinyl alcohol resin as the layer 33 and a polyethylene film (thickness: 45 μm) as the release layer 34 are attached to the other side surface to obtain a water-stop material having a laminated structure, and the width of the belt-like stop cut to 200 mm. The water material was Sample 4.

Comparative Example 3
Next, the water stop material shown in FIG. 4 was molded by the following procedure. In the manufacturing process of the strip-shaped water-stopping material described in Example 1, a polyester resin mesh (mesh sheet 45 in FIG. 4) is used instead of the polyethylene terephthalate resin water-impervious sheet (water-impervious sheet 12 in FIG. 1). Through the same process, a water-stop material having a laminated structure was obtained, and this was designated as Sample 5.

About the obtained samples 1-5, the water stop performance was confirmed by the following method.
<Waterproof performance test specimen>
The water-stopping performance test will be described with reference to FIG. 5. A cubic wooden box 507, which looks like a retaining wall, is manufactured, and holes 507 a having a diameter of 30 mm simulating the unevenness of the retaining wall are formed on the four surfaces positioned on the vertical surface. Further, five pipes having a water injection pipe 509 and a pressure gauge mounting pipe 510 provided on the upper surface were prepared. Samples 1 to 5 were temporarily fixed to the four vertical surfaces of the wooden box 507 by nailing. At this time, the water-stopping material sample 505 was nailed at a position where the hole 507a having a diameter of 30 mm was blocked, and a joint portion between the water-stopping materials was provided with an overlap margin of 50 mm. In Sample 1, Sample 3, Sample 4, and Sample 5, the release paper at the overlapping portion was peeled off, and the exposed water-swellable composition layer was brought into close contact with the adhesive force.
In addition, a wooden box 507 was prepared as a blank case to which no water stop material was attached, without drilling a hole with a diameter of 30 mm, and without temporarily attaching any sample.
Assemble the reinforcing bars so that the wall thickness is 150mm around the wooden box 507 (blank case is not water-stopping material) to which each water-stopping material sample 505 obtained in this way is temporarily attached. After placing, concrete was laid. In placing the concrete, the concrete lower portion 506a and the concrete upper portion 506b were placed in two stages so that the joint portion 508 was formed at the center of each water-stopping material sample 505. This was allowed to stand for 2 weeks, and the concrete was sufficiently hardened. Then, the surrounding mold was removed to expose the concrete surface.
<Water-stop performance test procedure>
The procedure of the water stop performance test will be described with reference to FIG. 5. A manual pressurization pump 514 and a pressure hose 513 are provided via a valve 511 a attached to a water injection pipe 509 protruding from the upper surface of each test specimen 50. After connecting and sufficiently venting the air in the wooden box 507 until water overflowed from the pressure gauge mounting pipe 510, the pressure gauge 512 was attached to the pressure gauge mounting pipe 510 via the valve 511b. After filling the inside of each specimen with water in this way, water pressure is applied using the manual pressure pump 514, and the valve 511a of the water injection pipe 509 is closed each time the water pressure of 0.1 MPa is increased, and the working water pressure at that time is maintained. Then, the work of leaving for 24 hours was repeated, and observation was performed up to 1 MPa until water leaked from the concrete joint 508. The results are shown in Table 1.

  As is clear from the results shown in the table, the water-stopping material of the present invention was excellent in that the water-stopping effect was exhibited up to a high water pressure. For the purpose of confirming the condition of the water-stopping material after completion of the test, each test specimen was disassembled, each water-stopping material was exposed, and the situation was observed. The water swelling agent layer that is in contact is in close contact, and the area where water has entered the interface between the concrete and the waterstop material is limited, and it has been confirmed that the water has not reached the concrete joint. It was. In addition, even in the part where a hole with a diameter of 30 mm is opened in the wooden box, the deformation of the water-stopping material due to the concrete placement pressure is suppressed to some extent by the tensile strength of the water-blocking sheet present in the center of the water-stopping material, There was no waterproof layer.

On the other hand, in the test specimen using the water-stopping material of Comparative Example 1, although the deformation of the water-stopping material in the portion where the hole of 30 mm in diameter was opened in the wooden box was suppressed, A concrete nodule entered the range of the stacking allowance, and the infiltrated water reached the concrete joint through the noro, causing water leakage. Further, in the test specimen using the water-stopping material of Comparative Example 2, the water-stopping material is greatly deformed by the concrete pouring pressure in the portion where the hole of 30 mm diameter is opened in the wooden box, and there are some waterproof layers of the water-stopping material. There are places where concrete has spilled to the inside of the wooden box, and this is considered to be a water drainage and water leakage occurred.
Further, in the test specimen using the water-stopping material of Comparative Example 3, the water swelling agent layer of the water-stopping material is completely swollen around the portion where the hole of 30 mm in diameter is opened in the wooden box, It is thought that water leakage occurred due to insufficient adhesion to the concrete surface due to a decrease in tensile strength of the water-stopping material and a decrease in self-healing performance.

It is sectional drawing which shows roughly the structure of the water stop material which concerns on an Example. It is sectional drawing which shows the structure of the water stop material which concerns on the comparative example 1 roughly. It is sectional drawing which shows the structure of the water stop material which concerns on the comparative example 2 roughly. It is sectional drawing which shows roughly the structure of the water stop material which concerns on the comparative example 3. FIG. It is a side view which shows typically the apparatus of a water stop performance test.

Explanation of symbols

1, 2, 3, 4 Water blocking material 11A, 11B, 21, 31, 41A, 41B Water swelling agent layer 12, 22 Water shielding sheet 13, 23, 33, 43 Protective layer 14, 34, 44 Release layer 45 Mesh sheet 50 Water-stopping performance test specimen 505 Water-stopping material sample 506a Concrete lower part 506b Concrete upper part 507 Wooden box 507a Wooden box side hole 508 Concrete joint 509 Water injection pipe 510 Pressure gauge mounting pipe 511a, 511b Valve 512 Pressure gauge 513 Water pressure hose 514 Manual pressure pump

Claims (9)

  A waterproofing material for underground structures having a laminated structure, in which a water-impervious sheet is disposed as an inner layer, and a water swelling agent layer having adhesiveness and water-absorbing swelling is provided on both sides of the water-impervious sheet. A waterproofing material for underground structures characterized by   The waterproofing material for underground structures according to claim 1, wherein a protective layer is provided on the outer surface of one of the water swelling agent layers, and a release layer is provided on the outer surface of the other water swelling agent layer.   The water-stopping material for underground structures according to claim 1 or 2, wherein the water-swelling agent layer comprises a composition containing a mineral having water-swelling property and an organic pressure-sensitive adhesive having adhesiveness.   The waterstop material for underground structures according to claim 3, wherein the mineral having water swellability is at least one selected from bentonite, smectite, and swellable mica.   The water-stopping material for underground structures according to claim 3, wherein the organic pressure-sensitive adhesive is one or a mixture of two or more selected from asphalt, gelled oil, liquid resin, and rubber-like substance.   The underground structure according to any one of claims 1 to 5, wherein the water shielding sheet is at least one selected from a polyester resin sheet, a polyvinyl resin sheet, a polyethylene resin sheet, and an asphalt-impregnated nonwoven fabric. Waterproof material.   The waterstop material for underground structures according to any one of claims 1 to 6, which has a protective layer of an alkali-decomposable resin film or a water-soluble resin film.   The water-stopping material according to any one of claims 1 to 7 is attached to an outer wall or a retaining wall of an underground structure that is erected by concrete placement, and water is submerged into the underground structure. Construction method to prevent. The construction method according to claim 8, which has a protective layer and is attached so as to be in contact with a concrete surface on which the protective layer of the waterstop material according to claim 1 is placed.

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