KR20090065046A - Wet gypsum based concrete floor underlayments self-levels to produce a smooth surface and mrthods thereof - Google Patents

Abstract

A wet gypsum-based concrete floor material with a self-leveling property and a manufacture method thereof are provided to show high mobility with a relatively fast hardening rate in no need of a large-scale floating or finishing process. A method for manufacturing a wet gypsum-based concrete floor material with a self-leveling property comprises the following steps of: mixing calcium sulfate alpha-hemihydrate, hydraulic cement, superplasticizer, defoamer and alkyl cellulose in order to prepare a gypsum-based concrete composition; mixing one aggregate selected among glass sand, sand and a mixture of sand and glass sand and the gypsum-based concrete composition in a ratio of 1:1 - 3:1 by weight; kneading the mixture with enough water; and pouring the mixture to manufacture the wet gypsum-based concrete floor material. The compressive strength of the wet gypsum-based concrete floor material is 2,000~4,000psi after hardening.

Description

WET GYPSUM BASED CONCRETE FLOOR UNDERLAYMENTS SELF-LEVELS TO PRODUCE A SMOOTH SURFACE AND MRTHODS THEREOF}

The present invention relates to a wet gypsum-based concrete flooring, and in particular, the surface is flattened and quickly cured by pouring only as a subfloor of a high-rise building such as an apartment. And to a method for producing the same.

Typically, gypsum-based building flooring or baseboards are installed in new or existing flooring structures such as wooden boards, plywood, and building concrete. It is installed by pouring, pumping or spreading liquid wet concrete mixtures into existing flooring.

These methods have some advantages. First, when the wet gypsum-based composition is applied on wood such as plywood flooring, it is possible to form a surface free of splinters, squeaks and nails by some degree of self-leveling of the wet mixture. Accordingly, after the mixture is cured, a lining material such as linoleum, wood parquet, vinyl or paper sheet, carpet, and the like can be easily laid on the flooring material. Second, because the wet mixture is a fluid, it fills the cracks at the interface between the flooring and the surrounding seams, so that the flooring hardens significantly reduces the leakage between the room and the floor. Third, since the composition is mostly made of gypsum, it can inhibit the spread of flame and smoke to the surroundings in case of fire. Fourth, pourable concrete flooring can be used to repair cracked, worn, or low-traffic concrete flooring. In other words, when the composition is applied to the existing floor, the gap between the flow composition is filled and the depressions or protrusions of the flooring material can be flattened.

To date, many methods have been proposed for producing high strength hardened flooring materials having a high compressive strength of at least 2,000 psi (psi, one pound pressure applied to one square inch) and building floorings having these requirements. For example, US Pat. No. 4,075,374, US Pat. No. 4,159,912, US Pat. No. 4,444,925 have proposed building flooring methods, respectively, but there is a problem in that the flooring having the required strength cannot be manufactured. In particular, in the case of US Pat. No. 4,159,912, there was a problem in that dust was generated on the surface of the flooring material after curing, and surface treatment such as washing and sealing was required to properly apply the concrete flooring material. In addition, the flooring prepared according to US Pat. No. 4,075,374 tends to peel off from the flooring in which the wet composition is introduced.

It is an object of the present invention that the surface is flat even without pouring or a separate finishing process, there is almost no foreign matter such as surface dust, and the curing speed is very fast to have a self-smoothness to shorten the entire concrete flooring production process The present invention provides a wet gypsum-based concrete flooring material and a method of manufacturing the same.

Another object of the present invention is to provide a wet gypsum-based concrete flooring material and a method of manufacturing the same, which have a high compressive strength as compared with light weight and have self-smoothness to have crack resistance and peeling resistance with the lower flooring material.

The present invention relates to 79 to 86% by mass of calcium sulfate alpha-hemihydrate, 5 to 20% by mass of hydraulic cement, and 0.5 to 0.75% by mass of superplasticizer. One step of preparing gypsum-based cement composition by mixing 0.2-0.5 mass% defoamer and 0.002-0.01 mass% alkylcellulose, and one of glass sand, sand, glass sand and mixture of sand Is selected as the aggregate, and the gypsum cement composition to the selected aggregate is mixed in a mass ratio of 1: 1 to 3: 1, and the mixture is kneaded in a sufficient amount of water to prepare a wet gypsum-based concrete flooring but It is characterized in that it comprises a second step to have a fluidity enough to form a flat surface and the compressive strength after curing is 2,000 to 4,000 psi.

According to the present invention, when the pump is pumped on the base floor, the surface itself can be leveled without the need for a large-scale floating or finishing process so as to form a lightweight, high-strength gypsum-based concrete floor by simply pouring the wet gypsum-based concrete flooring material. It has enough fluidity, dimensional stability which gives relatively fast curing speed, crack resistance and peeling resistance of hardened flooring, and compressive strength of 2,000 to 4,000 psi of hardened flooring can be realized.

The wet gypsum-based concrete flooring material having the self-smoothness of the present invention is excellent in flowability by mixing and kneading gypsum cement composition and glass sand or aggregates having the same functionality with water at a predetermined ratio. And it is constituent element to make the gypsum-based concrete floor is formed flat and quickly hardened to complete the lightweight high-strength gypsum-based concrete floor just by pouring because of its own smoothness.

Hereinafter, the wet gypsum-based concrete flooring material having its own smoothness will be described through a two-step manufacturing process.

The first step of manufacturing the wet gypsum-based concrete flooring of the present invention is to first prepare a gypsum-based cement composition.

The main component of the cement-based cement composition is calcium sulfate alpha-hemihydrate, and includes hydraulic cement, a superplasticizer, a defoamer, an alkylcellulose, and the like. do.

Calcium sulfate alpha-hemihydrate, which is the first component of the gypsum cement composition, is a type of gypsum, and among them, belongs to the alpha (α) type calcined gypssum.

An example of calcium sulfate alpha-hemihydrate is that manufactured by EK Industries, to which the applicant of the present invention belongs, which has a typical purity of 97.5%, a standard consistency of 40 to 41, and Vicat. The curing time is 20-30 minutes, and the compressive strength for one hour immediately after curing is very high, about 2,000-4,000 psi.

The calcium sulfate alpha-hemihydrate is prepared so as to contain 70% by mass or more of the whole gypsum cement composition, and is preferably formulated to maintain a content range of 79 to 86% by mass.

Hydraulic cement, the second component of gypsum-based cement composition, is cement hardened by chemical interaction with water. Typical types of cement include portland cement, alumina cement, fly ash, Silica fume and the like.

Among them, portland cement is used in the present invention, and V-type portland cement is used among I- and V-type portland cements. V-type Portland cement has excellent sulfuric acid resistance and hardly occurs in dimensional change due to shrinkage and expansion occurring during curing when wet, thereby making it possible to manufacture high-strength concrete flooring. On the other hand, if the use of the hydraulic cement that is weak in dimensional changes, the concrete flooring material of the present invention may be peeled from the base of the base due to the generation of the dimensional change.

In the gypsum cement composition of the present invention, the content of hydraulic cement is preferably 5 to 20% by mass of the total composition, more preferably 10 to 15% by mass.

Next, the remaining trace components of the gypsum cement composition in addition to the calcium sulfate alpha-hemihydrate and hydraulic cement will be described.

The high fluidizing agent is one of the compounds added to the cement according to the mixing ratio of water and cement to give higher wettability or slump to the wet mixture. As the high-purifying agent of the present invention, naphthalene sulfonates, naphthalene sulfonate-formaldehyde condensates, calcium lignosulfonate, melamine sulfonate-formaldehyde concentrate (melamine sulfonates) sulfonate-formaldehyde condensates) and polycarboxylic acids.

The content of the high fluidizing agent is generally 0.5 mass% or more, and in the present invention, it is preferable to be contained within the range of 0.5 to 0.75 mass%.

On the other hand, in addition to the high fluidizing agent (water reducing agents, plasticizers, cement dispersing agents) compounds such as cement dispersing agent (cement dispersing agents), if any compound can be used if it can exhibit the desired fluidity (fluidity) effect It is okay.

As other trace components of gypsum-based cement compositions, antifoaming agents include tributyl phosphate, silicones, borate esters, petroleum derivatives and tert-butyl phthalates. Select one and use it.

The content of the antifoaming agent is to be 0.2% by mass or more of the gypsum-based cement composition. In the present invention, the content of the antifoaming agent is preferably within the range of 0.2% by mass to 0.5% by mass.

This is sufficient to prevent the formation of bubbles so that after the application of the wet gypsum-based concrete flooring air bubbles are formed and rise to the flooring surface, unsightly cavities, well known as bugholes in this field, are not formed. It is enough.

And the gypsum-based cement composition of the present invention contains a trace amount of alkyl cellulose. Alkylcellulose is added in a minimum amount in a range effective to increase the glass sand or sand suspension uniformity of the wet composition and to reduce the water released on the surface of the wet gypsum-based concrete flooring of the present invention during curing. At this time, if the content of the alkyl cellulose is too high, the desired strength and fluidity of the wet composition will not be realized.

As the alkyl cellulose, one selected from hydroxyalkyl celluloses and 2-hydroxypropyl cellulose is used. The content of the alkyl cellulose is generally to be 0.002% by mass or more of the gypsum-based cement composition, in the present invention, it is preferable to be contained within the range of 0.002 to 0.01% by mass.

In conclusion, in the first step, 79 to 86% by weight calcium sulfate alpha-hemihydrate, 5 to 20% by weight hydraulic cement, 0.5 to 0.75% by mass of a high fluidizing agent, and 0.2 to 0.5% by mass of antifoaming agent Gypsum-based cement composition of the present invention is prepared by mixing a C2-0.001-0.01 mass% alkyl cellulose.

In preparing the gypsum-based cement composition mixture, the components are added in turn and stirred for about 2 minutes with a paddle type or ribbon type stirrer so that they are well mixed. Once the agitation is complete, pack in packs, but typically pack 40 kg (or 80 lb.) per pack.

Next, in the second step of the present invention, the gypsum-based cement composition mainly composed of calcium sulfate alpha-hemihydrate is mixed with fine aggregates and kneaded in a sufficient amount of water to prepare wet gypsum-based concrete flooring. To complete.

In this step, a method of manufacturing a wet gypsum-based concrete flooring material and pouring the basic gypsum-based concrete flooring material together will be described together.

In the second step, a sufficient amount of water is added to the gypsum-based cement composition and the fine aggregate mixed in a predetermined ratio and stirred for 1 ~ 2 minutes to prepare a uniform slurry.

In this case, as the aggregate of the present invention, glass sand or sand or a mixture of glass sand and sand or an equivalent aggregate is used. Then, the gypsum-based cement composition to (:) the selected agglomerates are mixed at a mass ratio of 1: 1 to 3: 1, and more preferably at a mass ratio of 1.5: 1 to 2.25: 1. In other words, the content of each aggregate and the aggregate having the equivalent function is 10 to 60 mass% of the gypsum concrete flooring mixture, more preferably 25 to 50 mass%, most preferably 40 to 50 mass. To be%.

The glass sand may be used in the form of glass powder (or granules), in particular, recycling various waste glass products such as glass bottles and glass bowls. That is, by using the recycled glass sand (crushed and crushed waste glass products) processed into 0.3 ~ 0.6㎜ range.

For example, agglomerates such as glass sand having a size sufficiently passing through Standard sieve screen NO. 30 (595 microns), but more preferably U.S. Standard sieve screen No.40 (420microns) aggregates, such as glass sand, is to ensure that more than 5% by mass of the aggregate. More preferably, U.S. The standard sieve screen NO.50 (297 microns), such as glass sand sized to pass the aggregate is to contain more than 15% by mass of the aggregate.

The present invention kneads a mixture of water and the gypsum-based concrete flooring mixture in a mass ratio of 0.4: 1 to 0.55: 1.

This is because, when the amount of water of the present invention is poured into a single tray of 600 ml of the wet gypsum-based concrete flooring of the present invention completed in a single continuous operation at a height of 12.7 cm in a tray of 15.2 cm x 20.3 cm x 1.9 cm. The dough itself is completely flat without any finishing or finishing process, so it is fluid enough to form a topographically smooth surface, cures quickly, and there is no dust on the surface after curing and a compressive strength of 2,000 to 4,000 psi. That's enough to be.

Since the fluidity of the wet gypsum-based concrete flooring of the present invention is different from that of general cement or the slump, the gypsum-based cement composition having the same or the same slump as the present invention is not the same.

When mixing gypsum-based cement composition and aggregates such as glass sand and water, the necessary fluidity is realized by controlling the amount of water. The addition of a larger amount of water improves the fluidity of the concrete, but the strength of the hardened concrete is increased. Degrades.

In addition, calcium sulphate alpha-hemihydrate has the property of hard gypsum-based concrete flooring to harden very rapidly. Therefore, in most cases, a hardening inhibitor is added to the dry cement composition so that the wet gypsum-based concrete flooring material of the present invention is hardened at a more convenient time. The convenient time is preferably 20 to 120 minutes, most preferably 30 to 90 minutes. The time is obtained by taking a sample of dry gypsum-based cement composition, mixing it with agglomerates and water, such as glass sand at a suitable ratio, and determining the amount of curing inhibitor required to obtain the desired result by measuring the curing time. This technique is obvious to those skilled in the art and need not be described in detail, but the use of sodium citrate should be avoided because it is disadvantageous in terms of fluidity of the wet composition. In the present invention, a protein inhibitor is used as a curing inhibitor, and any other curing inhibitor may be used as long as it does not harm the beneficial properties of the composition according to the present invention.

Any kind of stirrer used to combine the components constituting the wet gypsum-based concrete of the present invention may be used. However, Strong Manufacturing Company. It is advantageous to use stirrers such as PLACER II ^® , GROUTMATE ^® and GROUT-A-MATIC ^® manufactured by Strong Manufacturing Company, Inc. (Pine Bluff, Ark.). Such a device simplifies the production process of building floorings, as it allows for the preparation of wet compositions, pumping, and placement on building floors.

In manufacturing the wet gypsum-based concrete flooring, the composition is pumped onto the building base flooring to form a building flooring. Typical methods are to place a hose on a building base floor, pump a wet mixture, and move the hose end from one place to another to more easily cover the flooring with gypsum-based cement composition. The composition is excellent in its smoothness and does not require a separate treatment.

The surface of the building base floor, such as plywood, oriented strand board, wafer board or concrete, is primed to enhance bonding with the flooring composition, or the wet gypsum of the invention prior to curing. It should be noted that sealers may be treated to prevent excessive penetration of water from the concrete floor to the building base. Examples of such primers and sutures are rewettable latex copolymer emulsions prepared as LevelGREEN FLOOR PRIMER at EK Indusrties, and non-rewettable latex copolymers known as LevelGREEN FLOOR PRIMER. Emulsions and the like. In the case of using the suture, it is preferable to apply a primer thereon after the suture is dried, which is generally required for good bonding of the gypsum crab concrete flooring material of the present invention and its lower base floor.

Once wet gypsum-based concrete floors are pumped, they usually cure within 60 to 90 minutes. However, depending on the degree of coating, the coating is applied after 2 hours for heavy foot traffic and after 24 hours for heavy traffic. And, if the flooring is cured enough to accommodate heavy traffic, carpet, linoleum, tile, wood, or other floor coverings can be laminated onto the gypsum-based concrete flooring. have. Alternatively, the surface can be coated with a suture as described above.

Until now, in the description of the present invention, a gypsum cement composition is prepared mainly based on calcium sulfate alpha-hexahydrate, and a wet gypsum having its own smoothness by mixing and kneading a sufficient amount of water with the gypsum cement composition and mainly recycled glass sand. Although a concrete example of a method of manufacturing a concrete flooring material and the flooring material has been described as an exemplary embodiment, the present invention uses various aggregates other than calcium sulfate alpha-hemihydrate, and aggregates having the same functionality in addition to recycled glass powder. There are many ways to change it.

Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the equivalent of claims and claims.

The present invention can be mainly used in the field of radiant heat applications, such as flooring in residential, commercial, multi-storey apartments.

Claims (7)

79 to 86 mass% calcium sulfate alpha-hemihydrate, 5 to 20 mass% hydraulic cement, 0.5 to 0.75 mass% superplasticizer, and 0.2 to 0.5 mass A first step of preparing a gypsum cement composition by mixing% defoamer and 0.002-0.01 mass% alkylcellulose; One of glass sand, sand, a mixture of glass sand and sand is selected as an aggregate, and the gypsum cement composition to the selected aggregate is mixed in a mass ratio of 1: 1 to 3: 1 and these mixtures are mixed with a sufficient amount of water. Self-smoothness, characterized in that the wet gypsum-based concrete flooring is prepared by pouring it into a fluid, which is fluid enough to form a flat surface by pouring it, and has a compressive strength after curing to be 2,000 to 4,000 psi. Method for producing a wet gypsum-based concrete flooring having a. The method of claim 1, The hydraulic cement is Portland cement (Portland cement) characterized in that the wet gypsum-based concrete flooring manufacturing method having its own smoothness. The method of claim 1, The high fluidizing agent is naphthalene sulfonates, naphthalene sulfonate-formaldehyde condensates, calcium lignosulfonate, melamine sulfonate-formaldehyde concentrates Method for producing a wet gypsum-based concrete flooring having a self-smoothness characterized in that it is produced by selecting one of condensates) and polycarboxylic acids. The method of claim 1, The antifoaming agent is prepared by selecting one of tributyl phosphate (tributyl phosphate), silicone (silicones), borate esters (borate esters), petroleum derivatives and tert-butyl phthalates Method for producing a wet gypsum-based concrete flooring having its own smoothness. The method of claim 1, Glass sand in the aggregate is a wet gypsum-based concrete flooring manufacturing method having a self-smooth, characterized in that the recycled glass sand (recycled glass sand) produced by crushing and crushing the waste glass product within the range of particle size 0.3 ~ 0.6㎜. The method of claim 1, And mixing the gypsum-based cement composition and the aggregate and mixing the mixture with water in a mass ratio of 1: 0.4 to 1: 0.55. The wet gypsum-based concrete flooring material having its own smoothness prepared by the method of any one of claims 1 to 6.