KR101120078B1 - Method for production of high-performance self-purification concrete using effective micro-organisms - Google Patents

Abstract

The present invention provides a method for producing high-performance self-cleaning concrete comprising the step of curing by adding at least one microorganism selected from the group consisting of effective microorganisms and natto bacteria (Bacillus natto) to mortar or concrete. A high performance self-cleaning concrete produced by the method.

Effective microorganism, natto bacteria, mortar, high-performance midnight concrete, compressive strength, fish toxicity

Description

Method for production of high-performance self-purification concrete using effective micro-organisms}

The present invention relates to a method for producing high-performance self-cleaning concrete using effective microorganisms and concrete prepared by the above method, specifically, selected from the group consisting of effective microorganisms and natto bacteria (Bacillus natto) The present invention relates to a method for producing high-performance self-cleaning concrete comprising the step of curing by adding the above microorganisms to mortar or concrete, and a high-performance self-cleaning concrete produced by the method.

General concrete used up to now is just a simple material for making concrete structures in construction sites, there is no functionality other than the structure after hardening, and environmental problems are continuously raised due to its own toxicity. .

In detail, the commonly used concrete is a strong alkali having a pH of 12.5 to 13, and may cause fatal harm to indoor environments such as carbon dioxide (CO ₂ ), ammonia basic gas, and radon (Rn) when curing raw cement. Harmful hazards occur, which can cause sick house syndrome.

In particular, carbon dioxide and base generated when the concrete is hardened as the main cause to corrode the reinforcement, such as reinforced, there is a problem that the structure is weakened due to the expansion crack due to the steel corrosion and shortened building life.

In addition, when the pH of healthy concrete is 12 to 13, the oxidizing bacteria cannot be activated, but when the concrete is carbonated under the influence of carbonic acid gas and the pH is lowered to 8 to 9, the oxidizing bacteria predominantly grow in the area and the pH of the concrete surface is lowered. This provides an environment in which the following sulfated bacteria are proliferated. Then, finally, the aerobic sulfated bacteria tiobacillus tiooxidance is actively active to produce sulfuric acid, and in particular, since sulfuric acid is a strong acid, cement in concrete is dissolved by neutralization reaction, thereby deteriorating concrete stiffness.

In addition, when sulfate ions move inside and become supersaturated, monosulfate is converted into ethrinite to roughen the cement hardened structure and to generate cracks to promote the intrusion of corrosive substances, thereby shortening the life of concrete structures and furthermore, by invading microorganisms. There are many problems such as worsening the indoor environment.

Korean Utility Model Registration No. 20-392281 discloses an eco-friendly concrete block using microorganisms, and Korean Patent Publication No. 2008-61812 discloses an eco-friendly protection block containing an effective microorganism, but the high-performance self-cleaning concrete of the present invention. The production method of is not disclosed.

The present invention has been made in accordance with the above requirements, and while studying to develop high-performance self-cleaning concrete, the fluidity of mortar is increased by adding and curing certain microorganisms useful for concrete to mortar or concrete, Compressive strength is increased, it was confirmed that the concrete can be developed excellent self-cleaning capacity was completed the present invention.

In order to solve the above problems, the present invention is a high-performance midnight comprising the step of curing by adding at least one microorganism selected from the group consisting of effective microorganisms and natto bacteria (Bacillus natto) to mortar or concrete ) Provides a method for producing concrete.

The present invention also provides a high performance self-cleaning concrete produced by the above method.

The concrete to which the effective microorganism and / or natto bacterium of the present invention was added increased fluidity and increased compressive strength significantly. In addition, due to the strong antibacterial and deodorizing ability of the concrete structure, such as apartments can be improved by environmentally friendly sick house syndrome.

In addition, it is possible to describe the suppression of the natural purification capacity degradation that can occur due to the toxicity of the cement when the stream is refurbished using the concrete to which the microorganisms are added, thus protecting the water quality and protecting the ecosystem of aquatic flora and fauna, and improving the efficiency of river purification. It becomes possible to plan.

In order to achieve the object of the present invention, the present invention is a high-performance midnight comprising the step of curing by adding one or more microorganisms selected from the group consisting of effective microorganism (Bacillus natto) and mortar or concrete It provides a method for producing concrete.

In the method of the present invention, those skilled in the art will readily recognize that concrete to which microorganisms are added means concrete that is not hardened, and that cured concrete means concrete that is hardened.

In the context of the present invention, "high performance" refers to an increase in the compressive strength at the same time as the flow of mortar or concrete is increased. In the case of general concrete, increasing the fluidity decreases the compressive strength, but the high-performance concrete of the present invention is characterized by increasing the compressive strength while increasing the fluidity. In addition, "midnight" means that the produced concrete is an environmentally friendly concrete, has no characteristics such as no fish toxicity, and provides favorable environmental conditions for the vegetation of plants.

In the method of the present invention, the effective microorganism refers to a microorganism commonly referred to as EM in the art, more preferably may be one or more selected from the group consisting of photosynthetic bacteria, yeast, lactic acid bacteria, actinomycetes and filamentous fungi.

In the method of the present invention, the microorganism may be preferably Bacillus natto. Natto bacteria are parasitic in Cheonggukjang and grow well under alkaline environment. The compressive strength of natto bacteria added is the best.

In the method of the present invention, the microorganism may be obtained by standing incubation for 5-9 days at room temperature of 22 ~ 23 ℃ in a medium consisting of molasses and rice bran.

Molasses used in the method of the present invention is the main component necessary for the activation of the microorganisms to feed the microorganisms, but there is a disadvantage in that the initial strength is lowered by delaying the condensation of concrete, it is necessary to minimize the amount of molasses.

Rice bran used in the method of the present invention is a process of grinding rice flakes and rice bran, which is a treasure trove of excellent nutrition that our ancestors have frequently used in the past, and especially maintains homeostasis of human body such as iron, calcium, magnesium, sodium and vitamin E. It prevents the aging of tocopherols and has excellent effects on wrinkles, blemishes, freckles, acne and atopy. This rice bran was used to manufacture microorganisms to improve environmentally friendly performance.

In the method of the present invention, the culturing can be carried out at room temperature, preferably at a temperature of 22 ~ 23 ℃. The incubation period can be incubated for 5-9 days, preferably 7 days. Of course, shaking culture is also possible, but in order to reduce costs, it is also possible to culture static.

In the method of the present invention, the concentration of molasses and rice bran in the medium may be 0.5 to 3% by weight and 0.5 to 5% by weight, respectively. As described above, molasses has a disadvantage in that the initial strength is lowered by delaying the condensation of concrete, thereby minimizing the amount of molasses. In other words, when the concentration of molasses is lower than the range, there is a problem that the production of microorganisms is lowered, and when the concentration of molasses is higher than the range, there is a problem that the initial strength of the concrete is lowered.

In the method of the present invention, the amount of the microorganism added may be 3 to 15% by weight, preferably 7.5% by weight, based on mortar or concrete. If the added amount of the microorganism is less than 3% by weight, the effect of the antioxidant activity of the microorganism, such as improvement of compressive strength and environmental friendliness, may be reduced. In addition, when the amount of the microorganism exceeds 15% by weight, the economical efficiency is lowered, and there is a fear that the stress retardation phenomenon of the concrete may occur due to the increase of the sugar component in the concrete.

In the method of the present invention, the mortar may be one containing no cement. Cement causes symptoms of sick house syndrome, and it is harmful to humans by releasing a toxic gas called radon during curing. The addition of microorganisms to such cement does not significantly improve the effect. Of course, it is better than no microorganisms added, but mortar that does not contain cement is advantageous for the growth of microorganisms such as fish toxicity test results, and it is also excellent in environment-friendliness.

In the method of the present invention, the curing is preferably in water curing. In microbial addition, the compressive strength was higher in aquatic curing than in atmospheric curing (see Example).

The present invention also provides a high performance self-cleaning concrete produced by the method of the present invention. The addition of microorganisms to mortar or concrete enhances the slump flow of mortar, which increases the compressive strength of the prepared self-cleaning concrete. In addition, the prepared self-contained concrete was not fish toxic and provided favorable environmental conditions for the vegetation of plants.

Hereinafter, the present invention will be described in detail by way of examples. However, the following examples are illustrative of the present invention, and the present invention is not limited to the following examples.

Example  1: Cultivation of microorganisms to be added to mortar or concrete

As the microorganism used in the present invention, effective microorganisms and / or natto bacteria were used.

As an effective microorganism, a commercially available effective microbial stock solution (Ever Miracle Co., Ltd.) was introduced. In addition, in order to produce microorganisms that can be parasitic in concrete, natto bacteria, which are parasitic in Cheonggukjang, were added together.

Currently produced rice float fermentation broth has problems in supply of rice float. Therefore, in the present invention, rice bran was used to stably produce effective microorganisms in mass. Rice bran added to Production Examples A to C was 0.4 liter (170 g), respectively.

There are a total of three cultured microorganisms. Production Examples A to C, respectively, and its culture method and microorganisms are as follows.

Preparation Example A-Effective Microorganism + Natto + Molasses + Water + Rice Bran

Preparation Example B-Natto + Molasses + Water + Rice Bran

Preparation Example C-Effective Microorganism + Molasses + Water + Rice Bran

The culture was incubated for 7 days at room temperature of 22 ~ 23 ℃.

Preparation Example A

(Unit: ℓ)

Effective microorganism Natto molasses water Rice bran 0.2 0.2 0.2 17 0.4

Preparation Example B

(Unit: ℓ)

Effective microorganism Natto molasses water Rice bran - 0.2 0.2 17.2 0.4

Preparation Example C

(Unit: ℓ)

Effective microorganism Natto molasses water Rice bran 0.2 - 0.2 17.2 0.4

Example  2: Preparation of concrete by adding cultured microorganisms to mortar without cement

In this example, the effect of microbial species in the mortar without cement, that is, the fluidity and the compressive strength of each age according to Preparation Examples A to C were evaluated. The addition rate of microorganisms was fixed at 7.5%, and water / binder (W / B) and sand / binder (S / B) were fixed at 0.45 and 3.

No Kinds Microorganism types Microbial Addition Rate (%) W / B S / B One Cement A 7.5 0.45 3 2 Cement B 7.5 0.45 3 3 Cement C 7.5 0.45 3 4 Cement (D) - - 0.45 3

Figure 1 shows the slump flow of cement mortar according to the microorganism type. As can be seen in Figure 1, the addition of microorganisms enhance the flow of mortar and Preparation Example B showed the best fluidity.

In addition, in terms of the compressive strength, it is difficult to find a distinct difference in the compressive strength of each age in the air curing, but in the underwater curing showed the highest strength when using the microorganism B. In addition, when the microorganisms were added, the compressive strengths equal to or greater than the compressive strengths of the test bodies without addition of the microorganisms were shown (FIGS. 2 and 3).

Example  3: Preparation of concrete by adding cultured microorganisms to cement mortar

In this example, the effect of microorganisms on cement mortar was evaluated. There are three types of microorganisms, A, B, and C, and the addition rate of microorganisms is 5-15%, and W / B and S / B are fixed at 0.45 and 3.

No Kinds Microorganism types Microbial Addition Rate (%) W / B S / B One cement A 5 0.45 3 2 cement A 7.5 0.45 3 3 cement A 10 0.45 3 4 cement A 15 0.45 3 5 cement B 5 0.45 3 6 cement B 7.5 0.45 3 7 cement B 10 0.45 3 8 cement B 15 0.45 3 9 cement C 5 0.45 3 10 cement C 7.5 0.45 3 11 cement C 10 0.45 3 12 cement C 15 0.45 3 13 cement - - 0.45 3

Figure 4 shows the slump flow of cement mortar according to the type of microorganism and the amount added. As can be seen in Figure 4, the addition of microorganisms improve the slump flow of the cement mortar and the slump flow increased with the addition amount. In addition, the slump flow increased in all cases in which microorganisms were added than in that no microorganisms were added.

In addition, in terms of compressive strength, the compressive strength of the test article to which the microorganisms were added was equal to or higher than that of the test sample to which the microorganisms were added, in particular, the curing in water showed higher strength than the air curing (FIGS. 5 to 10).

In summary, the addition of microorganisms increased the compressive strength of concrete, and the increase was more pronounced for underwater curing than for atmospheric curing.

Example  4: acute using concrete of the present invention Fish toxicity  Experiment

Acute fish toxicity test was performed on the concrete prepared in Example 2 using the microorganism type B. As a control, a microorganism-free ordinary portland cement mortar was used. Acute fish toxicity experiments were performed according to the "Acute Toxicity Test by Fish (KS M 0111)" rule.

Specific experimental conditions are as follows.

1. Species species: Song-ri family

2. Purifying and breeding conditions

end. Period of Purification: April 30, 2008 ~ May 10, 2008

I. Breeding temperature: 25 ± 1 ℃

All. Light conditions: 16 hours light / 8 hours dark

la. Feed benefit: Salary feed for solid fish once a day

3. Test container: 1 liter container of cylindrical glass water tank

4. Test water: Groundwater stagnated for more than 1 week

5. Sample: Sample preparation of the same weight (200g)

6. Treatment method

After soaking the sample in a 1 liter glass tank, the purified celery was transferred to another tank for a week. Observations of the killifish were observed for 2 hours to 10 days after the start of the test.

11 and 12 are acute fish toxicity test results using high-performance self-cleaning concrete and microorganism-free cement mortar of the present invention. The high-performance self-cleaning concrete of the present invention can be seen that the killing until 10 days after the start of the experiment due to the addition of microorganisms, whereas the microorganism-free cement mortar used as a control was all dead 1 day after the start of the experiment.

Therefore, it can be seen that the high-performance self-cleaning concrete of the present invention is very environmentally friendly since there is no toxicity by fish.

Example  5: of the high-performance midnight concrete of the present invention pH  Control ability

The change in pH according to the immersion time for the high-performance midnight concrete prepared in Example 3 was measured. Figure 13 shows the pH change according to the immersion time of the high-performance midnight concrete of the present invention. As can be seen in FIG. 13, the pH decreases over time and may be lower than that of concrete without microorganisms when useful microorganisms are added, thereby providing favorable environmental conditions for plant vegetation.

Example  6: Water Purification Rate Experiment Using Concrete of the Present Invention

Water purification rate experiments were performed on the concrete prepared in Example 2 using the microorganism type B. As a control, a microorganism-free ordinary portland cement mortar was used. Concrete mortars were cured for 28 days and then tested in a circulation tank for a week. The circulation tank was turned on and off for 12 hours using a 2,000 lux artificial light with a 200 ℓ capacity, and 2 ℓ / min purified water (ppm) of solid substance suspended in water and BOD (biological oxygen). Requirement) and COD (chemical oxygen demand) were measured.

As a result, as can be seen in Figure 14, by adding microorganisms, the water purification rate was improved 30 to 40% than the addition of microorganisms.

In summary, the high-performance self-cleaning concrete of the present invention is a very useful concrete because it increases the fluidity of the concrete, increases the compressive strength, has no fish toxicity, provides environmental conditions favorable to vegetation of plants, and improves the water purification rate. It can be seen that.

Figure 1 shows the slump flow of cement mortar according to the microorganism type.

Figure 2 shows the compressive strength by age in air curing according to the type of microorganism.

Figure 3 shows the compressive strength of each age in the underwater curing according to the type of microorganism.

Figure 4 shows the slump flow of cement mortar according to the type of microorganism and the amount added.

5 shows the compressive strength (microbial A) with age at atmospheric curing.

6 shows the compressive strength (microbial B) with age at atmospheric curing.

7 shows the compressive strength (microbial C) with age at atmospheric curing.

8 shows the compressive strength (microbial A) with age at curing in water.

9 shows the compressive strength (microbial B) with age upon curing in water.

10 shows the compressive strength (microbial C) with age at curing time in water.

11 and 12 are acute fish toxicity test results using high-performance self-cleaning concrete and microorganism-free cement mortar of the present invention.

Figure 13 shows the pH change according to the immersion time of the high-performance midnight concrete of the present invention.

14 shows the water purification rate of high-performance self-cleaning concrete of the present invention.

Claims (9)

a) selecting at least one microorganism selected from the group consisting of an effective microorganism consisting of photosynthetic bacteria, yeast, lactic acid bacteria, actinomycetes and filamentous fungi and Bacillus natto; b) incubating the selected microorganisms for 5-9 days at room temperature of 22-23 ° C. in a medium consisting of molasses and rice bran; And c) adding the microorganisms cultured in step b) to mortar or concrete in a hardened state and curing the high-performance self-cleaning concrete. delete delete delete The method of claim 1, wherein the concentration of molasses and rice bran in the medium is 0.5 to 3% by weight and 0.5 to 5% by weight, respectively. The method of claim 1, wherein the amount of the microorganism added is 3 to 15 wt% based on mortar or concrete. delete The method of claim 1 wherein said curing is underwater curing. delete

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