JP7049377B2 - How to reinforce exterior wall tiles - Google Patents

Description

The present invention relates to a method for reinforcing exterior wall tiles.

In recent years, with the aging of concrete buildings, the demand for repairing concrete buildings has increased. Secular variation of concrete buildings causes deterioration of the concrete itself, protects the concrete itself, and tiles are attached to the outer walls to adjust the appearance of the building.

The outer wall tiles are usually made of fired ceramics, with or without a decorative coating, but the mortar is applied to the concrete housing, and the outer wall tiles are attached before the mortar hardens, or on the mortar. An adhesive for attaching tiles is applied to the mortar, and the outer wall tile is attached to the mortar layer via the adhesive, or the tile is attached to the concrete housing.

By the way, as the concrete building deteriorates, the adhesive strength of the outer wall tile attached to the concrete housing decreases, and the outer wall tile may peel off from the concrete housing. Concrete buildings generally have high altitudes, and stripping of exterior wall tiles can cause unexpected problems. In addition, the owner of the building may be held responsible for the peeling and deterioration of the outer wall tiles, and when repairing a concrete building, it may be required to reinforce the outer wall tiles. For example, from April 1, 2008, the periodic reporting system was reviewed based on Article 12 of the Building Standards Act, and in the past, it was good to consult the reachable range and other visual surveys, but after the revision, it will be completed. Ten years after the exterior wall repair, etc., it is required to conduct a full-scale consultation at the time of the first investigation (Reference: Building Disaster Prevention Countermeasures Office, Building Guidance Division, Housing Bureau, Ministry of Land, Infrastructure, Transport and Tourism, http: // www. mlit.go.jp/jutakukentiku/build/teikihoukoku/punflet.pdf).

Conventionally, in repairing an outer wall tile, an anchor pin is driven into the joint portion of the outer wall tile, and a polymer adhesive, a silicone-based sealing material, an acrylic silicone-based coating agent, or the like is coated in multiple layers so as to hide the anchor pin. As a result, a polymer coating is formed on the anchor pins, and the anchor pins and the coating prevent the outer wall tiles from peeling off.

Although it is possible to reinforce the outer wall tile by the conventional outer wall tile repair method, the conventional method does not improve the adhesiveness itself to the concrete housing or the mortar layer, and the concrete housing needs to be perforated. In addition, since a silicone-based organic material is used, there is also a problem that the construction durability is inferior, such as deterioration of ultraviolet rays.

In addition to this, a repair method for outer wall tiles is known. For example, in Japanese Patent No. 4435792 (Patent Document 1), an inorganic alkaline aqueous solution containing potassium silicate and modified active water around a defective tile is known. A repair method is described in which an inorganic alkaline aqueous solution is infiltrated into the mortar by spraying.

Potassium silicate used in the method described in Patent Document 1 has a problem that it has high reactivity with Ca element contained as a component of concrete or mortar and has poor permeability to a concrete housing, mortar, or tile itself. There is a point. Patent Document 1 solves such a problem by using activated water modified with sodium or other inorganic ions, but the quality of the activated water is not stable and is further contained in the inorganic alkaline aqueous solution. In addition, the ratio of the silicic acid component as the main component for reinforcement has to be low in the composition, and there is also a problem that sufficient strength cannot be given.

Further, a reinforcing method for reinforcing by adhering sodium silicate to the outer wall tile is also known (Non-Patent Document 1). In the repair method described in Non-Patent Document 1, an aqueous solution of sodium silicate is infiltrated into the tile joint to cause a pozzolan reaction between Ca, which is a component of concrete / mortar, and sodium silicate to form a silicate gel. It is to reinforce by doing. However, sodium silicate itself has a relatively low reactivity with Ca, and in the repair method of Non-Patent Document 1, in order to increase the Ca concentration, it is necessary to treat it with a conditioner containing an aqueous solution of calcium carbonate.

An aqueous solution of calcium carbonate can increase the concentration of Ca element and improve the efficiency of the pozolan reaction, but conversely, calcium hydroxide in concrete reacts with carbonate ions to form calcium carbonate, which forms a concrete housing. On the other hand, there is a risk of causing the problem of neutralization.

Japanese Patent No. 4435792

http: //www.kutai.co.jp/pdf/RC_tile/guardex_tile.pdf (downloaded on January 26, 2020)

The present invention has been made in view of the above-mentioned problems of the prior art, and provides a method for reinforcing the adhesiveness of outer wall tiles with stable quality without causing the problem of neutralization of concrete. The purpose is.

That is, in the exemplary embodiment
It is a reinforcement method for exterior wall tiles.
A permeable inorganic adhesive containing at least sodium silicate and potassium silicate is interposed between the outer wall tile and the base material to which the outer wall tile is attached, and between the base material, the mortar, and the outer wall tile. A reinforcing method is used to improve the adhesiveness of the tiles so that the adhesive strength is 2.4 N / mm ² or more and the cohesive failure at the interface between the base material and the mortar is 50% or more of the fracture state. Provided.

Further, in an exemplary embodiment, there is provided a reinforcing method including a step of infiltrating the inorganic adhesive into a mortar to which the outer wall tile is attached.

In yet another exemplary embodiment, there is provided a reinforcing method comprising a step of applying and curing the inorganic adhesive to the outer wall tile attached to the concrete housing by spray coating, brush coating, or roll coating. Be done

According to the present invention, it is possible to provide an efficient reinforcing method for outer wall tiles.

FIG. 1 is a schematic view illustrating a method of constructing an outer wall tile of the present embodiment. FIG. 2 is a schematic view illustrating the adhesive action of the inorganic adhesive 150 in the present embodiment. FIG. 3 is a diagram showing an exemplary third embodiment of the reinforcement method. FIG. 4 is a diagram showing the results of evaluating the adhesive strength and the fracture state of the specimen.

Hereinafter, the present invention will be described with reference to exemplary embodiments, but the present invention is not limited to the embodiments. In concrete buildings, exterior wall tiles are attached to the concrete surface to cover the concrete surface with tiles to improve the appearance and durability. FIG. 1 is a schematic view illustrating a method of constructing an outer wall tile of the present embodiment. FIG. 1A is a first exemplary embodiment of attaching tiles to a mortar, and FIG. 1B is a second exemplary embodiment of attaching tiles to the surface of a mortar via a tile adhesive. An embodiment is shown.

As shown in FIG. 1A, in tile construction, the surface of the hardened concrete housing 100 is coated with mortar 110 with a trowel or the like. The mortar 100 may be a composition containing cement and sand, or may be a polymer mortar in which a polymer component is added to a conventional mortar composition. When the mortar 110 has an appropriate hardness, the tile 120 is attached onto the mortar 110. After that, the attached tile is brought into close contact with the mortar 110 using a tapping rod, a plate, or the like, and is attached to the concrete housing 100 as the mortar 110 is cured.

Further, in the construction shown in FIG. 1 (b), the tile adhesive 140 is further adhered on the mortar 110, and the tile 120 is attached via the tile adhesive.

In the embodiment shown in FIG. 1, the inorganic adhesive 150 is attached to the mortar 110 or the tile adhesive 140 by spraying, brushing, a roller or other methods, and the tile 120 is adhered to the tile 120 while being wet with the inorganic adhesive. The tile 120 is attached by letting and curing.

An exemplary inorganic adhesive used in this embodiment is a mixed aqueous solution of an alkaline silicate. The aqueous solution of alkaline silicate used as an inorganic adhesive in the exemplary embodiment is highly fluid and does not by itself have the function of forming a film on the surface of an inorganic material such as concrete. However, as a result of diligent studies by the present inventors,
(1) After moistening the surface of the mortar with the inorganic adhesive of the present embodiment, the tiles are attached and the mortar is made effective to improve the adhesiveness between the mortar and the tiles.
(2) By applying to the joint after tiling, the joint itself functions as a strong anchor.
The two actions described above have been confirmed, leading to the present invention.

The inorganic adhesive 150 used in the present embodiment contains sodium silicate and potassium silicate, permeates the mortar 110, and reacts with the Ca ions contained in the mortar 110 by pozzolan to form a silicate polymer (gel). The inorganic adhesive 150 also permeates the tile 120 and forms a silicate gel by a pozzolan reaction with Ca ions existing in the tile 120 across the mortar 110-tile 120. The silicate gel formed in this embodiment functions as a strong anchor between the tile 120 and the mortar 110, and can fix the tile 120 to the mortar 110.

As the inorganic adhesive used in the present embodiment, a mixture of two or more kinds of alkaline silicates such as sodium silicate, potassium silicate, and lithium silicate can be used. Examples of such an inorganic adhesive 150 include sodium silicate, potassium silicate, sodium silicate, lithium silicate, potassium silicate and lithium silicate, or sodium silicate, potassium silicate and silicic acid. An aqueous solution of a mixture such as lithium can be used.

When the inorganic adhesive of the present embodiment is used as an aqueous solution, the aqueous solution can be used in a specific density range of 1.1 to 1.2 and a pH in the range of 11 to 12. Further, the alkaline silicate is preferably a silicate colloid having a particle size of about 1 to 10 nm. In the exemplary embodiment, the viscosity of the inorganic adhesive 150 is not particularly limited, but the viscosity is in the range of 1 to 30 mPa · s, more preferably the wettability to the surface, the permeability to the inside, and the ductility of the inorganic material. Considering the ductility, it can be 6 to 8 mPa · s.

In the present embodiment, the mixing ratio when mixing at least two of sodium silicate, potassium silicate, and lithium silicate may be in the range of 1: 9 to 9: 1 in terms of the molar ratio of the alkali metal element. It is possible, and more preferably, the molar ratio of the alkali metal element can be in the range of 3: 7 to 7: 3. When three kinds of alkaline silicates are blended, sodium element is 5 to 90 mol%, potassium element is 5 to 90 mol%, and lithium element is 5 to 90 with respect to all alkaline elements in the inorganic adhesive composition. The abundance ratio can be 20%, and it is preferable to mix the sodium element in the range of 15 to 70 mol%, the potassium element in the range of 15 to 70 mol%, and the lithium element in the range of 15 to 70 mol%.

As an inorganic adhesive having the above composition, which is more preferable and can be obtained inexpensively as a commercial product, Everprolong (registered trademark), which is a silicate-based concrete modifier containing approximately equimolar amounts of sodium element and potassium element, RC guard (registered trademark), RC gardenx (registered trademark) and the like can be exemplified.

The solid content concentration of the inorganic adhesive of the present embodiment can be 10 to 40% in the exemplary embodiment, 20 to 30% in the preferred embodiment, and the coating of the inorganic adhesive 150 itself. Is adjusted to the physical properties that penetrate the concrete to the extent that it cannot be confirmed.

In another embodiment, the inorganic adhesive is supplied and permeated into the mortar / concrete housing from above the tiles already attached to the concrete housing. It has been found that such a construction method also improves the adhesiveness between the mortar and the tile.

The inorganic adhesive 150 of the present embodiment penetrates into the concrete 100, the mortar 110, or the tile 120 through water, reacts with Ca contained in the inorganic material, and reacts with pozzolan between adjacent inorganic materials. To produce a silicate gel. Although the present embodiment is not related to a specific theory or the like, in the present embodiment, the inorganic adhesive that has penetrated between the inorganic materials penetrates into the pores and voids of the inorganic material to be adhered and is inorganic at the interface. It is considered that strong adhesion is formed by penetrating into the material and gelling across the interface.

Furthermore, the coexistence of at least two types of sodium ion, potassium ion and lithium ion in the aqueous solution exerts a mixed alkali effect in the silicic acid aqueous solution, and the reaction rate of the calcium ion in the concrete and the alkali metal ion or It is considered that the degree of motility in the solution of sodium ion and potassium ion is lowered, the alkali metal ion is delivered deeper, a thick adhesive layer is formed with the interface as a boundary, and the adhesiveness is improved.

FIG. 2 is a schematic view illustrating the adhesive action of the inorganic adhesive 150 in the present embodiment. Fine pores 160 are formed on the surface of the mortar 110, and the inorganic adhesive 150 permeates the pores 160 to form a silicate gel in the pores 160 via the pozzolan reaction. On the other hand, the inorganic adhesive 150 also permeates the pores 170 of the tile 120, elutes the Ca component contained in the tile 120, and permeates the silicate gel into the tile 120 by the pozzolan reaction.

As a result, the inorganic adhesive 150 forms a silicate gel straddling between the mortar 110 and the tile 120, and the silicate gel functions as an anchor to firmly and directly attach the tile 120 to the mortar 110 or the tile adhesive. Adhere to the mortar 110 across 140.

FIG. 3 shows a third exemplary embodiment of the reinforcement method. In the third embodiment, the adhesiveness of the tile 340 attached to the existing concrete 300 via the mortar 320 or the tile adhesive is improved.

FIG. 3 (a) is a schematic view showing a state before the construction of the inorganic adhesive 310, and FIG. 3 (b) is a schematic view showing a state after the construction of the inorganic adhesive 310. In the presence of the tile 340, the inorganic adhesive 310 is applied by a method such as brush coating, spray coating, or roll coating as shown in FIG. 3b). The surface of the tile 340 itself may be treated with enamel, coating, or the like, but there are often seams between the tiles 340.

The inorganic adhesive 310 penetrates from the seam into the mortar 320, the tile 340, or the joint surface between the mortar 320 and the tile 340 by capillarity. When left in this state, a silicate gel straddling between the inorganic adhesive 310, the mortar 320 and the tile 340 is formed on at least both sides and the interface with the mortar 110, and a strong adhesive layer is formed at the mutual interface. .. As a result, the adhesive strength of the tile 340 attached on the concrete housing can be improved, and reinforcement work becomes possible. The inorganic adhesive 310 not only improves the bondability between the inorganic materials, but also fills the fine cracks of the existing concrete 300 by forming a silicate gel inside the existing concrete 300, so that it also leaks water. Can be improved.

As a result, in the present embodiment, not only the adhesiveness between the inorganic materials is improved, but also the adhesiveness of the seam of the existing concrete 300 is improved, the strength is improved, and the water leakage is improved. To.

Hereinafter, the present invention will be described with reference to specific examples. The examples described later are described for the purpose of facilitating the understanding of the present invention, and do not limit the present invention.

<Adjustment of test piece>
The test body was prepared as follows. A 300 mm × 300 mm × 60 mm concrete slab was prepared using Portland cement, and a 45 mm × 95 mm tile was attached to the concrete slab on the surface by the following four procedures to prepare three samples. As the inorganic adhesive, Everprolong (a mixture of sodium silicate and potassium silicate) (registered trademark) manufactured by Nippon Prolong Co., Ltd. was used. Hereinafter, Everprolong (registered trademark) will be referred to as EP material. )

Specimen 1 (Example): After applying mortar, EP material is applied and permeated as an adhesive for tiles, and tiles are attached (specimen notation: EP + tiles).
Specimen 2 (Example): After applying mortar to a concrete flat plate, an EP material is applied from above the tile to a tile attached using an adhesive for tiles (specimen notation: joint EP).
Specimen 3 (Comparative example): A concrete flat plate coated with polymer mortar and then tiled (specimen notation: tile)
As the polymer mortar, a mortar mixed with a specified amount of NF Highflex HF-1000 manufactured by Nihon Kasei Co., Ltd. was used. Among the above, Specimen 1 and Specimen 2 are examples, and Specimen 3 is a comparative example.

<Test method>
The adhesive strength of the mortar was evaluated using the adhesive strength of the tile. In the adhesive strength test, cuts were made on the four sides of the constructed tile to reach the concrete substrate, and a steel attachment (40 mm x 40 mm) was adhered to each of the specimens using an epoxy resin adhesive. A sample was prepared after being cured for more than an hour. Next, the tiles were pulled at a speed of 1 mm / min using a 20 kN constant speed universal tester, the maximum tensile load until the tiles peeled off was measured, and the cross section of the fractured part was visually observed.

The adhesive strength was calculated by the following equation to one digit after the decimal point.

FIG. 4 shows the results of evaluating the adhesive strength and the fracture state of the specimen. As shown in FIG. 4, in the examples (Sample 1, Specimen 2), the fracture state of the specimen is due to the cohesive fracture of the concrete flat plate and the coagulation fracture of the interface between the base and the mortar as compared with the comparative example. Was shown. From this, it was shown that the bonding interface between the mortar and the tile adhered stronger than the adhesive strength between the concrete flat plate and the mortar.

In addition, the adhesive strength (average) of each specimen is summarized in Table 1 below.

As described above, according to the present embodiment, it is possible to improve the adhesive strength at the interface of inorganic materials such as concrete, mortar, and tile, and it is possible to provide a high-strength concrete structure. Further, according to the present embodiment, by improving the bondability of the concrete interface, it is possible to improve the water leakage in the gap of the concrete structure exemplified for the joint portion.

Although the present invention has been described in detail with embodiments so far, the present invention is not limited to the above-described embodiments, and other embodiments, additions, changes, deletions, and the like can be conceived by those skilled in the art. It can be changed within the scope of the present invention, and is included in the scope of the present invention as long as the action / effect of the present invention is exhibited in any of the embodiments.

100: Concrete 110: Mortar 120: Tile 130: Tapping rod 140: Tile adhesive 150: Inorganic adhesive

Claims (3)

It is a reinforcement method for exterior wall tiles.
A permeable inorganic adhesive containing at least sodium silicate and potassium silicate is interposed between the outer wall tile and the base material to which the outer wall tile is attached, and between the base material, the mortar, and the outer wall tile. A reinforcing method for improving the adhesiveness of the above so that the adhesive strength is 2.4 N / mm ² or more and the cohesive failure at the interface between the base material and the mortar is 50% or more of the fracture state . The reinforcing method according to claim 1, further comprising a step of infiltrating the inorganic adhesive into a mortar to which the outer wall tile is attached. The reinforcing method according to claim 1, further comprising a step of attaching the inorganic adhesive to the outer wall tile attached to the concrete housing by spray coating, brush coating, or roll coating and curing the tile.

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