KR20180138079A - Mortar composition for preventing explosion of high strength concrete and method for manufacturing mortar for preventing explosion of high strength concrete comprising there of - Google Patents

Abstract

The present invention provides a mortar composition for preventing explosion of high strength concrete which comprises 100 parts by weight of cement, and 10-30 parts by weight of blast furnace slag powder, and further comprises 0.05-0.5 part by volume of organic fiber and steel fiber per 100 parts by volume of the mixture of cement and blast furnace slag powder, and a method for manufacturing mortar for preventing explosion of high strength concrete. The mortar composition for preventing explosion of high strength concrete according to the present invention is characterized by having high fire resistance and high durability, and thus can be applied to a high-rise building and a large structure.

Description

TECHNICAL FIELD [0001] The present invention relates to a mortar composition for preventing the explosion of high strength concrete, and a method for manufacturing a mortar for preventing explosion of high strength concrete containing the mortar composition. [0002]

The present invention relates to a mortar composition for preventing the explosion of high strength concrete having high fire resistance and high durability and a method for manufacturing mortar for preventing explosion of high strength concrete.

High-strength concrete can reduce the weight of buildings and reduce the cross-section of buildings. Recently, the application of high - strength concrete has been increasing as the construction of super high - rise buildings and large structures has progressed actively in Korea.

However, high-strength concrete uses an admixture to increase the strength of the concrete. As a result, the internal structure becomes dense and the amount of internal porosity decreases. As a result, the heat transfer occurs rapidly and the surface of the member abruptly suddenly becomes high at a certain high temperature due to water vapor generated in the concrete. Causing a spalling phenomenon in which peeling and detachment occur together with blowing.

This sudden explosion is a threat to the safety of the structure due to the scattering of the fragments of the reinforced concrete member and the deterioration of the members due to the exposure of the reinforcing bars. In case of a fire in high-rise buildings and large structures, If the collapse of the building is caused, it is expected that the impact on the society and the environment will be extreme due to the huge human and property damage.

Conventionally, refractory materials have been developed to prevent such problems, but conventional refractory materials are vulnerable to impact, vulnerable to fire, and expensive.

As described above, in order to overcome the problems of the prior art, it is necessary to study the cause of the explosion problem of the high-strength concrete and to study the factors affecting the explosion, do.

It is an object of the present invention to provide a mortar composition for preventing the explosion of high strength concrete having high fire resistance and high durability, which can be applied to a super high-rise building and a large structure.

It is still another object of the present invention to provide a method for manufacturing the mortar for preventing explosion of concrete.

The present invention relates to a high-strength concrete heat insulating material comprising 100 parts by weight of cement and 10 to 30 parts by weight of fine powder of blast furnace slag, and further comprising 0.05 to 0.5 part of organic fiber and steel fiber per 100 parts of the mixture of cement and blast furnace slag powder. Mortar composition.

The blast furnace slag fine powder may have a particle diameter of 8 to 14 탆, a specific gravity of 2.8 to 3.0, and a powdery degree of 3,800 to 4,200 ㎠ / g.

The organic fibers may be any one selected from the group consisting of polyvinyl alcohol fibers, micro polypropylene fibers, and combinations thereof.

Any one selected from the group consisting of the organic fiber, the steel fiber, and both of them may be a hollow fiber.

The present invention also relates to a method for manufacturing a cement mortar composition, comprising the steps of: a dry beaming step of mixing and mixing 100 parts by weight of cement and 10 to 30 parts by weight of granulated blast furnace slag; mixing water into the mixture of the dry beaten cement and blast furnace slag; And a blending step of further mixing and mixing the organic fiber and the steel fiber with the blast furnace slag fine powder mixture, and a discharging and forming step of discharging and hardening the blended cement, blast furnace slag fine powder and fiber mixture, And the steel fiber comprises 0.05 to 0.5 part of organic fiber and steel fiber per 100 parts of the mixture of the cement and the blast furnace slag fine powder.

And further curing at 40 to 70 ° C for 3 to 7 hours after the above-described discharge and molding step.

The present invention can provide a mortar composition for preventing the explosion of high-strength concrete having high fire resistance and high durability, which can be applied to skyscraper buildings and large structures.

The present invention can also provide a method for manufacturing a mortar for preventing explosion of high strength concrete which is excellent in high vibration resistance and crack control ability.

1 is a view showing a crack pattern when concrete is exposed to high temperature.
FIG. 2 is a view showing a heat dissipation mechanism when the concrete is exposed to high temperature. FIG.
3 is a view showing a crack pattern and a heat dissipation mechanism when concrete is exposed to high temperature.
4 is a photograph showing a method of manufacturing a mortar for high-strength concrete according to an embodiment of the present invention.
FIG. 5 is a view for explaining the classification concept according to the explosion generation according to Experimental Example 3 of the present invention. FIG.
FIG. 6 is a view for explaining the concept of classification according to the explosion occurrence according to Experimental Example 3 of the present invention. FIG.
7 is a photograph showing the results of the external appearance test of the mortar according to the comparative examples and the examples of the present invention.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a high-strength concrete heat insulating material comprising 100 parts by weight of cement and 10 to 30 parts by weight of fine powder of blast furnace slag, and further comprising 0.05 to 0.5 part of organic fiber and steel fiber per 100 parts of the mixture of cement and blast furnace slag powder. Mortar composition.

The cement binds the aggregates and enhances the strength of the mortar. The cement may use Portland cement specified in KS.

When the content of the cement is high, it is effective in improving the strength. However, as the density and the thermal conductivity are increased and the heat is applied, water contained in the pores is changed into water vapor and the pressure is increased to cause explosion. Lt; / RTI > On the other hand, when the content of cement is small, the strength is lowered and the durability is decreased, so that the mechanical function as a refractory mortar may not be exhibited.

The mortar for preventing high-strength concrete explosion according to an embodiment of the present invention includes blast furnace slag fine powder.

Generally, concrete made of conventional mortar is resistant to compression, but has relatively low tensile strength and insufficient crack resistance in comparison with compressive strength. Therefore, there has been a problem of shortening the life of concrete caused by cracks and corrosion of steel bars. When the blast furnace slag is contained as a concrete material, the above problem can be solved because it contributes to an increase in durability.

Blast furnace slag is a by-product of the steel industry. Its components are mainly composed of silicon dioxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), and calcium oxide (CaO), mainly Portland cement (OPC). (MnO), iron oxide (FeO), sulfur (S), alkali (Na ₂ O, K ₂ O), and the like.

The blast furnace slag fine powder may be contained in an amount of 15 to 25 parts by weight based on 100 parts by weight of the cement. If the blast furnace slag fine powder is contained in an amount less than 15 parts by weight, the durability increase effect may be insufficient. If the blast furnace slag finishing amount is more than 25 parts by weight, the water permeability of the mortar may be lowered.

The blast furnace slag fine powder may have a particle diameter of 8 to 14 mu m, a specific gravity of 2.8 to 3.0, and a powder degree of 3,800 to 4,200 cm < 2 > / g. The mortar for preventing high-strength concrete explosion may contain a micro-sized blast furnace slag within the above-mentioned range to increase the heat insulating temperature.

However, since the initial strength of concrete using blast furnace slag powder is generally low, the performance such as strength, permeability and other properties of the concrete changes depending on the casting temperature, curing condition and curing temperature of the concrete, and various problems such as neutralization and drying shrinkage .

In addition, most of the fibers used in the conventional fiber-reinforced concrete use a new material, which increases the manufacturing cost of the fiber-reinforced concrete, so that it is very limited when the fiber-reinforced concrete requires economical efficiency.

The mortar for preventing high-strength concrete explosion prevention according to one embodiment of the present invention can solve the above problems and improve the fire resistance and durability of the mortar by using the blast furnace slag fine powder, the organic fiber and the steel fiber in combination.

Specifically, the organic fibers may be any one selected from the group consisting of polyvinyl alcohol fibers, micropolypropylene fibers, and combinations thereof.

The poly (vinyl alcohol) (PVA) fiber has excellent thermal properties, strength and chemical resistance, and is suitable for mortar to prevent high-strength concrete explosion. Specifically, the polyvinyl alcohol fiber may have a diameter of 1 to 20 mu m, a length of 10 to 20 mm, a specific gravity of 0.5 to 1.5, and a tensile strength of 2,600 to 2,800 MPa. If the length of the polyvinyl alcohol fiber is less than 10 mm, the contact area between the mortar composition and the fiber is narrowed, so that the effect of improving the tensile strength and compressive strength of the mortar may be deteriorated. If the length exceeds 20 mm, The dispersibility may deteriorate and the physical properties may be lowered. If the diameter is less than 1 탆, the surface area of the fiber increases to increase the contact area between the fiber and the mortar composition. However, the strength of the fiber itself may decrease and the dispersibility of the fibers in the mortar composition may deteriorate, If it is more than 20 占 퐉, it is preferable to use fibers having the above-mentioned diameters and lengths because the surface area of the fibers is reduced and the contact area is reduced and the strength may be lowered.

Polyproplene (PP) fiber is characterized by having a high water absorbing ability, including numerous micro voids produced by the microfiber of microfine fibers after the diameter of the polypropylene fiber is used. Specifically, the micropolypropylene fiber may have a diameter of 30 to 60 탆, a length of 50 to 100 탆, a specific gravity of 0.5 to 1.5, and a tensile strength of 2,600 to 2,800 MPa.

The mortar composition according to the present invention may include the polyvinyl alcohol fiber and the micropolypropylene fiber as the organic fibers, but polyvinyl alcohol fibers and micropolypropylene fibers having different diameters and different lengths may be mixed.

The steel fiber (SF) is suitable for a mortar composition which is high in strength and flexible and becomes a material of high strength concrete. Specifically, it may have a diameter of 1 to 20 mu m, a length of 10 to 20 mm, a specific gravity of 0.5 to 1.5, and a tensile strength of 3,600 to 3,800 MPa.

The organic fiber and the steel fiber may be contained in 0.05 to 0.5 part skin to 100 parts of the skin of the cement and the blast furnace slag, and the organic fiber and the steel fiber may be contained in an amount of 0.10 to 0.5 part It is more preferable to be included as skin. If the organic fiber and the steel fiber are contained in an amount of less than 0.05 part skin, a reinforcing effect through fiber inclusion is insufficient, and heat may be generated. If the organic fiber and steel fiber are more than 0.5 part skin, dispersibility may be lowered, and the strength of the mortar may be deteriorated.

The mortar for preventing explosion of high-strength concrete according to the present invention can improve not only the refractory performance but also the durability of the structure including the organic fiber and the steel fiber.

The mixing ratio of the organic fibers to the steel fibers is preferably 1: 1 to 1: 2 by volume. If the steel fiber contains less than 1 part by volume of the organic fiber, the strength may be lowered. If the weight of the steel fiber exceeds 2 parts by volume, the porosity may be lowered and the refractory effect may be insignificant.

In the high-strength concrete explosion-proof mortar, any one selected from the group consisting of the organic fibers, the steel fibers, and both may be hollow fibers.

Hollow fiber refers to a hollow fiber, specifically a macaroni-shaped fiber in which the central portion of the fiber is continuous or discontinuous in the longitudinal direction and hollow like a tunnel. Natural hollow fibers can be used, but man-made fibers can be used which are improved in polymer or produced in hollow form in the spinning stage. The hollow fiber is lightweight and easily melts when heated. In detail, the hollow fiber may have a porosity of 30 to 70% by volume and melt at 300 ° C or less.

1 is a view showing a crack pattern when concrete is exposed to high temperature. The crack pattern when the concrete member is exposed to high temperature by fire or the like can be explained with reference to FIG. The crack pattern may include a drying shrinkage crack 101, a horizontal crack 102, a tangential crack 103, a radial crack 104, and a crack in the constituent material 105, depending on the temperature change.

FIG. 2 is a view showing the explosion mechanism when the concrete is exposed to high temperature. FIG. The explosion mechanism when the concrete member is exposed to high temperature by fire or the like can be explained with reference to FIG. The main cause of the explosion phenomenon is known to be a result of the combined action with the crack 202 due to the thermal stress in addition to the rise of the water vapor pressure 201.

The cracking and explosion mechanism according to FIGS. 1 and 2 will now be described in more detail. 3 is a view showing a crack pattern and an explosion mechanism when concrete is exposed to high temperatures. When the concrete member is exposed to high temperature by fire or the like, first, heat penetration and water vapor migration (S301) occur. The moisture in the layer adjacent to the exposed surface moves to the relatively low temperature interior and is reabsorbed into the pores of the adjacent layer. However, in the case of conventional high-strength concrete, the internal structure is dense due to the admixture added to increase the strength, and accumulation of water vapor occurs (S302). Moisture clog is formed due to accumulation of water vapor to increase water vapor pressure (S303), and the thickness of the dry layer on the surface of the member increases, and a distinction is made between the dry layer and the saturated layer. As the fire progresses, water movement to the inside becomes difficult, and the pressure for moving the water vapor toward the exposed surface and the pressure for expanding the water vapor are larger than the tensile strength of the concrete, and the explosion phenomenon occurs (S304) .

The present invention can improve the strength of a mortar composition by using a blend of blast furnace slag fine powder, organic fiber and steel fiber to replace high-strength concrete, and mix blast-furnace slag fine powder with organic fiber and steel fiber, (201, S302) and cracks (202, S303) due to thermal stress can be prevented by using internal pores formed by melting of organic fiber and steel fiber as a passage of water when the temperature rises. have.

Meanwhile, the mortar for preventing high-strength concrete explosion may further include sand sand as fine aggregate. Silica sand may be included to improve strength, reduce shrinkage, and improve economic efficiency. The sand sand may have a grain size of 112 to 188 탆 and a specific gravity of 2.5 to 2.7. According to the micro-mechanical analysis, the size of the aggregate rather than the kind of the aggregate has a more decisive influence on the mechanical properties of the fiber composite mortar composition. In addition, it is generally known that it is advantageous to use a fine aggregate having a fine particle size. However, when the particle size is less than 112 탆, sandy sand within the above range is most preferable because it adversely affects workability. Also, the sand sand may be included in 80 to 90 parts by weight of sandy silica relative to 100 parts by weight of the cement.

The mortar composition for preventing high-strength concrete explosion may further include various additives such as an additional admixture, a binder and an aggregate. Any of the various additives may be used as long as it is commonly used in the field to which the present invention belongs, and the content thereof is not particularly limited as long as it depends on the compounding ratio used in a conventional mortar composition.

The mortar for preventing high-strength concrete explosion prevention according to the present invention comprises a dry beaming step of mixing and mixing 100 parts by weight of cement and 10 to 30 parts by weight of blast furnace slag fine powder, water mixing step of mixing water with the dry beaten cement and blast furnace slag fine powder mixture, A fiber mixing step of further mixing and mixing the organic fiber and the steel fiber with the water-mixed cement and blast furnace slag fine powder mixture, and a discharging and molding step of discharging and solidifying the cement, blast furnace slag fine powder and fiber mixture May be manufactured. However, the organic fiber and the steel fiber include 0.05 to 0.5 part of organic fiber and steel fiber for 100 parts of the mixture of the cement and the blast furnace slag fine powder.

The above-mentioned dry beaming step is a step of mixing the introduced cement and the blast furnace slag fine powder, and no water is introduced at this time. Therefore, it is easy to check the mixing state of the material by mixing the aggregate and the cement before the water is introduced. At this time, a rotary mixer is used, and mixing can be performed at a speed of 25 to 35 rpm to evenly mix the cement and blast furnace slag fine powder. Preferably, the mixing time is not limited to 1 minute and 30 seconds to 2 minutes. However, after mixing for a predetermined time, it is checked whether the materials are mixed, the rotation speed is maintained at 15 to 25 rpm, You may.

In the water mixing step and the fiber mixing step, water, organic fiber, and steel fiber are further mixed into the cement and blast furnace slag fine powder in a state where the drying step is completed. At this time, it is preferable that the rotational speed of the rotary mixer is maintained at 15 to 25 rpm. In addition, water may be added to the total amount, organic fibers and steel fibers may be partially mixed and partially mixed, and then the remaining organic fiber and steel fiber may be further mixed to be further mixed.

In the discharging and molding step, the mixture of the cement and the blast furnace slag powder into which the organic fiber and the steel fiber are further mixed is poured into the mold and hardened to prepare the mortar.

It is preferable that the discharged mixture is subjected to a flow test and then molded to prevent defective products.

4 is a photograph showing a manufacturing process of a high strength concrete mortar composition according to an embodiment of the present invention. Referring to FIG. 4, the method for manufacturing a high strength concrete mortar according to the present invention includes steps S401, S402, S403, S404, (S405), a forming step (S406), a constant temperature and humidity curing step (S407), a fire resistance testing step (S408), and a compressive strength testing step (S409).

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[Preparation Example: Preparation of Mortar Specimen]

Mortar compositions according to the following Examples and Comparative Examples were prepared using the compositions shown in Table 1 below. The mortar composition was prepared by dry blending cement and blast furnace slag powder without water, adding water, organic fiber and steel fiber, and mixing. The mortar composition thus prepared was discharged into a mold to prepare a mortar specimen. The prepared mortar specimens were cured at 50 DEG C for 5 hours and then subjected to an experiment.

cement
(Parts by weight) Blast furnace slag
(Parts by weight) Fly ash
(Parts by weight) Organic fiber 1
(Minor skin) Organic fiber 2
(Minor skin) Steel fiber
(Minor skin) Comparative Example 1 100 20 - - - - Comparative Example 2 100 20 - - - - Comparative Example 3 100 20 - - - - Comparative Example 4 100 - 20 - - - Comparative Example 5 100 20 - 0.05 Comparative Example 6 100 20 - 0.15 Comparative Example 7 100 20 - 0.25 Comparative Example 8 100 20 - 0.05 Comparative Example 9 100 20 - 0.15 Comparative Example 10 100 20 - 0.25 Comparative Example 11 100 20 - 0.05 Comparative Example 12 100 20 - 0.15 Comparative Example 13 100 20 - 0.25 Comparative Example 14 100 20 - 0.025 0.025 Comparative Example 15 100 20 - 0.075 0.075 Comparative Example 16 100 20 - 0.125 0.125 Example 1 100 20 - 0.025 0.025 Example 2 100 20 - 0.075 0.075 Example 3 100 20 - 0.125 0.125 Comparative Example 17 100 20 - 0.25 Comparative Example 18 100 20 - 0.15 Comparative Example 19 100 20 - 0.15 Comparative Example 20 100 20 - 0.075 0.075 Example 4 100 20 - 0.075 0.075

- Content of blast furnace slag and fly ash: Based on 100 parts by weight of cement, the blast furnace slag or the weight of fly ash

- Content of organic fibers and steel fibers: 100 parts of cement and blast furnace slag

- Blast furnace slag: Blast furnace slag fine powder having a particle diameter of 11 탆

- Fly ash: Fly ash fine powder having a particle size of 11 탆

- Organic fiber 1: Polyvinyl alcohol fiber (PVA)

- Organic fiber 2: Micropolypropylene fiber (PP)

- Steel fiber

[ Experimental Example  1: Mortar Specimen  Strength Remaining Characteristics Test]

In order to test the residual strength characteristics of the mortar specimens prepared in the above Examples and Comparative Examples, a standard fire temperature test was conducted for each of the non-fires, 300 ° C., 600 ° C. and 900 ° C., Were tested for compressive strength. Strength (MPa) was measured and the compressive strength retention ratio is shown in Table 2 below.

division Non-fire 300 ° C 600 ℃ 900 ℃ MPa MPa Remaining rate MPa Remaining rate MPa Remaining rate Comparative Example 1 - - - - - - - Comparative Example 2 20.7 16.5 79.7% 18.7 90.3% Explosion Explosion Comparative Example 3 27.7 28.6 103.2% 25.4 122.7% Explosion Explosion Comparative Example 4 25.8 20.3 78.7% Explosion Explosion Explosion Explosion Comparative Example 5 23.7 20.4 86.1% 23.6 114.0% Explosion Explosion Comparative Example 6 27.4 25.3 92.3% 19.3 93.2% 16.9 81.6% Comparative Example 7 28.9 28.9 100.0% 26.5 128.0% 18.2 87.9% Comparative Example 8 23.4 27 115.4% Explosion Explosion Explosion Explosion Comparative Example 9 23.4 25.5 109.0% 22.9 110.6% 16.3 78.7% Comparative Example 10 27.1 24.7 91.1% 21 101.4% 11.3 54.6% Comparative Example 11 23.8 24 100.8% 28.6 138.2% Explosion Explosion Comparative Example 12 27.4 17.6 64.2% Explosion Explosion Explosion Explosion Comparative Example 13 25.7 22.2 86.4% 27.1 130.9% Explosion Explosion Comparative Example 14 25.3 27.4 108.3% Explosion Explosion Explosion Explosion Comparative Example 15 28.6 26.7 93.4% 25.8 124.6% 21.2 102.4% Comparative Example 16 24.5 21 85.7% 24.1 116.4% 17.5 84.5% Example 1 25.5 25.8 101.2% Explosion Explosion Explosion Explosion Example 2 25.8 25.7 99.6% 25.1 121.3% 17.4 84.1% Example 3 24.9 27.3 109.6% 26.3 127.1% 16.4 79.2%

Referring to Table 2, it was confirmed that the compression strength retention ratios of Examples 2 and 3 were superior to those of Comparative Examples. In Example 1, the content of fibers is too small as compared with cement, and the effect of refractory and lubrication is expected to be insignificant.

[ Experimental Example  2: Weight change experiment]

In order to carry out the weight change experiments of the mortar specimens prepared in the above-mentioned Examples and Comparative Examples, the standard fire temperature heating test was carried out for the non-fires, 300 ° C., 600 ° C. and 900 ° C., Table 3 shows the weight of all the test pieces and the weight change of the test pieces after the completion of the heating test.

division 300 ° C 600 ℃ 900 ℃ Remarks I'm after Decrease (%) I'm after Decrease (%) I'm after Decrease (%) Comparative Example 1 - - - - - - - - - - Comparative Example 2 3050 2869 6% 3048 2524 17% 3063 Measure
Impossible - Explosion Comparative Example 3 3160 2998 5% 3140 2627 16% 3173 Measure
Impossible - Explosion Comparative Example 4 3150 2908 8% 3125 2577 18% 3169 Measure
Impossible - Explosion Comparative Example 5 3180 2916 8% 3168 2621 17% 3193 2569 20% Explosion Comparative Example 6 3160 2983 6% 3139 2636 16% 3174 2605 18% Comparative Example 7 3140 2910 7% 3172 2632 17% 3132 2527 19% Comparative Example 8 3227 2971 8% 3221 2618 19% 3226 2551 21% Explosion Comparative Example 9 3252 3093 5% 3251 2685 17% 3246 2622 19% Comparative Example 10 3235 2969 8% 3231 2645 18% 3238 2571 21% Comparative Example 11 3265 3042 7% 3258 2680 18% 3239 2580 20% Explosion Comparative Example 12 3266 3095 5% 3261 2707 17% 3275 2593 21% Explosion Comparative Example 13 3270 3018 8% 3270 2693 18% 3254 Measure
Impossible - Explosion Comparative Example 14 3254 3010 7% 3251 2646 19% 3256 2560 21% Comparative Example 15 3242 3087 5% 3235 2675 17% 3234 2616 19% Comparative Example 16 3240 2978 8% 3242 2647 18% 3229 2584 20% Example 1 3264 3021 7% 3251 2663 18% 3225 2587 20% Explosion Example 2 3240 3074 5% 3234 2664 18% 3244 2632 19% Example 3 3260 3028 7% 3256 2669 18% 3267 2634 19%

Since the fibers melt after the fire, voids are formed and the heat transfer is performed by the voids, so that the water vapor pressure and the thermal stress of the mortar are stabilized and the explosion can be prevented. In this experimental example, the weight was measured and the degree of porosity was confirmed.

Referring to Table 3, it was confirmed that the compression strength retention ratios of Examples 2 and 3 were superior to those of Comparative Examples. In Example 1, the content of fibers is too small as compared with cement, and the effect of refractory and lubrication is expected to be insignificant.

From the test results, it can be seen that the refractory mortar according to the present example is excellent in strength and durability without fire explosion even in a fire of 900 캜.

[Experimental Example 3: Appearance of fireproof mortar]

In order to classify fire-resistant mortar according to the occurrence of explosion, the concept of classification of explosion test bodies is shown as grades 1 to 4 as shown in FIGS. 5 and 6 based on the coating thickness specification on the concrete standard specification and the fire grade classification according to the blood on the fire. The external appearance of the refractory mortar was tested and shown in Fig.

As a result of examining the explosion class of the explosive test body classification concept and the explosion grade of the explosion of the fireproof mortar shown in the present technology development, it was found that the explosion grade or the crack was not generated at the heating temperature of 300 ° C, (Including PVA only), Comparative Example 12 (including only steel fiber), Comparative Example 14 (including PVA and PP only), Example 1 (including only PVA) PVA fiber, and steel fiber with less than 0.05 part skin), and all other specimens showed grade 1.

At 900 ° C., all of the specimens of Comparative Examples 1, 2, and 4 in which the fibers were not mixed showed a grade of 4 due to spalling, and only one type of fiber was included or a grade of 3 was included if the content was too small.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

101: drying shrinkage crack 102: horizontal crack due to temperature change
103: tangential crack 104: radial crack
105: Constituent material self-cracking
201: Rise of water vapor pressure 202: Thermal stress crack
S301: Heat penetration and water vapor transfer S302: Accumulation of water vapor
S303: Formation of a saturated layer and increase of steam pressure S304: Generation of explosion
S401: Drying step S402: Water mixing step
S403: Fiber incorporation step S404: Discharging step
S405: Flow test step S406: Forming step
S407: Curing of the thermo-hygroscopic device S408:
S409: Strength test step

Claims (6)

100 parts by weight of cement, and
10 to 30 parts by weight of a blast furnace slag fine powder,
A mixture of the cement and the blast furnace slag powder in an amount of from 0.05 to 0.5 parts by weight of the organic fiber and the steel fiber per 100 parts of the skin
Mortar composition for preventing the explosion of high strength concrete. The method according to claim 1,
Wherein the blast furnace slag fine powder has a particle diameter of 8 to 14 占 퐉, a specific gravity of 2.8 to 3.0, and a powder degree of 3,800 to 4,200 cm2 / g. The method according to claim 1,
Wherein the organic fiber is any one selected from the group consisting of polyvinyl alcohol fibers, micro polypropylene fibers, and combinations thereof. The method according to claim 1,
Wherein the organic fiber, the steel fiber, and either one selected from the group consisting of the organic fiber and the steel fiber are hollow fibers. 100 parts by weight of cement and 10 to 30 parts by weight of blast furnace slag powder are mixed and mixed,
Water mixing step of mixing water with the gunbeam-cemented cement and blast furnace slag fine powder mixture,
A fiber mixing step of further mixing and mixing the organic fiber and the steel fiber with the water-mixed cement and blast furnace slag fine powder mixture, and
And a discharging and forming step of discharging and hardening the cement mixed with the fiber, the blast furnace slag fine powder, the organic fiber and the steel fiber mixture,
The organic fiber and the steel fiber include 0.05 to 0.5 part of organic fiber and steel fiber per 100 parts of the mixture of the cement and the blast furnace slag powder
(METHOD OF MANUFACTURING MORTAR FOR PREVENTING HIGH STRENGTH CONCRETE). 6. The method of claim 5,
Further comprising the step of curing at 40 to 70 DEG C for 3 to 7 hours after the discharge and molding step.

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