JPH07172895A - Mortal composition for floor and method of construction using the same - Google Patents

Abstract

PURPOSE:To obtain a mortal composition for floor capable of easily being kneaded executed into 40-1mm thickness only at one process without complicated executing processes, freed from the generation of flat or crack caused by shrinkage or the like and being high in bending strength and the method of construction using the same. CONSTITUTION:This mortal composition for floor contains an aggregate 1 having a high bulk density and another aggregates 2 and 3 each having low bulk density and particle size than that of the aggregate 1 and if necessary, a high performance water reducing agent, a thickener, a shrinkage reducing agent, a powdery emulsifying resin and the like are added.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention allows easy kneading,
A mortar composition for floors, which can be applied to a thickness of about 40 to 1 mm in one step without complicated steps, is unlikely to cause floating or cracking due to shrinkage, etc., and has a high bending strength, and a method of using the same. It is about.

[0002]

2. Description of the Related Art Conventionally, cement mortar coating has been generally used for floor finishing of buildings. Applying cement mortar to the floor requires a great deal of labor and skill because it is an operation of applying the bent posture using a metal iron. In particular, for repairing beating (raining) due to rain immediately after placing concrete, removal of rained parts, removal of dust on concrete surface, base treatment, repair of large recesses, repair of small recesses It is necessary to go through each process of repairing and surface finishing. Since each of these processes often involves a cramped posture, it is a heavy labor for skilled workers who are aging in recent years.

[0003]

Therefore, recently, a self-leveling material (= SL material), which is a floor material with improved fluidity, has been developed in order to simplify the work and make it light labor, and its use record has increased. is doing. The SL materials include gypsum-based SL materials and cement-based SL materials. The gypsum-based SL materials have the advantage of having a small drying shrinkage, but since they are gypsum, they have poor water resistance,
It has the drawbacks that the place of use is limited and the metal rusts. On the other hand, cement SL materials also have many drawbacks such as large shrinkage, floating or cracking, and insufficient strength. In this way, there is no material that has both the workability that enables thin and thick coating and sufficient mortar physical properties, and it is necessary to select the material appropriately depending on the construction situation, or repair in advance. Is required, and construction and management are extremely troublesome.

Further, various methods have been studied and proposed over the years for preventing floating and cracks in floor cement mortar coating work. For example, Japanese Patent Publication Sho 60-
Japanese Patent No. 9186 discloses that a primer prepared by mixing natural rubber latex, chloroprene latex, SBR latex, etc. into cement is applied to a surface to be adjusted, and a water-retentive aggregate such as perlite or vermiculite, rubber latex, etc. while maintaining a wet state. A method of applying an undercoat material prepared by kneading cement is disclosed. However, this method can remove the floating and cracks of cement mortar, but especially when it is necessary to apply thick mortar and to finish the entire floor surface to a smooth surface such as a rain floor, However, it may take 3 steps or 4 to 5 steps depending on the condition of the groundwork, which is very hard work as mentioned above at a site with a large floor area.

Therefore, there has been a demand for a mortar composition for floors and a construction method capable of solving various problems in cement mortar coating work for floors at construction sites.
The required characteristics of the mortar composition for floors and the construction method are summarized below as AF. A. Easy to install. B. There are few construction processes. C. Little drying shrinkage, no floating and no cracking. D. High strength. E. The finished surface is beautiful. F. The same material can be applied from thin coating with a coating thickness of about 40 to 1 mm to thick coating.

[0006]

The present invention has been proposed in view of the above, and is an aggregate having a large bulk specific gravity, and one or more aggregates having a bulk specific gravity smaller than that of the aggregate and a small particle size. And a high performance water reducing agent, a thickening agent, a shrinkage reducing agent, a re-emulsifying powdery resin, and the like, if necessary, to a mortar composition for floors.

As described above, the mortar composition for floors of the present invention contains at least an aggregate having a large bulk specific gravity and a large particle size, and an aggregate having a smaller bulk specific gravity and a smaller particle size than the aggregate. When applied to a thickness of 40 to 1 mm, the aggregate having a large bulk specific gravity is distributed in the lower portion (near the concrete surface), and the aggregate having a small bulk specific gravity is distributed in the upper portion (near the finishing surface). Becomes

Specifically, for example, the bulk specific gravity is 3.0 to 1.5.
And 80 to 10 wt% of an aggregate having a particle size of 5.0 to 0.1 mm,
50 to 5 wt% of aggregate having a bulk specific gravity of 1.5 to 1.0 and a particle size of 2.0 to 0.1 mm, and a bulk specific gravity of 1.0 to 0.4 and a particle size of 1.0
When three kinds of aggregates of 50 to 1% by weight of 0.01 mm to 50% by weight are used, as shown in the schematic diagram of FIG. 3 layers of a layer 1 mainly containing aggregate b having a bulk specific gravity of 1.5 to 1.0, and a layer 2 mainly containing aggregate c having a bulk specific gravity of 1.0 to 0.4. Will be formed. Further, in the layer 1, since the aggregate a is large, thick coating is possible, and even if thick coating is applied, the shrinkage is small because the cement ratio is low. Layer 3 has a high cement ratio, a smooth surface, and strength. In addition, a layer 4 of about 1 mm composed only of cement paste is formed above the layer 3 to obtain a smooth finished surface. That is, the above A to F
All the required characteristics of are satisfied. Further, since the aggregates a, b, and c have smaller grain sizes and the difference therebetween is small, there is no peeling between the layers 1 and 2 and between the layers 2 and 3. .

As the aggregate having a bulk specific gravity of 3.0 to 1.5, silica sand, blast furnace slag, zircon sand (ZrO ₂ .SiO _2
2 ), chromite sand ((FeMg) O.Cr ₂ O ₃ ),
Olivine sand (2 (Mg · Fe) O · SiO ₂ ), garnet, copper entrapment, steel shot, natural emery, or specially processed spinel (Spin)
el) ・ MgO ・ Al ₂ O ₃ and forsterite (Fo)
Rasterite) · 2MgO · SiO ₂ · FeO crystals having a dense structure can be used, and the grain size is adjusted to 5 to 0.1 mm, and 80 to 10 wt%
Use in the range of. Particle size is preferably 2.5-0.5 m
If it is used in the range of m, and it exceeds 2.5 mm, thin coating cannot be performed, and if it is 0.5 mm or less, thick coating causes cracks.

Further, as the aggregate having a bulk specific gravity of 1.5 to 1.0, silica sand, cold water stone, crushed stone and the like can be used, and the particle size is adjusted to 2 to 0.3 mm, and 50 to 5 wt%. Used in the range. If it exceeds 50 wt%, thin coating cannot be done.
If it is less than wt%, cracks may occur.

As the aggregate having a bulk specific gravity of 1.0 to 0.4, rhyolitic natural vitreous lightweight aggregate, tuff natural vitreous lightweight aggregate and the like can be used, and the grain size is 1 .0 to
It is adjusted to 0.01 mm and used in the range of 50 to 1 wt%. If it exceeds 50 wt%, the surface finish is not good and the surface strength becomes weak, and if it is 1 wt% or less, cracks are likely to occur on the surface.

The aggregate satisfies the above-mentioned conditions (including at least an aggregate having a large bulk specific gravity and a large grain size, and an aggregate having a small bulk specific gravity and a small grain size than the aggregate), and its application A material that exhibits a surface strength according to the above is appropriately selected.

As the high-performance water reducing agent added together with these aggregates, naphthalenesulfonic acid formalin condensate salt, sulfonated melamine formalin condensate salt, methylol melamine condensate salt and the like can be used. The floor mortar composition, by increasing the amount of mixed water compared to a normal mortar composition, improves the fluidity and improves the workability, but if the amount of mixed water is increased, the strength decreases, It is not preferable because the shrinkage becomes large. Therefore,
It is necessary to add the above-mentioned high-performance water reducing agent to reduce the amount of mixed water as much as possible while keeping the fluidity. The addition ratio thereof is usually about 1.5 to 0.5% with respect to cement, but it may be appropriately set in consideration of fluidity and workability according to construction conditions.

As the thickener, methyl cellulose,
It can be appropriately selected and used from commonly used ones such as hydroxypropylmethyl cellulose. Further, as the shrinkage reducing agent, an inorganic expansive admixture,
An alkylene oxide adduct of a lower alcohol, or both can be used in combination, and cracks due to shrinkage can be reduced. Further, as the re-emulsified powder resin, ethylene vinyl acetate-based, vinyl acetate-based, vinyl acetate-Veova-based, acrylic-based, etc. can be used,
It has the effect of improving the adhesiveness, and the addition amount thereof is appropriately determined in consideration of the result of the adhesive strength test conducted in advance. Further, in addition to the above, granulated blast furnace slag powder, fly ash, etc. may be added to improve the fluidity.

In order to sufficiently adhere the floor mortar composition composed of the above-mentioned materials to the concrete surface so as not to float or peel off, a synthetic resin emulsion diluent or a synthetic resin emulsion is contained as a pre-step. The cement-based composition is applied. As the synthetic resin emulsion, acrylic type, ethylene vinyl acetate type, SBR
Latex or the like can be appropriately selected.

When the concrete surface is fragile due to raining or the like, isocyanate groups of 10 to 0.
Containing 5% by weight and 7.5 to 0.4% by weight of hydrolyzable silane groups (based on silicon atoms) and having an average molecular weight of 50.
The one-part curable resin composition containing a polymer of 000 to 3000 as a main component may be applied to reinforce the concrete surface. The one-component curable resin composition has a low molecular weight,
Generally, it has a solid content of 17 to 13% and a viscosity of 30 to 10 cps and deeply penetrates into minute voids in a fragile portion of concrete, so that it can be hardened in this state to reinforce the concrete surface. Since this one-pack curable resin composition exhibits extremely high adhesiveness to the above-mentioned floor mortar composition or cement composition containing the above-mentioned synthetic resin emulsion to be applied thereafter, it may cause floating or peeling. There is no. Further, since it is a one-part type, it can be handled more easily than a two-part type.

[0017]

EXAMPLES Examples of the present invention will be shown below.

Formulation Examples 1 to 4 and Comparative Formulation Example 1 A floor mortar composition was prepared according to the formulation shown in Table 1 below, and the performance evaluation test shown below was conducted.

[0019]

[Table 1]

Crack test; JIS A 6915
^-1975 , a tape was attached around a steel crack tester to prevent the test material from flowing, and then each floor mortar composition of the above-mentioned formulation examples 1 to 4 and comparative formulation example 1 had a thickness of 1
It was poured so as to have a thickness of 0 mm, and flattened with a trowel. Next, the molded floor mortar was aged in a constant temperature and humidity room at 20 ° C. and 65%, and the presence or absence of cracks on the surface was visually observed after 28 days of age. The results are shown in Table 2.

Bending strength test: In accordance with JASS15M102 (quality standard of already prepared mortar), the above-mentioned formulation examples 1-4
Specimens of each floor mortar composition of comparative formulation example 1 were prepared and aged in a constant temperature and humidity chamber at 20 ° C and 65% until 28 days of age, and Shimadzu Corporation Autograph AG-5000C (crosshead speed: 0). Bending strength was measured using 0.5 mm / min). The results are shown in Table 2.

Length change: According to the dial gauge method of JIS A 1129 (Testing method for length change rate of mortar and concrete), 20 mortar compositions for floors of each of the above-mentioned formulation examples 1 to 4 and comparative formulation example 1 were prepared. 24 at 80 ℃
The baseline length was measured after curing for a period of time and demolding. afterwards,
After curing in a constant temperature and humidity room at 20 ° C and 65% for 28 days,
The change in baseline length was measured. The results are shown in Table 2.

Adhesive strength; in accordance with the Japan Building Finishing Society "Quality Standards for Water Absorption Control Material for Cement Mortar Coating (Draft)"
Concrete substrate (30 cm x 30 cm x thickness 5 cm)
Was prepared and aged to 28 days to obtain a substrate. The cured substrate has a thickness of 10 mm, a width of 10 mm, and a length of 30.
After applying cm plastic to prevent it from flowing, triple solution of Fujikawa Seelex (manufactured by Fujikawa Kenzai Kogyo) (1;
(3 diluted solution) was applied at 150 g / m ^{2 and} aged for 24 hours, then the floor mortar compositions of the above-mentioned Formulation Examples 1 to 4 and Comparative Formulation Example 1 were poured and flattened with a trowel. After curing in a constant temperature and humidity room at 20 ° C. and 65% for 28 days, it was used as a specimen. 40x4 mortar surface of the specimen after curing
Make a cut with a dimension of 0 mm until it reaches the substrate, and JIS
According to the test method specified in A 6916 (cement-based undercoating coating material), an adhesive strength test was performed, and the average of the measured values at 5 points was obtained. The results are shown in Table 2.

[0024]

[Table 2]

Construction Example 1: Floor repair work was performed on the veranda and the common passage at the condominium construction site.
First, about 150 g / m ^{2 of a} triple solution of Fujikawa Cirex was applied and dried. Then, the floor mortar composition of the above-mentioned formulation example 1 was applied. No cracking or floating was observed. The adhesive strength of a material of age 4W (4 weeks) was measured using a small adhesive strength tester (manufactured by Sakuma Koki Co., Ltd.) and found to be 23.7 kgf / cm ² .

Construction example 2: Repair work on a rain floor was carried out at a construction site of a distribution warehouse. First, after cleaning the rain floor, the one-component curing type resin primer (EX-
1500: Showa High Polymer Co., Ltd. was applied. Next, 25 kg of Fujilite # 10 (manufactured by Fujikawa Kenzai Kogyo) and 9 kg of SBR latex (KT9185C: manufactured by Nippon Latex Co., Ltd.)
And 6 kg of water were applied, and then the floor mortar composition of Formulation Example 2 was applied. No cracking or floating was observed, and a tough floor surface was obtained. In addition, using a small adhesive strength tester, material age 4W
When the adhesive strength (for 4 weeks) was measured, it was 27.9 kg.
It was f / cm ² . For comparison, when a portion not coated with the one-component curing type resin primer was prepared, the adhesive strength was 6.5 kgf / cm ² , and the permeation reinforcing effect of the one-component curing type resin primer was confirmed.

Although the present invention has been described based on the embodiments, the present invention is not limited to the above-mentioned embodiments, and may be carried out in any manner as long as the configuration described in the claims is not changed. You can

[0028]

As described above, the floor mortar composition of the present invention can be easily kneaded, and the obtained floor mortar has an aggregate having a large bulk specific gravity and a large particle size distributed in the downward direction. Since the aggregate with a small bulk specific gravity and a small particle size will be distributed, thick coating is possible in the lower part, and even if thick coating is applied, the shrinkage is small due to the low cement ratio, and the upper part has a high cement ratio and a smooth surface. The finished surface is obtained.

Further, the construction method of the present invention does not take a lot of complicated construction steps as in the prior art, but a concrete composition containing a diluent of a synthetic resin emulsion or a cement composition containing a synthetic resin emulsion on the concrete surface. Since it suffices to perform the step of applying and the step of applying the floor mortar composition to a thickness of about 40 to 1 mm, it is not necessary to have skilled techniques and can be applied simply and in a short time. You can

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing a floor mortar obtained according to the present invention.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area // (C04B 28/02 14:04 A 14:06 Z 24:22 A 24:38) A

Claims (4)

[Claims] 1. A high-performance water-reducing agent and a thickening agent, which contain an aggregate having a large bulk specific gravity and one or more other aggregates having a smaller bulk specific gravity and a smaller particle size than the aggregate. , A shrinkage-reducing agent, a re-emulsified powdery resin, etc. are added. 2. A bulk specific gravity of 3.0 to 1.5 and a particle size of 5.0 to
80 to 10 wt% of aggregate of 0.1 mm and bulk specific gravity of 1.5 to
50 to 5 wt% of an aggregate having a particle size of 2.0 to 0.1 mm at 1.0
And a bulk specific gravity of 1.0 to 0.4 and a particle size of 1.0 to 0.01 mm
The mortar composition for floors, which contains 50 to 1 wt% of the aggregate, and a high performance water reducing agent, a thickening agent, a shrinkage reducing agent, a re-emulsified powdery resin, etc. are added as needed. object. 3. The concrete surface is coated with a cement-based composition containing a synthetic resin emulsion diluent or a synthetic resin emulsion, and then the floor mortar composition according to claim 1 is coated to a thickness of 40 to 1 mm. Construction method characterized by working. 4. A concrete surface containing 10 to 0.5% by weight of isocyanate groups and 7.5 to 0.4% by weight of hydrolyzable silane groups (based on silicon atoms) and having an average molecular weight of 50,000 to 3,000. The mortar composition for floors according to claim 1, wherein the one-component curable resin composition containing the polymer as a main component is applied, and then a cementitious composition containing a synthetic resin emulsion is applied, if necessary. A method of coating an object having a thickness of 40 to 1 mm.