JPH0621512B2 - Non-breathing finish layer underlayer for blistering prevention - Google Patents

Description

TECHNICAL FIELD The present invention relates to a breathable underlayer which prevents the non-breathable finish layer from blistering.

Here, the term "non-breathable finishing layer" is used throughout the present specification, "including a waterproof layer, a wall surface finishing layer, and a floor surface finishing layer, has no breathability in the field of construction / construction industry, or It means "any finishing layer with poor breathability".

(Conventional Technology) In a concrete-structured building, moisture contained in concrete gradually diverges over many years, so it is desirable that the finishing material that covers the surface be as permeable as possible.

On the other hand, in reality, most of the materials such as waterproof layer, wall surface finishing material and floor finishing material that are often used in the finishing method of concrete structure construction are airtight structural materials mainly composed of synthetic polymer materials. Although the membrane blocks water and air from the outside, it interferes with the absorbing action of the concrete to be adhered, and prevents the moisture contained in the concrete from escaping to create a sealed state. This water vaporizes during the warm season, especially during sunshine, and pushes up the adhesion surface between the non-breathable finishing layer and the concrete, and brings about various adverse effects typified by blistering of the non-breathing finishing layer.

In addition, since concrete containing water has a relatively high thermal conductivity, it is easy to cool it, and it is a big problem for residents of concrete-structured houses to cause dew condensation due to the temperature difference between indoors in the cold season. I'm running.

On the other hand, as the porous concrete, the mortar and the molded body thereof, there are conventionally, for example, AE concrete and mortar, in which an AE material (air-entraining agent) is mixed into the concrete and the mortar to contain countless fine bubbles,
Resistance to workability, freezing, and thawing of concrete and mortar, as well as durability are being improved. ALC made by reacting and foaming aluminum powder and cement with autoclave curing is widely used as a porous lightweight concrete molding. The structure of these porous bodies is substantially independent of pores, and it is desired to have the objective effect of minimizing ventilation between pores.
The reason is that invasion of water must be prevented in order to achieve low resistance to freezing and thawing, and the property of blocking the flow of air is required to maintain heat insulation.

Therefore, porous concrete made by the above purpose, if the mortar has air permeability, moisture, hot and cold air will be present or pass, and it easily freezes.
It is in a state of poor heat insulation and defeats the purpose.

Porous concrete made from the above AE agent,
As a result of the experiment, the structure of the pores of the mortar is almost independent pores, and it is difficult for water and air to pass therethrough, so that it has a performance that is convenient for resistance to freezing and thawing to some extent.

(Problems to be solved by the invention) However, when the building is covered with a water-tight finish material such as a waterproof layer, a wall surface finish layer, or a floor finish layer using these porous concrete and mortar as a base, the base is not vented. Even if water is present below the layer film such as the waterproof layer, it cannot diffuse by aeration, and the water vaporizes to cause a blistering phenomenon in the finishing layer film.

The present invention solves the above-mentioned problems such as swelling of a concrete structure on which a non-breathable finishing layer has been applied, and a novel breathable underlayer that facilitates and completes the construction and maintenance of the finishing material coating film and the like. The purpose is to provide.

(Means for Solving the Problems) According to the present invention, a mortar-like underlayer provided between a concrete structure and an air-impermeable finishing layer, which comprises a hydraulic cement and an antifoaming material for binding an aggregate. There is provided a base layer for preventing blistering of the non-breathable finishing layer, which comprises a continuous porous ventilation passage in a joint portion composed of a polymer dispersion which is not added.

That is, the underlayer of the present invention, when kneading a mortar-like flowable material obtained by adding an appropriate amount of water to a composition containing a polymer dispersion, a hydraulic cement and an aggregate, is usually easy to foam by stirring. An antifoaming agent is added to the above polymer dispersion to prevent the mortar from lowering its density, whereas the foaming property is positively utilized without defoaming and the mortar layer after solidification is breathable. It is a porous body.
The person who imparts air permeability is continuous pores, and the main purpose of the present invention is to apply a polymer dispersion containing no antifoaming agent as a means for forming these pores.

Any polymer dispersion can be used as long as it is miscible with cement, but practically it is JIS A
It is necessary that the cement-mixing rubber latex and the cement-mixing resin emulsion specified in 6203-3 do not contain at least an antifoaming agent. Representative examples of the former include SBR (styrene butadiene rubber) which is a synthetic rubber latex, rubber asphalt rubber latex, and representatives of the latter include EVA (ethylene = vinyl acetate copolymer resin emulsion), PAE (polyacrylate ester emulsion), PVDC. (Vinylidene chloride resin emulsion).

As the hydraulic cement, any hydraulic cement generally used for construction and construction can be used in the present invention. For example, common Portland cement, early-strength cement, and alumina cement can be mentioned. Of these, ordinary Portland cement is the most practical one, and early-strength cement is used when the construction period is urgent.

As the aggregate, sand such as river sand and silica sand which are generally used for construction and construction can be used in the present invention.
In the case of river sand, the grain size is 1/2 of the thickness of the underlying layer formed.
The following is desirable.

The base layer of the present invention is an amount suitable for coating and curing on a composition containing a polymer dispersion containing no antifoaming agent, hydraulic cement and aggregate, that is, a flowable material of 13%.
A flowable material for coating is prepared by adding water in an amount that provides a flow value in the range of 0 to 200 mm and thoroughly kneading. This material is applied and cured on a concrete structure in a thickness sufficient to form a continuous air passage and to achieve the object of the invention, i.e. preferably 2 mm or more and particularly preferably 3-5 mm. At the very least, an underlayer is formed. A non-breathable finish layer is provided on the formed underlayer by a conventional method.

(Operation) When the foundation layer of the present invention is provided between the concrete structure and the non-breathable finish layer, the water content of the concrete is guided to the continuous ventilation passages in the foundation layer and diffused to the outside. . Further, moisture, volatile substances and the like exuding from the finishing material provided on the surface are simultaneously removed through the continuous ventilation passage. Therefore, the drying of the concrete structure is promoted.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.
The present invention is not limited to this.

In the following Examples, Comparative Examples, and Application Examples, "part" represents "part by weight".

Examples 1-38, Comparative Examples 1-8 In the case of Examples 1-38 and Comparative Examples 1-5, the polymer dispersion (Example) which does not add the defoaming agent which has the compounding ratio shown in the following table, and Water is added to the added polymer dispersion (comparative example), hydraulic cement, and silica sand or river sand that is an aggregate so that the flow value becomes 170 ± 5 mm.
Kneading was carried out for a minute to prepare a fluid material for coating.

In the case of Comparative Examples 6 to 7, the flow value is 170 ± 5 mm in the AE agent in place of the hydraulic cement, silica as the aggregate, and the polymer dispersion in which the defoaming agent is not added or the polymer dispersion in which the antifoaming agent is added. Thus, water was added and the mixture was kneaded with a general-purpose flat mixer or hand mixer for 1 to 3 minutes to prepare a fluid material for coating.

These materials were applied to a pavement concrete plate (30 x 30 x 5 cm) with a through hole of φ5 mm in the center of the surface and a thickness of 5
After 48 hours, it is coated with elastic polyurethane resin as a floor coating, self-leveling epoxy resin as a coating floor material, elastic polyurethane resin waterproof spray finish as a coating wall material, elastic acrylic resin mastic finish, coating film. As a waterproof material, a polyurethane coating waterproof material (JIS A 6
021 type 1), a rubber asphalt coating film waterproof material, and a vulcanized rubber-based sheet waterproof material as a sheet waterproof material (all of which are adhesion methods) are applied to the cured surface of the above-mentioned composition to be a breathable underlayer according to the order of steps. Or stuck. Separately, one of the through-hole openings of the concrete plate with a similar through-hole is put on a thin putty with a low modulus acrylic sealing material to prevent the inflow of coating material etc., and then directly to the surface. A coated floor material, a coated wall material, a coating waterproof material, and a sheet waterproof material were applied or adhered in the order of steps to prepare a comparative sample. For each of these specimens, the attachment shown in Fig. 1 and Fig. 2 was attached to the opening of the through hole on the back surface of the concrete plate, and nitrogen gas was pressure-inserted from a cylinder equipped with a pressure gauge at a pressure of 0.2 kg / cm ² , The aeration state and change state of the non-air permeable various finishing material layer membranes were observed. The results are shown in the composition of the material for forming the underlayer and the performance table of the underlayer below.

In Comparative Example 8, the underlayer has the same composition as that of the mortar of the ordinary finishing material, and the finishing material is applied directly to the mortar of the ordinary ordinary.

As shown in the above table, when the polymer dispersion without addition of the defoaming agent was used, all showed air permeability, whereas when the polymer dispersion with addition of the defoaming agent was used, all of them were vented. Moreover, when the AE agent was used in place of the polymer dispersion, the ventilation was weak and the practically practical ventilation was not obtained. In the cases of Examples 1 to 38 having a breathable underlayer, the internal atmospheric pressure was diffused and all abnormalities were found, whereas in the cases of Comparative Examples 1 to 8 having no breathable underlayer, the scale was large. There were big and small, but all blisters occurred.

In addition, the specific gravity of each of the specimens with the antifoaming agent was the largest, whereas the specimens without the antifoaming agent and the specimens with the AE agent both contained fine pores due to foaming. Therefore, it had a relatively light specific gravity, which was roughly similar.

Application Example 1 The outer wall of an 8-story mansion with an RC structure, which has been in construction for more than 20 years, is washed with high pressure water to remove deteriorated materials, and the underlayer forming material having the composition shown in Example 2 is applied to a thickness of about 4 mm. After curing and curing for one day, an acrylic resin outer wall mastic finish material [Fujikura Kasei Co., Ltd., trade name Plus Wall C] was applied. It was noticed that the concrete swelling contained a large amount of water due to small cracks, and the occurrence of blistering was noticed, but the breathable underlayer worked effectively, and blistering did not occur even after 3 months.

Application example 2 In the case of rooftop waterproofing work in which the moisture content of the roof slab is 10% or more in a newly built RC building, and blistering of the waterproof layer is a concern,
The material for forming an underlayer having the composition shown in Example 7 was applied to a thickness of 5 mm to form a breathable underlayer, and after curing and curing for 3 days, a rubber asphalt coating waterproofing [manufactured by Nippon Latex Processing Co., Ltd.,
Product name Hullcoat GP method] was applied. When a similar waterproofing is provided by providing a part where the underlayer is not applied,
While blistering occurred within a few days, it was confirmed that the place with the breathable underlayer had no abnormalities even after 3 months, and that it has a blistering prevention function.

Application Example 3 Conventionally, a painted floor finish has been performed on a concrete ground floor surface continuing to a single floor, but the condition that the moisture of the concrete constantly causes the coating film to swell. Upon repair work,
The swelled existing coating floor material was removed, the breathable underlayer according to the present invention was applied, and the urethane coating floor material and the epoxy coating floor material were divided and applied on it. Therefore, as a polymer dispersion, SBR dispersion (one coat mix manufactured by Chugai Shoko Co., Ltd., without defoaming agent)
Was used to prepare a breathable underlayer by removing the existing finishing material and then applying it to a cleaned concrete floor surface material to a thickness of about 4 mm. The application method is plastering with square iron.

After curing and curing for 3 days, the coating area is divided into two parts, one of which is coated with an epoxy resin floor [Art Floor EP manufactured by Chugai Shoko Co., Ltd.] to a thickness of 1.0 mm, and the other is coated with a polyurethane resin floor [ Art floor N made by Chugai Shoko Co., Ltd.
S] was applied to a thickness of 2 mm. As a result of observing the state of the coating film for 3 months, it was confirmed that there was no blistering that had occurred around one week after the conventional construction this time, and that the function of the breathable underlayer worked effectively.

(Effect of the invention) As described above, by providing the breathable underlayer of the present invention between the concrete structure and the non-breathing finish layer, the non-breathing finish layer constructed on the concrete structure can be formed. It was possible to solve problems such as blistering and to complete and maintain the finishing layer easily and economically. Further, since the underlayer of the present invention contains a large amount of air, it is lightweight and has a heat insulating effect, and it is possible to prevent dew condensation.

[Brief description of drawings]

FIG. 1 is a main part of a test apparatus showing the structure and effect of the breathable underlayer of the present invention, and FIG. 2 is a comparative example in the case where the breathable underlayer is not provided. 1 ... Vessel (pavement board), 2 ... Through hole, 3 ... Breathable underlayer, 4 ... Finishing layer (non-permeable layer), 5 ... Attachment, 6 ... Hose, 7 ... Nitrogen Cylinder, 8 ... Pressure gauge, 9 ... Pressurized nitrogen, 10 ... Exhaust gas, 11 ... Pressure-blown finish layer.

Claims (1)

[Claims] 1. A mortar-like underlayer provided between a concrete structure and a non-breathing finish layer, wherein the joint comprises a hydraulic cement for binding an aggregate and a polymer dispersion containing no defoaming agent. A base layer for preventing blistering of the non-breathable finishing layer, which constitutes a continuous porous ventilation path.