JPH01219047A - Lightweight aggregate for plastering - Google Patents

Abstract

PURPOSE:To obtain lightweight aggregate for plastering which is excellent in coating workability of primer morter of a tile by constituting it of a CaCO3 foaming agent and a mineral lightweight aggregate having prescribed volume ratio in which degree of water absorption, bulk specific gravity and maximum particle diameter are specified respectively. CONSTITUTION:The above lightweight aggregate for plaster is constituted of both a CaCO3 foaming agent contg. alumina powder as the forming agent and 100-500pts.wt. mineral lightweight aggregate having <=30% degree of water absorption, <=0.5 bulk specific gravity and <=2.5mm maximum particle diameter for 100pts.vol. CaCO3 forming agent. As the mineral lightweight aggregate, the mineral foaming lightweight aggregate such as both material obtained by mixing asphalt with cement paste and perlite coated with organic or mineral material having waterproofness is utilized. Since the above-mentioned lightweight aggregate is light in weight fatigue is not accompanied with coating operation of primer morter of a tile and workability is made excellent and a defect such as floating and cracking is hardly caused because sagging is not formed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lightweight aggregate for plastering, and particularly to a lightweight aggregate for tile base mortar used in the plastering process in which mortar is applied to a concrete base and tiles are pasted on top of it. The invention relates to lightweight aggregate for plastering.

[Prior Art] In recent years, tiles have come to be frequently used as an exterior finishing material for concrete buildings.

Such exterior wall tiles are generally attached to concrete buildings in a structure as shown in FIG. 2, and the work process for attaching the exterior wall tiles is carried out in the usual manner.

First, a tile base mortar 4 is applied to a thickness of 5 to 155 m on the concrete frame 1 in order to adjust the unevenness, and the tile base is completed. On top of this, a tile mortar 3 for adhering tiles is usually applied to a thickness of 2 to 3 layers, and the tile 2 is pressed onto it.

For pasting such exterior wall tiles, a tile base mortar is essential, and the following aggregates have conventionally been used for this tile base mortar:

(Rikawa sand, mountain sand.

(2) Pearlite alone or a mixture of pearlite and silica sand, kansui stone or blast furnace slag.

(3) Calcium carbonate foam granules, styrene foam granules, or a mixture thereof.

[Problem to be solved by the invention] However, the river sand and mountain sand mentioned in (1) above have a high specific gravity, and when covering a large area with mortar using these aggregates, it is necessary to handle the mortar with great effort. There is a problem with workability in that the plastering process is tiring and requires a lot of effort. In addition, if the mortar is applied thicker than 7 to 81111, it will cause blurring, floating,
It has the disadvantage of causing defects such as cracks.

When only pearlite is used, pearlite or a mixture thereof in (2) above is lightweight but has a round particle size, so unless it is enriched with an increased amount of cement, the mortar will lack viscosity. Because of the so-called "shaku", workability is poor in terms of trowel elongation and adhesiveness. For this reason, if the mixture is made by adding silica sand, kansui stone, blast furnace slag, etc. to pearlite, workability will be improved, but the specific gravity will increase, making the work tiring and causing blurring in one mortar.

Moreover, since pearlite is lightweight, it has low mortar strength, and when heavy tiles are attached to the outer surface of a wall, the breaking strength (tensile strength or shear strength) necessary for resistance to tile peeling is insufficient. Furthermore, since pearlite has a high water absorption rate, mortar using pearlite has the disadvantage of low freeze-thaw resistance and poor durability, and its use on exterior walls is generally restricted in many cases.

In addition, the calcium carbonate foam granules, foamed styrene granules, or a mixture thereof described in (3) above have extremely good workability when used in tile base mortar because of their light weight. When only grains are used, the shape of these aggregates is elastic grains like a torn sponge, so even if the mortar is pressed down with a trowel during the surface leveling work, it will not work. The crushed aggregate rises again and forms unevenness on the mortar surface,
With the usual coating thickness of tile mortar, there is a problem that the adhesion of the tiles is weak, and therefore the tile mortar must be applied thickly, which is disadvantageous in that it is uneconomical.

In addition, since the tile base mortar using only calcium carbonate foam or expanded polystyrene particles has a large surface unevenness, it is overcoated with a pre-mixed (commercially available) or on-site thin coating mortar 5 as shown in Figure 3. Although this method is conceivable, it has the drawback that it requires two steps and the construction period becomes long.

In order to reduce and flatten the surface irregularities of the tile base mortar to a level suitable for the tile base, inorganic foamed lightweight aggregates such as perlite, vermiculite, and shirasu balloons or organic foamed lightweight aggregates such as expanded polystyrene and calcium carbonate foam are used. (An example of the combined use of expanded polystyrene particles and expanded calcium carbonate particles is Japanese Patent Publication No. 513-34144.)

However, although the unevenness of the mortar surface can be improved in this case, the above-mentioned inorganic foamed lightweight aggregate has a high water absorption rate and poor durability, so it cannot be used as an outdoor material.

In addition, the organic foamed lightweight aggregate also has the disadvantage that it cannot be used as an outdoor material because it deteriorates due to sunlight's ultraviolet rays and its mortar strength decreases, causing cracking and tile peeling (2). ing.

When anthracite calcium foam is used together with river sand, mountain sand, silica sand, etc., the durability of the tile base mortar can be ensured, but the degree of improvement of the mortar surface is insufficient.
In addition, there is a problem in workability because the specific gravity becomes large.

[Means for solving the problem] Therefore, we have developed a lightweight plastering material that is lightweight, has good workability, is durable due to low water absorption, and has a somewhat small irregularity on the mortar surface, forming a suitable mortar as a tile base. As a result of extensive research into aggregates, the lightweight aggregate for plastering of the present invention was obtained.

That is, in the present invention, the calcium carbonate foamed granules have a water absorption rate of 30% with respect to 100 parts by volume of the calcium carbonate foamed granules.
The bulk density is 0.5 or less, and the maximum particle size is 2.
This lightweight aggregate for plastering is characterized by comprising 100 to 500 parts by volume of inorganic lightweight aggregate of 5 mm or less.

[Detailed Description of the Invention] Calcium The foamed calcium carbonate particles used in the lightweight plastering aggregate of the present invention are foamed calcium carbonate particles (with a diameter of about 1 to 7 arms, preferably about 4 to 5 mm). ), but generally commercially available foamed calcium carbonate granules are manufactured as follows.

That is, powder of calcium carbonate and paste of vinyl chloride or ethylene/vinyl acetate copolymer are mixed, and toluene is added as a swelling agent to the mixture to give a powder of 120 to 17
Heating at 0℃ for 45 minutes to 1 hour, then cooling it to a temperature slightly higher than room temperature, adding a foaming agent (alumina powder), mixing well to make it viscous, and putting it into a mold. Expand by steaming. Add this to another 30 to 4
Steam dry for 0 minutes to evaporate the toluene contained. Next, leave it in a dry place for 1 to 2 days to harden, and then crush the hardened material with a sawing means to create irregularly shaped pieces. The result is crushed fragments, i.e., elastic, grass-like fragments about the size of sawdust.

111 Kasa 1tJt The water absorption rate used in the lightweight aggregate for plastering of the present invention is 3
0% or less, preferably 0 to 15%, bulk specific gravity.

is 0.5 or less, preferably 0.01 to 0.2, and the maximum particle size is 2.5 mm or less, preferably the total particle size is 1.2 to 2.5). As a material,
Inorganic foam lightweight aggregates such as perlite, verminiculite, and shirasu balloons coated with waterproof organic or inorganic materials such as asphalt, cutback asphalt, or materials mixed with cement paste, etc., fly ash foam sintered bodies, etc. is exemplified.

Mortar using aggregate with a water absorption rate of more than 30% has poor freeze-thaw resistance and is not suitable for external use.

Applying mortar using aggregate with a bulk specific gravity of more than 0.5 is tiring and tends to cause blurring with normal coating thickness.

Aggregates with a maximum particle size exceeding 2.5 mm cannot flatten the irregularities on the mortar surface created by the calcium carbonate foam, which not only impairs the workability of the mortar, but also makes it necessary to use a thinner material with a thickness of 2 to 3 mm in some cases. Painting becomes impossible.

The mixing volume ratio of the expanded calcium carbonate granules and the inorganic lightweight aggregate having the above performance is 100:100-500, preferably +00:250-350. Too:
If it is less than 100:50, the unevenness of the surface of the tile base mortar will not be improved to a flat surface, and if it is more than 100:500, the mortar will be too lightweight and the tensile and shear strength of the mortar will be insufficient for the strength required to prevent tiles from falling off. However, due to the lack of viscosity of the mortar, it stretches with a trowel, resulting in poor adhesive workability.

In addition, methylcellulose is added to give mortar viscosity.
There is no problem with adding cellulose, powdered resin, etc.

[Example] Hereinafter, the lightweight aggregate for plastering of the present invention will be specifically explained with reference to Examples.

The various aggregates used in these Examples and Comparative Examples are as follows.

(a) Calcium carbonate foamed grain Asano Mild Sand manufactured by Nippon Cement■ (b) Asphalt-coated pearlite: Cutback asphalt, which is a mixture of straight asphalt with a penetration degree of 0 to 20 and xylene at a weight ratio of 428, is prepared using the following ( (C) Fly ash foamed sintered body coated with 40% by weight of pearlite pearlite from d) manufactured by Ube Industries ■, trade name U-Lite No. 1 (c-1) and
No. 2 (c-2) (d) Nacreous pearlite: Made by Asatubalite ■, product name Asatubalite P-
2. Maximum particle size of 2.5++e or less (2) River sand: produced in Fujitsuki Table 1 shows the physical properties of these aggregates.

Table 1 Example 1 +00 parts by volume of expanded calcium carbonate granules (a) and 100 parts by volume of asphalt-coated barley (b) were mixed to prepare a tile base mortar with the composition shown in Table 2.

Apply this tile base mortar to a vertical concrete wall.
It was applied to a thickness of 0 layers, and a plasterer evaluated the workability and suitability of the mortar surface as a tile base.

The results are shown in Table-2.

After 10 days, a tile was attached using the tile base mortar as an adhesive, and a week later, the periphery of the tile was cut down to the base concrete surface using a diamond cutter, and the adhesion strength was measured using a Kenken type adhesion tester. (n=El) Also, the above tile base mortar is IOX IOX 40
It was molded into a beam-shaped specimen with a diameter of 1 cm and was cured in water (
20° C.), repeated underwater freezing-underwater thawing was performed up to 300 cycles according to the ASTM C66B test method, and the relative dynamic elastic modulus, which indicates the degree of durability, was measured.

The test results are shown in Table-2.

Examples 2 and 3 100 parts by volume of calcium carbonate foam granules (a) and Example 1
A mortar was prepared by mixing 300 parts by volume and 500 parts by volume of the same asphalt-coated pearlite (b) as shown in Table 1-2.

This mortar was used in the same manner as in Example 1, and the workability and suitability of the mortar surface to the tile base were evaluated by plasterers. The results are shown in Table-2.

In addition, adhesive strength and the like were measured in the same manner as in Example 1.

The results are shown in Table-2.

Example 4 Mortar was prepared by mixing 100 parts by volume of calcium carbonate foam granules (a) and 300 parts by volume of fly ash foam sintered body U-Lye) No. 1 (c-1) to have the composition shown in Table 2.

This mortar was used in the same manner as in Example 1, and the workability and suitability of the mortar surface to the tile base were evaluated by plasterers. The results are shown in Table-2.

In addition, adhesive strength and the like were measured in the same manner as in Example 1.

The results are shown in Table-2.

Comparative Examples 1-2 Calcium Carbonate Expanded Granules (a) Loo Volume Part and Example 1
and 550 parts by volume of the same asphalt-coated pearlite (b) were mixed to prepare a mortar with the composition shown in Table 2.

This mortar was used in the same manner as in Example 1, and the workability and suitability of the mortar surface to the tile base were evaluated by plasterers. The results are shown in Table-2.

In addition, adhesive strength and the like were measured in the same manner as in Example 1.

The results are shown in Table-2.

Comparative Examples 3 to 5 Mortar was prepared using the calcium carbonate foam (a), perlite (d), and asphalt surface-covered perlite (b) alone, each having the composition shown in Table 2.

This mortar was used in the same manner as in Example 1, and the workability and suitability of the mortar surface to the tile base were evaluated by plasterers. The results are shown in Table-2.

In addition, adhesive strength and the like were measured in the same manner as in Example 1.

The results are shown in Table-2.

Comparative Examples 6 to 7 River sand (
e) and fly ash foamed sintered U-Lite No. 2 (c-2) with a maximum particle diameter of 3 mm or less similar to Example 4, 300 parts by volume each were mixed to prepare mortar with the composition shown in Table 2. did.

This mortar was used in the same manner as in Example 1, and the workability and suitability of the mortar surface to the tile base were evaluated by plasterers. The results are shown in Table-2.

In addition, adhesive strength and the like were measured in the same manner as in Example 1.

The results are shown in Table-2.

[Effects of the Invention] The lightweight aggregate for plastering of the present invention has the following effects by combining lightweight aggregates with different shapes and low water absorption rates.

■ Since the aggregate is extremely lightweight, the work of applying mortar on the tile base is not tiring and has excellent workability, and since there is no wobbling, defects such as lifting and cracking are less likely to occur.

■ Since the water absorption rate of the aggregate is low, the mortar has high freeze-thaw resistance and excellent durability.

■ The lightweight aggregate fills the gaps between the moxa-like foamed calcium carbonate particles, creating a mortar surface with small irregularities that is suitable as a tile base.

■ As a result, the adhesion of the tiles is improved, there are no accidents such as tiles falling off, and there is no need for future maintenance.

■ Excellent workability and a mortar surface suitable for tile bases can be obtained without the need for two-step coating, increasing construction efficiency and shortening the construction period.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the outer wall of a tiled concrete building constructed using the lightweight aggregate for plastering of the present invention, and Figures 2 and 3 are cross-sectional views of the outer wall of a conventional tiled concrete building. . 1: Concrete frame 2: Tile 3: Tile mortar 4: Tile base mortar 5: Thin coating mortar

Claims (1)

[Claims] (1) Calcium carbonate foamed granules, and lightweight inorganic particles with a water absorption rate of 30% or less, a bulk specific gravity of 0.5 or less, and a maximum particle size of 2.5mm or less, based on 100 parts by volume of the calcium carbonate foamed granules. A lightweight aggregate for plastering, characterized by comprising 100 to 500 parts by volume of aggregate.