KR101085044B1 - Inorgarnic binder for manufacturing secondary concrete product - Google Patents

Abstract

PURPOSE: An inorganic binder for manufacturing a steam-cured secondary concrete product is provided to reduce enormous energy required for a plasticizing process and to reduce the generation of carbon dioxide in a cement manufacturing process by replacing cement using industrial byproducts. CONSTITUTION: An inorganic binder for manufacturing a steam-cured secondary concrete product includes 15-60 parts by weight of a sulfate activator, 1-5 parts by weight of sulfate promoter, 5-30 parts by weight of alkali activator, and 1-5 parts by weight of alkali promoter with respect to 100 parts by weight of slag fine powder of 3000/g or more of specific surface area. The slag fine powder is the mixture of one or more selected from blast furnace slag fine powder, stainless slag fine powder, and copper smelting slag powder. The sulfate activator is the mixture of one or more selected from sodium aluminum sulfate or sodium aluminum fluoride, hydrofluoric acid gypsum, and phosphoric acid gypsum. The hydrofluoric acid gypsum and the phosphoric acid gypsum are industrial byproducts.

Description

Inorganic binder for steam secondary concrete production {INORGARNIC BINDER FOR MANUFACTURING SECONDARY CONCRETE PRODUCT}

The present invention relates to an inorganic binder for the production of low-alkaline steam-cured concrete secondary products, and more specifically, to significantly reduce the amount of limestone mining that destroys nature by replacing all cement used in concrete with industrial by-products, and occurs in the cement manufacturing process. The present invention relates to an inorganic binder for producing low alkali steam cured concrete secondary products, which can reduce the generation of CO ₂ , which is the main culprit of greenhouse gases, and reduce enormous energy used in firing.

In general, products that are poured into a mold and molded into a certain type of product are called precast concrete or concrete secondary products.For example, bricks, blocks, fume pipes, VR pipes, electric poles, manhole blocks, lake blocks, ecology Blocks, Adobe Blocks, Interlocking Blocks, PC Segments, Railroad Sleepers, Plume and Benchful Room, among others.

When manufacturing such a concrete secondary product, since the price of the molding mold is expensive, demoulding the mold early is an essential condition for improving productivity and reducing investment costs. Therefore, concrete secondary products are demolded mold about 24 hours after molding by increasing the amount of unit cement and steam curing to obtain high strength early.

On the other hand, a large amount of CO in the main cause of the look to the manufacture of cement mining the main ingredient of limestone, iron ore, clay, etc., and consumes enormous fuel in relationship to be produced by sintering at a 1450 high-temperature, greenhouse gases in the decarbonation process of limestone ₂ Gases are generated and cause harmful effects to the atmosphere. According to the Korea Energy Management Corporation, one ton of cement generates about 0.8 tons of CO ₂ gas. In the case of cement, the alkali is strong enough to have a pH of 13, so it has a strong alkali even when manufactured as a secondary product, and has an undesirable effect on the soil due to the characteristics of concrete secondary products mainly used in civil engineering. It is known that it is not preferable when it is used for lakeside, fishery, waterway, etc. because of the influence of alkali, the vegetation is not good and the access of fish is blocked.

In the case of domestic patents 10-0362087, 03-0063985, 10-0039006, 97-0017475, etc., cement is used as a main raw material for the purpose of early mold release and initial high strength, and fine slag powder, fly ash, quicklime, etc. One technique, however, is that the blend material also has a strong alkalinity, which limits the environmental damage of concrete.

Therefore, there is an urgent need for the development of eco-friendly concrete products to be used for fish and river guards and pier guards.

The present invention has been made to solve the above problems, an object of the present invention is to significantly reduce the amount of limestone mining that destroys nature by replacing all the cement used in concrete with industrial by-products, greenhouse gases generated in the cement manufacturing process In order to reduce the generation of CO ₂ , which is the main culprit, and to reduce the enormous energy used in firing, it is to provide an inorganic binder for the production of low alkali steam cured concrete secondary products.

In order to solve the technical problems as described above, the inorganic binder for preparing the steam-cured concrete secondary product according to the present invention has a sulphate stimulant 15 to 60 parts by weight, sulphate stimulator 1-5 based on 100 parts by weight of slag having a powder degree of 3,000 cm ² / g or more. It includes weight part, 5-30 weight part of alkali stimulants, and 1-5 weight part of alkali stimulation accelerators.

In addition, the slag is preferably any one or a mixture of two or more selected from the group consisting of blast furnace slag fine powder, stainless slag fine powder, copper slag fine powder.

In addition, the sulfate stimulant is preferably any one selected from the group consisting of sodium aluminum sulfate (SAS) or sodium aluminum fluoride (SAF), fluorite gypsum, and phosphate gypsum produced as a by-product in the polysilicon manufacturing process.

In addition, the sulfate stimulant is preferably pH 3 or less.

In addition, it is preferable to further include 1 to 5 parts by weight of a sulfate stimulation accelerator in order to promote the stimulation, the sulfate stimulation accelerator is any one selected from the group consisting of sodium sulfate, aluminum sulfate, calcium sulfate, magnesium sulfate or a mixture of two or more. desirable.

In addition, the alkali stimulant is preferably any one or a mixture of two or more selected from the group consisting of white cement, slag cement, one ordinary portland cement, fly ash cement, quicklime, light dolomite. These materials have strong alkalis with a pH of 12 or more as Korean industrial standards or generally distributed products, and are inexpensive and easily obtained.

In addition, it is preferable that 1 to 5 parts by weight of an alkali stimulation accelerator is added to promote the stimulation. The alkali stimulation accelerator is any one selected from the group consisting of calcium hydroxide, sodium hydroxide, potassium hydroxide, sodium silicate and potassium silicate, or a mixture of two or more thereof. Is preferably.

The present invention drastically reduces the amount of limestone mining that destroys nature by replacing all cement used in concrete with industrial by-products, and reduces the generation of CO ₂ , which is the main culprit of greenhouse gases generated in the cement manufacturing process, and uses enormous energy when firing. There is an effect to reduce.

In addition, the damage of soil and water caused by strong alkali, which is a disadvantage of cement concrete, can be minimized.

Figure 1 shows a schematic diagram of the hydration reaction of the inorganic binder according to the present invention.
Figure 2 is an electron microscope to observe the internal microstructure according to the age of Example 1-1 of the inorganic binder according to the present invention.
3 is an XRD analysis result according to the age of Examples 1-2 of the inorganic binder according to the present invention.
4 is an XRD analysis result according to the age of the comparative example.
5A is a result of DTA analysis of Example 1-1, FIG. 5B is a result of DTA analysis of Example 1-2, and FIG. 5C is a result of DTA analysis of Comparative Example 1. FIG.

Hereinafter, the inorganic binder according to the present invention will be described in detail.

First, the strength expression principle and action according to the inorganic binder according to the present invention will be described.

The inorganic binder according to the present invention contains a fine slag powder as a main raw material and includes a sulfate stimulant, a sulfate stimulator, an alkali stimulator and an alkali stimulator.

The slag fine powder is an amorphous particle and these amorphous particles do not cure because they do not undergo a hydration reaction by themselves because a dense impermeable acidic film is formed on the particle surface when contacted with water.

Therefore, in order to continue the hydration reaction of the fine slag powder, the incorporation of a stimulant that can destroy the coating is required.

The stimulants are sulfate stimulants, sulphate stimulators, alkali stimulants and alkali stimulators, and the combined action of these compounds destroys the acidic film of the slag fine powder. It begins to be. In order to accelerate the curing, the CSH gel is rapidly produced and the Ca ²⁺ ions are rapidly consumed and the pH is changed to a weak alkali state.

Hydrates of fine slag powders include calcium silicate hydrates (CSH, representative composition C ₃ S ₂ H ₃ ) similar to tobermorite, although somewhat different depending on the type and composition of the stimulant. Alkali stimulants such as sodium hydroxide (NaOH) or potassium hydroxide (KOH) produce CSH, hexagonal flaky calcium aluminate hydrate C ₄ AH ₁₃ and gehlenite hydrate C ₂ ASH ₈ , calcium oxide and calcium hydroxide, etc. for the alkali stimulant, the CSH and C ₄ AH ₁₃ created and C ₂ ASH ₈ is not generated, lactate stimulant in the CSH, Et Lin gayiteu (ettringite) and similar to C ₃ A3H ₃₂ and aluminum hydroxide, Al (OH) ₃ Is generated.

When the sulfate stimulator and the alkali stimulant are used together as the inorganic binder of the present invention, Al (OH) ₃ may be changed to ethrin gite to increase resistance to initial strength and shrinkage cracking.

The chemical composition of the slag fine powder is simplified to C ₅ AS ₃ to give the following stoichiometry.

As can be seen from the above chemical formula, it can be seen that the sulfate stimulator and the alkali stimulant not only act as a stimulus but also act as a reaction material with the fine slag powder.

 Strength expression at early age following hydration is achieved by C-S-H gels produced simultaneously with large amounts of ettringite. In addition, C-S-H gel surrounds the ettringite, and as the age of the aging continues to increase, the C-S-H gel tightly fills the pores of the cured paste, forming a dense networked network with the ettringite, and continuously expressing high strength. Figure 1 shows a schematic diagram of the hydration reaction of the above-described slag powder, sulfate stimulant and alkali stimulant.

Hereinafter will be described in detail with respect to the composition and action of the inorganic binder for producing low-alkali steam curing concrete secondary products according to the present invention.

Inorganic binder according to the present invention is 15 to 60 parts by weight of sulfate stimulant, 1 to 5 parts by weight of sulfate stimulation accelerator, 5 to 30 parts by weight of alkali stimulant and alkali stimulation accelerator 1 based on 100 parts by weight of slag having a powder degree of 3,000 cm ² / g or more. And ˜5 parts by weight.

The slag is preferably any one or a mixture of two or more selected from the group consisting of blast furnace slag fine powder, stainless slag fine powder, copper slag fine powder. When the slag powder is less than 3,000 cm ² / g, the activity is poor due to the lack of fine powder, which adversely affects the strength development.

In addition, the sulfate stimulant is preferably any one selected from the group consisting of sodium aluminum sulfate (SAS) or sodium aluminum fluoride (SAF), fluorite gypsum, and phosphate gypsum produced as a by-product in the polysilicon manufacturing process. In addition, the sulfate stimulant is preferably pH 3 or less.

The polysilicon is made of small silicon crystals that convert light energy into electrical energy in solar cells. As polysilicon is developed with the development of modern photovoltaic industry, the production capacity of the polysilicon is operating in Korea. . Such polysilicon is prepared by melting and reducing carbon of silicon, that is, by adding silicon silicon (MG-Si) produced by heating a mixture of quartz extracted from silicon with a carbon compound and heating it with a monosilane or trichlorosilane. The chemical reaction gives a purified polysilicon. In particular, polysilicon is produced using sulfuric acid, silica sand, and fluorspar as main materials, and is a SAS (Sodium Aluminum Sulfate) or SAF (Sodium Aluminum Fluoride) which is discharged as a by-product, and has a strong acidity of 3 or less.

The phosphate gypsum is a by-product generated from the manufacture of phosphate fertilizers using phosphate ore as a raw material, and the phosphate gypsum is also generated as a by-product of industrial processes. . When these sulfate stimulants enter less than 15 parts by weight, SO ₃ ^{2 -} ion emission amount is small and the irritation effect is weak, so that the initial strength cannot be obtained. When the amount exceeds 60 parts by weight, the sulfate stimulant is present in the form of sulfate which does not react with slag. In addition to lowering the strength of the cured product, the pH shows acidity.

In addition, it is preferable to further include 1 to 5 parts by weight of a sulfate stimulation accelerator in order to promote the stimulation, the sulfate stimulation accelerator is any one selected from the group consisting of sodium sulfate, aluminum sulfate, calcium sulfate, magnesium sulfate or a mixture of two or more. desirable. These stimulators are industrial products that are easily obtained on the market and maintain a stable quality level. If these stimulation promoters are less than 1 part by weight, the stimulation may be delayed to obtain a predetermined initial strength. If the stimulation promoter is added in excess of 5 parts by weight, the risk of abnormal condensation occurs and the product is inexpensive because it is an expensive product.

In addition, the alkali stimulant is preferably any one or a mixture of two or more selected from the group consisting of white cement, slag cement, one ordinary portland cement, fly ash cement, quicklime, light dolomite. These materials have strong alkalis with a pH of 12 or more as Korean industrial standards or are commonly distributed in the market, and are inexpensive and easily obtained. If the alkali of these stimulants is less than pH 12, the irritation effect is lowered, so that the predetermined strength cannot be expressed, or the excessive injection is performed to obtain the predetermined strength, so the economic efficiency is low. In addition, when the alkali stimulant is less than 5 parts by weight, the predetermined initial strength cannot be obtained. When the alkali stimulant is added more than 30 parts by weight, the amount of OH ^- ions released is excessively lowered, thus lowering the strength of the cured product, and the pH is strongly alkaline.

In addition, it is preferable to add 1 to 5 parts by weight of an alkali stimulation accelerator in order to promote the stimulation. The alkali stimulation accelerator is any one or a mixture of two or more selected from the group consisting of calcium hydroxide, sodium hydroxide, potassium hydroxide, sodium silicate and potassium silicate. Is preferably. These stimulators are industrial products that are easily obtained on the market and maintain a stable quality level. If these stimulation promoters are less than 1 part by weight, the stimulation may be delayed to obtain a predetermined initial strength. If the stimulation promoter is added in excess of 5 parts by weight, the risk of abnormal condensation occurs and the product is inexpensive because it is an expensive product.

Hereinafter, the examples of the inorganic binder according to the present invention, and the performance of the comparative example for comparing the physical properties with the above examples.

Example  One

In this embodiment, blast furnace slag fine powder (GBFS) was used as a main material for the preparation of the inorganic binder for the secondary concrete products. Sulfate stimulant for induction of hydration reaction was used by mixing SAS (Sodium Aluminum Sulfate), a by-product of polysilicon manufacturing process, and waste phosphate gypsum discharged as waste during phosphate production.Alkali stimulant mixed with white cement and quicklime Sulfate stimulator was used aluminum sulfate, alkali stimulator was used sodium hydroxide.

The waste phosphate gypsum was used by grinding the raw material of pH 2.3 to the type of anhydrous gypsum calcined at 450 ° C. and using SAS (Sodium Aluminum Sulfate) by grinding the raw material of pH 2.1. Industrial products were purchased and used.

The formulation of this example is shown in Table 1.

division Compounding weight part Slag Sulfate Stimulant Sulfate Stimulator Alkali stimulant Alkali stimulation accelerator Example 1-1 100 55 3 25 3 Example 1-2 100 45 3 20 3

Comparative example  One

In Comparative Example 1 for comparing the physical properties with the examples according to the present invention, 100% of ordinary portland cement (OPC) was used.

Experiment method

According to the formulation of Table 1, the raw materials were mixed to be sufficiently mixed, and then, water was added and the mixture was beamed for 1 minute and 30 seconds with a mortar mixer to prepare a paste, which was prepared in a 5 × 5 × 5 cm mold to prepare a paste at 40˜90 ° C. After steam curing at 500 ° C, the cured paste was crushed with UTM to take an internal fractured surface, which was used as an electron microscope (SEM) sample. After crushing to 75 or less, X-ray diffraction analysis (XRD) ) And thermal analysis (DTA) analyzes were performed to compare the types and amounts of hydrates produced.

2 is an electron microscope of the internal microstructure according to the age of Example 1-1. Although the ettringite in the early three-day age is thin and long bed, it is produced in a large amount in a very dense form, and the continuous hydration reaction shows that the ettringite developed in the form of a thick needle in the seven-day age. In the 28-day age, a large amount of hydrate was found in addition to ettringite, which appears to be a C-S-H gel. Therefore, the hydration reaction of this example in early age is considered to form a high strength with a dense form of ettringite as a skeleton, but after a long period of age, the ettringite forms a dense network type network structure with a C-S-H gel as a skeleton.

3 is an XRD analysis result according to the age of Example 1-2. At 3 days of age, it can be seen that there are many gypsum crystals, and ettringite crystals are weak. However, at 7-day age, the main product mineral appears to be ettringite, and the peak of C-S-H () gel tends to increase as compared to the 3-day age, and the peak of gypsum decreases gradually with age. At 28 days of age, the main product appears as a C-S-H () gel and the peaks of ettringite are relatively reduced. This means that the phosphate gypsum, which did not initiate the hydration reaction in its early age, is present as a mineral of its own and gradually reacts with the slag to produce hydrates, indicating that the produced ettringite is also transferred to a more stable CSH () gel. .

4 is an XRD analysis result according to the age of Comparative Example 1. The peak of ettringite is weakly observed in the early three-day age but not in the seven-day age. The main products are Ca (OH) ₂ and CSH gels, and their production increases with age.

5A is a result of DTA analysis of Example 1-1, FIG. 5B is a result of DTA analysis of Example 1-2, and FIG. 5C is a result of DTA analysis of Comparative Example 1. FIG.

As shown in Figure 5a, in the case of Example 1-1 the endothermic peak is observed at 125 ℃, 150 ℃, 175 ℃, 690 ~ 860 ℃ and the exothermic peak is observed at 880 ~ 900 ℃, which is respectively evaporation of gel water, ettringite And dehydration of gypsum, decomposition of CSH (I) (tobermorite), and glassy destruction of slag.

The endothermic peak of ettringite near 125 ° C increased as the endothermic peak decreased as the dihydrate gypsum near 150 ° C was transferred to hemihydrate gypsum, indicating that gypsum was consumed to produce ettringite. The endothermic peak of ettringite peaks at 7 days and decreases at 28-day age, and the endothermic peak of gypsum decreases gradually with age.

The endothermic peak that appears minutely at 175 is considered to be due to dehydration during the transfer of the hydrated gypsum phosphate to the anhydrous gypsum. On the other hand, no peak appears at around 450 ° C, which means that the inorganic binder according to the present invention does not generate calcium hydroxide during the hydration reaction.

As can be seen from FIG. 5B, the endothermic peak of Example 1-2 is similar to that of Example 1-1, but the endothermic peak of ettringite at 125 ° C. in the initial 3 days of age is relatively Example 1-1. It can be seen that it is weak compared to 1.

However, after 7 days of age, the endothermic peak of ettringite was not significantly different from that of Example 1-1, and the peak of C-S-H () gel was similar to that of Example 1-1 in 28 days of age.

As can be seen from FIG. 5c, in Comparative Example 1, the endothermic peaks in the heating temperature range of 100 to 160 ° C. showed similar levels regardless of age, since pyrolysis of ettringite or monosulfate was performed in this temperature range. to be. In addition, the endothermic curve appearing in the range of heating temperature around 450 ℃ as the endothermic peak of calcium hydroxide was found to increase continuously with age. Tricalcium silicate or dicalcium silicate hydrates to produce large amounts of calcium hydroxide, the presence of which weakens resistance to chemical erosion. However, in the hydration reaction of the inorganic binder according to the present invention, almost no Ca (OH) ₂ component is produced, and therefore, it is considered to be excellent in resistance to various salts, particularly sulfate and seawater action.

Hereinafter, a method of manufacturing a concrete secondary product using the inorganic binder according to the present invention will be described.

In order to manufacture a concrete secondary product, 200-600 weight part of coarse aggregates are mixed with respect to 100 weight part of inorganic binders mentioned above. If the coarse aggregate content is less than 200 parts by weight, the strength of the secondary product is lowered, if it exceeds 600 parts by weight, material separation and honey comb phenomenon may occur.

In addition, 100 to 400 parts by weight of fine aggregates may be added to the inorganic binder in an amount of less than 100 parts by weight. If the content is less than 100 parts by weight, honey comb may occur. Increase, and the input amount of the inorganic binder increases, thereby reducing economic efficiency.

Moreover, with respect to 100 weight part of inorganic binders, 1-10 weight part of inorganic pigments can be mix | blended further.

After mixing the inorganic binder and aggregate as described above, the mixture is molded by vibrating pressure or by centrifugal force.

The molded article molded by the above-described method is steam cured at least 40 cities at 40 ~ 90 ℃ to produce a concrete secondary product.

Hereinafter, the results of analyzing the performance of the concrete secondary product according to the present invention through the examples.

Example  2

Example 2 according to the present invention, first, using the same raw materials as in Example 1-1, 30 parts by weight of sulfate stimulant, 3 parts by weight of sulfate stimulator, 15 parts by weight of alkali stimulant and alkali using 100 parts by weight of the blast furnace slag fine powder In addition to 3 parts by weight of the stimulation accelerator was added to the powder mixer was mixed homogeneously to prepare an inorganic binder.

Next, 325kg of inorganic binder, 760kg of fine aggregate and 1,020kg of coarse aggregate, and 97.5kg of water were uniformly mixed, and then charged into a relief block mold and vibratory pressure molding. These moldings were steam cured at 60 to 9 hours to produce a lake block.

Comparative example  2

Comparative Example 2 for the comparative analysis of the performance of the protection block prepared in Example 2 was prepared in the same manner as in Example 2 except that one type of ordinary portland cement instead of the inorganic binder.

The compressive strength was measured at 14 days on the lanthanum blocks prepared by Example 2 and Comparative Example 2. As a result, Example 2 exhibited a compressive strength of 45.2 MPa and Comparative Example 2 exhibited 34.3 MPa, which is about 1.3 times higher than that of the case of using the ordinary cement for inorganic secondary materials according to the present invention. Expression was confirmed. In addition, as a result of measuring the pH according to the waste process test method by sampling the crushed specimens, the pH was measured at pH 9.8 in Example 2, pH 11.7 in Comparative Example 2 was confirmed that the alkali is much lower level.

Claims (7)

To 100 parts by weight of fine slag powder having a specific surface area of 3,000 / g or more,
15 to 60 parts by weight of sulfate stimulant, 1 to 5 parts by weight of sulfate stimulation accelerator,
5 to 30 parts by weight of an alkali stimulant and 1 to 5 parts by weight of an alkali stimulation accelerator,
The slag fine powder is any one or a mixture of two or more selected from blast furnace slag fine powder, stainless slag fine powder, copper smelting fine powder,
The sulphate stimulant is a polysilicon by-product by-product (Sodium Aluminum Sulfate), SAF (Sodium Aluminum Fluoride), by-products of industrial processes, phosphate gypsum, phosphate gypsum generated by the industrial processes, or any mixture of two or more Inorganic binder for steam-cured concrete secondary products, characterized in that the.
delete delete The method of claim 1,
The sulfate stimulant is an inorganic binder for the production of secondary steam curing concrete, characterized in that the pH is 3 or less.
The method of claim 1,
The sulfate stimulation accelerator is sodium binder, calcium sulfate, aluminum sulfate and magnesium sulfate, any one or a mixture of two or more selected from inorganic binders for producing steam secondary concrete secondary product.
The method of claim 1,
The alkaline stimulant is any one selected from white cement, slag cement, one kind of ordinary portant cement, fly ash cement, quicklime, light dolomite or a mixture of two or more inorganic binders for the production of secondary steam curing concrete.
The method of claim 1,
The alkali stimulator is an inorganic binder for the production of steam cured concrete secondary products, characterized in that any one or a mixture of two or more selected from calcium oxide, calcium hydroxide, sodium hydroxide, potassium hydroxide, sodium silicate and potassium silicate.

Images