KR100362087B1 - The method for manufacturing of composition of cement - Google Patents

Abstract

The present invention relates to a high strength high flow low heat cement composition and a method for producing concrete.

In the high strength high flow low heat cement composition, the high strength mixture is composed of 10-40 wt% substitution based on 100 wt% of cement, and the high strength mixture is blast furnace slag 40-80% and anhydrous gypsum 30-60% limestone 0-20 It is a fine powder mixed material composition which mixed% and grind | pulverized about average particle diameter about 6 +/- 1micrometer.

In the method of manufacturing concrete with high strength high flow low heat cement composition, 50-70% of the number of kneading water and 50% of the amount of high performance AE reducing agent added as admixture to the high strength high flow low heat cement and fine aggregate when manufactured at a predetermined concrete mixing ratio After 30 seconds to 1 minute and 30 seconds of stirring, the remaining amount of dough and high performance AE sensitizer was added 30-50% and 50% respectively, and then stirred for 30 seconds to 1 minute and 30 seconds, and finally the coarse aggregate Stirring for 1 minute 30 seconds to produce a high strength high flow low heat concrete.

Description

High strength high flow low heat cement composition and concrete manufacturing method {The method for manufacturing of composition of cement}

The present invention relates to a high strength high flow low thermal cement composition and a method of manufacturing the same. High-strength concrete refers to concrete that has higher compressive strength than general concrete. Currently, the term high strength or ultra high strength is not defined and used in Korea. However, in recent years, the application of high strength concrete is difficult due to the increase in size, height, and weight of concrete structures. In the construction, the compressive strength of 400 ~ 600kgf / ㎠ began to be used for the main parts of the building, and in the civil engineering field, 400 ~ 800kgf / ㎠ applied to the bridges and special structures. High-strength concrete not only reduces the member cross-section of high-rise buildings, but also reduces the weight of the building and secures a larger space. In addition, in bridges, the strength of slabs and beams is increasing, which makes it possible to increase the size of bridges. In Korea, the demand for high-strength concrete is expected to increase in civil and building structures.

There are two methods of increasing the strength of concrete: a method of increasing the strength of the binder itself, and a method of increasing the interfacial bonding force between the binder and the aggregate. In the former case, the porosity is increased by filling the ultrafine particles, increasing the hydrate, and reducing the water / cement ratio to increase the strength of the binder itself. In the latter case, a method of increasing the strength of the cement paste itself is improved by using a polymer-mixing agent to increase the interfacial bonding force between the binder and the aggregate. Currently, the former is mainly used for the production of high strength concrete.

Ultra-fine particles for the high strength of the binder itself include high-strength mixtures such as SILICA, FUME, METAKAOLINE, etc., but the situation is burdened by related industries because they are mostly imported and expensive.

In order to solve the above problems, the present inventors have developed a 'high strength mixed material' of fine powder whose main raw materials are blast furnace slag, anhydrous gypsum, and limestone, which are industrial wastes, to give high strength as well as high fluidity in general concrete structures. It is an object to provide a high strength high flow low heat cement composition and a manufacturing method.

In order to solve the above problems, the present invention is to improve the high-strength mixture composition of the steam curing cement of the present invention filed by the applicant of the Korean Patent Application No. 97-48758, the high-strength inherent of the high-strength mixture and cement The present invention relates to a copper low heat cement composition and a method of manufacturing the same.

The high-strength mixture is a fine powder mixture composed of slag, anhydrous gypsum, and limestone, and is used after 10 to 40% substitution is added to the amount of cement. Hydration of high strength honhapjae First, the hydration is activated by the increase in bond strength CSH-based, second, generation, third, promoting hydration of calcium silicates _{ETTRINGITE (3CaO · Al 2 O 3} · 3CaSO 4 · 32H 2 O). As a result, the concrete structure becomes dense and high strength can be expressed in a short period of time and has excellent advantages such as durability improvement and reduction of hydration heat.

High-performance AE water reducing agents used in the present invention include Gyeonggi Chem. Ezcon-K (trade name). Generally, the admixtures used in concrete include ① AE agent (Air Entrance agent) ② Plasticizer ③ High performance sensitizer (super plasticizer) ④ High performance AE sensitizer There are many products. It is set and purchased from admixture manufacturers, and the characteristics of each product are almost the same.

Through the following examples will be described in detail the present invention.

EXAMPLES 1-16

The high-strength mixture is finely pulverized by mixing 40-80% by weight of hydrated slag as a by-product from the steel blast furnace, 30-60% by weight of anhydrous gypsum and 0-20% by weight of limestone as a by-product when hydrofluoric acid is refined. To prepare a fine powder high strength mixed material.

20% by weight of the high-strength mixture as described above is mixed with 100% by weight of cement to prepare high-strength high-flow cement, and the unit yield is 160, 170, 180 kg / m ³ , water binder ratio 26-44%, fine aggregate rate 39- 44%, a high-performance AE reducing agent was blended 1.4-1.8% of the weight of the binder to prepare a high strength high flow low-temperature concrete with the composition components as shown in Table 2.

In the method of manufacturing high strength high flow low heat concrete, 50% of the amount of high-performance AE reducing agent added as a admixture to 70% of the high-strength high-molecular cement, fine aggregate, and kneading water to which the high-strength mixture is added is stirred for 1 minute, and then the remaining kneading water and 30% and 50% of high-performance AE water reducing agent was added and stirred for 1 minute, and finally, coarse aggregate was added and stirred for 1 minute and 30 seconds. SLUMPFLOW was 60 kg in 600 kgf / cm 3 and 800 kgf / cm 3 high strength Concrete was prepared.

Homogeneous concrete cannot be manufactured without the multi-stage mixing process, and the integral mixing method causes the coating of high-strength mixture, which is a fine powder, to the shaft in the mixer, resulting in drastically low process problems and mixing efficiency. Lose.

Table 1 below shows the chemical composition of the high-strength mixture.

Table 1. Chemical Composition of High Strength Mixtures

Chemical composition SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO SO ₃ Ig-LOSS SUM Content (wt%) 26.72 13.97 0.93 40.94 4.84 10.67 0.11 98.18

Table 2. Mixing ratio with 20% substitution of high strength mixture

Example Water / binder (%) Aggregate aggregate rate (%) Unit weight (㎏ / ㎥) water cement High Strength Mixture Aggregate Coarse aggregate High performance AE water reducer (B ×%) One 26 39 160 492 123 645 1056 1.8 2 28 40 457 114 677 1062 1.8 3 30 41 427 108 706 1064 1.6 4 32 42 400 100 735 1064 1.4 5 34 45 377 94 799 1022 1.5 6 26 40 170 523 131 639 1003 1.5 7 28 41 523 131 639 1003 1.5 8 30 42 453 113 701 1013 1.5 9 32 43 425 106 731 1013 1.5 10 26 41 180 554 139 631 950 1.5 11 28 42 514 129 664 958 1.5 12 30 43 480 120 694 964 1.5 13 32 44 450 113 725 965 1.5 14 36 44 400 100 748 996 1.4 15 40 45 360 90 783 1002 1.4 16 44 45 327 82 799 1022 1.4

Binder: Cement + High Strength Mixture

The physical properties of fine aggregate and coarse aggregate are shown in Table 3. In this experiment, a coarse aggregate with a maximum dimension of 20 mm was used as the main aggregate, and an additional 25 mm aggregate application experiment was conducted.

Table 3. Properties of Aggregate

division Maximum coarse aggregate importance Assembly rate Remarks Aged Aggregate - 2.58 2.71 Coarse aggregate 20mm aggregate 2.70 6.70 25mm aggregate 2.65 6.82

Water / binder (cement + high-strength mixture) ratio at unit quantities of 160, 170 and 180㎏ / ㎥, aiming at SLUMP 25 ± 3㎝, SLUMPFLOW 60 ± 5㎝ and air volume 3 ± 1% of concrete not hardened by the formulation of Table 2. The compressive strength and flow characteristics according to the change are shown in Table 5 for the concrete properties according to various conditions.

Table 4. Experimental Results According to Table 2 Formulation

Example Compressive strength (kgf / ㎠) SLUMP (cm) Slump-FLOW (cm) 50 cm (seconds) Air volume (%) 3 days 7 days 28 days One 538 716 796 25 60 - 1.9 2 538 697 807 25 61 - 2.0 3 517 651 746 25 61 - 2.3 4 490 651 754 25 59 - 2.5 5 462 564 660 25 63 - 3.4 6 634 730 825 24 55 17 2.0 7 594 724 770 26 60 12 2.1 8 542 643 750 26 64 10 2.3 9 549 648 728 25 59 12 2.4 10 660 786 850 27 65 10 2.1 11 651 784 847 23 57 13 2.3 12 612 713 831 26 62 10 2.4 13 532 656 743 26 65 8 2.6 14 502 597 631 25 65 6 3.3 15 442 529 594 25 62 9 3.1 16 328 438 531 23 61 5 2.8

The strength characteristic tendency according to the amount of high strength mixture added is shown in Table 7 and the strength characteristic in Table 8.

Table 5. Adjusting the Amount of High Strength Mixture

High strength mixture replacement amount (%) Water / binder (%) Aggregate aggregate rate (%) Unit weight (㎏ / ㎥) water cement High strength mixture Aggregate Coarse aggregate High performance AE water reducer 10 35.9 47 160 401 45 846 998 1.5 20 356 89 844 996 30 312 134 843 994 40 267 178 841 993

Table 6. Experimental Results of High Strength Mixture Addition

High strength mixture replacement amount (%) Compressive strength (kgf / cm3) SLUMP (cm) S-FLOW (cm) 50 cm (seconds) Air volume (%) 3 days 7 days 28 days 10 404 465 573 23 55 15 3.0 20 494 608 627 23 55 16 3.2 30 452 601 688 22 54 18 3.1 40 - 597 728 22 55 20 3.1

The larger the substitution amount of the high strength mixture (high strength mixture) is, the higher the strength tends to increase.

Table 7. Hydration Temperatures

High strength mixture replacement amount (%) Water / binder (%) Aggregate aggregate rate (%) Unit weight (㎏ / ㎥) water cement High Strength Mixture Aggregate Coarse aggregate High Performance AEr Reducer 0 32 44 563 - 728 972 1.5 40 338 225 721 961

Table 8. Hydration Temperature Curves of Concrete

The addition of 40% high strength mixture reduces the hydration temperature. It is applicable to low heat cement.

As described above, the present invention has the effect that the concrete structure becomes dense and has high strength in a short period of time and has excellent advantages such as durability improvement and heat of hydration reduction.

Claims (3)

delete Cement, in the fine aggregates, high-strength high fluidity low heat cement composition consisting of a superplasticizer, a unit dose to an in 160-185kg / m ³ of water, 26-44% cement ratio, fine aggregate ratio of 38-45%, by weight of superplasticizer on binder It is composed of 1.4-2.0%, the high-strength mixture is composed of 10-40% by weight relative to 100% by weight of cement, blast furnace slag 40-80%, anhydrous gypsum 30-60% and limestone 0-20% High strength high flow low thermal cement concrete composition, characterized in that the high-strength mixture having a particle diameter of 6 ± 1㎛. In the method of manufacturing concrete with high strength high flow low heat cement composition, Pulverized blast furnace slag 40-80%, anhydrous gypsum 30-60%, limestone 0-20% was prepared to prepare a fine powder high-strength mixture pulverized to an average particle diameter of 6 ± 1㎛, and then the high-strength mixture to 100% by weight of cement Substituting and mixing at -40% by weight to prepare a high strength high-temperature low heat cement, 50-70% of the number of kneading water and 50% of the high-performance AE reducing agent added amount as a admixture to the high-strength high-temperature low heat cement and fine aggregates for 30 seconds After stirring for 1 minute and 30 seconds, the remaining dough water and high performance AE reducing agent were added 30-50% and 50%, respectively, and stirred for 30 seconds to 1 minute and 30 seconds, and finally, coarse aggregate was added and stirred for 1 minute and 30 seconds. Method for producing concrete from high strength high flow low heat cement composition.