JP7357229B2 - Production method of renovated waterproof structure - Google Patents

Description

The present invention relates to a method for producing a retrofitted waterproof structure.

As a waterproof structure applied to the rooftop of a building, there is a waterproof structure having a sheet waterproof layer (asphalt roofing) using an asphalt sheet (for example, see Patent Document 1). The sheet waterproof layer is constructed by, for example, a plurality of asphalt sheets laid side by side. The sheet waterproof layer deteriorates over time and needs to be repaired. As a repair method, for example, there is a method of forming an insulating layer (polymer cement mortar layer, etc.) on the surface of the sheet waterproof layer, and then forming a waterproof coating film.

JP2010-255336A

However, in the above-mentioned repair method, the waterproof coating film may become partially thin in areas such as uneven areas, and there is a possibility that the waterproof performance may deteriorate in these areas.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing a modified waterproof structure that can ensure high waterproof performance when repairing a waterproof structure using an asphalt sheet.

One aspect of the present invention is a method for repairing a waterproof structure having a sheet waterproof layer made of an asphalt sheet, the method comprising: applying a primer liquid to the surface of the sheet waterproof layer to form a primer layer; forming a paint film waterproof layer on the primer layer, the paint film waterproof layer having a fiber base material and a resin composition impregnated in the fiber base material, the resin composition The article provides a method for retrofitting waterproof structures containing polyurethane resins.

The sheet waterproof layer may be formed by laying the plurality of asphalt sheets side by side, and a stepped portion may be formed by partially overlapping adjacent asphalt sheets among the plurality of asphalt sheets. The asphalt sheet may be a sanded asphalt sheet with sand attached to its surface.

Another aspect of the present invention includes a sheet waterproof layer made of an asphalt sheet, a primer layer formed on the surface of the sheet waterproof layer, and a paint film waterproof layer formed on the primer layer. The waterproof coating layer has a fiber base material and a resin composition impregnated into the fiber base material, and the resin composition includes a polyurethane resin to provide a waterproof structure.

According to one aspect of the present invention, the waterproof coating layer includes a fiber base material and a resin composition impregnated into the fiber base material. Therefore, the paint film waterproof layer does not become locally thin even at the uneven portions of the sheet waterproof layer, and a sufficient thickness can be ensured. Therefore, it is possible to prevent a decrease in the waterproof properties of the waterproof coating layer. Therefore, a waterproof structure having high waterproof performance can be formed.

It is a schematic diagram showing the waterproof structure repaired by the repair method of a 1st embodiment. FIG. 2 is a schematic diagram showing a first example of a waterproof structure before renovation. It is a schematic diagram showing an example of an asphalt sheet. FIG. 3 is a process diagram illustrating an overview of a method for repairing a waterproof structure according to the first embodiment. This is a process diagram following the previous figure. It is a schematic diagram showing an example of a paint film waterproof layer. FIG. 2 is a schematic diagram showing an example of a fiber base material used for a waterproof coating layer. FIG. 2 is a schematic diagram showing a waterproof structure repaired by the waterproof structure repair method according to the first embodiment. It is a schematic diagram showing a second example of a waterproof structure before renovation. It is a schematic diagram showing the waterproof structure repaired by the repair method of a 2nd embodiment.

[First embodiment]
FIG. 1 is a schematic diagram showing a waterproof structure repaired by the repair method of the first embodiment. FIG. 2 is a schematic diagram showing a first example of a waterproof structure before renovation. FIG. 3 is a schematic diagram showing an example of an asphalt sheet.
As shown in FIG. 1, the target of the repair method according to the first embodiment is an existing waterproof structure 2A provided on a base 101. The waterproof structure 1 repaired by the repair method according to the first embodiment includes a sheet waterproof layer 2, a primer layer 3, a paint film waterproof layer 4, and a top coat layer 5.

The base 101 is, for example, a flat surface 103 surrounded by a parapet section 102 on the roof of a concrete building, and an inner surface (rising surface 104) of the parapet section 102. "Upper" and "lower" in the following description are defined according to the vertical direction in FIG. In FIG. 1, a waterproof structure 2A is provided on the surface of the base 101 (flat surface 103 and rising surface 104). Note that "planar view" refers to viewing from a direction perpendicular to the flat surface 103 of the base 101.

As shown in FIG. 2, the waterproof structure 2A has a sheet waterproof layer 2 (asphalt roofing). The sheet waterproof layer 2 is constructed by laying a plurality of sand-covered asphalt sheets 11 side by side.
As shown in FIG. 3, the sanded asphalt sheet 11 includes, for example, an asphalt sheet 12 and sand 13. The asphalt sheet 12 is constructed by impregnating and covering a core material 14, such as a fiber sheet, with an asphalt material 15, for example. As the asphalt material constituting the asphalt sheet 12, modified asphalt can be used. The sand 13 is attached to the upper surface 12a (surface) of the asphalt sheet 12. The sand 13 is, for example, mineral powder such as silica sand. The sand 13 has a function of protecting the asphalt sheets 12 and a function of preventing the asphalt sheets 12 from blocking each other.

As shown in FIG. 2, the sand-covered asphalt sheet 11 is formed, for example, in a band shape. The sanded asphalt sheet 11 is laid with the side to which the sand 13 (see FIG. 3) is attached facing upward. Among the plurality of sanded asphalt sheets 11, adjacent sanded asphalt sheets 11, 11 are partially overlapped. Specifically, among the plurality of sanded asphalt sheets 11, the side edge of the second sanded asphalt sheet 11B is placed on the side edge 11a (band-shaped portion including the side edge 11b) of the first sanded asphalt sheet 11A. The portions 11a are overlapped. Since the side edges 11a, 11a of the adjacent sand-covered asphalt sheets 11, 11 are overlapped, the waterproof performance at the joint can be improved.

A portion where the side edges 11a, 11a of the sand-covered asphalt sheets 11, 11 are overlapped is called an overlapping portion 16. Since the overlapped portion 16 is thicker than other portions, the overlapped portion 16 forms a stepped portion 17 (uneven portion). The stepped portion 17 is a discontinuous portion formed by a height difference between the second sanded asphalt sheet 11B and the first sanded asphalt sheet 11A in the overlapping portion 16.

Hereinafter, a method for repairing the existing waterproof structure 2A will be described with reference to FIGS. 4 to 8.
FIG. 4 is a process diagram illustrating an overview of the waterproof structure repair method according to the first embodiment. FIG. 5 is a process diagram following FIG. 4. FIG. 6 is a schematic diagram showing an example of a waterproof coating layer.
FIG. 7 is a schematic diagram showing an example of a fiber base material used in the waterproof coating layer. FIG. 8 is a schematic diagram showing a waterproof structure repaired by the waterproof structure repair method according to the first embodiment.

(First step: Formation of primer layer)
As shown in FIG. 4, a primer layer 3 is formed on the surface of the sanded asphalt sheet 11. The primer layer 3 is formed to improve the adhesion between the sheet waterproof layer 2 and the coating waterproof layer 4 (see FIG. 5), which will be described later. The primer layer 3 preferably has a resin such as an epoxy resin, an epoxy urethane resin, a urethane resin, an acrylic urethane resin, a synthetic rubber resin, or a silane resin as a main component. The primer layer 3 is formed by applying a primer liquid to the surface of the sanded asphalt sheet 11 and curing it.

(Second step: Formation of waterproof coating layer)
Next, as shown in FIG. 5, a waterproof coating layer 4 is formed on the surface of the primer layer 3. As shown in FIG. 6, the waterproof coating layer 4 includes a fiber base material 41 and a resin composition 42 impregnated into the fiber base material 41.
The thickness T1 of the waterproof coating layer 4 is, for example, 1 mm or more and 12 mm or less. When the thickness T1 is 1 mm or more, the waterproof performance of the waterproof coating layer 4 can be improved. When the thickness T1 is 12 mm or less, the time required for curing the waterproof coating layer 4 can be shortened, so that the construction period can be shortened.

As shown in FIG. 7, as the fibers 41a constituting the fiber base material 41, for example, inorganic fibers such as glass fibers, carbon fibers, and metal fibers; organic fibers such as aramid fibers, polyester fibers, and nylon fibers can be used. . As the fibers 41a constituting the fiber base material 41, it is particularly preferable to use glass fibers.

The fiber base material 41 may be in the form of a woven fabric, a knitted fabric, a braided fabric, a drawn fabric, or the like, made of long fibers. Examples of the woven fabric include biaxial fabrics such as plain weave, satin weave, and twill weave, and multiaxial fabrics having three or more axes. The fiber base material 41 may be a nonwoven fabric. The fiber base material 41 may be formed into a mat shape. Specific examples of the form of the fiber base material 41 include roving cloth and chopped strand mat. The content of the fiber base material 41 in the waterproof coating layer 4 may be, for example, 30 to 40% by volume.

The basis weight of the fiber base material 41 may be, for example, 100 g/m ² or more and 1000 g/m ² or less. When the basis weight is 100 g/m ² or more, it is possible to prevent the waterproof coating layer 4 from becoming locally thin. When the basis weight is 1000 g/m ² or less, the time required for curing the waterproof coating layer 4 can be shortened, particularly when the polyurethane resin constituting the resin composition 42 is a one-component type, thereby shortening the construction period. Cheap.

The thickness T2 of the fiber base material 41 is, for example, 0.1 mm or more and 10 mm or less. When the thickness T2 is 0.1 mm or more, the waterproof coating layer 4 can be prevented from becoming locally thin. When the thickness T2 is 10 mm or less, especially when the polyurethane resin constituting the resin composition 42 is a one-component type, the time required for curing the waterproof coating layer 4 can be shortened, so that the construction period can be shortened. The ratio T2/T1 of the thickness T2 of the fiber base material 41 to the thickness T1 of the waterproof coating layer 4 is preferably 10% or more. When the ratio T2/T1 is 10% or more, it is possible to prevent the waterproof coating layer 4 from becoming locally thin.

The resin composition 42 contains polyurethane resin. As the polyurethane resin, a one-component type (moisture curing type) or a two-component type may be used. One-component (moisture-curing) polyurethane resins can be classified into two types. One type is a type in which the moisture in the air and the isocyanate component in the liquid waterproofing material directly react and harden. This type is called the first type. The other type is a type that contains at least two components, namely component 1 and component 2, in the liquid waterproofing material. Component 2 does not react with component 1, but becomes component 2' due to moisture in the air, and as this component 2' reacts with component 1, curing progresses. Component 2 is generally referred to as a latent curing agent. This type is called the second type.

The first type of waterproofing material includes, for example, polyisocyanate and polyol. Examples of the polyisocyanate include diphenylmethane-4,4'-diisocyanate (MDI), carbodiimide-modified diphenylmethane diisocyanate (liquid MDI), polymethylene polyphenylisocyanate (crude MDI), and 2,4-tolylene diisocyanate (2,4-TDI). ), 2,6-tolylene diisocyanate (2,6-TDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI), etc. Examples include isocyanate compounds. The polyol is not particularly limited as long as it has two or more hydroxyl groups, and examples thereof include polyether polyol, polyester polyol, polytetramethylene glycol, and the like. The first type of waterproof material may be, for example, a urethane prepolymer obtained by reacting a polyisocyanate and a polyol.

The second type of waterproofing material includes, for example, a polyisocyanate (component 1) and a latent hardener (component 2). As the polyisocyanate (component 1), the polyisocyanates exemplified as polyisocyanates that can be used in the first type of waterproof material can be used. As the polyisocyanate (component 1), the above-mentioned urethane prepolymers can be used.

A two-component liquid waterproofing material is used, for example, by mixing a main agent containing polyisocyanate and a curing agent containing a polyfunctional active hydrogen compound reactive with isocyanate groups on-site.

The resin composition 42 may contain additives such as a solvent, a plasticizer, a curing catalyst, a filler, an antioxidant, a flame retardant, a stabilizer, an ultraviolet absorber, a surfactant, and a colored pigment. As the plasticizer added to the resin composition 42, carboxylic acid esters such as phthalic acid ester, adipic acid ester, sebacic acid ester, azelaic acid ester, and trimellitic acid ester can be used. Particularly suitable are diisononyl adipate (DINA), di-2-ethylhexyl phthalate (DOP), diisononyl phthalate (DINP), and the like. These may be used alone or in combination of two or more. Note that the resin composition 42 may contain resins other than polyurethane resin.

The amount of plasticizer used is preferably 40 parts by weight or less (preferably 20 parts by weight or less) based on 100 parts by weight of the polyisocyanate. If the amount of plasticizer used is 40 parts by mass or less, the solvent component of the sheet waterproof layer 2 will be difficult to transfer to the coating waterproof layer 4. The amount of plasticizer used is, for example, 5 parts by mass or more. When the amount of plasticizer used is 5 parts by mass or more, sufficient plasticity can be imparted to the waterproof coating layer 4.

As shown in FIG. 6, the coating film waterproof layer 4 is formed by, for example, applying a liquid waterproofing material to the surface of the primer layer 3 (see FIG. 5), overlaying the fiber base material 41 on top of the liquid waterproof material, and then applying the liquid waterproof material to the surface of the primer layer 3 (see FIG. 5). It can be formed by applying a liquid waterproofing material to the surface and curing the liquid waterproofing material. The fibrous base material 41 is impregnated with the liquid waterproofing material. The surface of the fiber base material 41 may be coated with the liquid waterproofing material.
The liquid waterproofing material can be applied by hand, pressure-feeding hand-coating, pressure-feeding spraying, or the like. In manual application, an operator applies the liquid waterproofing material to the surface of the primer layer 3 using, for example, a trowel, a roller, a rake, or the like. In the pressure-feeding manual coating, liquid waterproofing material discharged from a coating device equipped with a pressure-feeding pump is spread over the surface of the primer layer 3 using a trowel or the like. In the pressure spraying, a liquid waterproofing material is sent from a coating device equipped with a pressure pump and sprayed from a spray nozzle onto the surface of the primer layer 3.

(Third step: Formation of top coat layer)
Next, as shown in FIG. 8, a top coat layer 5 is formed on the surface of the waterproof coating layer 4. For the top coat layer 5, acrylic resin (for example, acrylic urethane resin, acrylic silicone resin, etc.), fluororesin, silicone resin, etc. can be used. The top coat layer 5 is formed for the purpose of protecting the waterproof coating layer 4 by blocking ultraviolet rays, etc., and improving the appearance of the waterproof structure 1. The top coat layer 5 is formed by applying a raw material liquid onto the surface of the waterproof coating layer 4 by hand coating, pressure-feeding hand-coating, pressure-feeding spraying, etc., and curing it. Thereby, the waterproof structure 1 shown in FIGS. 1 and 8 is obtained.

According to the repair method of the first embodiment, the waterproof coating layer 4 includes a fiber base material 41 and a resin composition 42 with which the fiber base material 41 is impregnated. Therefore, the paint film waterproof layer 4 does not become locally thin even at the step portion 17 of the sheet waterproof layer 2, and can ensure sufficient thickness. Therefore, a decrease in the waterproof property of the waterproof coating layer 4 can be prevented. Therefore, the waterproof structure 1 having high waterproof performance can be formed.

The overlapping part 16 of the adjacent sand-covered asphalt sheets 11, 11 has a structure that is advantageous for improving the waterproof performance of the sheet waterproof layer 2, but the stepped part 17 formed by the overlapping part 16 is not formed on the overlapping part 16. This can affect the thickness of the layer being applied. In contrast, according to the repair method of the first embodiment, the waterproof coating layer 4 using the fiber base material 41 avoids the negative effects caused by the overlapping portions 16 and reduces the waterproof performance of the waterproof coating layer 4. can be prevented.

According to the repair method of the first embodiment, the primer layer 3 is formed between the sheet waterproof layer 2 and the paint film waterproof layer 4. Since the primer layer 3 prevents the solvent components of the sheet waterproof layer 2 from migrating to the paint film waterproof layer 4, the solvent components of the sheet waterproof layer 2 become difficult to migrate to the paint film waterproof layer 4. Therefore, a decrease in the waterproof performance of the waterproof coating layer 4 can be prevented.

According to the repair method of the first embodiment, since the waterproof coating layer 4 has the fiber base material 41, deformation such as thinning is unlikely to occur. Therefore, formation of depressions due to raindrops hitting the surface of the top coat layer 5 or the waterproof coating layer 4 can be suppressed. Therefore, construction is easier even when the weather is unstable, which is advantageous in shortening the construction period.

According to the repair method of the first embodiment, since there is no need to form an insulating layer (polymer cement mortar layer, etc.), the process can be simplified, and the construction cost and construction period can be shortened.

[Second embodiment]
FIG. 9 is a schematic diagram showing a second example of the waterproof structure before renovation. FIG. 10 is a schematic diagram showing a waterproof structure 51 repaired by the repair method of the second embodiment. Hereinafter, components common to the repair method of the first embodiment will be designated by the same reference numerals and a description thereof will be omitted.

As shown in FIG. 9, the target of the repair method according to the second embodiment is an existing waterproof structure 52A provided on the base 101. The waterproof structure 52A has a sheet waterproof layer 52. The sheet waterproof layer 52 is constructed by laying a plurality of sand-covered asphalt sheets 11 side by side. Adjacent sanded asphalt sheets 11, 11 have side edges 11b, 11b separated from each other. Therefore, a stepped portion may be formed on the side edge 11b of the sand-covered asphalt sheet 11, and a recess may be formed between the side edges 11b.

As shown in FIG. 10, a primer layer 53 is formed by applying a primer liquid to the surface of the sheet waterproof layer 52 and curing it. A portion of the primer liquid is filled into the gap between the side edges 11b, 11b of the sand-covered asphalt sheets 11, 11. Next, the waterproof coating layer 4 is formed on the primer layer 53. A top coat layer 5 is formed on the waterproof coating layer 4. The waterproof structure 51 repaired by the repair method according to the second embodiment includes a sheet waterproof layer 52, a primer layer 53, a paint film waterproof layer 4, and a top coat layer 5.

According to the repair method of the second embodiment, the waterproof paint layer 4 includes the fiber base material 41 and the resin composition 42 impregnated into the fiber base material 41. The thickness does not change easily even at the location between the matching sand-coated asphalt sheets 11, 11. Therefore, a decrease in the waterproof property of the waterproof coating layer 4 can be prevented. Therefore, the waterproof structure 51 having high waterproof performance can be formed.

Although the waterproof construction method according to the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be freely modified within the scope of the present invention. For example, side edges of adjacent sand-covered asphalt sheets may be butted against each other. The resin composition constituting the waterproof coating layer may contain resins other than polyurethane resins. In the repair method of the embodiment, a primer layer is formed on the sheet waterproof layer. It is preferable to form a primer layer because it has the effect of increasing the adhesion of the waterproof coating layer to the sheet waterproofing layer, but even in the absence of the primer layer, the effect of preventing a decrease in the waterproof properties of the waterproof coating layer can be obtained. In the repair method of the embodiment, a stepped portion formed by an overlapping portion that is a convex portion is exemplified as an uneven portion of the sheet waterproof layer, but the uneven portion is a recess formed between the side edges of an asphalt sheet. You can.

1, 51 Waterproof structure 2, 52 Sheet waterproof layer 2A, 52A Waterproof structure 3 Primer layer 4 Paint film waterproof layer 11 Asphalt sheet with sand (asphalt sheet)
16 Overlapping portion 17 Step portion 41 Fiber base material 42 Resin composition

Claims (1)

A method for producing a renovated waterproof structure, the production method comprising:
a preparatory step of preparing a waterproof structure that has a sheet waterproof layer made of asphalt sheets and that requires renovation;
a repair step of repairing the waterproof structure that requires repair;
The refurbishment step includes:
forming a primer layer by applying a primer liquid to the surface of the sheet waterproof layer;
forming a waterproof coating layer on the primer layer,
The waterproof coating layer has a fiber base material and a resin composition impregnated into the fiber base material in the step of forming the waterproof coating layer,
The resin composition includes a polyurethane resin,
The sheet waterproof layer is formed by laying a plurality of the asphalt sheets side by side,
The fiber base material is a chopped strand mat made of long fibers that are glass fibers,
In the step of forming the waterproof coating layer, the first liquid waterproofing material containing the polyurethane resin is applied to the surface of the primer layer, the fiber base material is layered thereon, and the Forming the coating waterproof layer by applying a second liquid waterproofing material containing a polyurethane resin and curing the first liquid waterproofing material and the second liquid waterproofing material,
Using a one-component polyurethane resin as the polyurethane resin ,
Method of producing waterproof structures.

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