KR20210086782A - Composite of lightweight dry mixed cement mortar by using ash and manufacturing method thereof - Google Patents

Abstract

Disclosed are a lightweight dry cement mortar composition, and a method for producing the same. According to a preferred embodiment of the present invention, a lightweight dry cement mortar composition is provided, wherein the composition comprises 20-30 wt% of ordinary cement, 25-75 wt% of bottom ash, 1-10 wt% of fly ash, 1-3 wt% of expanded perlite or vermiculite, 5-15 wt% of blast furnace slag, and 1-3 wt% of calcium sulfoaluminate. According to the present invention, it is possible to enhance the efficiency of work by reducing the weight of a dry cement mortar composition, and to reduce the safety and fatigue of workers. Although the dry cement mortar composition is lightweight, the present invention has excellent surface finish and surface adhesion. By using all ash, which is a by-product of fossil fuel combustion, the present invention has the effect of greatly contributing to the environment.

Description

A lightweight dry cement mortar composition using ash and a method for manufacturing the same

The present invention relates to a cement mortar composition and a method for manufacturing the same, and more particularly, to a lightweight dry cement mortar composition using ash and a method for manufacturing the same.

Cement is currently the most widely used building material, and the most widely used and most widely used cement is usually Portland cement type 1 (hereinafter referred to as ordinary cement).

Such cement is generally used by mixing aggregates such as sand or gravel with water, and in particular, it is used together with sand for plastering.

For this reason, there are cases where cement and sand are mixed in advance and packaged before being sold, which is often called dry cement mortar or dry cement mortar composition.

Meanwhile, in Korea, dry cement mortar prepared by mixing cement and sand was marketed in the 1980s, when the construction industry was active.

These dry cement mortars are widely used because there is no need to separately prepare sand at the site, and it can be used directly with only water bibim in a narrow place.

However, in the case of such dry cement mortar, it is widely used with a packing weight of 40 kg/bag in consideration of the fact that the density is generally 1,850 kg/m3 due to the mixing of cement and sand and the amount of work in the field.

However, due to this, repeated transportation of dry cement mortar and plastering of heavier water kneading mortar when water is added to it increases the fatigue limit, lowering work efficiency, and reducing the weight of the product is urgently required due to muscle and joint diseases of the worker.

On the other hand, in the past, various studies and attempts have been made to reduce the weight of dry cement mortar. However, in the case of plastering, where dry cement mortar is widely used, even if the dry cement mortar composition is lightened, its surface adhesion, surface finish, etc. There was a problem that this significantly lowered.

In order to solve the problems of the prior art as described above, the present invention proposes a lightweight dry cement mortar composition that can reduce the weight of the dry cement mortar composition to increase work efficiency, and also reduce the safety and fatigue of workers.

In addition, it is to propose a lightweight dry cement mortar composition excellent in surface finish and surface adhesion even if the weight is reduced.

Other objects of the present invention will be easily understood through the description of the following embodiments.

In order to achieve the above object, according to one aspect of the present invention, there is provided a lightweight dry cement mortar composition.

According to a preferred embodiment of the present invention, in the lightweight dry cement mortar composition, usually 20 to 30% by weight of cement; 25-75 wt % bottom ash; 1-10 wt% fly ash; 1-3% by weight of expanded perlite or vermiculite; 5-15 wt% of blast furnace slag; And there is provided a lightweight dry cement mortar composition comprising 1 to 3% by weight of calcium sulfoaluminate.

The lightweight dry cement mortar composition may further include 1-3 wt% of slaked lime.

The lightweight dry cement mortar composition may further include methylcellulose in an amount of 0.1 wt% or less.

The fly ash may be a heavy oil fired fly ash.

The bottom ash may have a particle size of 2.0 mm or less, and a density of 800 to 1,000 kg/m3.

The expanded perlite may have a particle size of 1.2 mm or less, and a density of 50 to 100 kg/m3.

The vermiculite may have a particle size of 1.6 mm or less and a density of 100 to 200 kg/m3.

The calcium sulfoaluminate may be a mixture pulverized by mixing and pulverizing bauxite, limestone, and gypsum at a predetermined mixing ratio, calcined in a kiln at 1,350° C., and then pulverized to a specific surface area of about 4,000 cm 2 /g.

According to another aspect of the present invention, there is provided a method for preparing a lightweight dry cement mortar composition.

According to a preferred embodiment of the present invention, there is provided a method for manufacturing a lightweight cement mortar composition, the method comprising: crushing bottom ash; sieving the crushed bottom ash; Dry mixing the sieved bottom ash and fly ash, ordinary cement, expanded perlite or vermiculite, blast furnace slag, calcium sulfoaluminate and anhydrite; and storing and/or packaging the dry blended composition. The composition is usually 20-30 wt% cement, 25-75 wt% bottom ash, 1-10 wt% fly ash, 1-3 wt% expanded perlite or vermiculite, 5-15 wt% blast furnace slag, and calcium sulfoaluminate There is provided a method for producing a lightweight dry cement mortar composition, characterized in that it comprises 1 to 3% by weight.

The dry mixing of the sieved bottom ash and fly ash, cement, expanded perlite or vermiculite, blast furnace slag and calcium sulfoaluminate further includes slaked lime, and the slaked lime may be further included in 1-3 wt% .

The dry mixing of the sieved bottom ash and fly ash, cement, expanded perlite or vermiculite, blast furnace slag and calcium sulfoaluminate further comprises methyl cellulose, and the methyl cellulose is 0.1% by weight or less. may be included.

The step of sieving the crushed bottom ash may be performed using a sieve of 2 mm or less.

In the step of storing and/or packaging the dry-mixed composition, the dry-mixed composition may be packaged in a bag of 20-25 kg.

As described above, according to the lightweight dry cement mortar composition according to the present invention, there is an effect that the dry cement mortar composition can be made light in weight, thereby increasing work efficiency and reducing the safety and fatigue of workers.

In addition, although the dry cement mortar composition is lightweight, there is an effect of excellent surface finish and surface adhesion.

and fossil fuels such as coal and heavy oil. By using both ash, such as bottom ash and fly ash, which are by-products of combustion, it has the effect of greatly contributing to the environment.

1 is a graph showing a comparison of the shrinkage change of a lightweight dry cement mortar composition according to a preferred embodiment of the present invention.
Figure 2 is a flow chart showing a sequence in which the manufacturing method of the lightweight dry cement mortar composition according to a preferred embodiment of the present invention is made.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

In describing each figure, like reference numerals have been used for like elements. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component.

and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being “connected” or “connected” to another component, it is understood that the other component may be directly connected or connected to the other component, but other components may exist in between. it should be

On the other hand, when it is mentioned that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention.

The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings, but the same or corresponding components are given the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted.

First, a light dry cement mortar composition subject to the present invention will be described.

As described above, the lightweight dry cement mortar composition is sold after pre-mixing cement and sand and packaging, and is generally packaged in units of 40 kg/bag considering the amount of work.

In addition, this lightweight dry cement mortar composition is widely used for plastering work. In the present invention, it is important to reduce worker fatigue and increase productivity by lowering the density of the lightweight dry cement mortar composition and making the weight less than 40 kg even if packaged in the same unit. Do.

In addition, it is important not to cause a decrease in strength or construction shrinkage even though the lightweight dry cement mortar composition is lightweight in consideration of the intended use and purpose.

In order to satisfy these requirements, the lightweight dry cement mortar composition according to a preferred embodiment of the present invention is usually 20 to 30% by weight of cement, 25 to 75% by weight of bottom ash, 1 to 10% by weight of fly ash, expanded perlite or vermiculite 1 ∼3 wt%, blast furnace slag 5∼15 wt%, and calcium sulfoaluminate 1-3 wt%.

In addition, it may further include 0.1 wt% or less of methylcellulose.

In the case of methylcellulose, the lightweight dry cement mortar composition is for improving troweling in plastering work, and may not necessarily be included if the lightweight dry cement mortar composition according to the present invention is not used for plastering.

In addition, it may further include 1 to 3% by weight of slaked lime.

However, since fly ash is included in the present invention, shrinkage cracks and lifting defects can be prevented due to the lime component of the fly ash, so slaked lime is not necessarily included.

On the other hand, as can be seen from the above composition ratio, the dry cement mortar composition according to the present invention does not use sand.

Looking at the constituent materials and functions, first, ordinary cement is generally widely used ordinary cement, and there is no particular limitation on this.

Bottom ash is used in the present invention to reduce the weight of the dry cement mortar composition, and as is widely known, bottom ash is a by-product of a thermal power plant, which is ash remaining at the bottom of the remaining coal ash after burning coal.

Fly ash is a by-product of combustion of heavy oil, which is ash remaining at the top of the ash remaining after heavy oil is burned.

That is, in the present invention, bottom ash and fly ash, which are by-products of combustion of fossil fuels such as coal or heavy oil, are all will be used

In general, fly ash is collected through a dust collector, and unlike bottom ash, it has a very small particle size and is widely known as a material that improves workability.

In addition, various types of fly ash are possible, but more preferably, it may be a heavy oil burning fly ash.

This heavy oil-fired fly ash is a by-product collected in the dust collector of a heavy oil-fired boiler, and its main chemical components are known as anhydrite and quicklime.

Therefore, as described above, fly ash, especially heavy oil burning fly ash, contains some lime component, thereby preventing shrinkage cracks and lifting defects.

Therefore, in the present invention, by mixing the bottom ash and the fly ash in an appropriate ratio, the workability is further improved and the effect of preventing shrinkage cracks and the like can be expected.

The expanded perlite or vermiculite is performed while functioning as a fine aggregate together with the bottom ash, and in the present invention, it is preferable to crush it into different particle sizes to improve the compactness of the aggregate, but is not limited thereto.

When using bottom ash and expanded perlite or vermiculite as fine aggregates, the particle size and density may preferably be as shown in [Table 1] below.

properties of fine aggregates Item granularity Density (kg/m3) bottom ash 2.0 mm 800 - 1,000 inflated perlite 1.2 mm 50 - 100 vermiculite 1.6 mm 100 - 200

Blast furnace slag is used to supplement the strength of mortar, and to prevent cracking due to drying shrinkage, 1-3 wt% of calcium sulfoaluminate (4CaO.3Al2O3.SO3) and 1-3 wt% of anhydrite (CaSO4) and The lime component of fly ash or additionally added slaked lime (CaO or Ca(OH)2) produces needle-shaped ethrinzite hydrate (3CaO.Al2O3,3CaSO4.32H2O), By densely filling the voids, the needle-like crystals make the cement hardened body or concrete structure dense, thereby increasing the strength in a short period of time and suppressing cracks by compensating for drying shrinkage. The chemical equation for the formation of such etrinzite hydrate is as follows.

[Equation 1]

4CaO.3Al2O3.SO3 + CaSO4 + CaO ----> 3CaO.Al2O3.3CaSO4.32H2O

On the other hand, methyl cellulose may be included in order to improve the water retention and stickiness of the mortar. In this case, the content ratio is preferably 0.1 wt % or less.

And for the production of calcium sulfoaluminate, bauxite, limestone, and gypsum are combined and pulverized at a certain mixing ratio, calcined in a kiln at about 1,350 o C, and finely pulverized to a fineness (blain value) of about 4,000 cm2/g can be used. .

In addition, when slaked lime is additionally added, the strength of the mortar can be supplemented, and when the lightweight dry cement mortar according to the present invention is used for plastering work, an effect of improving workability (troweling) can be expected.

When the lightweight dry cement mortar according to the present invention thus produced is constructed, the target physical properties are shown in Table 2 below.

These target properties are not yet established in the Korean industrial standard for lightweight dry cement mortar, so the physical performance of the present invention cannot be prepared for the Korean industrial standard. Based on the existing industrial standard KS L 5220 of dry cement mortar for general plastering. It was set as the target physical property that the performance beyond that generate|occur|produced.

Target properties of lightweight dry cement mortar setting time Compressive strength (MPa) cracks due to drying shrinkage sequel closing 7 days 28 days 28 days dry curing 1 or more 8 or less 7 or more over 10 No shrinkage and no cracks

In order to meet these target properties, an experiment was performed to find the optimal mixing ratio, that is, the composition ratio, using various mixing ratios as shown in [Table 3] below.

mixing ratio Item Example 1 Example 2 Example 3 Example 4 bottom ash fine aggregate weight % 45 50 55 47 Expanded Perlite Fine Aggregate weight % 3 3 3 - Vermiculite Fine Aggregate weight % - - - 3 plain cement weight % 32 29 26 32 Blast Furnace Slag weight % 12 10 8 8 fly ash weight % 4 4 4 5 Calcium sulfoaluminate weight % 2 2 2 2 slaked lime weight % 2 2 2 3 methylcellulose weight % 0.05 0.05 0.05 0.05

The results of measuring each physical performance according to the above-mentioned mixing ratio are shown in [Table 4] below.

physics performance Item Example 1 Example 2 Example 3 Example 4 Density of dry mortar kg/m3 1,100 1,080 1,060 1,080 Density of water dough mortar kg/m3 1,500 1,490 1,480 1,490 Density of the hardened body kg/m3 1,370 1,360 1,358 1,369 lethargy % 38 38 38 38 setting time sequel hours: minutes 5:12 5:35 5:39 5:03 closing hours: minutes 6:20 6:55 7:10 6:08 compressive strength 7 days Mpa 13 12 8 12 28 days Mpa 20 19 15 19 content of fine aggregate % 48 53 58 50

In addition, the results of comparing these physical performance results with the conventional industrial standard KS L 5220 of dry cement mortar for general plastering are shown in [Table 5] below.

Physical performance of lightweight dry cement mortar Item the present invention Based on KS L 5220 compressive strength 7 days MPa 12 7 or more 28 days MPa 20 over 10 setting time sequel hours: minutes 5:35 - closing hours: minutes 6:55 - cracks due to drying shrinkage No cracks -

In particular, in order to compare the performance against drying shrinkage, a lightweight dry cement mortar according to the present invention was prepared at the mixing ratio as shown in Table 6, and the superiority of the present invention was demonstrated with reference to FIG. 1, which compared the drying shrinkage results. First, in [Table 6] below, it is the mixing ratio for testing the construction shrinkage performance due to the addition of fly ash.

As the fine aggregate, a mixture of bottom ash and expanded perlite or vermiculite was used as described above, and heavy oil burning fly ash was used as the fly ash.

division Weight ratio formulation (%) remark fine aggregate admixture cement Distilled Fired Fly Ash Plain 57 0.1 27 0 Example 1(A) 57 0.1 26 One Example 2(B) 57 0.1 24 3 Example 3(C) 57 0.1 22 5 Example 4(D) 57 0.1 21 7

1 is a graph showing a comparison of shrinkage changes of a lightweight dry cement mortar composition according to a preferred embodiment of the present invention. It can be seen that the change decreases.

In addition, it can be seen that as the amount of fly ash increases, the degree of drying shrinkage is improved, and thus, the amount of cement can be relatively reduced slightly.

In addition, the results of examining the performance of the lightweight dry cement mortar according to the present invention before construction, that is, when packaged and sold, are shown in [Table 7] below.

Comparison of the present invention and the conventional lightweight dry cement mortar Item the present invention conventional dry cement
mortar Density of dry cement mortar kg/m3 1,000 - 1,100 1,850 Coma (W/C) % 37 - 39 18 Density of water dough mortar kg/m3 1,400 - 1,500 1950 Density of the hardened body kg/m3 1,300 - 1,400 1.920 Product required per area kg/m2.mm t 1.05 - 1.15 1.70 Surface area per product m2.mm t/cannon 22.5 - 24.5 23.5 Surface area per product m2.18mm t/cannon 1.25 - 1.35 1.30 packaging weight kg/pack 25 40

As described above, the lightweight dry cement mortar composition according to the present invention reduces the weight per bag by about 15 kg or more compared to the prior art, and there is no significant difference in the plastering area. It can be confirmed that cracks due to construction shrinkage do not occur.

Therefore, the dry cement mortar composition can be lightened to increase work efficiency and reduce worker safety and fatigue, and although the dry cement mortar composition is lightweight, there is an excellent effect of reducing compressive strength, setting time, cracking, and the like.

And bottom ash, a by-product of fossil fuel combustion, and circulating fluidized bed By using all of the fly ash, it is expected to greatly contribute to the environment.

Hereinafter, with reference to FIG. 2, a procedure for preparing a method for manufacturing a lightweight dry cement mortar composition according to a preferred embodiment of the present invention will be described.

FIG. 2 is a flowchart illustrating a method for preparing a lightweight dry cement mortar composition according to a preferred embodiment of the present invention.

As shown in FIG. 2 , in the preparation of the lightweight dry cement mortar composition according to a preferred embodiment of the present invention, the bottom ash is first crushed (S200).

The crushed bottom ash performs a sieving process (S202). It is preferable to perform this sieve sieve with a sieve of 2 mm or less.

And bottom ash and fly ash, expanded perlite or vermiculite, ordinary cement, blast furnace slag, calcium sulfoaluminate, slaked lime, and methyl cellulose selected through the sieving process are dry-mixed (S204).

As described above, slaked lime and methylcellulose may be selectively included depending on the purpose or use.

Then, the dry-mixed lightweight dry cement mortar composition is stored or immediately packaged in a bag unit (S206).

The packaging of the sack unit may be made in units of 20-25 kg, which are similar in volume and work load to the conventional dry cement mortar composition, but have a reduced weight, but is not limited thereto.

The dry cement mortar composition according to the present invention reduces the weight of the dry cement composition by about 40% compared to the conventional one in consideration of the amount of work or volume, so that workers can carry it much more easily.

Accordingly, it is possible to increase work efficiency and reduce worker safety and fatigue.

In addition, there is an excellent effect of reducing compressive strength, setting time, and cracking, and furthermore, it is possible to greatly contribute to the environment by using both bottom ash and fly ash, which are combustion by-products of thermal power plants.

The above-described preferred embodiments of the present invention have been disclosed for purposes of illustration, and various modifications, changes, and additions may be made by those skilled in the art with respect to the present invention within the spirit and scope of the present invention, and such modifications, changes and Additions should be considered to fall within the scope of the following claims.

Claims (13)

A lightweight cement cement mortar composition comprising:
20-30% by weight of ordinary cement;
25-75 wt % bottom ash;
1-10 wt% fly ash;
1-3% by weight of expanded perlite or vermiculite;
5-15 wt% of blast furnace slag; and
A lightweight dry cement mortar composition comprising 1 to 3% by weight of calcium sulfoaluminate.
According to claim 1,
The lightweight dry cement mortar composition,
Lightweight dry cement mortar composition, characterized in that it further comprises 1 to 3% by weight of slaked lime.
According to claim 1,
The lightweight dry cement mortar composition,
Lightweight dry cement mortar composition, characterized in that it further comprises 0.1% by weight or less of methylcellulose.
According to claim 1,
The fly ash is a lightweight dry cement mortar composition, characterized in that heavy oil burning fly ash.
According to claim 1,
The bottom ash has a particle size of 2.0 mm or less, and a density of 800 to 1,000 kg/m3. Lightweight dry cement mortar composition, characterized in that.
According to claim 1,
The lightweight dry cement mortar composition, characterized in that the expanded perlite has a particle size of 1.2 mm or less and a density of 50-100 kg/m3.
According to claim 1,
The light weight dry cement mortar composition, characterized in that the particle size of the vermiculite is 1.6 mm or less and a density of 100 to 200 kg/m3.
According to claim 1,
The calcium sulfoaluminate is a lightweight dry cement mortar composition, characterized in that it is pulverized by mixing and pulverizing bauxite, limestone, and gypsum at a predetermined mixing ratio in a kiln at 1,350° C. .
A method for preparing a lightweight cement cement mortar composition, comprising:
crushing the bottom ash;
sieving the crushed bottom ash;
Dry mixing the sieved bottom ash and fly ash, ordinary cement, expanded perlite or vermiculite, blast furnace slag and calcium sulfoaluminate; and
storing and/or packaging the dry blended composition.
The composition is usually 20-30 wt% cement, 25-75 wt% bottom ash, 1-10 wt% fly ash, 1-3 wt% expanded perlite or vermiculite, 5-15 wt% blast furnace slag and calcium sulfoaluminate 1 A method for producing a lightweight dry cement mortar composition, characterized in that it comprises ~3% by weight.
10. The method of claim 9,
Dry mixing of the sieved bottom ash and fly ash, ordinary cement, expanded perlite or vermiculite, blast furnace slag and calcium sulfoaluminate,
Further comprising slaked lime, the method for producing a lightweight dry cement mortar composition, characterized in that the slaked lime further comprises 1 to 3% by weight.
10. The method of claim 9,
Dry mixing of the sieved bottom ash and fly ash, ordinary cement, expanded perlite or vermiculite, blast furnace slag and calcium sulfoaluminate,
Further comprising methylcellulose, the method for producing a lightweight dry cement mortar composition, characterized in that the methylcellulose is included in an amount of 0.1% by weight or less.
10. The method of claim 9,
The step of sieving the crushed bottom ash,
A method for producing a lightweight dry cement mortar composition, characterized in that it is carried out using a sieve of 2 mm or less.
10. The method of claim 9,
Storing and/or packaging the dry mixed composition comprises:
A method for producing a lightweight dry cement mortar composition, characterized in that the dry-mixed composition is packaged in 20 to 25 kg units.

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