JP2011058219A - Construction method for renovating asphalt roofing with sand - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a construction method for simply renovating a waterproof layer without removing asphalt roofing with sand, which is the existing waterproof layer. <P>SOLUTION: In this construction method for renovating the waterproof layer employing the asphalt roofing with the sand, a primer liquid, which contains a base compound, a curing agent and powder and which satisfies the following requirements (1)-(3), is applied onto the surface of the asphalt roofing layer with the sand; and an air-permeable buffer sheet is superposed after the curing of a coated film. In the requirement (1), the total mass of the base compound and the curing agent based on that of the primer liquid is in the range of 5-90 mass%. In the requirement (2), the powder contains cement, silica sand with a particle diameter of 1.0 mm or less, and calcium carbonate. In the requirement (3), the ratio of the powder to the total mass of the primer liquid is in the range of 10-95 mass%. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for repairing asphalt roofing with sand, and more particularly, to a method for repairing a waterproof layer without removing existing asphalt roofing with sand.

  The rooftops of buildings such as buildings and condominiums are exposed to sunlight and wind for many years, so they are waterproofed with sand asphalt roofing. However, since the waterproof layer by asphalt roofing with sand also deteriorates over time, renovation work is required to prevent corrosion of the building due to inundation from the deteriorated part.

  Conventionally, when refurbishing sandy asphalt roofing, first remove the existing sandy asphalt waterproofing layer (sandy asphalt roofing) with a lifting machine, discard the generated waste as industrial waste, and then The repair work is performed in a process in which a foundation surface is adjusted with a mortar on a concrete surface, a ventilation cushioning sheet is stuck with an adhesive, and a waterproof material layer is formed thereon.

  In the above renovation work, the removal of existing asphalt roofing with sand and the preparation of the groundwork are necessary, and a large amount of industrial waste is generated. A renovation method is required. From such a point of view, Patent Documents 1 and 2 propose a method for repairing an existing waterproof layer while leaving it. In these documents, after removing and repairing the defective portion of the asphalt waterproof layer to be repaired, a breathable underlayer cushioning material is laid, and a waterproof material layer is formed thereon.

Japanese Patent No. 2954303 Japanese Patent Publication No.6-221505

As another method of repairing while leaving the existing waterproof layer, a waterproof sheet is laid on the existing waterproof layer, drilled from above, and anchored with anchor pins to form a floating tension and then waterproof There is a method of coating. However, this method has a problem that about 3 holes per 1 m ² must be drilled, and noise is generated when drilling.

  On the other hand, as described above, when renovation work is performed after removing the existing sandy asphalt waterproofing layer, it is necessary to secure a disposal place to dispose of a large amount of generated industrial waste. Since the waterproof layer was removed, there was a problem that it was difficult to avoid a water leakage accident due to sudden rain during construction. Furthermore, in the conventional renovation method, removal of the existing waterproof layer, preparation of a base for providing a new waterproof layer, and application of an adhesive for attaching a ventilation cushioning sheet are essential processes. There were also many economic disadvantages. In addition, conventional base preparation materials that have been used in the past have extremely low elongation, it is difficult to follow an asphalt waterproofing layer that expands and contracts due to heat, and mechanical performance tends to deteriorate, such as deterioration in strength due to fatigue. There was a point.

  The present invention has been made paying attention to the circumstances as described above, and its purpose is to provide a method for easily renovating a waterproof layer without removing the existing asphalt roofing with sand that is a waterproof layer. There is.

The repair method of the present invention that has solved the above problems is a waterproof layer repair method using a sand-coated asphalt roofing layer as a waterproof layer, and a main agent, a curing agent, and a powder on the surface of the sand-coated asphalt roofing layer. And a primer solution that satisfies the following requirements (1) to (3) is applied, and a breathable cushion sheet is laminated after the coating film is cured.
(1) The total amount of the main agent and the curing agent with respect to the total mass of the primer solution is 5% by mass to 90% by mass.
(2) The powder contains cement, cinnabar with a particle size of 1.0 mm or less, and calcium carbonate, and
(3) The ratio of the powder to the total mass of the primer solution is 10% by mass to 95% by mass.

  As described above, in the refurbishment method of the present invention, the primer liquid is directly applied onto the sand asphalt roofing without using the existing sand asphalt roofing. Moreover, since the existing sandy asphalt roofing that is a waterproof layer is not destroyed, the risk of water leakage due to rain during the renovation work can be avoided. Furthermore, since the removal work of asphalt roofing with sand can be omitted, the number of man-hours can be greatly reduced, the repair work can be performed in a short period of time, and the repair cost can be reduced.

The adhesive strength between the sandy asphalt roofing layer and the coating film formed from the primer solution is preferably 7 N / cm or more. The primer solution preferably has a tensile elongation at break of 30% or more and a tensile strength at break of 0.3 N / mm ² or more of the coating film formed from the primer solution. Furthermore, it is preferable that the ventilation cushion sheet has a partial adhesive layer on one surface.

  According to the present invention, since the waterproof layer can be repaired without removing the existing waterproof layer, there is no generation of waste and no water leakage accident during the construction period. Furthermore, the repair work can be completed in a short period of time.

It is a fragmentary sectional view which shows an example of the structure repaired by the repair construction method of this invention.

<Renovation method>
The repair method of the present invention is a waterproof layer repair method using asphalt roofing with sand as a waterproof layer, and includes a main agent, a curing agent and powder on the surface of the asphalt roofing layer with sand. It is characterized in that a primer solution that satisfies the requirements of (3) is applied, and a breathable cushion sheet is laminated after the coating film is cured.
(1) The total amount of the main agent and the curing agent with respect to the total mass of the primer solution is 5% by mass to 90% by mass.
(2) The powder contains cement, cinnabar with a particle size of 1.0 mm or less, and calcium carbonate, and
(3) The total mass of the powder with respect to the total mass of the primer solution is 10% by mass to 95% by mass.

  The inventors of the present invention focused on the problems of the above prior art, and as a result of repeated studies on a method for repairing a waterproof layer without attaching a sandy asphalt roofing layer to be repaired, a specific primer solution was obtained. The present invention was completed by finding that the waterproof layer can be repaired without applying sand asphalt roofing by coating directly on the asphalt roofing with sand and laminating a ventilation cushioning sheet thereon.

  First, an example of the repair method of the present invention and a waterproof structure obtained by the method will be described with reference to FIG.

  As shown in FIG. 1, it is the asphalt roofing 2 with sand provided in the structural housing 1 that is to be repaired in the present invention. First, the asphalt roofing 2 with sand to be repaired is cleaned to remove foreign substances present on the surface.

Subsequently, the primer solution prepared beforehand is apply | coated on the asphalt roofing 2 with sand after cleaning, and this coating film is dried, and the primer layer 3 is formed. At this time, it is preferable that the application amount of the primer liquid is 0.5 kg / m ² or more and 2.0 kg / m ² or less. More preferably, it is 0.6 kg / m ² or more and 1.5 kg / m ² or less, and further preferably 1.0 kg / m ² or more and 1.3 kg / m ² or less. When the application amount of the primer solution is too large, it takes time to dry the coating film, so that workability is deteriorated. On the other hand, when the amount is too small, the effect of leveling the unevenness of the asphalt roofing surface with sand may not be obtained, and between the aeration buffer sheet 4 and the asphalt roofing with sand 2 laminated after the coating film is dried. This is because the adhesion may be insufficient.

  The primer solution is preferably applied using a material other than a roller such as a rubber rake, rubber spatula, or hammer. This is because the resin and the aggregate can be uniformly applied over a wide range and a certain amount of the aggregate component can be reliably filled in the recess.

  After forming the primer layer 3, the ventilation buffer sheet 4 is laminated (placed) on the primer layer 3. As will be described later, this aeration buffer sheet has a structure in which water vapor generated from a base layer such as a structural enclosure or sand asphalt roofing can pass through a non-adhesive portion communicating with the lower surface of the sheet, Are exhausted from the deaerator to the atmosphere.

  Thereafter, in order to prevent the intrusion of water from the gap between adjacent ventilation cushioning sheets, the gap is covered with a joint tape (not shown). Moreover, a terminal tape is similarly stuck also to the edge part of a ventilation | gas_flowing cushioning sheet, and the clearance gap which water infiltrates from the outside is closed. As said joint tape, the tape which provided the adhesive to the polyester-type film is preferable, and the tape which provided the butyl-type adhesive to the nonwoven fabric base material as a terminal tape is preferable.

  After attaching the joint tape and the terminal tape and installing the deaeration device, the repair work is completed by applying a waterproof material and forming the waterproof material layer 5 on the ventilation cushioning sheet 4.

  The waterproof material layer 5 is a layer that covers the ventilation cushioning sheet 4 and prevents entry of rainwater after curing. As the waterproofing material, any conventionally known coating film waterproofing material in the field can be used. For example, one-pack type or two-pack type urethane, urethane rubber waterproof material, acrylic rubber waterproof material, chloroprene waterproof material Material, rubber asphalt waterproofing material, polymer cement, unsaturated polyester resin, and vinyl ester resin. Moreover, you may use the general waterproofing material for rooftops, for example, using the commercially available urethane-based waterproofing material for rooftops containing 3 mass%-10 mass% of solvents (toluene, xylene, mineral spirit, etc.). Also good. Furthermore, a colorant such as carbon black, titanium oxide, cisazo orange, and cyanine blue may be added to the waterproof material in addition to the resin serving as the base material.

The coating amount of the waterproof material, preferably with ^{2.0kg / m 2 ~6.0kg / m 2} . More preferably ^{2.5kg / m 2 ~5.0kg / m 2} , more preferably in there ^{3.0kg / m 2 ~4.5kg / m 2} , the thickness of the coating film is 2.0~4.0mm It is preferable to apply so that. In addition, the application | coating method of a waterproof material is not specifically limited, Either spraying construction or hand-painting construction may be sufficient.

  Further, a top coat for protecting the waterproof material layer from ultraviolet rays or the like may be provided on the waterproof material layer. Examples of the top coat include acrylic urethane paint, water-based acrylic urethane paint, fluororesin, urethane aluminum paint, and acrylic emulsion.

  The thickness of the top coat layer is preferably 10 μm to 300 μm. More preferably, it is 15 micrometers-250 micrometers, More preferably, they are 20 micrometers-200 micrometers.

  In the above repair method, the adhesive strength between the primer layer formed from the primer solution and the asphalt roofing with sand is preferably 7 N / cm or more. More preferably, it is 8 N / cm or more, More preferably, it is 9 N / cm or more. It can be said that the higher the adhesive strength, the stronger the asphalt roofing with sand and the primer layer are adhered, and a long-term waterproof effect can be expected, and the strength of the repaired structure is high. The upper limit of the adhesive strength is not particularly limited. In addition, the said adhesive strength is a value measured by the method as described in an Example.

<Primer solution>
Next, the primer solution according to the present invention will be described. The primer liquid according to the present invention includes a main agent, a curing agent, and powder. First, the main agent will be described.

(Main agent)
The main ingredient component contains a urethane prepolymer. The content of the urethane prepolymer is preferably 80% by mass or more based on the total mass of the main component. Moreover, you may use only this urethane prepolymer as a main ingredient component.

  The urethane prepolymer contained in the main component is not particularly limited, and conventionally known urethane prepolymers can be used. For example, a reaction product obtained by reacting a polyol compound and a polyisocyanate compound so that an isocyanate group (NCO group) is excessive with respect to a hydroxy group (OH group) can be used as a urethane prepolymer. .

  The polyisocyanate compound used when producing the urethane prepolymer is not particularly limited as long as it has two or more isocyanate groups in the molecule. Specific examples of the polyisocyanate compound include TDI (for example, 2,4-tolylene diisocyanate (2,4-TDI)).

  On the other hand, the polyol compound used when producing the urethane prepolymer is not particularly limited as long as it has two or more hydroxy groups. Specific examples of the polyol compound include polyether polyols, polyester polyols, other polyols, and mixed polyols thereof. Specifically, polypropylene ether diol and polypropylene ether triol are preferably exemplified.

  The manufacturing method of a urethane prepolymer is not specifically limited, For example, what is necessary is just to heat-stir the polyol compound and polyisocyanate compound of the above-mentioned equivalent ratio at 50 to 130 degreeC. Moreover, you may use urethanation catalysts, such as an organic tin compound, organic bismuth, and an amine, as needed.

  The said urethane prepolymer can be used individually or in combination of 2 or more types.

  It is preferable that the compounding quantity of the urethane prepolymer at the time of preparing a primer liquid is 10 mass parts-1100 mass parts with respect to 100 mass parts of solid content of the hardening | curing agent component mentioned later, More preferably, 15 mass parts-1000 parts. It is a mass part, More preferably, it is 20 mass parts-800 mass parts. When the content of the urethane prepolymer is in the above-described range, the solvent resistance and flexibility of the primer layer obtained are good.

  The solid content of 100 parts by mass of the curing agent component is the total amount of these solid contents when the curing agent contains both an acrylic emulsion described later and a styrene-butadiene emulsion (hereinafter referred to as “solid content”). The same).

  Components other than the urethane prepolymer may be included in the main component, and for example, a silicone resin, a modified silicone resin, an epoxy resin, or the like may be added as a main component.

(Curing agent)
The curing agent component contained in the primer liquid is preferably an acrylic emulsion and / or a styrene-butadiene emulsion. The solid content in these emulsions is preferably 40% by mass or more with respect to 100% by mass of the curing agent component. The upper limit is not particularly limited, and all of the curing agent component may be an acrylic emulsion and / or a styrene-butadiene emulsion.

  In the present invention, regarding the calculation of the content, water that can be separately added as a curing agent component is handled as water constituting the emulsion.

Acrylic emulsion The acrylic emulsion is not particularly limited, and a conventionally known acrylic emulsion can be used. For example, an aqueous emulsion obtained by copolymerizing (emulsion polymerization) a plurality of types of (meth) acrylic acid and / or an ester monomer thereof using an emulsifying dispersant can be preferably used. In the above copolymerization, other monomers than the (meth) acrylic acid ester monomer may be copolymerized as necessary.

  The acrylic emulsion preferably has a solid content of 30% by mass to 70% by mass, and more preferably 35% by mass to 65% by mass.

  Commercially available products may be used as the acrylic emulsion. Specific examples thereof include Asahi Kasei Latex (“A1500”, solid content: 45 mass%, average particle size: 190 nm, manufactured by Asahi Kasei Chemicals), Asahi Kasei Latex (“Z871”). ”, Solid content: 49% by mass, average particle size: 220 nm, manufactured by Asahi Kasei Chemicals Corporation).

Styrene-butadiene emulsion The styrene-butadiene emulsion (hereinafter referred to as “SBR emulsion”) is not particularly limited, and is a conventionally known aqueous dispersion of a synthetic polymer mainly composed of styrene and butadiene. SBR emulsions can be used.

  In addition, in addition polymerization of styrene and butadiene, other monomers may be copolymerized as necessary.

  Moreover, it is preferable that solid content is 30 mass%-70 mass%, and, as for the said SBR type | system | group emulsion, it is more preferable that it is 35 mass%-65 mass%.

  Commercially available products may be used as the SBR emulsion, and specific examples thereof include Asahi Kasei Latex (“L3200”, solid content: 48 mass%, average particle size: 167 nm, manufactured by Asahi Kasei Chemicals), Asahi Kasei Latex ( “A6500”, solid content: 50% by mass, average particle size: 220 nm, manufactured by Asahi Kasei Chemicals Corporation) and the like.

  Moreover, you may use things other than the above as a hardening | curing agent, for example, other emulsions, such as ethylene-vinyl acetate emulsion and an epoxy-type emulsion, in the quantity of less than 10 mass% with respect to the total weight of a hardening | curing agent component, A polyether polyol having an active hydrogen group or an amine may be used as a curing agent.

  From the viewpoint of excellent workability, it is preferable to use an acrylic emulsion.

The coating film formed from the primer solution preferably has a tensile elongation at break of 30% or more. More preferably, it is 35% or more, More preferably, it is 40% or more. If the tensile elongation at break is too small, it cannot follow the expansion and contraction of asphalt, and it is difficult to obtain the reinforcing effect of asphalt roofing with sand. The tensile strength at break of the coating film is preferably 0.3 N / mm ² or more. More preferably, it is 0.35 N / mm ² or more, and further preferably 0.4 N / mm ² or more. When the tensile strength at break is too small, the predetermined hardness cannot be obtained, and it becomes difficult to obtain an adhesive force with the ventilation cushioning sheet. The tensile elongation at break and the tensile strength at break are measured by the methods described in the examples.

  As described above, the primer liquid according to the present invention includes a two-component curable urethane coating having a urethane prepolymer as a main component and an acrylic emulsion or the like as a curing agent. Therefore, the primer layer formed from this primer solution is composed of urethane resin. Since the urethane resin has good adhesiveness with asphalt, the gap in the asphalt roofing with sand caused by aging is filled with the urethane resin, and as a result, the entire asphalt roofing layer with sand can be reinforced.

(Powder component)
The powder component contained in the primer liquid is a component that reinforces the primer layer by suppressing separation between the emulsion used as the curing agent component and the urethane prepolymer used as the main component. In addition, the powder component has an effect of smoothing the asphalt roofing surface with sand by entering the recesses formed on the asphalt roofing surface with sand, and improving the adhesiveness with the ventilation buffer sheet laminated on the primer layer. .

  The powder component desirably contains at least one selected from the group consisting of silica sand, cement, and calcium carbonate.

As the above-mentioned cement, Portland cement is generally used, and with Portland cement, powders such as calcareous components and viscous components mainly composed of CaO, Al ₂ O ₃ , SiO _{2 and the} like are mixed at an appropriate ratio. It is a cement that hardens by reacting with water to form a hydrate.

  By using calcium carbonate, the fluidity of the primer solution can be improved, and the water retention of the primer layer after the coating film is cured is improved. Therefore, it is preferable to use calcium carbonate as an essential component of the primer solution.

  As the silica sand, either natural silica sand or artificial silica sand can be used. However, it is desirable that the silica sand has a particle size of 1.0 mm or less. More preferably, it is 0.6 mm or less, More preferably, it is 0.4 mm or less. When the particle diameter is too large, it is impossible to enter the recesses formed on the asphalt roofing surface with sand and it is difficult to obtain a surface smoothing effect. On the other hand, if the particle size is too small, a large amount of powder components must be used to level the concave portions of the asphalt roofing with sand, which is not economical. Therefore, the particle diameter is preferably 0.02 mm or more, more preferably 0.05 mm or more, and still more preferably 0.1 mm or more. In addition, the said particle diameter is measured by the sieving method, for example using the metal knitted sieve etc. which have the predetermined opening prescribed | regulated to JISZ8801-1.

  As the powder component, silica sand, cement or calcium carbonate may be used alone, or two or more of these may be used in combination. When the total amount of the powder components is 100% by mass, silica sand: cement: calcium carbonate is 60% by mass to 80% by mass: 0% by mass to 20% by mass: 10% by mass to 10% by mass. It is preferable to be 30% by mass.

  The ratio of the powder component to the total mass of the primer solution according to the present invention is desirably 10% by mass or more and 95% by mass or less. More preferably, it is 20 mass% or more and 80 mass% or less, More preferably, it is 40 mass% or more and 70 mass% or less. This is because when the proportion of the powder is too large, it is difficult to paint, and when it is too small, it is difficult to obtain the leveling effect of the asphalt roofing surface layer with sand and the effect of suppressing the separation between the main agent and the curing agent.

(Other additives)
The primer solution according to the present invention can contain additives in addition to the above components as long as the object of the present invention is not impaired. Examples of the additive include a plasticizer, an antifoaming agent, a curing aid, a colorant, a flame retardant, a fungicide, and a catalyst.

  When these various additives are contained, they can be contained in any of the main component, the curing agent component and the powder component described above.

  In addition, when it contains an additive in this way, content (mass%) in the hardening | curing agent component of the acrylic emulsion and / or styrene-butadiene-type emulsion mentioned above, and content in the hardening | curing agent component of the urethane prepolymer mentioned above ( In the calculation of (mass%), the contents of these various additives are not included.

  The method for producing the primer solution of the present invention is not particularly limited, but it is preferable to store the main component and the curing agent component separately and mix them before construction to produce the primer solution. For example, the above-mentioned main agent component, curing agent component and powder component, and a method of mixing and preparing the additive to be blended if desired at the time of construction; the main agent component and powder component and the additive to be blended if desired Are prepared in advance, and the above-described curing agent components are mixed and prepared at the time of construction.

  The primer solution is applied to asphalt roofing with sand to form a primer layer. The urethane resin constituting the primer layer has good adhesiveness to asphalt and has flexibility to follow the expansion and contraction of asphalt by heat, so that the asphalt roofing layer with sand is reinforced as a whole. In addition, since the powder component penetrates into cracks and the like generated in the asphalt roofing layer with sand due to aging, the unevenness of the surface is leveled, so the adhesiveness with the air-permeable cushion sheet laminated on the primer layer is improved. Can be improved.

<Ventilation cushion sheet>
Next, the ventilation cushioning sheet will be described. As the ventilation cushioning sheet, any conventionally known one can be used. For example, a base material, a modified asphalt layer provided on one surface of the base material, and the modified asphalt layer are covered. Those having a coating layer are preferred, and those having a partial adhesive layer on the surface of the ventilation cushioning sheet located on the primer layer side (construction surface side) are preferred (aeration cushioning sheet with a self-adhesive layer). The pressure-sensitive adhesive layer allows the aeration buffer sheet to be adhered and fixed to the primer layer, and prevents the sheet from being displaced at the time of construction and from wrinkling and displacement resulting from the expansion of the sheet due to temperature changes after construction. it can. Here, “self-adhesion” means having adhesiveness with the primer layer.

  Examples of the substrate include a synthetic resin film such as a PET film, a nonwoven fabric formed from polyester fiber or glass fiber, a glass mesh, and a combination of two or more of these.

  Examples of the modified asphalt constituting the modified asphalt layer include those obtained by adding synthetic rubber or synthetic resin to asphalt. For example, those obtained by adding blown and wax to asphalt are preferable.

  The said coating layer should just be a layer which can coat | cover a modified asphalt layer, and can use the material illustrated as a base material as a coating layer, for example.

  As described above, the adhesive layer is partially present on the surface located on the construction surface side of the ventilation cushioning sheet. Therefore, although the site | part (non-adhesion part) in which an adhesion layer does not exist exists in the construction surface side of a ventilation | gas_flowing cushioning sheet, it is preferable that this non-adhesion part is connected. It is because the vapor | steam etc. which were produced on the construction surface can be guide | induced to deaerators, such as a decylinder, and a drain by the non-adhesion part communicating. In addition, it is preferable that the said adhesion part and a non-adhesion part are provided in the aspects like a tile (adhesion part) and a joint (non-adhesion part). Examples of the material constituting the adhesive layer include conventionally known adhesives such as acrylic adhesives, rubber adhesives, urethane adhesives, and polyester adhesives.

  In addition, the adhesive layer is covered with the release paper before using the ventilation cushioning sheet.

  According to the above repair method of the present invention, the primer solution is applied directly on the existing sandy asphalt roofing and the repair work is performed, so it is not necessary to remove the sandy asphalt roofing which is the old waterproof layer, and the industrial disposal Generation of things can be suppressed. In addition, since the old waterproof layer is not destroyed at the refurbishment stage, it is possible to avoid the risk of water leakage due to sudden rainfall.

  Furthermore, since the primer solution contains a resin component (urethane resin) that has good adhesion to asphalt roofing with sand, the primer solution penetrates into the cracked part that occurs in asphalt roofing with sand due to aging. The entire asphalt roofing layer with sand is reinforced. In addition, since the urethane resin constituting the primer layer is flexible and can follow the expansion and contraction of the asphalt roofing layer with sand by heat, the waterproof effect of the structure can be further enhanced by using the primer solution. In addition, the primer solution according to the present invention contains a powder component, and when the powder component enters the concave portion of the asphalt roofing layer with sand, the surface becomes smooth, and the aeration buffer sheet and sand with asphalt Good adhesion to roofing. That is, it can be said that the primer layer according to the present invention has the function of a base material that has been provided as a different process in the conventional repair method. Therefore, according to the refurbishment method of the present invention, in addition to the removal work of the old waterproof layer, which has been essential in the past, the base adjustment work can be omitted, the number of processes can be greatly reduced, the construction period can be shortened, and the cost can be reduced. It becomes possible.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention.

[Adhesion strength 180 ° peel test]
The primer solution produced in the below-mentioned experimental example is 2 mm on the asphalt surface and the asphalt roofing surface with sand (size: thickness 4 mm, “Polytex CP40 (trade name)” manufactured by Shizuoka Seisho Kogyo Co., Ltd.). It was applied as follows. At this time, a cloth of material: polyester spun bond, basis weight: 50 g / m ² was applied in the primer layer so as not to contact the asphalt or the asphalt roofing with sand. This was cured for 168 hours under the conditions of 23 ° C. and 50% relative humidity, then placed in a tensile tester, the edge of the cloth was held by a gripper, pulled at a pulling speed of 100 mm / min, and peeled 180 °. A test was performed and the adhesive strength (N / cm) was measured.

[Tensile elongation at break and strength at break]
A sheet was prepared from the primer solution produced in the experimental examples described later, and this was cured for 168 hours under the conditions of 23 ° C. and 50% relative humidity to prepare a dumbbell type No. 2 test piece (JIS K7113). The obtained test piece is attached to a tensile tester so that the distance between chucks is 60 mm, pulled at a pulling speed of 100 mm / min, and the elongation (%) and tensile strength (N / mm ² when the test piece breaks). ) Was measured. In addition, the measurement was performed 3 times and the average value was described in the table as tensile strength and elongation.

[Flexibility (flexibility)]
The primer solution was cured under conditions of 23 ° C. and 50% relative humidity for 24 hours to obtain a cured product (size: 50 mm × 50 mm × 2 mm).

  When the obtained cured product is bent by about 180 degrees with a finger (folded in half at the center of the long side), those that easily break are evaluated as “x” as inferior in flexibility and are not broken. The one that was bent in a circle was evaluated as “◯” as having excellent flexibility.

<Preparation of primer solution>
The main agent, curing agent and powder were mixed at a ratio of 1: 2: 4 (mass ratio).

  As the main agent, a urethane prepolymer obtained by the following method was used. 1600 parts by mass of a polypropylene ether triol having a number average molecular weight of 4000 (“EXCENOL (registered trademark) 4030” manufactured by Asahi Glass Co., Ltd.) and a polypropylene ether diol having a number average molecular weight of 2000 (“EXCENOL (registered trademark) 1020” manufactured by Asahi Glass Co., Ltd.) 900 Part by mass was placed in a reaction vessel, heated to 110 ° C. under reduced pressure, and dehydrated for 6 hours.

  Next, tolylene diisocyanate (“Cosmonate (registered trademark) T-80”, manufactured by Mitsui Chemicals Polyurethanes Co., Ltd.) is placed in the reaction vessel after the dehydration treatment so that the NCO group / OH group equivalent ratio is 1.9. Was added with stirring. Thereafter, the inside of the reaction vessel was heated to 80 ° C. and further mixed for 24 hours under a nitrogen atmosphere to obtain a urethane prepolymer.

  As the curing agent, an acrylic emulsion (“Z871”, manufactured by Asahi Kasei Chemicals Corporation, solid content 49 mass%, average particle size: 220 nm) is used, and as the powder, Portland cement 10 parts by mass, No. 7 silica sand (stock) 70 parts by mass of Nichetsu “Chichibu 7 No. Silica”, average particle size: 0.2 mm or less, 20 parts by mass of calcium carbonate (“Super S” manufactured by Maruo Calcium Co., Ltd., average particle size of 2.7 μm (notified value)) A mixture of was used.

  First, after mixing and stirring a hardening | curing agent and powder, the main ingredient was added here and it stirred using the electric stirrer, and the primer liquid (4 Pa * s (4000 cp)) was prepared.

  Using the primer solution, the physical properties of the coating film formed from the primer solution and the adhesion of the primer layer to the underlayer (such as asphalt roofing with sand) were evaluated. The results are shown in Table 1.

  From Table 1, it can be seen that the primer layer formed from the primer solution according to the present invention has good adhesion to various materials such as asphalt and asphalt roofing layer with sand. In addition, the primer layer according to the present invention is considered to follow the expansion and contraction of the asphalt waterproof layer (former waterproof layer) with heat and hardly cause the mechanical properties of the waterproof layer to deteriorate.

Example 1
A primer solution was applied to the asphalt roofing with sand that had been passed for 15 years using a hammer. The coating amount was 1.2 kg / m ² . After standing at 25 ° C. for 18 hours and confirming that the primer solution was completely dried and a primer layer was formed, a ventilation buffer sheet having a urethane resin coating layer on one surface (Shizuoka Bituminous Industrial Co., Ltd.) "Polytex VF08", 1040mm width) is placed, the sheet is covered with a joint tape ("VF wrap tape", 30mm width, manufactured by Shizuoka Biting Industrial Co., Ltd.), and the end of the sheet is end tape (Shizuoka Bitumen Kogyo Co., Ltd., “VF terminal tape”). Thereafter, urethane-based waterproofing material (“Cosmic pro12” manufactured by Uplex Co., Ltd.) was applied so that the coating amount was 3.6 kg / m ^2, and the asphalt roofing with sand was repaired.

  There were no wrinkles on the surface after the repair, and the surface properties were good. In addition, the conventional renovation method required 1 day to remove the old waterproof layer, 2 days to adjust the concrete surface of the frame with mortar, etc., and then required time to form and renovate the waterproof layer. However, in the method of the present invention, it is not necessary to remove the existing waterproof layer, so that the waterproof layer could be repaired in a shorter period of time than the conventional construction method.

  According to the repair method of the present invention, the waterproof layer can be repaired without removing the existing waterproof layer, so that the generation of industrial waste can be greatly reduced, and the occurrence of water leakage accidents during the construction period is also reduced. be able to. Furthermore, since the man-hour can be reduced, the repair work can be completed in a short period of time.

1 Structure frame 2 Asphalt roofing with sand (asphalt waterproofing layer with sand)
3 Primer layer 4 Air cushioning sheet 5 Waterproof material layer

Claims (4)

A renovation method of a waterproof layer with sand asphalt roofing as a waterproof layer,
On the surface of the asphalt roofing layer with sand, a primer solution containing a main agent, a curing agent, and powder and satisfying the following requirements (1) to (3) is applied, and after the coating film is cured, an aeration buffer sheet is applied. A modified asphalt roofing method with sand, characterized by stacking.
(1) The ratio of the total amount of the main agent and the curing agent to the total mass of the primer solution is 5% by mass to 90% by mass.
(2) The powder contains cement, cinnabar with a particle size of 1.0 mm or less, and calcium carbonate, and
(3) The ratio of the powder to the total mass of the primer solution is 10% by mass to 95% by mass.   The repair method according to claim 1, wherein an adhesive strength between the sandy asphalt roofing layer and a coating film formed from the primer solution is 7 N / cm or more. The repair method according to claim 1 or 2, wherein the primer liquid has a tensile breaking elongation of a coating film formed from the primer liquid of 30% or more and a tensile breaking strength of 0.3 N / mm ² or more. .   The repair method according to any one of claims 1 to 3, wherein the ventilation cushioning sheet has a partial adhesive layer on one surface.