JPS61266340A - Composition for gypsum-base flow-spread flooring material and treating method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a gypsum-based sink flooring composition and its construction method, and particularly to a composition containing ■-type anhydrite, Portland cement, and fly ash as essential components. The present invention also relates to a method of mixing the composition with commonly used additives, aggregate, and water and applying the mixture.

(Prior art) Conventionally, a hydraulic mixture with good fluidity is spread on a concrete slab surface, etc., and a horizontal floor surface is formed by natural flow due to the mixture's own weight. or self-leveling floor) construction method is popular.

The advantage of this construction method is that it does not require any skill,
The advantage is that it can be constructed with extremely high efficiency.

Various cement-based and gypsum-based compositions are known as compositions for cast flooring, and these have the characteristics necessary for cast flooring: 1. fluidity, 2. curing speed, 3. workability, and 4. surface condition. Efforts have been made to improve dimensional accuracy, water resistance, etc.

And the cast flooring material using plaster was published in Japanese Patent Publication No. 59-30.
It is known from Japanese Patent Publication No. 58-2188 and Japanese Patent Application Laid-Open No. 58-21745, which uses ■ type anhydrite.
This is known from Publication No. 5.1.

(Problems to be Solved by the Invention) Type anhydrous gypsum is generally used as a raw material for building materials, and in particular, as mentioned above, it is used in combination with blast furnace slag or blast furnace cement for cast flooring materials.

However, in the conventional technology using the above-mentioned ■-type anhydrite, (1) cracks occur due to expansion and contraction of the construction material;
(2) Occurrence of unevenness (small waves) when repainting, (3) Air bubbles,
The finish of the construction work was inadequate in terms of wrinkles, etc.

For this reason, there are problems in that careful attention is required during construction, various post-treatments, etc. must be carried out, and it is difficult to obtain high-quality construction products.

(Means for Solving the Problems) The present inventor has completed the present invention as a result of intensive research to solve the problems of the prior art. That is, the present invention provides a gypsum-based cast flooring composition containing 150 parts by weight of type anhydrite, 45 parts by weight of Portland cement, and 724772150 to 15 parts by weight.
A gypsum-based poured flooring composition characterized by blending a mixture consisting of parts by weight of ■-type anhydrite: 150 parts by weight, Portland cement: 45 to 100 parts by weight.
724772150 to 15 parts by weight are mixed with commonly used additives, aggregate, and water, and the mixture is spread on the subfloor and then hardened. It is the law.

The special feature of the composition of the present invention is that it contains fly ash, which was not used in conventional cast flooring compositions using type 1 anhydrite. The inventor is ■
It was discovered that by blending Fly 7 Tsushi with molded anhydrite in a certain range of ratios, it was possible to significantly reduce the occurrence of cracks in the cured product and the occurrence of irregularities on its surface during the aging process.

A preferred composition ratio of the composition of the present invention is, in terms of weight ratio,
o weight ts, fly ash 4o to 20 parts by weight, and the most suitable one is type anhydrite 1501i1.
It consists of around 70 parts by weight of Pol F land cement and around 30 parts by weight of fly ash.

By the way, the high-quality conventionally constructed product has a surface strength of 7 kg/am" at 7 days old and a compressive strength of 209 kg/am" at 28 days old.
kg/cm" and water resistance of about 150 kg/cm2 or more, and the product of the present invention naturally possesses such performance, and is ranked as a high-class product as a construction product.

Furthermore, another feature of the present invention is that the difference in expansion and contraction (absolute value of expansion and contraction) during the curing process is smaller than that of conventional products, which prevents cracks from occurring in the construction product.

In other words, in general, the construction material reaches its maximum expansion value around the third day after construction (the 3rd day of age), and then shrinks and becomes almost stable around the 14th day. If the absolute value of the difference from the shrinkage value is large, cracks will occur in the construction object. Figure 2 is a diagram to explain this, and shows that the difference in expansion and contraction (this is the absolute value of the volume change) between the 3rd day of age and the 14th day of age for the composition in A is
This means that it is considerably larger than that for the mouth or the mouth, but the absolute value of the expansion and contraction of the present invention is reduced.

Type anhydrite is mainly orthorhombic anhydrous calcium sulfate obtained as a by-product during the production of 77 acid, but its strength is high, and Portland cement's main components are tricalcium sulfate and dicalcium silicate. Although hydraulic in nature, it reacts with pozzolans such as fly ash to form solids with high long-term strength. Fly ash is a byproduct of pulverized coal combustion in thermal power plants, and although it is not hydraulic in itself, when mixed with cement, the siliceous material in it is produced by the hydration reaction of the cement. It gradually reacts with calcium hydroxide to create insoluble and stable compounds such as calcium silicate, which increases its strength over a long period of time and improves its properties and durability. Since they are approximately spherical particles of 30 μm in size and have smooth surfaces, they act like a pawl bearing in Funkurishi and improve fluidity.

In the present invention, the blending composition is limited to a certain range of numerical values as described above, and the reason for this is that the inventor's experimental results revealed the following.

In other words, (1) Visual observation and evaluation by multiple people regarding the three problematic properties of the finished floor: cracks, wrinkles, and air bubbles revealed that [7-Lay, 7-Tssie, which was prepared in an appropriate amount] J (2) Regarding the unevenness that occurs at the joints of coating during construction, [Those containing an appropriate amount of fly ash have an effect similar to that of conventional pole bearings, and J(3) The difference between expansion and contraction (absolute value of expansion and contraction) is smaller when an appropriate amount of fly ash is blended than with conventional products.

In other words, "It is effective in preventing cracks."
If it is less than 5 parts by weight, you will not be able to obtain a hardened product with good strength, and if it exceeds 100 parts by weight, cracks will easily occur and the fluidity will decrease, making it difficult to apply the product smoothly. The generation of small waves will also increase. *Furthermore, if the amount of fly ash is less than 15 parts by weight, the fluidity will decrease, the degree of shrinkage will also be greatly reduced and cracks will occur, and the long-term strength will not increase, and if the content exceeds 50 parts by weight, the flowability will decrease. When this happens, the viscosity increases, the fluidity decreases, and the strength also decreases.

It goes without saying that in the present invention, conventional additives may be added in conventional amounts.

Commonly used additives include alkaline agents such as slaked lime and quicklime;
water reducing agents such as melamine-formalin condensed sulfonates;
Water retention agents such as methylcellulose and hydroxyethylcellulose, antifoaming agents such as silicone surfactants, etc. are used, and are appropriately added as necessary.

During construction, aggregate and water are further added, and the aggregate used is silica sand, etc.

In construction, aggregate, additives, and water are added to the composition of the present invention and mixed to form a slurry, which is spread on the concrete slab floor to allow self-leveling to proceed, and then wait for hardening.

Note that the composition of the present invention, aggregate, additives, and water are mixed at 7
0-value is 220±151. Preferably it is 22G±10-1, particularly 220±5-.

As an additive, the alkaline agent is 9 to 18 parts by weight per 150 parts by weight of type ■ anhydrite, and the water reducing agent is 1 part by weight of type ■ anhydrite.
1 to 4 parts by weight per 50 parts by weight, a water retention agent of 0.12 to 0.25 parts by weight per 150 parts by weight of ■-type anhydrite, and an antifoaming agent of 0 per 150 parts by weight of ■-type anhydrite. .065~
Preferably, 0.125 parts by weight is added.

And, the aggregate is 50 parts by weight for 150 parts by weight of type Kumasui gypsum.
It is preferable to blend 100 parts by weight.

Next, the results of a comparative test using a composition within the scope of the present invention and another composition will be explained.

The following various tests were conducted on test specimens of each formulation listed in Table 1.

The measurement method for each test is as follows.

[70-value 1 inner diameter 5c, height 5. IC theory polyvinyl chloride cylinder (
A cylinder with a capacity of 100 m1) was filled with slurry, and the cylinder was quickly pulled up, and the diameters of the spread of the slurry in two orthogonal directions after 2 minutes were measured.

[Surface Strength 1] Pour the slurry into a frame with a height of 30 mm and a width of 500 square meters on a 20th plate (500 x 500 x 50 -1) and leave it at room temperature for 3 days, and then leave it at room temperature for an additional 25 days. Measurements are made using a Saku open type surface strength tester 7 days and 28 days after pouring, respectively.

That is, three or five steel attachments each having a diameter of 100 mm are bonded together using epoxy resin, and the stress required to separate each attachment is measured.

[Self-strength and compressive strength] Internal length 160 Wheel plow 1 Width 40-1 Depth 40-JrsR
Pour the slurry into the 5201 triple formwork, let it stand at room temperature for 3 days, then take out the assimilated compound and measure it as a test piece after 7 days, and measure it as a test piece after letting it stand at room temperature for 25 days. .

The bending strength was measured using a Michaelis tester. 2@
A roll (diameter 8 I) i5 span is set as a 100-wheel, and a load is applied to the center of the span using one roll (diameter 8-) with the test specimen left up and down to reach the maximum load. demand.

Bending strength (kg/am”) = 0.234X The compressive strength under large load (kg) is determined by measuring the bending strength (kg/am”) = 0.234 Compressive strength test W with a maximum capacity of 20) by pressing with a pressure plate
Crushing at an average pressurizing speed of 80 kg per second using a compressor,
Measure the maximum load.

Compressive strength (kg/am”) = Maximum load (kg)/16
(am'') [Water Resistance] After the test specimen was left indoors for 21 days, it was immersed in water for 7 days, and the bending strength and compressive strength of the test specimen were measured.

[F & large expansion/contraction amount] Pour the test specimen slurry (7t!-value: 220-230) into a mold to make a 4X4X16cm test piece, and hold it at room temperature for 14 hours.
The amount of expansion and contraction in the long axis direction was measured using a contact gauge over a period of days.

[Small wave height] Several joint bars (diameter 10-m) on 20 plates of 550 mm square
11I￥a to form a formwork, pour the test specimen slurry into it sufficiently, leave it for 30 minutes, then remove one joint bar. Recoating is performed by pouring another new sample slurry to the same thickness in contact with the slurry, and after leaving it for one day to harden, the surface irregularities (small waves) of the cured product that occur along the recoating area are removed. ) was measured with an accuracy of 1/100 mm using a dialage. A schematic diagram is shown in Fig. 3.

In addition, among the additives added to all of the above test specimen numbers,
The water retention agent is methylcellulose (Metrose 90SH30000 manufactured by Shin-Etsu Chemical Co., Ltd.), and the water reducing agent is melamine formalin condensed sulfonate (Melmen manufactured by Showa Denko) FI
O), and antifoaming agent is silicone j! % antifoaming agent (SN Deformer 14-HP manufactured by San Nobuco) and silica sand (No. 5) were used as the aggregate.

The test results are shown in Table 2.

Further, changes in expansion and contraction rates over time are shown graphically in FIG.

As can be seen from the above test results, the absolute value of the difference between expansion and contraction was large (causing cracks), and small waves (1!
! However, test specimens Nos. 3 to 6, which are within the scope of the present invention, have a convex surface and poor flatness. Maximum expansion/contraction amount (x i
o-'-1)" was 5.4 to 8.0, and the "small wave height" was 5.7 to 27.0 m-, which was significantly lower than that of the other test specimens.

There are other test specimens that have performance comparable to that of the present invention when looking only at either the FR large expansion/contraction amount or the small wave height, but if one performance is good, the other is good. The result is bad.

(Effect of the invention) As described above, according to the present invention, the concrete obtained through construction not only has the performance of a high-grade product, but also has a low difference in expansion and contraction depending on the age of the material, and has a convex surface. Since the height of the small waves indicating the undulation is not large, as a result, cracks may occur in the product (and the surface flatness is also good. Therefore, compared to conventionally known gypsum-based poured floor compositions, the present invention exhibits much superior effects, and is one of the most popular in the industry. It has a huge contribution to make.

[Brief explanation of drawings]

I/s1 diagram is a graph showing the expansion and contraction states of the examples and comparative examples according to the present invention, Figure 2 is a graph explaining the absolute value of the difference between expansion and contraction, and Figure #3 is the joint of the test specimen. A schematic diagram of the surface unevenness (small waves) that occurs at the site is shown.

Claims (6)

[Claims] (1) In a gypsum-based poured flooring composition, the weight ratio
A gypsum-based cast flooring composition comprising a mixture of 150 parts by weight of Type II anhydrite, 45 to 100 parts by weight of Portland cement, and 50 to 15 parts by weight of fly ash. (2) The gypsum-based cast flooring material according to claim 1, wherein the weight ratio is 150 parts by weight of type II anhydrite, 60 to 80 parts by weight of Portland cement, and 40 to 20 parts by weight of fly ash. Composition for use. (3) In terms of weight ratio, type II anhydrite is 150 parts by weight, Portland cement is around 70 parts by weight, and fly ash is 3 parts by weight.
The gypsum-based cast flooring composition according to claim 1, which contains approximately 0 parts by weight. (4) Add commonly used additives, aggregate, and water to a mixture consisting of 150 parts by weight of type II anhydrite, 45 to 100 parts by weight of Portland cement, and 50 to 15 parts by weight of fly ash. A method of constructing a gypsum-based cast flooring material, which is characterized by mixing, distributing the mixture on the subfloor, and then curing it. (5) Claim 4, wherein the mixture consists of 150 parts by weight of type II anhydrite, 60 to 80 parts by weight of Portland cement, and 40 to 20 parts by weight of fly ash. Construction method for plaster-based poured flooring as described. (6) The gypsum system according to claim 4, wherein the mixture consists of 150 parts by weight of type II anhydrite, 70 parts by weight of Portland cement, and 30 parts by weight of fly ash. Construction method for cast flooring.