JP2020041411A - Construction method of box culvert, and protective sheet for constructing box culvert connection joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method of a box culvert which can be easily constructed on site. SOLUTION: A concrete box body having a hollow part 1a is connected to each other so that the hollow part 1a communicates with each other, and a joint material 2 is filled in a joint joint portion between the concrete boxes 1 to provide a facility. When installing a box culvert consisting of a series of joints, a glass cloth and the like, which are sealed with a silicone rubber cured product having a hardness of 10 to 90 by a durometer A hardness tester, at least on the hollow side ceiling portion of the joint joint. A base layer composed of a silicone rubber cured product layer having a hardness of 10 to 90 by a durometer A hardness tester provided on one side of a glass cloth and an Asker C hardness laminated on the silicone rubber cured product layer of 1 to 60. The protective sheet 3 having the silicone-based adhesive layer is coated, and the adhesive layer is adhered or adhered to the concrete wall of the concrete box 1 to prevent the joint material and the like from falling and flowing out from the adhesive joint portion. [Selection diagram] Fig. 4

Description

  TECHNICAL FIELD The present invention relates to a method for constructing a box culvert composed of a series of concrete boxes and a protective sheet for constructing a box culvert joint.

  The box culvert is a concrete box having a hollow portion penetrated, and a concrete box connected body in a state where the concrete boxes are tandemly connected so that the hollow portions communicate with each other, and it is used in the ground and It is installed under roads, and the hollow part is used for waterways, underpasses of sidewalks and roadways, and as accommodation for communication lines.

  At the time of this construction, a bituminous joint base plate made mainly of asphalt (asphalt mixture, trade name: elastite, etc.) at the joint joint between concrete boxes to prevent water from entering the hollow part and prevent inflow of earth and sand Although the joint material is filled as a joint material, the joint material 2 ages as shown in FIG. 7 (a) due to long-term use of more than 10 years after construction, and jumps out of the joint joint portion 10a or peels off. Problems, and furthermore, cracks and the like are generated in the joint filler-filled portion, and the sediment and the water (eg, groundwater, rainwater, etc.) contained in the sediment from the joint joint are in a liquid state and / or a solid state (such as icicles) Problems such as outflow.

  At present, as a countermeasure, as shown in FIG. 7 (b), the joint material 2 is removed from the concrete surface due to aging at the joint joint portion 10a on the hollow side of the continuous concrete box body. At the same time, a cover member 90 made of a metal plate such as a tin plate or a molded product of plastic and having a cross-sectional shape opened upward is prepared, and a hole is made in the concrete wall surface of the concrete box 1 to connect the ceiling joint. A method of hitting the cover member 90 with an anchor bolt 91 so as to cover the portion is adopted. According to the cover member 90, it is possible to prevent the joint material 2 from the connection joint portion 10a from being received and peeled down, and also prevent outflow and leakage of earth and sand from the connection joint portion 10a.

However, this method has the following problems.
i Since the dimensions and shape of the joints are different for each constructed concrete box connected body, it is necessary to prepare a cover member on a bespoke basis, and it takes time to install the cover member.
ii Since the anchor bolt is used for fixing the cover member, the concrete box will be damaged.
iii When the anchor member is fixed with the anchor bolts, it is difficult for the cover member to follow the movement of the concrete box such as vibration in the concrete box connected body.
iv Since the cover member protrudes from the ceiling on the hollow portion side of the concrete box continuous body of about 40 mm, there is a case where a passing vehicle comes into contact and the cover member is damaged, which may cause a damage accident. If the cover member is damaged, it is necessary to pay attention to the secondary disaster caused by the fragments, so it is necessary to remove the fragments and the damaged cover member after the accident.
v In the case of a metal cover member, the state of the connection joint portion of the covered portion becomes invisible. In addition, when the metal cover member is damaged, there is a possibility that the corner of the damaged portion may be injured.
vi A plastic cover member may generate toxic gas in the event of a fire.
In addition, as a prior art relevant to this invention, the following are mentioned, for example.

JP-A-9-3290 JP-A-10-184921 JP 2001-25300A

  The present invention has been made in view of the above circumstances, and it is possible to easily repair and construct a joint joint of a concrete box joint body on site without damaging the concrete box, and further repair the joint or It is an object of the present invention to provide a construction method and a construction protection sheet for box culvert connection joints that can suppress damage due to contact of a passing vehicle at a construction location.

In order to achieve the above object, the present invention provides the following construction method and construction protection sheet for box culvert connection joints.
[1] A box consisting of concrete boxes connected to each other so that the concrete boxes having penetrating hollow portions are connected to each other so that the hollow portions communicate with each other, and joints between the concrete boxes are filled with joint materials. When a culvert is installed, a glass cloth sealed with a cured silicone rubber having a hardness of 10 to 90 by a durometer A hardness meter is provided on at least the hollow side ceiling portion of the connection joint part, and on one surface of the glass cloth. A base layer made of a cured silicone rubber layer having a hardness of 10 to 90 as measured by a durometer A hardness meter and a silicone adhesive layer having an Asker C hardness of 1 to 60 laminated on the cured silicone rubber layer And the adhesive layer is adhered or adhered to the concrete wall of the concrete box, and the adhesive joint is bonded to the hollow side ceiling portion. A method for constructing a box culvert, characterized by preventing the joint material, earth and sand, and water contained in the earth from falling and flowing.
[2] The silicone-based pressure-sensitive adhesive layer is
(A) an organopolysiloxane containing an alkenyl group bonded to at least two silicon atoms in one molecule,
(B) a resinous composition containing R ₃ SiO _1/2 units (wherein R is an unsubstituted or substituted monovalent hydrocarbon group, but R contains an alkenyl group) and SiO ₂ units as main components; Polymer,
(D) an organohydrogenpolysiloxane containing at least two hydrogen atoms (SiH groups) bonded to silicon atoms in one molecule;
(E) The method for applying a box culvert according to [1], wherein the cured product containing an addition reaction catalyst is a cured product of an addition-curable silicone rubber composition or a silicone gel composition having surface tackiness.
[3] A glass cloth sealed with a cured silicone rubber having a hardness of 10 to 90 by a durometer A hardness meter and a silicone having a hardness of 10 to 90 by a durometer A hardness meter provided on one surface of the glass cloth. A box culvert joint joint protection sheet having a base material layer composed of a cured rubber layer and a silicone adhesive layer having an Asker C hardness of 1 to 60 laminated on the cured silicone rubber layer.
[4] The silicone-based pressure-sensitive adhesive layer is
(A) an organopolysiloxane containing an alkenyl group bonded to at least two silicon atoms in one molecule,
(B) a resinous composition containing R ₃ SiO _1/2 units (wherein R is an unsubstituted or substituted monovalent hydrocarbon group, but R contains an alkenyl group) and SiO ₂ units as main components; Polymer,
(D) an organohydrogenpolysiloxane containing at least two hydrogen atoms (SiH groups) bonded to silicon atoms in one molecule;
(E) The protective sheet for construction of a box culvert joint joint according to [3], wherein the cured product containing an addition reaction catalyst is a cured product of an addition-curable silicone rubber composition having surface tackiness.
[5] Construction of the box culvert connection joint according to [3] or [4], wherein the thickness of the base material layer is 0.2 to 5 mm and the thickness of the silicone-based adhesive layer is 0.3 to 3 mm. Protective sheet.

  According to the present invention, repair or construction can be performed simply by attaching a thin protective sheet to the concrete wall surface of the concrete box, so that it is not necessary to make a custom made like a cover member, and repair or construction on site is easy, and concrete It can be done without damaging the box. In addition, if the protective sheet is adhered by adhesion, the protective sheet can flexibly follow the movement of the concrete box due to a difference in temperature and temperature or vibration in the concrete box connected body. In addition, since the protective sheet is thin, there is only a slight protrusion from the ceiling on the hollow portion side of the continuous body of concrete boxes, and damage due to contact with a passing vehicle can be suppressed as much as possible. Further, if the base material layer of the protective sheet is a rubber elastic body, even if a breakage accident occurs, the influence of the secondary disaster is negligible, and repair thereof is easy.

It is a side view schematic diagram showing the example of composition of a concrete box serial connection object. It is AA sectional drawing of the connection joint part at the time of the installation of the concrete box continuous body shown in FIG. It is a ceiling partial sectional view after a secular change of the joint joint part of a concrete box continuous body. It is sectional drawing of the connection joint part of the ceiling part which applied this invention to the concrete box continuous body shown in FIG. 1, (a) is sectional drawing of the concrete box continuous body length direction, (b) ) Is an AA cross-sectional view. It is sectional drawing which shows the structural example of the protective sheet used by this invention. It is sectional drawing which shows the other structural example of the connection joint part of the ceiling part after applying the repair method of the box culvert concerning this invention. It is sectional drawing of the connection joint part which shows the repair state of the ceiling part in the conventional box culvert repair method, (a) shows the state before repair, (b) shows the state which attached the protective cover.

Hereinafter, a method of repairing a box culvert according to the present invention will be described.
The method for repairing a box culvert according to the present invention is characterized in that concrete boxes having penetrated hollow portions are connected to each other so that the hollow portions communicate with each other, and joint joints between the concrete boxes are filled with joint material to provide facilities. A method for repairing a box culvert comprising a series of concrete box connected bodies, wherein a protection sheet is laid over a concrete wall surface of a concrete box adjacent to at least a connection joint section of a ceiling portion to cover the connection joint section, The protective sheet is attached to a concrete wall surface of a concrete box near a joint joint by adhesion or adhesion.

  Here, as shown in FIG. 1, the installed concrete box continuous body 10 is provided by connecting concrete boxes 1 having the hollow portions 1 a penetrated so that the hollow portions 1 a communicate with each other. The joint joints 10a of the boxes 1 are filled with joint materials 2. Such a continuous concrete box body 10 is installed underground or under a road, and the hollow portion 1a is used for a waterway, an underpass of a sidewalk or a roadway, a grade-crossing road, a housing section of a communication line, and the like.

  The concrete box 1 is called a box culvert, and is often a precast concrete product. The dimensions of the concrete box 1 are, for example, about 1 m × 1 m in length and width, 5 m × 30 m, and about 5 to 50 m in length.

  The joint material 2 is filled in the joint joint portion 10a between the concrete boxes 1 in order to prevent water stoppage and inflow of earth and sand into the hollow portion 1a, and is preferably a joint material mainly composed of asphalt, for example, bitumen. It consists of a textured ground plate (asphalt mixture, trade name: elastite, etc.).

  The joint joints 10a are joints formed between the end faces (connection surfaces) of the concrete boxes 1 when the concrete boxes 1 are arranged close to each other. The width of the connection joint portion 10a (the interval between the end surfaces (connection surfaces) of the concrete box 1) is about 30 to 150 mm.

Here, at the time of installation of the concrete box continuous body 10, as shown in FIG. 2, the joint material 2 is densely filled in the joint joint portion 10a without protruding into the hollow portion 1a.
When this occurs more than 10 years after the facility, as shown in FIG. 3, the joint material 2 changes over time and jumps out of the joint joint portion 10a to the hollow portion 1a side or comes off. At the same time, the filling of the joint material 2 in the joint joint portion 10a becomes insufficient, and earth and sand and rainwater from the outside may flow out of the joint joint portion 10a. This phenomenon is remarkable in the ceiling portion of the concrete box continuous body 10. FIG. 3 is a cross-sectional view of the ceiling portion including the joint joint portion 10a of the continuous concrete box body 10, the upper side of the figure is the outside of the continuous concrete box body 10, and the lower side of the figure is the hollow portion 1a. Side. The horizontal direction in FIG. 3 is the direction in which the hollow portion 1a communicates (the length direction of the concrete box connected body 10 and the width direction of the joint joint 10a), and the direction perpendicular to the paper surface is the concrete box connected body 10 In the width direction (the length direction of the connection joint portion 10a).
The repair method of the present invention is performed to prevent or prevent such problems, and is performed in the following procedure.

  In this case, a protective sheet having a base material layer and an adhesive layer on one side thereof is used as a protective sheet for repair. First, as shown in FIG. 3, the joint material 2 may be in a protruding state. If so, the protruding part is removed. In this case, if there is a gap in the connection joint portion 10a, the gap can be filled with a sealing material, for example, a silicone sealing material, if necessary. A commercially available sealing material can be used.

  Next, if necessary, after performing surface adjustment such as removing stains on the concrete wall surface of the concrete box 1 to which the adhesive layer is to be attached, as shown in FIG. The adhesive layer is attached to the concrete wall surface of the concrete box 1 so as to cover the joint portion 10a.

  As shown in FIG. 4 (b), the joint material 2 is partially removed on the hollow portion 1a side of the connection joint portion 10a over the entire length of the ceiling portion and the side wall portion of the continuous concrete box body 10. I have. In addition, the protection sheet 3 is attached to the entire length of the ceiling portion of the continuous concrete box body 10 and the upper portions of both side walls. Note that the protective sheet 3 may be attached to the entire length of each side wall (ie, to the bottom) of the concrete box continuous body 10 or to a position about 10 cm above the bottom, but at least the ceiling is protected. A sheet is attached.

  As the attachment of the protection sheet 3, one sheet may cover at least the entire connection joint portion 10a at the ceiling portion, or a plurality of sheets may be overlapped at a predetermined width and at least the entire connection joint portion 10a at the ceiling portion. May be covered.

  Here, as the base layer of the protective sheet 3, a base layer made of ethylene propylene diene rubber, chloroprene rubber, styrene butadiene rubber, acrylic rubber, urethane rubber, acrylic silicone rubber or silicone rubber, or epoxy-based fiber reinforced plastic The base layer composed of In addition, in consideration of using the protection sheet 3 outdoors, a material having long-term heat resistance, cold resistance, and weather resistance and having as low a temperature dependency as possible is preferable, and furthermore, a material having good compatibility with the adhesive layer. Some things need to be considered. From these points, a base material layer made of silicone rubber is more preferable.

  The protective sheet 3 composed of the base material layer may be bonded and adhered to a predetermined concrete surface using an adhesive, but in consideration of the fact that the protective sheet 3 may be re-applied in construction, It is preferable to use a substrate provided with an adhesive layer on a base material layer, and to adhere through the adhesive layer.

  The adhesive layer is preferably a silicone adhesive layer, an acrylic adhesive layer, an acrylic silicone adhesive layer, or a urethane adhesive layer. Among these, in the case of an acrylic pressure-sensitive adhesive layer, it is preferable to form a primer-treated film with a primer in order to enable the protective sheet 3 to be reattached. In the case of a urethane-based pressure-sensitive adhesive layer, it is preferable to form a primer-treated film with a primer in order to ensure sufficient tackiness. In consideration of using the protection sheet 3 outdoors, the adhesive layer is preferably made of a material that can withstand various environments such as a cold region or a hot and humid region. Therefore, a silicone-based adhesive layer is more preferable.

FIG. 5 shows a configuration example of the protection sheet 3 used in the present invention.
As shown in FIG. 5, the protective sheet 3 is formed by laminating an adhesive layer 3b on one side of a base rubber (base layer) 3a, and a cover film 3c is usually laminated on the adhesive layer 3b so as to be peelable. Then, the cover film 3c is peeled off at the time of use, and the adhesive layer 3b is adhered to the concrete surface at the required place.

Here, a silicone rubber is preferable as the rubber substrate constituting the base rubber from the viewpoint of heat resistance, weather resistance, and cold resistance. As the silicone rubber, silicone having a hardness of 10 to 90, more preferably 20 to 80, still more preferably 25 or more, particularly preferably 40 or more and 80 or less, particularly 75 or less, as measured by a durometer A hardness meter specified in JIS K 6249. Use of rubber is preferred in terms of elasticity and rubber strength. If the hardness is less than 10, the strength as rubber may be inferior, and if it exceeds 90, the elasticity may be inferior.
In the present invention, silicone rubber having a rubber hardness (that is, hardness measured by a durometer A hardness meter specified in JIS K 6249) of 1 or more and exhibiting an effective rubber hardness value is referred to as a silicone rubber (a composition for providing the cured product). Is a silicone rubber composition), and those having a rubber hardness of less than 1 and low in hardness (soft) so as not to exhibit an effective rubber hardness value are referred to as silicone gel (a composition which gives the cured product is referred to as a silicone gel composition).

  As the silicone rubber composition for obtaining the silicone rubber, an addition (hydrosilylation) reaction-curable silicone rubber composition or an organic peroxide-curable silicone rubber composition is preferred because molding can be performed in a short time by heating. The obtained one is preferred. This addition reaction-curable silicone rubber composition comprises an alkenyl group-containing organopolysiloxane having two or more alkenyl groups represented by a vinyl group in one molecule, and two or more, preferably three or more, SiH groups in one molecule. And a platinum group metal-based addition reaction catalyst (typically, alkenyl) represented by platinum or a platinum compound (normally, an amount in which the molar ratio of SiH groups to alkenyl groups is 0.5 to 4). Those containing 1 to 1,000 ppm (based on the group-containing organopolysiloxane) are used. The composition may also be a known composition as an organic peroxide-curable silicone rubber composition. Preferably, an effective amount of an organic peroxide as a curing agent is added to an organopolysiloxane having two or more alkenyl groups in one molecule. (Usually, 1 to 10 parts by mass with respect to 100 parts by mass of the organopolysiloxane) is used.

  As the silicone rubber composition that provides the cured silicone rubber having a hardness of 10 to 90 as measured by a durometer A hardness meter specified in JIS K 6249, a commercially available product can be used. For example, an addition reaction-curable silicone rubber composition can be used. Shin-Etsu Chemical Co., Ltd. KE-1935A / B, KE-1950-60A / B, KEG-2000-40A / B, etc. are used as organic peroxide-curable silicone rubber compositions as Shin-Etsu Chemical Co., Ltd. KE-551-U, KE-571-U, KE-1571-U, KE-951-U, etc. are used. The strength may be improved by inserting a glass cloth into the base rubber.

  The pressure-sensitive adhesive layer is composed of a silicone rubber or gel having tackiness. In particular, by setting a cured product of an addition-curable silicone rubber composition or a silicone gel composition, a certain rubber hardness and rubber strength can be obtained. While having it, it can be made to have adhesiveness that can adhere and fix to the base rubber or concrete surface.

Here, as the adhesive layer,
(A) an organopolysiloxane containing an alkenyl group bonded to at least two silicon atoms in one molecule,
(B) a resinous composition containing R ₃ SiO _1/2 units (wherein R is an unsubstituted or substituted monovalent hydrocarbon group, but R contains an alkenyl group) and SiO ₂ units as main components; Polymer,
(D) an organohydrogenpolysiloxane containing at least two hydrogen atoms (SiH groups) bonded to silicon atoms in one molecule;
(E) The cured product containing the addition reaction catalyst is preferably formed from a cured product of an addition-curable silicone rubber composition or silicone gel composition having surface tackiness.
In this case, the addition-curable silicone rubber composition or the silicone gel composition may further comprise, if necessary, (C) an R ′ ₃ SiO _1/2 unit (where R ′ is an unsubstituted or substituted monovalent hydrocarbon group). However, R ′ does not contain an alkenyl group, or even if it does contain an alkenyl group, the amount is smaller than the alkenyl group content of the component (B)) and a resinous copolymer mainly composed of SiO ₂ units. Is also good.

The component (A) of the addition-curable silicone rubber composition or the silicone gel composition is an organopolysiloxane having an average of at least two alkenyl groups in one molecule. , The following average composition formula (1)
R ¹ _a SiO _{(4-a) / 2} (1)
Are used.

In the formula, R ¹ is the same or different and is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10, preferably 1 to 8 carbon atoms, and a is 1.5 to 2.8, preferably 1.8. To 2.5, more preferably a positive number in the range of 1.95 to 2.05. Here, the unsubstituted or substituted monovalent hydrocarbon group bonded to the silicon atom represented by R ¹ includes a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, Alkyl groups such as pentyl group, neopentyl group, hexyl group, cyclohexyl group, octyl group, nonyl group and decyl group, aryl groups such as phenyl group, tolyl group, xylyl group and naphthyl group, benzyl group, phenylethyl group and phenylpropyl Alkenyl groups such as aralkyl groups, vinyl groups, allyl groups, propenyl groups, isopropenyl groups, butenyl groups, hexenyl groups, cyclohexenyl groups, octenyl groups and the like, and a part or all of the hydrogen atoms of these groups , Bromine, those substituted with halogen atoms such as chlorine, cyano groups, etc., for example, chloromethyl Group, bromoethyl group, trifluoropropyl group, but cyanoethyl group and the like, Preferably, at least 90 mol% of all R ¹ is a methyl group.

In this case, at least two of R ¹ must be an alkenyl group (preferably one having 2 to 8 carbon atoms, more preferably 2 to 6 carbon atoms). Incidentally, the content of the alkenyl group is 0.0001 to 20 mol%, preferably 0.001 to 10 mol%, particularly preferably 0.001 to 10 mol% in all organic groups (that is, the above-mentioned unsubstituted or substituted monovalent hydrocarbon groups) R ^1. The content is preferably set to 0.01 to 5 mol%. This alkenyl group may be bonded to a silicon atom at the terminal of the molecular chain, may be bonded to a silicon atom in the middle of the molecular chain, or may be bonded to both. Those containing a bound alkenyl group are preferred.

The degree of polymerization is not particularly limited, and it can be used from a liquid state at room temperature to a raw rubber state. Usually, the average degree of polymerization in terms of polystyrene by gel permeation chromatography (GPC) is 50 to 20,000, preferably 100. Those having a molecular weight of about 10,000 to 10,000, more preferably about 100 to 2,000 are suitably used.
Further, the structure of the organopolysiloxane is basically consists repetition of main chain diorganosiloxane units (R ¹ ₂ SiO _2/2), both ends of the molecular chain triorganosiloxy groups (R ¹ ₃ SiO ¹ _/ has a straight-chain structure are blocked with ₂₎ or hydroxy diorgano siloxy group _{^{((HO) R 1 2 SiO}} 1/2), in part the structure of the branched, it may be a cyclic structure.

The resinous copolymer of the component (B) (ie, a copolymer having a three-dimensional network structure) is an alkenyl group-containing resinous copolymer containing R ₃ SiO _1/2 units and SiO ₂ units as main components. is there. Here, R is an unsubstituted or substituted monovalent hydrocarbon group, and preferably has 1 to 10 carbon atoms, particularly 1 to 8 carbon atoms. Examples of the monovalent hydrocarbon group represented by R include a methyl group and an ethyl group. , An alkyl group such as a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, a cyclohexyl group, an octyl group, a nonyl group, and a decyl group, a phenyl group, a tolyl group, and a xylyl group. Group, aryl group such as naphthyl group, aralkyl group such as benzyl group, phenylethyl group, phenylpropyl group, vinyl group, allyl group, propenyl group, isopropenyl group, butenyl group, hexenyl group, cyclohexenyl group, octenyl group, etc. Alkenyl group, or part or all of the hydrogen atoms of these groups may be replaced with a halogen atom such as fluorine, bromine, chlorine, or a cyano group. Those conversion, such as chloromethyl group, chloropropyl group, bromoethyl group, trifluoropropyl group, cyanoethyl group and the like.

The alkenyl group-containing resinous copolymer (B) may be composed of only the above-mentioned R ₃ SiO _1/2 unit and SiO ₂ unit, and if necessary, may contain R ₂ SiO unit or RSiO _{3 / 2} units (R is as defined above) as the total amount thereof, with respect to the total copolymer mass, 50% or less, preferably comprise from 40% or less but, R ₃ SiO _1/2 units and SiO The molar ratio [R ₃ SiO _1/2 / SiO ₂ ] to ₂ units is preferably from 0.5 to 1.5, particularly preferably from 0.5 to 1.3. If the molar ratio is smaller than 0.5 or larger than 1.5, sufficient hardness and strength as an adhesive layer cannot be obtained. Further, the resinous copolymer of the component (B) has at least two alkenyl groups in one molecule. In this case, the content of the alkenyl group is usually 0.00005 mol / g or more, preferably 0.0001 mol / g or more, more preferably 0.0001 to 0.003 mol / g, and still more preferably 0.1 to 0.003 mol / g. 0002-0.002 mol / g. When the content of the alkenyl group is less than 0.00005 mol / g, sufficient rubber or gel physical properties as an adhesive layer cannot be obtained, and when it is more than 0.003 mol / g, the hardness becomes too high and the adhesive strength becomes too high. There is a possibility that it will decrease.
The resinous copolymer may be a liquid (eg, 10 mPa · s or more, preferably 50 mPa · s or more) having fluidity at normal temperature (25 ° C.) or a solid having no fluidity. . This resinous copolymer can be usually produced by hydrolyzing a suitable chlorosilane or alkoxysilane by a method well known in the art.

  When the total amount of the components (A) and (B) is 100 parts by mass, the amount of the component (A) is 20 to 100 parts by mass, particularly 30 to 90 parts by mass. Yes, the component (B) is 0 to 80 parts by mass, particularly 10 to 70 parts by mass. If the amount of the component (A) is too small, the elasticity of the pressure-sensitive adhesive layer is lost and the film becomes brittle. If the amount is too large, the adhesion and strength become insufficient. If the amount of the component (B) is too large, the adhesiveness is also reduced, and the physical properties of the rubber or gel as the adhesive layer are significantly reduced.

In the present invention, in addition to the alkenyl group-containing resinous copolymer of the component (B), if necessary, the component (C) may further comprise, as a component, a functional group involved in a hydrosilylation addition reaction such as an alkenyl group in the molecule. A (non-functional) resinous copolymer containing no groups can be blended. The resinous copolymer of the component (C) (that is, a copolymer having an alkenyl group-free three-dimensional network structure) has R ' ₃ SiO _1/2 units and SiO ₂ units as main components. Here, R ′ is an unsubstituted or substituted monovalent hydrocarbon group excluding an alkenyl group, and preferably has 1 to 10 carbon atoms, particularly preferably 1 to 8 carbon atoms. As the monovalent hydrocarbon group represented by R ′, , Methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, octyl, nonyl, alkyl groups such as decyl, phenyl Group, tolyl group, xylyl group, aryl group such as naphthyl group, aralkyl group such as benzyl group, phenylethyl group, phenylpropyl group, vinyl group, allyl group, propenyl group, isopropenyl group, butenyl group, hexenyl group, cycloalkyl Alkenyl groups such as hexenyl group and octenyl group, and part or all of the hydrogen atoms of these groups may be substituted with halogen atoms such as fluorine, bromine and chlorine. Atom and substituted with a cyano group or the like, such as chloromethyl group, chloropropyl group, bromoethyl group, trifluoropropyl group, cyanoethyl group and the like.

The resinous copolymer of the component (C) may be composed of only the above-mentioned R ' ₃ SiO _1/2 units and SiO ₂ units, and if necessary, may comprise R' ₂ SiO units or R 'SiO ₃ units. _{/ 2} units (R 'is as described above) may be contained in a range of 50% or less, preferably 40% or less based on the total amount of the copolymer as a total amount of these, but R' ₃ SiO _1/2 the molar ratio between the unit and SiO ₂ unit _{[R '3 SiO 1/2 / SiO} 2] is 0.5 to 1.5, particularly 0.5 to 1.3 is preferred. If the molar ratio is smaller than 0.5 or larger than 1.5, the tackiness is reduced.
The resinous copolymer may be a liquid having fluidity at room temperature (for example, 25 ° C.) or a solid having no fluidity. preferable. This resinous copolymer can be usually produced by hydrolyzing a suitable chlorosilane or alkoxysilane by a method well known in the art.

  The compounding amount of the component (C) is preferably 0 to 400 parts by mass, particularly preferably 0 to 300 parts by mass based on 100 parts by mass of the total of the components (A) and (B). If the amount of the component (C) is too large, the adhesiveness may be reduced, and the physical properties of the rubber or gel as the adhesive layer may be reduced.

The component (D) is an organohydrogenpolysiloxane having at least two, preferably at least three, hydrogen atoms (SiH groups) bonded to a silicon atom in one molecule. It crosslinks with the alkenyl group bonded to the silicon atom in the component, the component (B) and the component (C) by a hydrosilylation addition reaction, and acts as a curing agent for curing the composition. The organohydrogenpolysiloxane of the component (D) has the following average composition formula (2)
R ² _b H _c SiO _{(4-bc) / 2} (2)
(Wherein, R ² is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, b is 0.7 to 2.1, c is 0.001 to 1.0, and b + c is a positive number satisfying 0.8 to 3.0.)
And one having at least 2 (usually 2 to 200), preferably 3 to 100, and more preferably 3 to 50 silicon-bonded hydrogen atoms in one molecule is suitably used. Here, as the monovalent hydrocarbon group for R ² , those similar to those exemplified for R ¹ can be mentioned, but those having no aliphatic unsaturated group are preferable. Further, b is preferably 0.8 to 2.0, c is preferably 0.01 to 1.0, b + c is preferably 1.0 to 2.5, and the molecular structure of the organohydrogenpolysiloxane is The structure may be any of linear, cyclic, branched, and three-dimensional network. In this case, the number of silicon atoms in one molecule (or the degree of polymerization) is preferably from 2 to 300, and particularly preferably from 4 to 150, which is liquid at room temperature (25 ° C.). Note that the hydrogen atom bonded to the silicon atom may be located at the terminal of the molecular chain, at any point in the molecular chain, or at both positions.

Further, instead of or in addition to the organohydrogenpolysiloxane of the formula (2), a resinous copolymer containing R ″ ₂ HSiO _1/2 unit and SiO ₂ unit as main components, or R ′ and _'2 HSiO _1/2 units and R'_'3 SiO _1/2 units and SiO ₂ units can be used resinous copolymer mainly. Here, R ″ is an unsubstituted or substituted monovalent hydrocarbon group, examples of which are the same as those of R ′, and those that do not contain an alkenyl group are preferred. The resinous copolymer may be composed of only R '' ₂ HSiO _1/2 units or R '' ₂ HSiO _1/2 units and only R '' ₃ SiO _1/2 units and SiO ₂ units, If necessary, R''HSiO _2/2 units, R '' ₂ SiO _2/2 units, HSiO _3/2 units and R''SiO _3/2 units may be added in a total amount of 50 to the total copolymer mass. %, Preferably 40% or less, but the molar ratio of R ″ ₂ HSiO _1/2 units, R ″ ₃ SiO _1/2 units to SiO ₂ units [(R ″ ₂ HSiO _1/2 + R ″ ₃ SiO _1/2 ) / SiO ₂ ] is preferably 0.5 to 1.5, particularly preferably 0.5 to 1.3.

Examples of the organohydrogenpolysiloxane of the component (D) include a methylhydrogenpolysiloxane having trimethylsiloxy groups at both ends, a dimethylsiloxane / methylhydrogensiloxane copolymer having trimethylsiloxy groups at both ends, and a dimethylhydrogensiloxy group at both ends. Blocked dimethylpolysiloxane, both ends dimethylhydrogensiloxy group blocked dimethylsiloxane / methylhydrogensiloxane copolymer, both ends trimethylsiloxy group blocked methylhydrogensiloxane / diphenylsiloxane copolymer, both ends trimethylsiloxy group blocked methylhydrogen diphenylsiloxane-dimethylsiloxane copolymers, copolymers consisting of (CH _{3) 2} HSiO _1/2 units and SiO _4/2 units, (CH _{3) 2} H iO _1/2 unit and the SiO _4/2 units (C ₆ H _5), such as copolymers comprising SiO _3/2 units and the like.

  The compounding amount of the organohydrogenpolysiloxane of the component (D) is 0.5 to 30 parts by mass, particularly 0.6 to 20 parts by mass based on 100 parts by mass of the total of the components (A) and (B). . If the amount is too small or too large, sufficient strength as an adhesive layer cannot be obtained. Further, the organohydrogenpolysiloxane of the component (D) is bonded to a silicon atom in the component (D) with respect to an alkenyl group bonded to a silicon atom contained in the components (A), (B) and (C). The amount of the hydrogen atom (SiH group) is 0.2 to 1.5, more preferably 0.25 to 1.2, and even more preferably 0.3 to 0.9 in terms of molar ratio.

  Examples of the addition reaction catalyst for the component (E) include platinum black, platinous chloride, chloroplatinic acid, a reaction product of chloroplatinic acid and a monohydric alcohol, a complex of chloroplatinic acid and olefins, chloroplatinic acid and vinyl chloride. Examples thereof include complexes with siloxanes, platinum-based catalysts such as platinum bisacetoacetate, palladium-based catalysts, and rhodium-based catalysts. The compounding amount of the addition reaction catalyst can be a catalytic amount, and is usually 0.5 to 1,000 ppm, particularly preferably 0.5 to 1,000 ppm based on the total amount of the components (A), (B) and (C) as the platinum group metal. It is about 1 to 500 ppm.

Addition reaction-curable silicone containing the components (A), (B), (D) and (E), and giving a silicone rubber or silicone gel having a surface tackiness with an Asker C hardness of 1 to 60. As the rubber composition or the silicone gel composition, commercially available products can be used. For example, KE-1012A / B, KE-1056, KE-1151, FE-57, KE-1051JA / B manufactured by Shin-Etsu Chemical Co., Ltd. , Etc. are used.
The cured product of the adhesive layer having an Asker C hardness in the range of 1 to 60 is silicone rubber having an Asker C hardness of 14 to 60, and silicone gel having an Asker C hardness of 1 to less than 14. is there.

  The addition-curable silicone rubber composition or silicone gel composition for forming the pressure-sensitive adhesive layer can be cured usually at 100 to 180 ° C., particularly at 110 to 140 ° C. for 5 to 20 minutes. A curing (post-cure) step is not required, but does not prevent post-curing in some cases.

The hardness of the pressure-sensitive adhesive layer is smaller than the hardness of the base rubber, and is preferably in the range of 1 to 60, more preferably in the range of 2 to 55, and still more preferably in the range of 2 to 40 in Asker C hardness. is there. If it is less than 1, the strength as an adhesive layer may be poor, and if it exceeds 60, the adhesiveness may be reduced.
In addition, in accordance with JIS Z 0237, the adhesive strength was 0.5 to 10 N / 25 mm when adhered to glass (Nippon Sheet Glass Co., Ltd., FL2.0) and subjected to a 180 ° peel test at a peeling speed of 300 mm / min. In particular, it is preferable to be 0.7 to 8 N / 25 mm. If it is less than 0.5 N / 25 mm, when the pressure-sensitive adhesive layer is adhered to the required adhered portion, the adhesive strength to the adhered portion is low, and there is a problem in the adherence. Adhesion may be affected.

  The composition for forming the base rubber layer and the adhesive layer includes, in addition to the components described above, if necessary, other components such as fumed silica, precipitated silica, quartz powder, diatomaceous earth, and calcium carbonate. Or a filler such as a conductive agent such as carbon black, conductive zinc oxide, or metal powder, or a heat-resistant agent such as iron oxide or cerium oxide. Furthermore, a hydrosilylation reaction control agent such as a nitrogen-containing compound, an acetylene compound, a phosphorus compound, a nitrile compound, a carboxylate, a tin compound, a mercury compound, and a sulfur compound; an internal mold release agent such as dimethyl silicone oil; an adhesion-imparting agent; The addition of a property imparting agent or the like is optional.

  The thickness of the base rubber is preferably 0.2 to 5 mm, more preferably 0.5 to 5 mm, and particularly preferably 0.5 to 3 mm. If the thickness is less than 0.2 mm, the elasticity of the sheet may not be sufficient, and if it exceeds 5 mm, the weight may increase, affecting the attachment and disadvantageous in terms of cost. In addition, the thickness of the adhesive layer is preferably in the range of 0.3 to 3 mm, more preferably in the range of 0.5 to 2 mm, in order to secure the adhesive force to the concrete surface. Further, in order to absorb vibrations in the continuous body of concrete boxes, it is preferable that the pressure-sensitive adhesive layer be as thick as possible within this range. If the thickness is less than 0.3 mm, the surface unevenness of the concrete surface to which the adhesive layer is adhered cannot be absorbed, and if the thickness exceeds 3 mm, the rubber strength of the adhered surface depends on the adhesive layer and rubber breakage may occur. There is. That is, the thickness of the protective sheet 3 is preferably 0.5 to 8 mm.

  As shown in FIG. 5, when a protective sheet 3 composed of a base rubber 3a composed of silicone rubber and a silicone-based adhesive layer 3b is used, the protective sheet 3 can be adhered with a non-primer unless the surface has large irregularities. Can be. The width of the protective sheet 3 to be attached to the concrete wall surface of the concrete box 1 is 100 to 400 mm, particularly 150 to 250 mm, respectively attached to each concrete box 1 sandwiching the joint joint 10a. Preferably.

  Further, the protective sheet 3 is preferably transparent or translucent. Thereby, the state of the joint joint portion 10a and the surrounding concrete surface can be visually confirmed through the attached protective sheet 3, and deterioration observation of the adhered surface by visual inspection can be performed.

  When the protective sheet 3 is formed, an adhesive layer is laminated on the base rubber, and the composition for forming the base rubber is cured to form the base rubber after forming the base rubber so that the adhesive layer is formed. Alternatively, the composition for forming the base rubber may be calender-molded on a film such as polyethylene terephthalate (PET) and separated, and a composition for forming an adhesive layer in an unvulcanized state may be laminated. Good.

  The composition for forming the adhesive layer is preferably a method of obtaining a laminated sheet by a method of dipping, coating, screen printing, or the like on the base rubber layer or the composition for forming the same, and is preferably used because coating molding can be suitably used. . The curing conditions are preferably in the range of 80 to 250 ° C. for 10 seconds to 1 hour. Further, after-curing may be performed at 120 to 250 ° C. for about 1 to 100 hours for the purpose of, for example, removing low-molecular siloxane.

  As described above, when the repair direction of the present invention is applied, as shown in FIG. 4, the protection sheet 3 is connected to the joint material 10 a at least at the ceiling joint portion 10 a on the hollow portion 1 a side of the continuous concrete box body 10. 2 is prevented from jumping out or falling off (falling out) into the hollow portion 1a and outflow of earth and sand. Further, there is no problem that icicles are formed at the joint joint 10a in a cold region.

Further, according to the present invention, since only the thin protective sheet 3 is affixed to the concrete surface of the concrete box 1, it is not necessary to make a custom made like a cover member, so that repair on site is easy and the concrete box is 1 can be performed without damage. In addition, since the protective sheet is thin, the protrusion from the ceiling on the hollow portion 1a side of the concrete box continuous body 10 is small, and damage due to contact with a passing vehicle can be suppressed as much as possible. Further, if the base material layer of the protective sheet 3 is a rubber elastic body, even if a breakage accident occurs, the influence of the secondary disaster is negligible, and the repair is easy. Further, even if a fire occurs in the hollow portion 1a, the protective sheet 3 made of the base rubber 3a made of silicone rubber and the silicone-based adhesive layer 3b does not generate harmful gas and has a self-extinguishing performance. And is safe.
In addition, if the protective sheet 3 is adhered by adhesive, the protective sheet 3 can flexibly follow the movement of the concrete box due to the difference in temperature between the concrete box and the vibration such as the traffic of the vehicle, etc. Reliability is obtained.

  In addition, water containing earth and sand may leak to the connection joint portion 10a. In this case, as shown in FIG. 6, a drainage pipe 6 is provided with a drainage pipe 6 in the joint joint 10a, and a drainage pipe 6 having a small hole through which only water containing earth and sand passes is provided in the gap 4. And can be drained to the outside through this pipe.

  Further, a sealing material may be applied around the protection sheet 3. FIG. 6 shows a state in which the outer peripheral edge of the protective sheet 3 is bonded with the sealing material 5. When the protective sheet 3 is bonded with the sealing material 5 as described above, the outer peripheral edge of the protective sheet 3 is sequentially turned up. It is preferable that the outer peripheral side of the adhesive layer is slightly peeled off from the concrete surface, and the sealing material 5 is supplied to the generated gap. Thereby, the sealing layer 5 is formed on the outer peripheral edge of the adhesive layer.

  The sealing material is not particularly limited, and any known silicone-based, polysulfide-based, and polyurethane-based sealing materials can be used. However, a silicone sealing material is preferably used because of its affinity with the material of the protective sheet 3. Can be As such a sealing material, a commercially available product may be used. For example, as the silicone sealing material, a sealant master 300, a sealant 70, a sealant 701, etc., manufactured by Shin-Etsu Chemical Co., Ltd. may be used.

Next, a method for constructing a box culvert according to the present invention will be described.
The construction method of the box culvert according to the present invention is a construction method to be performed on the joint joint portion when constructing the concrete box continuous body, and the contents to be performed are basically the same as the repair method of the box culvert of the present invention described above. Is the same as That is, in the box culvert construction method of the present invention, the concrete boxes 1 having the penetrated hollow portions 1a are connected to each other so that the hollow portions 1a communicate with each other. A method of performing a box culvert for filling joint materials 2, wherein the joint joints 10 a are filled with joint materials 2, and then, of the joint joints 10 a, the concrete adjacent to the joint joints 10 a at least at the ceiling joint joint 10 a is sandwiched. The protective sheet 3 is laid over the concrete wall surface of the box 1 to cover the connection joints 10a, and the protective sheet 3 is adhered to the concrete wall surface of the concrete box 1 near the connection joints 10a by adhesion or adhesion.
According to the construction method of the present invention, the same operation and effect as those of the above-described repair method of the present invention can be obtained.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

[Example 1]
(Preparation of protective sheet)
A protective sheet was produced under the following conditions.
A 230 μm thick glass cloth sized to a predetermined size (600 mm in width and 400 mm in length) is subjected to an addition reaction-curing type which gives a cured silicone rubber having a hardness of 57 by a durometer A hardness meter specified in JIS K 6249. Liquid silicone rubber composition: immersed in KE-1950-60A / B (manufactured by Shin-Etsu Chemical Co., Ltd.), and the immersed glass cloth was cured at 80 ° C. × 5 m + 100 ° C. × 5 m + 120 ° C. × 5 m. The glass cloth was filled by passing through a heating furnace at a speed of 1.5 m / min to cure the impregnated liquid silicone rubber composition.
Then, after coating the liquid silicone rubber composition; KE-1950-60A / B with a thickness of 0.45 mm on one surface of the sealed glass cloth, the cure zone is again 80 ° C. × 5 m + 100 ° C. × It is passed through a heating furnace of 5 m + 120 ° C. × 5 m at a speed of 1.5 m / min, and has a silicone rubber cured product layer having a JIS A hardness of 57 and a thickness of 0.45 mm on one surface and having a thickness of about 0.7 mm. A glass cloth (base sheet) was produced.
Next, on the outer surface of the cured silicone rubber layer of the base sheet, an addition reaction-curable silicone gel composition which further provides a cured silicone gel having an Asker C hardness of 2; KE-1012A / B (Shin-Etsu Chemical (Manufactured by Kogyo Co., Ltd.) at a thickness of 1.0 mm, and then passed through a heating furnace having a curing zone of 110 to 150 ° C. × 3 m at a speed of 0.5 m / min. A laminated sheet (total thickness of about 1.7 mm) was formed by laminating a silicone gel layer (adhesive layer) having a C hardness of 2 and a thickness of 1.0 mm, and finally an adhesive surface (silicone gel layer) of the laminated sheet was produced. A protective film made of PET was attached to the surface of the layer) to prepare a protective sheet to be subjected to a punching test.

(Punching test)
Using the obtained laminated sheet (protective sheet), a punching test was performed as follows.
The punching test was performed using East Japan Expressway Co., Ltd., Central Japan Expressway Co., Ltd., and West Japan Expressway Co., Ltd. “NEXCO Test Method Part 7 Tunnel Related Test Method (July 2013) Test Method 732-2011 Tunnel Fall Prevention Test method for fiber sheet bonding for textiles ". That is, first, a hole for inserting a punching indenter was provided in the center of a concrete flat plate (600 mm in width, 400 mm in length, 60 mm in thickness), and a separately manufactured concrete indenter was installed in the hole. After fixing the indenter, peel off the PET protective film on the adhesive layer side of the laminated sheet obtained above, and attach it to one side of a flat plate through the adhesive layer to a size of 400 × 600 mm centering on the indenter and testing. Two bodies were made.
In addition, the punching test was carried out by using a universal material testing machine (Model Model5582) manufactured by Instron Japan Company Limited and applying a displacement in the vertical direction to the concrete indenter of the test body. The loading speed was 1.0 mm / min, and the relationship between the vertical displacement of the indenter and the punching load was measured.
Table 1 shows the test results.

  All of the test pieces satisfied the load value (0.5 kN or more load value up to a displacement of 50 mm) required for the fiber sheet bonding work for preventing tunnel fall. In addition, when the conventional fiber sheet breaks at a displacement of up to 50 mm and shows a maximum load, it was found that the protective sheet used in the present invention can withstand a displacement of more than 50 mm.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited to these embodiments, and other embodiments, additions, modifications, deletions, and the like can be made by those skilled in the art. The present invention can be modified within the range, and any aspect is within the scope of the present invention as long as the effects of the present invention are exhibited.

DESCRIPTION OF SYMBOLS 1 Concrete box 1a Hollow part 2 Joint material 3 Protective sheet 3a Base rubber 3b Adhesive layer 3c Cover film 4 Space 5 Sealing material (sealing layer)
6 Drainage pipe 10 Concrete body continuous body 10a Connection joint 90 Cover member 91 Anchor bolt

Claims (5)

  A box culvert consisting of a series of concrete box bodies is installed by connecting concrete boxes with penetrating hollow parts so that the hollow parts communicate with each other, filling joint joints between the concrete boxes with joint materials. At this time, a glass cloth sealed with a silicone rubber cured material having a hardness of 10 to 90 by a durometer A hardness meter is provided on at least one surface of the glass cloth at least at the hollow side ceiling portion of the connection joint. A base layer comprising a cured silicone rubber layer having a hardness of 10 to 90 as measured by a durometer A hardness meter, and a silicone adhesive layer having an Asker C hardness of 1 to 60 laminated on the cured silicone rubber layer. The protective sheet is covered, and the adhesive layer is adhered or adhered to the concrete wall of the concrete box. Wood, sand and construction method of box culvert, characterized in that to prevent dropping outflow of water contained in 該土 sand. The silicone-based adhesive layer,
(A) an organopolysiloxane containing an alkenyl group bonded to at least two silicon atoms in one molecule,
(B) a resinous composition containing R ₃ SiO _1/2 units (wherein R is an unsubstituted or substituted monovalent hydrocarbon group, but R contains an alkenyl group) and SiO ₂ units as main components; Polymer,
(D) an organohydrogenpolysiloxane containing at least two hydrogen atoms (SiH groups) bonded to silicon atoms in one molecule;
The method according to claim 1, wherein (E) the cured product containing an addition reaction catalyst is a cured product of an addition-curable silicone rubber composition or a silicone gel composition having surface tackiness.   A glass cloth filled with a cured silicone rubber having a hardness of 10 to 90 as measured by a durometer A hardness meter, and a cured silicone rubber having a hardness of 10 to 90 as measured by a durometer A hardness meter provided on one surface of the glass cloth A box culvert joint joint protection sheet having a base material layer comprising a layer and a silicone-based adhesive layer having an Asker C hardness of 1 to 60 laminated on the silicone rubber cured material layer. The silicone-based adhesive layer,
(A) an organopolysiloxane containing an alkenyl group bonded to at least two silicon atoms in one molecule,
(B) a resinous composition containing R ₃ SiO _1/2 units (wherein R is an unsubstituted or substituted monovalent hydrocarbon group, but R contains an alkenyl group) and SiO ₂ units as main components; Polymer,
(D) an organohydrogenpolysiloxane containing at least two hydrogen atoms (SiH groups) bonded to silicon atoms in one molecule;
4. The protective sheet according to claim 3, wherein the cured product containing the addition reaction catalyst is a cured product of an addition-curable silicone rubber composition having surface tackiness.   The protective sheet according to claim 3 or 4, wherein the thickness of the base material layer is 0.2 to 5 mm, and the thickness of the silicone-based adhesive layer is 0.3 to 3 mm.

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