JPH10102720A - Construction method of external wall of building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability by installing a metal lath rustproof processed article by laying a waterproof sheet on a wooden bed member and finish- constructing after pressurizing a net material by applying light cement mortar on a metal lath. SOLUTION: A waterproof sheet 2 of an asphalt felt, etc., is laid on a bed 1 of a building, and a metal lath 3 is installed on this waterproof sheet 2 by a staple. Thereafter, light cement mortar 4 containing 20-60wt% of cement, 20-60wt% of an inorganic additive and 2-10wt% of an organic additive and unit volume mass at the time of milling up of which is 1.0-1.5 is applied on this metal lath 3. Thereafter, an external wall is molded by constructing it by a finishing material 6 after pressurizing and burying a net material 5 mass of which is 40-250g/m and tensile strength of which is more than 100kfg/mm<2> on a surface of this light cement mortar 4. Consequently, it is possible to prevent cracking and spalling of a mortar layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the improvement of the durability of a mortar layer, the prevention of cracks and spalling of a mortar layer, and the protection performance of a mortar when constructing an outer wall of a wooden building or a steel-framed building. The present invention relates to a method for constructing an outer wall of a building capable of realizing reinforcement at the same time.

[0002]

2. Description of the Related Art Conventionally, when an outer wall of a wooden building is constructed, a waterproof sheet is attached to a structural member as shown in FIGS. 1 and 2, and then a metal lath is attached. After that, mortar is applied, and after dry curing, finishing work is performed.

However, in the conventional outer wall structure, cracks occur with the passage of time, and the appearance is impaired. In addition, rust is generated on the metal lath due to water leakage from the cracks, etc., so that the durability of the metal lath is remarkably reduced, and an accident that the metal lath comes off sometimes occurs. Possible causes of the cracks include the structure of the building, problems with the groundwork (type of groundwork, type of metal lath, type of aggregate) and construction problems, which are often complicatedly intertwined with each other. . Therefore, the following four points can be considered as measures for preventing mortar from cracking. Reduction of mortar drying shrinkage Improvement of mortar tensile strength Disperses mortar tensile stress. Addition of rubber elasticity to mortar Concretely, various proposals such as addition of a shrinkage reducing agent, examination of mortar composition and strength, addition of various fibers, use of lightweight aggregate, or already prepared products have been proposed, but those that are still satisfactory Not found.

[0004]

Therefore, it is possible to prevent the occurrence of cracks in the mortar, to prevent all problems such as peeling of the mortar layer over a long period of time, and to use only a wooden building. In addition, a construction method that can be widely applied to buildings such as reinforced concrete, precast concrete, block, brick, and ALC, and has ensured the reliability of construction has been demanded.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been proposed in view of the above, and has been proposed for a wooden building such as a framing method, a framing method, a wooden assembly structure, and a wooden base member of a steel frame, asphalt felt or the like. After applying a waterproof sheet, fasten the metal lath anti-rust treated product with a stable, apply a lightweight cement mortar, press the net material on the surface, embed it, and finish the construction The present invention relates to a method for constructing an outer wall of a building.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The lightweight cement mortar used in the present invention is not particularly limited with respect to its raw materials and composition, but cement 20 to 60 wt%, inorganic admixture 20 to 60 wt%, organic admixture 2 to 2 10w
t%, and the unit volume mass at the time of kneading is 1.0 to 1.0%.
It is desirable to use a lightweight cement mortar of 1.5. In addition, as the inorganic admixture, one or more of dolomite plaster, fly ash, blast furnace slag powder, pearlite, silica sand, etc. can be used. As the organic admixture, EVA-calcium carbonate foam aggregate,
One or more of styrene foam aggregate, thickener, vinylon fiber and the like can be used. The lightweight cement mortar in the above range has a small drying shrinkage of the mortar when applied to the outer wall, has rubber elasticity, hardly generates cracks, can ensure durability, and has fireproof performance, fireproof structure and semi-fireproof structure. There is an advantage that can be secured.

The mesh material to be embedded on the surface of the lightweight cement mortar is not particularly limited in terms of its material and properties, but has a mass of 40 to 250 g / m ² and a tensile strength of 100 kgf / mm ² or more. It is desirable to use netting. The mesh material in the above range does not crack when the outer wall is constructed, and is excellent in durability and aesthetics.

In the present invention, the mesh material embedded in the lightweight cement mortar reduces drying shrinkage of the lightweight cement mortar and reinforces the tensile strength, so that cracks can be suppressed. In addition, since the net material is provided over the entire outer wall, the tensile stress can be dispersed over the entire surface without partially concentrating the tensile stress. Furthermore, since rubber elasticity can be imparted to the lightweight cement mortar layer, even if this mesh material and the internal metal lath resonate and a great deal of stress such as an earthquake occurs, the fine finish layer on the surface becomes fine. It is only cracking, and does not cause large cracks such as cracks reaching inside.

[0009]

【Example】

[Performance Experiment] <1. Basic Experiment> 1.1 Preparation of Specimen (n = 3) The specimen was prepared by mixing and mixing a premixed lightweight cement mortar (Lasmol: manufactured by Fujikawa Building Materials Co., Ltd.)
Poured into a size of 00mm x 75mm x thickness 20mm,
After that, place each net material (fiber net) on the surface, hold it lightly with an iron, and keep it in a moist air curing room (temperature 20 ° C ± 2 ° C, humidity 8
(0% or more) for 48 hours. After that, the mold was removed
Humidity room (temperature 20 ℃ ± 2 ℃, humidity 65% for up to 4 days)
(10%) was used as a test body (Example). 1.2 Test Method As shown in FIG. 3, the test specimen was autographed (Shimadzu AG-
5000C), crosshead speed 0.5mm
A one-point bending load was applied at / min, and the maximum load, the load at the time of crack occurrence, and the energy value from the start of the test to the end of the test (up to 0.5% of full scale) were determined.
In addition, what did not have reinforcement, such as a glass fiber net, was similarly evaluated as a comparative example. 1.3 Test Results Table 1 shows the obtained maximum load, the load at the time of occurrence of cracking, and the energy value for the above Examples and Comparative Examples. FIG. 4 shows the chart.

[Table 1]

<2. Application Experiments> 2.1 Preparation of Test Specimen (n = 3) An MT sheet (made by Asahi DuPont) is placed on a plywood base having a length of 800 mm, a width of 150 mm and a thickness of 9 mm, and a W-lass (made by Nippon Steel Building Con) ) Is fixed with a stable 1010 (plus product), and a ready-mixed lightweight cement mortar (Rasmol: manufactured by Fujikawa Building Materials Co., Ltd.) is applied to a thickness of 16 mm, and an alkali-resistant glass fiber net (Nippon Electric Glass Co., Ltd.) is applied to the surface. Is placed in a moist air curing room (temperature 20 ° C. ± 2 ° C., humidity 80% or more) for 48 hours. Thereafter, the specimens cured in a constant temperature and humidity chamber (temperature 20 ° C. ± 2 ° C., humidity 65% ± 10%) for up to 14 days were used as test specimens (Examples). 2.2 Test Method As shown in FIG. 5, the test piece was a universal strength tester (Shimadzu UD).
-100A), crosshead speed 0.5mm
A one-point bending load was applied at a rate of / min, and the load and displacement at the time of crack occurrence were determined. In addition, what did not have reinforcement, such as a glass fiber net, was similarly evaluated as a comparative example. 2.3 Test Results Table 2 shows the load and displacement at the time of crack occurrence for the above Examples and Comparative Examples.

[Table 2]

<3. On-site construction experiment> 3.1 Test method A construction test was performed on a building (approximately 160 m ² ) of the framework method. First, "MT sheet" as a waterproof sheet on the plywood base
Made of Asahi Dupont, over which metal lath ("W Lass")
Nippon Steel Building Container) is fastened with Stable 1016 (Plus) using an air tucker, and a ready-mixed lightweight cement mortar (“Rasmol” manufactured by Fujikawa Building Materials Co., Ltd.) is applied to a thickness of 16 mm, and immediately on the surface thereof As a net material, an alkali-resistant glass fiber net TD5 × 5 (manufactured by Nippon Electric Glass Co., Ltd.) was applied, rubbed with a trowel and blended with the mortar. After that, a curing period of 2 weeks was taken, and finished with an inorganic finishing material. Thereby, the outer wall shown in FIG. 6 is obtained. In the figure, 1 is a base, 2 is a waterproof sheet, 3 is a metal lath, 4 is a lightweight cement mortar, 5 is a net material, and 6 is a finishing material. Similar materials were used as the lightweight cement mortar, using materials having various compositions shown in Table 3 (formulation examples 1 to 5), and using the materials having various characteristics shown in Table 4 as the mesh material. . In addition, a material without using the net material was similarly constructed as a comparative example.

[Table 3]

[Table 4] 3.2 Test Results Regarding the above Examples and Comparative Examples, the surface was observed one year after construction, and the state of occurrence of cracks and the like was examined. In the examples, no cracks occurred even after one year, and the appearance was maintained. In particular, Formulation Example 3 in which the inorganic admixture is in the range of 20 to 60% by weight as a lightweight cement mortar.
Those using the samples of Nos. 4 and 5 had no cracks and were excellent. On the other hand, in the comparative example using no net material, a large crack was generated on the construction surface.

Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and may be implemented in any manner unless the configuration described in the claims is changed. Can be.

[0013]

As described above, the method for constructing an outer wall of a building according to the present invention improves the durability of a mortar layer and improves cracking of a mortar layer when constructing an outer wall of a wooden building or a steel frame building. In addition, it is possible to prevent the mortar from peeling off and to enhance the protection performance of the mortar at the same time. That is, in the present invention, the net material embedded in the lightweight cement mortar,
Reduces the drying shrinkage of lightweight cement mortar and reinforces the tensile strength. Further, it is possible to disperse the tensile stress over the entire outer wall without partially concentrating the tensile stress, thereby suppressing cracking. it can. Furthermore, the mesh material can impart rubber elasticity to the lightweight cement mortar layer, so that even if a great stress such as an earthquake occurs due to resonance between the mesh material and the internal metal lath, the surface finishing material can be provided. The layer has only small cracks, and does not cause large cracks such as cracks reaching inside.

In particular, the composition of the lightweight cement mortar is such that the cement is 20 to 60 wt%, the inorganic admixture is 20 to 60 wt%.
%, The organic admixture is 2 to 10 wt%, and when the unit volume mass at the time of kneading is 1.0 to 1.5, the workability of the construction site is good, and the durability, fire prevention performance and the like are excellent. ing.

When a net material having a mass of 40 to 250 g / m ² and a tensile strength of 100 kgf / mm ² or more is used, no cracks are generated, and the durability and the appearance are excellent. ing.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a conventional method for constructing an outer wall.

FIG. 2 is a perspective view showing another example of a conventional method of constructing an outer wall.

FIG. 3 is a side view showing an installation position of a test body used for a basic experiment of the present invention.

FIG. 4 is a measurement chart showing an energy value when a one-point bending load is applied, in which (a) no fiber, (b) glass fiber net ¹⁾ , (c) glass fiber net ²⁾ , (d) vinylon This is a test body in which a fiber net, (e) an aramid fiber net, and (f) a carbon fiber net are embedded.

FIG. 5 is a side view showing an installation position of a test body used for an application experiment of the present invention.

FIG. 6 is a partially cutaway perspective view showing the structure of an outer wall obtained by the construction method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base 2 Waterproof sheet 3 Metal lath 4 Light weight cement mortar 5 Netting 6 Finishing material

Claims (3)

[Claims] Claims: 1. A waterproof sheet is laid on the foundation of a building, a metal lath is attached, a lightweight cement mortar is applied,
A method of constructing an outer wall of a building, characterized in that a net material is pressed against the surface and buried, followed by finishing. 2. The composition of the lightweight cement mortar is 20 to 60% by weight of cement, 20 to 60% by weight of an inorganic admixture,
The organic admixture is 2 to 10 wt%, and the unit volume mass at the time of kneading is 1.0 to 1.5.
Construction method of the outer wall of the building described in. 3. The net material has a mass of 40 to 250 g / m.
^{3. The} method according to claim 1, wherein the tensile strength is 100 kgf / mm ² or more.