KR100702471B1 - Super high early strength blast furnace slag cement - Google Patents

Abstract

The present invention relates to a super-tough steel blast furnace slag cement, comprising a blast furnace slag, portland cement or clinker, a gypsum combination with a Auin-based cement or clinker, a water reducing agent or a high softening agent, the blast furnace slag, portland cement, gypsum The content is at least 70% of the total weight of the total mixture, and the content of the Augustin-based cement and the water reducing agent is characterized in that less than 30% of the total weight of the total mixture. According to the present invention, it is possible to solve the problem of low initial strength, which is a disadvantage of blast furnace slag cement, and to exhibit high strength characteristics, which is very excellent in product quality, and may contain a large amount of blast furnace slag, thereby greatly reducing manufacturing costs. Not only is it faster to harden than conventional cemented steel portland cement, but also has good initial and late strength.

High strength steel, Blast furnace slag, Inner, Curing rate, Initial strength, Lateral strength

Description

Ultra High Strength Blast Furnace Slag Cement {SUPER HIGH EARLY STRENGTH BLAST FURNACE SLAG CEMENT}

Figure 1a to 1e is an electron microscope (SEM) photograph of the cured body of the curing period of the roughened blast furnace slag cement prepared according to the present invention.

Figure 2 is an X-ray diffraction analysis (XRD) graph of the cement paste by curing period of the super-tough steel blast furnace slag cement prepared according to the present invention.

The present invention relates to a super-tough steel blast furnace slag cement, and more particularly to a super-tough steel blast furnace slag cement that has a low initial production cost and excellent initial strength and long-term strength.

Cement is a binder used as a building material. Humans have been using cement for thousands of years. The cement used in the pyramids is a mixture of lime and gypsum, and in the Roman era a mixture of lime and volcanic ash. These cements were used as hardening cements until the 18th century, and the hydraulic cements were from about 1756 to 1759. After that, the raw materials mixed with limestone and clay were baked to make cement. It is named Portland Cement because it is similar in shape and color to Portland Island's natural stone.

Today, what is commonly referred to as cement is Portland cement. Portland cement is a powder obtained by appropriately mixing a raw material containing lime, silica, alumina, and iron oxide as a main component in a proper proportion, melting a portion of it, and adding an appropriate amount of gypsum to a calcined clinker. Portland cement is mainly a clinker obtained by mixing calcite raw materials and clay raw materials in suitable proportions (sometimes adding siliceous raw materials and iron oxide raw materials to adjust the ingredients) and pulverizing them until they melt (about 1,450 ° C). It is made by pulverizing by adding some gypsum as a coagulation regulator.

When Portland cement is kneaded with water, it loses its fluidity and hardens after a while. This process is called setting, and then the process of getting strength is called curing. Among the constituents of cement, tricalcium silicate is fast in hydration and good in strength, contributing to early strength. Lithium silicate has a slow hydration rate and increases strength over a long period of time. Tricalcium aluminate is hydrated faster than other constituents and reacts rapidly with water to harden. If gypsum is present, the setting time is controlled by reaction with gypsum. The constituents of cement generate heat of hydration when hydrated. Hydrated heat is the largest in the aluminate tricalcite, followed by the silicate tricalcite. Therefore, the amount of trisilicate silicate is required for the crude steel cement that requires early strength, and the amount of tricalcite or silicate lime is limited for cement used in large structures such as dams.

As a blended cement in which new components are expressed by mixing other components with such portland cement, there are blast furnace slag cement, silica cement, fly ash cement, and alumina cement.

Among them, blast furnace slag cement is a blast furnace slag (blast furnace material) used in blast furnaces in steel mills. It is chemically resistant and has excellent long-term strength, which is mainly used for civil works such as wastewater, ports and rivers. .

Blast furnace slag cement is prepared by mixing and grinding Portland cement (or clinker), gypsum, blast furnace slag, blast furnace slag cement has a disadvantage in that the curing is slow and the initial strength is weak compared to ordinary cement.

Accordingly, it is an object of the present invention to provide blast furnace slag cement that is fast in curing and excellent in initial strength.

In addition, another object of the present invention is to provide a roughened steel blast furnace slag cement that can be produced at a low manufacturing cost.

In order to achieve the above object, the present invention includes a blast furnace slag, portland cement or clinker, gypsum combination of the Auin-based cement or clinker, a water reducing agent or a high fluidizing agent, the content of the blast furnace slag, portland cement, gypsum is a whole mixture 70% or more of the total weight of the, and the content of the outer cement and the water reducing agent provides a super-rigid blast furnace slag cement, characterized in that less than 30% of the total weight of the total mixture.

The auxin (4CaO ₃ Al ₂ O ₃ SO ₃ ) is prepared from a blended material such that Cm (lime saturation ratio) = 0.80 or more, A / S '(aluminate hydrosulfuric acid ratio) = 2.5-5.0, in particular It is characterized in that the obtained raw material is obtained by calcining at a high temperature of 1250 ~ 1400 ℃.

The inner is suitable to be included in the range of 8 to 20% by weight, gypsum is 5 to 15%, a reducing agent or a high fluidizing agent is preferably in the range of 0.3% or more. As a type of water reducing agent or a high fluidizing agent, any material that is generally used in cement compositions may be used, and there is no particular limitation.

The portland cement may be usually any one or more selected from portland cement, crude steel portland cement, ultra-light steel portland cement, medium heat portland cement, low heat portland cement, sulfuric acid portland cement, white portland cement.

The method of manufacturing the roughened steel blast furnace slag cement according to the present invention is Portland cement (or clinker), blast furnace slag, gypsum (dihydrate or gypsum), Auin (4CaO3Al ₂ O ₃ .SO ₃ ) -based cement (or clinker) The blast furnace slag cement thus prepared is characterized by fast curing and high initial strength and late strength.

The crude steel blast furnace slag cement of the present invention is much larger than the strength of the crude steel portland cement. In the present invention, by adding a very small amount of a cement reducing agent (or a high fluidizing agent), it is possible to prepare the ultra-tough steel blast furnace slag cement of the high-strength steel Portland cement quality level.

According to the present invention, the blast furnace slag cement can exhibit the properties such as superelastic stiffness and high strength, and in addition to excellent quality itself, the blast furnace slag can be contained in a large amount (for example, 60 to 70% by weight). It is very economical.

The reason why the rough steel blast furnace slag cement of the present invention expresses the roughness and high strength is that in the early stage of hydration of the cement, lime (CaO) and gypsum (CaSO ₄ ) from the cement, blast furnace slag, and Augustin (4CaO · 3Al ₂ O _3. This is because the SO ₃ ) component produces ettringite (3CaO.Al ₂ O _3. 3CaSO ₄ .32H ₂ O), which enhances the strength of the cement. The formation reaction of such ethrinzite is as follows.

[Scheme]

_{4CaO · 3Al 2 O 3 · SO} 3 + 6CaO + 3CaSO 4 + 32H 2 O -> 3CaO · Al 2 O 3 · 3CaSO 4 · 32H 2 O

Ethrinzite hydrate products have the property of expanding, which enhances strength by filling many pores in the cement hardened body and densifying the hardened body, while suppressing the occurrence of cracks due to dry shrinkage.

The brother of _{(4CaO · 3Al 2 O 3 ·} SO 3) the CaO component, limestone, Al ₂ O ₃ component of beam used in the present invention is greater inorganic material, which contains a site or an alumina component and a SO ₃ component, gypsum Is combined to have the following compounding ratio,

Cm (lime saturation ratio: Cm = C-0.7 (F + T + S ') / 1.87S + 0.55A) = 0.80 or more,

A / S '(Aluminum hydrosulphate ratio) = 2.5-5.0

(C: CaOwt%, F: Fe ₂ O ₃ wt%, T: TiO ₂ wt%, S ': SO ₃ wt%, S: SiO ₂ wt%, A: Al ₂ O ₃ wt% are respectively shown. .)

The combined raw materials are obtained by firing at a high temperature of 1250-1400 ° C.

The prepared Auin calcium aluminosulfate may contain a large amount of 4CaO · 3Al ₂ O _{3 ·} SO ₃ and a small amount of 2CaO · SiO ₂ minerals. Larger than cement (or clinker). The outer cement-based cement or clinker obtained by high temperature firing exhibits rapid rigidity, high strength, and expandability in the hydrated cured body of cement.

1A to 1E are electron microscopy (SEM) photographs of cured bodies according to curing periods of the roughened steel blast furnace slag cement prepared according to the present invention.

Ethrinzite is produced early in the hydration (5-30 minutes) and contributes to the initial strength development while filling the gel pores and capillaries in the cement hydration product.

Figure 2 is an X-ray diffraction analysis (XRD) of the cement paste according to the curing period of the super-tough steel blast furnace slag cement prepared according to the present invention, it can be seen that the ethrinzite is produced early in the hydration.

Hereinafter, a specific embodiment of the method of manufacturing a super-tough steel blast furnace slag cement according to the present invention. However, these examples are only to aid the understanding of the present invention and should not be understood as limiting the scope of the present invention, the present invention will be determined within the scope of the technical spirit set forth in the claims to be described later.

Example 1

By weight ratio blast furnace slag (manure) 40%, usually Portland cement 39%, auine 10%, gypsum 10.5% and 0.5% high plasticizer. Standard mixing amount (w / c%) of the cement mixture was 40, and the change in compressive strength with time and setting time of the blast furnace slag cement was investigated.

Example 2

By weight ratio, 60% of blast furnace slag (manure), 15% of Portland cement, 10% of Auin, 14.5% of gypsum and 0.5% of a high softening agent were mixed. Standard mixing amount (w / c%) of the cement mixture was 40, and the change in compressive strength with time and setting time of the blast furnace slag cement was investigated.

Example 3

By weight ratio blast furnace slag (manure) 69%, usually Portland cement 9.5%, auine 6%, gypsum 15% and 0.5% high plasticizer. Standard mixing amount (w / c%) of the cement mixture was 40, and the change in compressive strength with time and setting time of the blast furnace slag cement was investigated.

Example 4

By weight ratio blast furnace slag (manure) 38%, white Portland cement 34%, auine 16%, gypsum 11.5% and a high fluidizing agent 0.5%. Standard mixing amount (w / c%) of the cement mixture was 40, and the change in compressive strength with time and setting time of the blast furnace slag cement was investigated.

Example 5

By weight ratio blast furnace slag (manure) 62%, white Portland cement 20%, Augustin 8%, gypsum 9.5% and 0.5% high plasticizer. Standard mixing amount (w / c%) of the cement mixture was 40, and the change in compressive strength with time and setting time of the blast furnace slag cement was investigated.

The physical properties of the blast furnace slag cement prepared according to each embodiment is shown in Table 1 below.

[Table 1] Condensation time and compressive strength of the roughened steel blast furnace slag cement according to the embodiment (kg / cm ² )

Example 1 Example 2 Example 3 Example 4 Example 5 Setting time First 1:22 1:30 1:42 1:16 1:28 closing 1:38 1:45 1:58 1:32 1:40 Compressive strength 1 day 262 260 228 268 258 3 days 396 398 348 402 392 7 days 468 462 420 472 460 28 days 612 604 542 624 612

For comparison, the physical properties of the crude steel Portland cement of the excluded countries are shown in Table 2 below.

[Table 2] setting time and compressive strength (kg / cm ² )

Setting time Compressive strength (kg / cm ² ) First closing 1 day 3 days 7 days 28 days O company product (Japan) 1:30 2:25 216 342 456 548 Company B (UK) 2:08 3:15 165 337 428 542 D company product (Germany) 2:40 3:25 222 300 358 421

From the measurement results of the physical properties of Table 1 and Table 2, it can be seen that the roughened steel blast furnace slag cement prepared according to the present invention is not only harder than the existing roughened steel portland cement but also has excellent initial strength and late strength.

As described above, according to the present invention, it solves the problem of low initial strength, which is a disadvantage of blast furnace slag cement, and exhibits high strength characteristics, thus the product quality is very good, and it can contain a large amount of blast furnace slag, thus producing a cost. It can be greatly lowered, and in particular, it is not only faster to harden than conventional super-tight steel Portland cement, but also excellent in initial strength and late strength.

Claims (3)

Blast furnace slag 38-70 wt%; Gypsum 5-15 wt%; Auxin (4CaO ₃ Al ₂ O ₃ SO ₃ ) 6-20 wt%; 0.3 to 2.5 wt% of a water reducing agent or a high fluidizing agent; And Portland cement or clinker balance; The ain contains limestone as CaO component, bauxite or inorganic material as Al ₂ O ₃ component, and gypsum as SO ₃ component, and Cm (lime saturation ratio) (= C-0.7 (F + T + S) ') /1.87S+0.55A) is 0.80 or more, and A / S' (aluminate hydrosulfuric acid ratio) is prepared by calcining the blended raw material at a temperature of 1250 ~ 1400 ℃ High strength steel blast furnace slag cement. (C: CaO wt%, F: Fe ₂ O ₃ wt%, T: TiO ₂ wt%, S ': SO ₃ wt%, S: SiO ₂ wt%, A: Al ₂ O ₃ wt%) delete delete

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