KR20200135109A - Alginate latex precast concrete composition using silica fume - Google Patents

Abstract

The present invention relates to an alginate latex precast concrete composition that introduces alginic acid to compensate for problems such as an increase in costs, difficulty in supplying and demanding materials, and deterioration in constructability due to the use of latex, and improves fluidity and strength by using silica fume. The present invention includes an admixture including: 100 parts by weight of cement; 400 to 500 parts by weight of aggregates; 3 to (15) parts by weight of latex; 0.1 to 0.8 parts by weight of alginic acid; and silica fume.

Description

Alginate latex precast concrete composition using silica fume {ALGINATE LATEX PRECAST CONCRETE COMPOSITION USING SILICA FUME}

The present invention relates to an alginic acid latex precast concrete composition, and more particularly, in order to compensate for problems such as an increase in cost, difficulty in material supply, and decrease in workability due to the use of latex, the introduction of alginic acid and further silica fume It relates to an alginate latex precast concrete composition with improved fluidity and strength.

Concrete is the most fundamental material used to manufacture structures having a certain shape throughout industries such as roads, bridges, and buildings. It is applied in a liquefied state and hardened to maintain a specific shape.

As a type of concrete, there is a latex-modified concrete in which latex, which is a particle of natural rubber extracted from a rubber tree, is mixed with cement in order to enjoy effects such as improving compressive strength, improving flexural strength, and improving adhesion strength.

As a conventional technology for latex-modified concrete, there is Registration Patent No. 10-1239075 (February 26, 2013) (hereinafter, prior art), which has a higher heat absorption rate than the conventional ultra-fast-hard latex-modified concrete, so the outside temperature By minimizing the effect of changes and preventing freezing, we not only increase the durability of concrete structures, but also improve the visibility and traffic stability of lanes at night, and propose a super fast-curing latex-modified concrete composition that can create a comfortable driving environment. have.

However, latex itself is a very expensive material, and as it is collected from a rubber tree, the supply and demand is limited, so the supply and demand is not smooth. Therefore, it is true that the use of latex has an economic burden and a burden on the supply and demand of materials despite the many advantages described above.

In addition, the core properties of concrete include fluidity (workability), compressive strength, and economy, and the necessity of a technology that can improve this from the conventional latex-modified concrete is reconsidered.

An object of the present invention is to solve the above problems, and it is an object of the present invention to minimize the amount of latex used to compensate for problems such as an increase in cost, difficulty in supplying and demanding materials, and deterioration in workability due to the use of latex.

In addition, it aims to significantly improve fluidity and strength, especially among the core properties of latex-modified concrete.

The present invention for the purpose of solving the above problems includes 100 parts by weight of cement, 400 to 500 parts by weight of aggregate, and 3 to 15 parts by weight of latex, and 0.1 to 0.8 parts by weight of alginic acid, and an admixture including silica fume Is composed.

The present invention having the above configuration minimizes the amount of latex by introducing alginic acid, thereby improving problems such as an increase in unit cost, difficulty in supplying and demanding materials, and deterioration in workability due to the use of latex.

In addition, silica fume is used as an admixture, and by appropriately controlling its content, it has the effect of greatly improving fluidity and strength, especially among the core properties of latex-modified concrete.

1 is a chart comparing the economics between the present invention and the prior art.
Figure 2 is a chart comparing the quality between the present invention and the prior art.

The present invention will be described in detail in the text of the bar, implementation (態樣, aspect) (or embodiment) that can apply various changes and can have various forms. However, this is not intended to limit the present invention to a specific form of disclosure, and it should be understood that all changes, equivalents, and substitutes included in the spirit and scope of the present invention are included.

The terms used in the present specification are only used to describe specific embodiments (sun, 態樣, aspect) (or examples), and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as ~include~ or ~consist~ are intended to designate the presence of features, numbers, steps, actions, components, parts, or a combination thereof described in the specification, but one or more other features It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance the possibility of being added.

Unless otherwise defined, all terms, including technical and scientific terms, used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in this application. Does not.

The ~1~, ~2~, etc. described in the present specification will only be referred to to distinguish different constituent elements, and are not limited to the order of manufacture, and the names in the detailed description and claims of the invention It may not match.

The present invention is an alginic acid latex precast concrete composition in which alginic acid is introduced to compensate for problems such as an increase in cost, difficulty in material supply, and decrease in workability due to the use of latex, and further improves fluidity and strength by using silica fume. It is about.

Hereinafter, an alginate latex precast concrete composition (hereinafter, the present composition) according to the present invention will be described in detail with reference to the accompanying drawings.

This composition largely contains cement, aggregate, latex, alginic acid, and admixture.

For each composition, 100 parts by weight of cement may be included. Here, the cement is fixed at 100 parts by weight in order to be able to change the ratio of the other composition based on the cement to be mixed. Cement is a basic material that generally forms concrete, and Portland cement can be used as a representative. The concept of including cement in the concrete composition is widely known, and a more detailed description of the cement will be omitted.

This cement is preferably mixed with water, and the ratio between water and cement is preferably about 35 W/C (%).

Next, the composition further comprises an aggregate, the aggregate is a general composition of the concrete composition, it is preferable to include 400 to 500 parts by weight based on 100 parts by weight of cement.

In addition, the aggregate may include fine aggregate and coarse aggregate, the fine aggregate ratio of the fine aggregate is preferably composed of 56 S/a (%), and the maximum dimension of the coarse aggregate is preferably composed of 19 mm.

These aggregates are preferably composed of about 1: 0.7 ~ 0.8 ratio of the fine aggregate and the coarse aggregate.

Next, the composition further contains latex, which is a particle of natural rubber extracted in a liquid form from a rubber tree, the specific gravity is 0.98, the component is water 60%, rubber 35%, soap, fatty acid, sterol, etc. 1 %, inorganic matter 0.4%, etc. It is used by concentrating the rubber component content to 60 ~ 70% by various methods such as centrifugation, cleaning, and evaporation. SB latex may be used as a representative of such latex.

Such latex improves workability by improving the fluidity of concrete, and precast concrete containing latex has the advantage of excellent adhesion, waterproofness, and flexural strength. In addition, it also has the advantage of having an anti-slip function by itself.

In the present composition, it is preferable that the latex contains 3 to 15 parts by weight relative to 100 parts by weight of cement, but when less than 3 parts by weight is used, the effect is insignificant, and when it is used in excess of 15 parts by weight, there is a problem of lowering the economy .

In particular, the present invention has a disadvantage in that the latex itself is a very expensive material in using latex, and the supply and demand is not smooth due to the limited supply and demand.It is advantageous in terms of economy and workability to minimize the content of latex. Since it has, the present invention has a main purpose to further improve the effect provided by the latex while minimizing the content of such latex.

Next, the composition further contains alginic acid, which is a type of polysaccharide that constitutes the cell membrane by being contained in seaweeds, especially brown algae (eg, kelp, seaweed, etc.). It has a molecular weight of about 15000 and has a property of swelling without dissolving in water. In particular, alginic acid is insoluble, but sodium salt is soluble in water and has a very high viscosity.

Such alginic acid, particularly in concrete, produces a gel, has dispersion, emulsification and adhesion properties, aids in mixing of concrete, improves application and workability, and provides solid adhesion and viscosity.

In the present composition, alginic acid is preferably contained in an amount of 0.1 to 0.8 parts by weight relative to 100 parts by weight of cement, but when using less than 0.1 parts by weight, the effect is insignificant, and alginic acid is more expensive than the above latex, 0.8 weight If it is used in excess of part, there is a disadvantage in that the economical efficiency is deteriorated and the compressive strength is less than the standard value.

The present invention has the effect of providing a precast concrete with improved quality by adding the above advantages of alginic acid by introducing alginic acid to significantly reduce the content of latex to improve economy.

In one embodiment, the composition is characterized in that alginic acid may be included by mixing seaweeds with cement, and seaweeds, especially brown algae, are directly mixed in the process of mixing cement or latex. In this case, it is preferable that the operation of washing the seaweeds with dilute sulfuric acid is preceded.

In the above embodiment, there is an advantage that the extraction of alginic acid can be naturally performed by heat generated in the process of mixing cement or latex, and in particular, the remnants of seaweeds in which the pores generated inside the concrete composition are melted as seaweeds melt by the heat of hydration. It has the advantage of filling up.

The effects of the present invention will be described with reference to Fig. 1, which is a chart comparing economics between the present invention and the prior art, and Fig. 2, which is a chart comparing quality between the present invention and the prior art.

1 shows the ratio of the latex mixed in the ultra-fast cement 400kg / m ³ . It can be seen that in the existing method, 120kg/m ³ of latex was used, whereas 20 kg/m ³ of the present invention was used. The present invention reduce the amount of the latex 100kg / m ³ by a 1.2kg / m ³ The alginate used. The unit price of latex is 2800 won per kg, and the unit price of alginic acid is 10000 won per kg. Accordingly, it can be seen that the total cost is reduced to 20% compared to the existing method.

FIG. 2 shows a comparison of quality when only ultrafast cement is used, when ultrafast cement and latex are used, and when ultrafast cement and latex and alginic acid are used.

First, comparing the case of using'ultra-fast-hard cement' and'super-fast-hardening cement + latex', it can be seen that the case of using a mixture of ultra-fast-hard cement and latex is excellent in all aspects of compressive strength, flexural strength and adhesion strength.

Next, comparing the case of using'ultra-fast cement + latex' and the case of using'ultra-fast cement + latex + alginic acid', compressive strength, flexural strength, adhesion strength, and freeze-thaw when using a mixture of ultra-fast cement, latex and alginic acid It can be seen that it is excellent in all aspects of resistance, and through this, it can be seen that in the case of using'ultra-fast-hard cement + latex + alginic acid', it is excellent in terms of quality, or at least the same level of quality can be guaranteed.

Therefore, it can be clearly seen that the present invention has the same or superior quality compared to the concrete composition in which latex and ultra-fast cement are mixed, and has a distinct advantage in economy.

Next, the composition further includes an admixture containing silica fume, which reduces friction between the micro-filler effect of filling the pores of the cement particles in the form of fine solid particles and the aggregate particles, the mortar, and the pump and the transport hose. As a result, it increases wordability and pumpability, improves mortar adhesion, material separation resistance, and reduces bleeding.

In particular, silica fume has the advantage of superior compressive strength compared to other pozzolanic reactive admixtures such as fly ash, and through this, it is possible to construct precast concrete with improved strength.

It is preferable that the silica fume contains 1 to 5 parts by weight relative to 100 parts by weight of cement, but if it is used in less than 1 part by weight, sufficient compressive strength cannot be obtained, and if it is used in excess of 5 parts by weight, the fluidity is excessive. In particular, there is a problem that the initial strength development time is delayed. The most preferred silica fume content is 2.21 parts by weight.

[Experimental Example]

The most ideal blending ratio of the composition derived through repeated experiments is shown in Table 1 below.

As an experimental method, water, cement, fine aggregate, coarse aggregate, latex, seaweed, admixture, and retardant are added to a blender and mixed, and then the mixed composition is poured into a mold for producing a test concrete block, compacting, plastering, A concrete block for testing was manufactured through a curing process.

water
(kg) cement
(kg) Fine aggregate
(kg) Coarse aggregate (kg) Latex
(kg) Seaweed
(kg) Admixture
(kg) Retardant
(kg) 1.000 3.620 9.100 7.200 0.030 0.004 0.080 0.010

The physical properties of the prescast concrete blended according to the blending ratio of Table 1 are shown in Table 2 below, and it can be seen that it shows excellent fluidity and compressive strength.

Slump(cm) Compressive strength (Mpa) 21Mpa standard 18 23.9 O.K.

On the other hand, the present composition is characterized in that it may further include 0.1 parts by weight of a functional additive relative to 100 parts by weight of cement. This functional additive is self-granulated between cement particles to improve structural stability and rust prevention. In particular, it enhances the kneading performance between cement particles and aggregates, latex, seaweed, admixtures, etc. through self-heating by sunlight.

These functional additives are based on 100 parts by weight of tetrachlorogold(III) acid, 5 parts by weight of manganese dioxide, 3 parts by weight of silica gel, 3 parts by weight of surfactant, 1 part by weight of bentonite, 40 parts by weight of hydroxyethyl acrylate, and ethylenediamine tetraacetate It characterized in that it contains 3 parts by weight.

Tetrachlorogold(III) acid, manganese idealized and silica gel (hereinafter referred to as exothermic particles) are added to allow self-heating under sunlight so that the cement of the composition and each composition can be fused and kneaded on their own. Since the kneading time is longer than 24 hours, it is a configuration provided to shorten the kneading time to within 30 minutes by providing a temperature condition of about 40 to 60°C.

For each composition, tetrachlorogold(III) acid (HAuCl4) is a pale yellow crystal obtained by dissolving gold in aqua regia or dissolving gold(III) chloride in hydrochloric acid. It is preferable that those having a particle diameter of 15 to 30 nm are used. Compositions constituting the following functional additives are determined based on 100 parts by weight of tetrachlorogold(III) acid.

And manganese dioxide (MnO2) is a compound that combines manganese and supernatant, and is added to facilitate dispersion of heat-generating particles and optimize the utilization area of sunlight wavelength. Among the transition metals of four cycles such as titanium, chromium, nickel, and copper, far-infrared rays It was adopted because of its good radiant rate and radiant energy efficiency in the area. Such manganese dioxide is prepared by sintering at about 1000°C in the presence of oxygen, and the smaller the particle diameter, the greater the induction heating effect, so it is preferable to use an average particle diameter of 10 to 100 nm, and the amount of the manganese dioxide is preferably used as a result of repeated experiments. It is preferably 5 parts by weight as seen.

And silica gel (Silica Gel) is added to sustain the exothermic effect of the exothermic particles and shorten the exothermic saturation time, and as a result of repeated experiments, it was confirmed that the optimum exothermic efficiency was exhibited when 3 parts by weight were included.

These exothermic particles are made into an aqueous solution by adding a small amount of citric acid after heating an aqueous tetrachloroauric acid solution at about 100° C. for 10 minutes, and then mixing and dispersing manganese dioxide and silica gel in the above mixing ratio, It is manufactured through the drying process of. Here, the specific content of the drying process is to follow the known technology and the general common sense of a person skilled in the art.

Next, surfactants, bentonite, hydroxyethyl acrylate, and ethylenediaminetetraacetate (hereinafter referred to as protective particles) are used to add the protective function and rust preventive function of the present composition by acting with the silica fume.

For each composition, a surfactant is added to improve workability, and bentonite is added as a viscoelastic modifier to prevent dropping, thereby performing the function of a thixotropic agent. These surfactants and bentonite are sufficient if commercially available products are added in the above composition ratio with reference to known techniques and common sense. If the composition is out of the above composition ratio, the flowability is excessive or less than the reference value.

And hydroxyethyl acrylate (Hydroxyethylacrylate) is added as an adhesion promoter, and was particularly adopted because it has the advantage of excellent curability. As a result of repeated experiments, the preferred amount is 40 parts by weight, and when used in less than the composition ratio, the adhesion promoting effect is insignificant, and when used in excess of the composition ratio, the volatility increases and the toxicity becomes strong.

In addition, ethylenediaminetetracetate is added as an adsorption enhancing agent, and as a result, adhesion is improved by enhancing the adsorption power during initial formation of protective particles. As a result of repeated experiments, it was confirmed that the amount used to express the optimal adsorption enhancing effect was 3 parts by weight.

These protective particles are added to a stirrer together with the above-described heating particles, mixed and stirred, and then prepared through a predetermined drying and curing process.

The present invention described above with reference to the accompanying drawings can be variously modified and changed by a person skilled in the art, and such modifications and changes should be construed as being included in the scope of the present invention.

Claims (4)

100 parts by weight of cement;
400 to 500 parts by weight of aggregate;
3 to 15 parts by weight of latex;
0.1 to 0.8 parts by weight of alginic acid; And
Admixtures including silica fume;
Alginate latex precast concrete composition comprising a.
The method according to claim 1,
The silica fume is an alginate latex precast concrete composition, characterized in that it contains 1 to 5 parts by weight based on 100 parts by weight of the cement.
The method according to claim 1,
The alginic acid is alginic acid latex precast concrete composition, characterized in that contained by mixing seaweeds in the cement.
The method according to claim 1,
Compared to 100 parts by weight of the cement, further comprising 0.1 parts by weight of a functional additive,
The functional additive is, based on 100 parts by weight of tetrachlorogold(III) acid, 5 parts by weight of manganese dioxide, 3 parts by weight of silica gel, 3 parts by weight of surfactant, 1 part by weight of bentonite, 40 parts by weight of hydroxyethyl acrylate, and ethylenediamine tetra Alginate latex precast concrete composition comprising 3 parts by weight of acetate.

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