JPH0475195B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to improvements for plastering materials containing perlite. Perlite mortar, which is used as a plastering material containing perlite, is generally made by mixing cement and perlite, or cement and perlite, and replacing some of the perlite with aggregate such as river sand or lightweight aggregate, by adding water and kneading it. It is used as a coating material (wet method). Perlite mortar is lighter and has superior insulation properties compared to conventional river sand and crushed sand mortar, so it has been used for a variety of purposes, including reducing the weight of buildings, providing fireproof coatings, preventing condensation, and improving heating and cooling efficiency. Although pearlite mortar has many advantages as described above, it is also well known that it has one major drawback due to the characteristics of pearlite in construction. That is, when mortar is kneaded using perlite as an aggregate in a pan mixer or the like, the particles are damaged and the volume is reduced.
Perlite with a smaller unit weight tends to have a smaller kneaded volume, and the weight loss reaches about 50% in large cases. For example, in order to obtain the same volume of kneaded volume as a 1:3 mortar, which is the standard composition of cement mortar using river sand, if perlite with a unit volume weight of approximately 0.05 to 0.07 is used, the cement:perlite volume ratio must be At 1:6,
Similarly, when using 0.15 to 0.20, 1:
It has to be 4. Moreover, even if the kneading order and kneading time are determined, the kneaded volume obtained is not constant and is difficult to control. This kneaded volume is related to the number of areas to be coated and is the basis for calculating the required amount of material, so in anticipation of the fact that the amount of kneading loss cannot be controlled, extra material must be added during kneading, which is economical. was also at a disadvantage. Therefore, the inventor of the present invention has conducted various studies on methods that do not reduce the above-mentioned kneading volume while maintaining the light weight and other characteristics of pearlite mortar.
We have arrived at the present invention. Thus, the gist of the invention is for perlitic plastering materials, typified by perlitic mortars, containing strips of materials with elastic functionality, such as organic or inorganic foams or elastomers. Materials with elastic functions (hereinafter sometimes simply referred to as elastic materials) used in the present invention include expanded polystyrene, expanded polyurethane, and calcium carbonate foam, as well as natural rubber and styrene-butadiene rubber (SBR). Examples include elastomers such as synthetic rubbers such as chloroprene rubber (CR). This material only needs to have elasticity at room temperature, and can be either organic or inorganic. In addition, when using the above materials, 5mm
It is preferable to use finely crushed pieces. By replacing a portion of the pearlite in the pearlite mortar with this elastic material, damage to the pearlite due to mixing is reduced. That is, as shown in FIG. 1, the change in kneaded volume when pearlite is replaced with an elastic material increases as the replacement ratio (hereinafter simply referred to as ratio) increases. The so-called kneading loss is reduced (cement: aggregate = 1:2.5). The reason for this is not clear, but there is probably a difference in the elastic action between the various elastic materials, but in response to the shearing force that occurs when mortar is mixed with a mixer, etc., they expand and contract freely and act as cushions. It is thought that this acts to weaken the influence of shearing force on the pearlite particles interposed around the pearlite particles, thereby reducing damage to the particles. In the present invention, the proportion of elastic material in the aggregate (perlite+elastic material) is 3 to 50% by volume.
If it is less than 3% by volume, there is no effect of replacement and pearlite is often damaged. If it exceeds 50% by volume, the effect of reducing kneading is sufficient, but since the amount of pearlite is reduced, the drawbacks caused by this, especially water retention and fire resistance, become significant. In addition, 5-40
Volume % is more preferred. The mixing ratio of cement and aggregate is determined depending on the application, such as top coating, intermediate coating, and undercoating, but it is generally mixed in a range of 1:1 to 1:5 (volume ratio). Further, the above cement is a Portland cement commonly used for plastering. As pearlite, commercially available pearlite, obsidian, etc., heated and expanded and having a particle size of about 5 mm or less are used, and any of these materials can be replaced as the elastic material and still have the effect. In particular, when pearlite, which is expanded pearlite, is used, it has a greater effect on reducing wear when compared to obsidian. Next, an example of a method for manufacturing improved pearlite mortar using the material structure of the present invention will be described. First, the elastic material and perlite are sequentially introduced into a pan mixer for plastering, a Hobart mixer for mortar, or a tilting mixer for concrete.
Next, after adding the entire amount of cement to almost the entire surface of the mixer, mixing water is evenly added. Begin stirring immediately and mix for 1 to 5 minutes. The amount of water mentioned above is smaller as the proportion of the elastic material increases. In addition, at the beginning of mixing, the water suddenly disappears and it appears that the mortar is not soft enough, but as time passes, the water absorbed by the pearlite gradually oozes out, and the softness increases and a pearlite mortar with the required consistency is obtained. It will be done. We have explained above the case where pearlite mortar contains elastic material, but when some of the cement is replaced with plaster (e.g. dolomite plaster, gypsum plaster, etc.), or when the elastic material is added to pearlite plaster where the entire amount of cement is replaced with plaster. Even when used, it has the effect of reducing kneading loss, similar to pearlite mortar. According to the present invention, when pearlite mortar is kneaded and mixed, by partially replacing the elastic material, damage to the pearlite is reduced, the amount of kneading is increased, and the area of coating can be significantly increased. Moreover, the bulk density of the hardened pearlite mortar is reduced, making it lightweight, and the heat insulating properties can be further improved. Next, the present invention will be specifically explained using examples. Example 1 The effect on the amount of kneading when pearlite was replaced with an elastic material was investigated under the following conditions. Cement: Aggregate 1:2.5 (volume) Perlite pearlite particle size used: 5
Unit volumetric weight below mm (light equipment)
0.06Kg/l Elastic material used: Expanded polystyrene Particle size: 5mm or less Unit weight: 0.02Kg/l Calcium carbonate foam: Particle size: 5mm or less (Asano Mild Sand () sold by Nippon Cement Co., Ltd.)
(Product name)) Unit volume weight 0.08Kg/l Cement Ordinary Portland cement Water-cement ratio 46.5% Mixing time 3 minutes The elastic material and perlite were uniformly poured into a pan mixer in order, and then the entire amount of cement was poured into the mixer. After that, water in which methylcellulose equivalent to 0.2% of the cement had been dissolved was poured into the mixture, and stirring was immediately started. After kneading and mixing, the entire amount of raw mortar in the mixer was taken out and its volume was measured. According to the above procedure, the amount of fresh mortar was measured by varying the replacement ratio of the elastic material, and the results are shown in FIG. Note that the plot is the average value of each ratio measured three times. A ratio of 0% is when only pearlite is used as the aggregate, and a ratio of 100% is when only elastic material is used. From the results obtained, it was confirmed that a replacement ratio of elastic material of 3% by volume or more is effective. Example 2 Pearlite:elastic material ratio 70:30 (volume)
An experiment was conducted in which the mixture ratio of cement and aggregate was varied. Other conditions and operating procedures are the same as in Example 1. In addition, the comparative values are listed in Table 1, assuming that the amount of kneaded mortar when river sand is used is 100.

【table】

[Table] (1) When using river sand (2) When using only pearlite (3) Elastic material: Expanded polystyrene (4) Elastic material: Calcium carbonate foam Based on the results obtained, we decided to replace conventional pearlite mortar with Compared to this, the amount of raw mortar of the present invention is significantly larger,
It has been found that it is possible to increase the number of coating areas by that much.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the replacement ratio of the elastic material and the amount of kneaded mortar.

Claims (1)

[Claims] 1. A pearlite-based plastering material characterized in that it contains strips of a material with an elastic function, such as an organic or inorganic foam or an elastomer.