KR101069772B1 - Snow melting system and pavement method for road using slag - Google Patents

Abstract

The present invention utilizes oxidized slag, a by-product generated in the steelmaking process, as a fine aggregate and significantly reduces the content of cement in concrete, thereby improving the overall strength of concrete while improving the thermal conductivity of the road snow melting system and road snow melting pavement Regarding the method, in detail iii) 8 to 16% by weight of cement, 3 to 6% by weight of water, 28 to 59% by weight of fine aggregate, 30 to 50% by weight of coarse aggregate, 30 to 100% by weight of the fine aggregate Road furnace snow melting system comprising the electric furnace oxidized slag, the particle size of the electric furnace oxidized slag is 1.2 ~ 5.0mm, and ii) heating wire embedded in the concrete to generate heat when the power is applied. It is about. As described above, by reducing the content of cement constituting the concrete composition and replacing most of the aggregates with oxidized slag with electricity, it is possible to maximize the snow melting effect with a small amount of power. Can be prevented.

Description

Snow Melting System And Pavement Method For Road Using Slag}

The present invention utilizes oxidized slag, a by-product generated in the steelmaking process, as a fine aggregate and significantly reduces the content of cement in concrete, thereby improving the overall strength of concrete while improving the thermal conductivity of the road snow melting system and road snow melting pavement It is about a method. As described above, by reducing the content of cement constituting the concrete composition and replacing most of the aggregates with oxidized slag with electricity, it is possible to maximize the snow melting effect with a small amount of power. Can be prevented.

Downtown and highways are representative structures that are very vulnerable to user safety and vehicle accidents due to winter snowfall and surface freezing. Currently, snow melting and thawing work on roads promotes the safety of users by spraying a large amount of chloride. However, chlorides corrode the roads, causing secondary damage such as desorption, breakage, and cracking, which burdens both road managers and users in the long run. have.

In order to realize effective snow melting and road surface thawing, a method of building a snow melting system on the road itself has been developed. Existing road snow melting systems can be largely divided into a method of embedding a hot wire in the front of the road shown in Figures 1a, 2a and a method of landfilling after home cutting the road shown in Figures 1b, 2b.

The method of embedding hot wires on the front of the road is a method developed during the early stages of melting snow packaging. Sand and gravel occupy about 60 ~ 80%, and concrete pavement with low thermal conductivity is required for surface melting and thawing using heating elements. Excessive power is consumed to increase the heating wire, excessive heating wire, and there is a problem that there is a possibility of cracking due to the temperature difference between the inside and outside of the concrete.

In addition, the method of paving the heating wire after home cutting the road is a method of cutting the heating wire buried portion to groove the heating wire in order to increase the thermal conductivity, and then the heating wire is embedded and filled with epoxy, and the power consumption can be reduced. It takes a lot of work time, damage to the cutting edge due to artificial cutting on the road surface, there was a problem that the tensile stress and cracks occur due to the local temperature rise.

Therefore, while improving the thermal conductivity, there is a need for the development of a technology that can maximize the snow melting effect with no tensile stress and cracks due to the even temperature rise of the package, less power.

On the other hand, slag (slag) refers to a solvent, a non-metallic substance, a metal oxide, etc. that floats or remains as waste when melting iron ore or scrap in melting furnaces, electric furnaces, cupolas, etc. It serves to prevent the molten steel surface from being oxidized by air and to preserve the surface.

The blast furnace slag and steel slag currently occurring in Korea are 9.5 million tons and 7.5 million tons, respectively, totaling 17 million tons, and electric furnace slag of steelmaking slag is about 3.4 million tons, and about 4.1 million tons of converter slag are produced and collected. The slag collected in this way is used as road roadbed, cement admixture, civil engineering material and concrete aggregate.

On the other hand, concrete aggregates are commonly used as the main components of mortar or concrete together with cement in the manufacture of concrete, but gravel, crushed stone, crushed stone, crushed sand, and natural sand are generally used, but recently, natural aggregate for concrete is depleted and insufficient. In addition, strict regulations are expected in the future for the collection of river aggregates and the development of quarries based on river maintenance and environmental preservation.

Therefore, the technology of using oxidized slag as a substitute material for the aggregate used as the main component in the concrete manufacturing has been studied, but the conventional concrete composition using oxidized slag has a very low replacement ratio of 11 ~ 30% as well as As the cement content is high, there is a limit to lower the unit price.

Accordingly, the present invention significantly reduced the amount of cement constituting the concrete composition and replaced most of the natural aggregates with oxidized slag with electricity, and developed economical high-strength concrete with high thermal conductivity. It has developed a snow melting system and a snow melting packaging method that can maximize the snow melting effect with little power and no cracking.

The present invention was devised to solve the above-mentioned problems, and has a high thermal conductivity, without the occurrence of tensile stress and cracks due to the uniform temperature rise of the package, snow melting system and snow packaging method that can maximize the snow melting effect with little power The purpose is to provide.

In addition, an object of the present invention is to provide a snow melting system and a snow melting packaging method that can expand the usability of industrial waste, and also obtain an economic effect of cost reduction.

In order to achieve the above object, the present invention includes iii) 8 to 16% by weight of cement, 3 to 6% by weight of water, 28 to 59% by weight of fine aggregate, 30 to 50% by weight of coarse aggregate, and 30 of the fine aggregate. ~ 100% by weight of the electric furnace oxidized slag, the particle size of the electrically oxidized slag is 1.2 ~ 5.0mm concrete, and ii) road snow melting including a heating wire embedded inside the concrete to generate heat as power is applied Provide a system.

On the other hand, in order to achieve the above object, the present invention comprises the steps of iii) excavating the heating wire after cutting the road front; And
Ii) 8 to 16% by weight of cement, 3 to 6% by weight of water, 28 to 59% by weight of fine aggregates, 30 to 50% by weight of coarse aggregates, 30 to 100% by weight of the fine aggregates It is an oxide slag, and paving concrete with a particle size of 1.2 ~ 5.0mm of the oxidation slag by the electric; road snow melting paving method comprising a.

At this time, the road snow melting system may further include a control device for adjusting the amount of power or current applied to the heating wire, the daily strength of the concrete is preferably 300kgf / ㎠ or more.

In addition, the concrete may further comprise a polymer of 5 to 35% by weight of the cement, the polymer is SB (60 to 70% by weight of styrene, 30 to 40% by weight of butadiene) latex, PAE emulsion, EVA emulsion, epoxy It is preferably a water-soluble liquid polymer composed of any one or a mixture thereof selected from the group consisting of resin, acrylic resin, polyester, water-soluble MMA.

In the snow melting system and packaging method of the present invention, by replacing most of the aggregates with oxidized slag with electricity having a more uniform density than natural aggregates, and using concrete having significantly reduced expensive cement content, tensile stress and cracking are generated with high thermal conductivity. Almost no, it can maximize the snow effect with little power, improve the overall strength of concrete, expand the usability of industrial waste, and achieve the economic effect of cost reduction.

In addition, the high-performance concrete composition of the present invention by reducing the cement content, significantly lower the heat of hydration generated during the concrete hydration reaction to suppress the expansion and contraction of the initial concrete, the amount of dry shrinkage that acts as a major cause of cracking in concrete It can significantly reduce the water, maximize the water tightness of the concrete to increase the waterproofness, and greatly increase the fluidity can significantly reduce the amount of use in the production of concrete.

Figure 1a-Photo showing a method of embedding a hot wire on the front of the conventional road
1b-Photo showing a method of landfilling after home cutting a conventional road
2A-A conceptual diagram illustrating a method of embedding a heating wire in the front of a conventional road
2b-A conceptual diagram illustrating a method of embedding a conventional road after home cutting
Figure 2c-conceptual diagram showing a road snow melting system using the slag of the present invention
3a, 3b-Experimental photograph for verifying the thermal conductivity enhancement effect of the concrete using the slag of the present invention
4-Graph showing the surface temperature change of the concrete using the slag of the present invention when heating the bottom
5-Comparison of dry shrinkage measurement of concrete according to the composition of the present invention and the existing concrete

Hereinafter, preferred embodiments of the present invention will be described in detail. Prior to this, terms or words used in the present specification and claims should not be construed as being limited to ordinary or dictionary meanings, but should be construed as meanings and concepts consistent with the technical spirit of the present invention.

Road snow melting system of the present invention includes: 8) 16% by weight of cement, 3-6% by weight of water, 28-59% by weight of fine aggregate, 30-50% by weight of coarse aggregate, and 30-100% by weight of the fine aggregate Concrete which is an oxidized slag of electricity, and ii) a heating wire embedded in the concrete to generate heat as power is applied, and further comprising a control device for adjusting the amount of power or current applied to the heating wire as needed. Can be.

In addition, the road snow melting pavement method of the present invention for implementing the road snow melting system is iii) discharging the heating wire after cutting the road front, and ii) 8 to 16% by weight cement, 3 to 6 weight of water on the excreted heating wire %, Fine aggregates containing 28 to 59% by weight, coarse aggregates include 30 to 50% by weight, and 30 to 100% by weight of the fine aggregates consists of paving concrete which is oxidized slag with electricity.

Conventional concrete used in hot snow landfill or home cutting method, which is a typical snow melting system, is a composite material composed of cement, water, sand, and gravel. Sand and gravel occupy about 60 ~ 80%, resulting in low thermal conductivity. It requires very high energy and has many problems such as tensile stress and cracking due to local temperature rise.

Thus, the snow melting system and the packaging method of the present invention, as shown in Figure 2c, it is characterized in that the concrete density and thermal conductivity to increase by using the iron oxide-containing electric furnace slag as fine aggregate.

On the other hand, the conventional concrete using the oxidized slag is very low replacement ratio of the natural aggregate of the slag as 11 ~ 30% by weight, there is a limit to lower the manufacturing cost because it can not only maintain the content of cement to maintain the strength of the concrete .

However, the present invention significantly reduces the content of cement to 8 to 16% by weight, and replaces 30 to 100% by weight of the natural aggregate used for concrete production with oxidized slag with electricity, greatly increasing the content of oxidized slag with electricity in concrete Increased.

Therefore, it is possible to reduce costs by reducing expensive cement, and at the same time, by using electric furnace oxidized slag having a uniform density than natural aggregates, watertightness and filling are increased, and the strength of 300kgf per day is reduced even with a small amount of cement. It is possible to implement high strength concrete of / cm 2 or more, preferably 400kgf / cm 2 or more. At this time, in order to maintain the strength of the concrete, the particle size of the oxidation furnace slag is preferably 1.2 ~ 5.0mm.

In addition, by using the oxide slag of the high content of electricity as described above, it is possible to increase the ratio of the iron component in the concrete, thereby at the same time obtain the effect of increasing the thermal conductivity. Tables 1 and 2 show the composition and particle size of the oxidized slag aggregate aggregate in the concrete electric furnace containing the iron component of the domestic quality standards KS F 4571.

division Calcium oxide
(CaO) Magnesium oxide
(MgO) subway
(FeO) basicity
(CaO / SiO2) Weight ratio
standard
40.0 or less
10.0 or less
50.0 or less
2.0 or less 3.1 to 4.0 (N) 4.0-4.5 (H)

Classification (pass percentage) 10 mm 5 mm 2.5mm 1.2 mm 0.6mm 0.3mm 0.15mm 5mm furnace oxidation
Slag fine aggregate 100 90-100 80-100 50-90 25-65 10-35 2-15 2.5mm Furnace Oxidation Slag Fine Aggregate 100 95-100 85-100 60-95 30-70 10 to 45 5-20 1.2mm electric oxidation
Slag fine aggregate 100 95-100 80-100 35-80 15-50 10-30

In addition, the reduction of cement amount greatly reduces the heat of hydration generated during the concrete hydration reaction, thereby suppressing the expansion and contraction of the initial concrete, and the amount of dry shrinkage, which is the largest cause of cracking in concrete, by reducing the amount of cement. Can significantly reduce the

In addition, concrete is not a complete waterproof body, but when using oxidized slag with electricity, the watertightness of concrete can be maximized, and the waterproofness is dramatically increased. In addition, the fluidity is greatly increased in the hardened state due to the effect of slag particles. The quantity to be done can be greatly reduced.

On the other hand, the concrete used in the present invention may further include a polymer of 5 to 35% by weight of the cement in order to increase the durability, wherein the polymer may be used a variety of materials that can increase the durability, preferably A water-soluble liquid polymer including any one or more of SB (60 to 70% by weight, butadiene 30 to 40% by weight) latex, PAE emulsion, EVA emulsion, epoxy resin, acrylic resin, polyester, water-soluble MMA may be used.

Table 3 below shows the mixing examples of the existing fast-hard polymer concrete (Comparative Example 1) and the concrete composition (Example 1) of the present invention, Table 4 below shows a comparison of the respective performance effects.

division Unit weight (kg / ㎥) cement water Latex sand Pebble Comparative example 360 75 115 914.40 756 Example 1 300 75 95 1138 992

division
W / B
S / a
Binder
Slump (mm)
Air volume (%)
Compressive strength (Kgf / ㎠) 4 hours 1 day Comparative example 38% 55% 360 210 5.5 281 378 Example 1 42% 46% 300 235 5.6 348.1 460

Looking at Tables 1 and 2, it can be seen that the concrete using the composition of the present invention exhibits much higher compressive strength even with less cement than conventional fast-hard polymer concrete.

On the other hand, Table 5 below shows the mixing example of the existing fast-hard polymer concrete (comparative example) and the concrete composition (Example 2) of the present invention, Table 6 and Figure 4 compares the effect of temperature increase with each time It is shown.

As shown in FIGS. 3A and 3B, the temperature increase effect was applied to heat the bottom of the concrete specimen of 10 cm length by using a hot plate, and the surface temperature rise time and the rise temperature change surface were changed according to the difference in the thermal conductivity of the concrete. Equipped with a thermometer to measure automatically. At this time, in order to reduce the experimental error due to heat loss in the atmosphere, the concrete specimen was wrapped with an insulation material and tested.

Specification W / B
S / a
Unit weight (kg / ㎥) cement water Latex sand Pebble Comparative example 38% 55% 360 76 115 914 760 Example 2 34% 47% 300 58 64 1182 992

Measuring time Plain concrete Furnace Oxide Slag Concrete 0:00 20.1 21.2 0:05 18.2 17.4 0:10 18.3 17.7 0:15 18.7 18.7 0:20 19.6 19.0 0:25 20.6 22.0 0:30 22.0 24.4 0:35 23.6 27.1 0:40 24.8 28.8 0:45 26.1 30.7 0:50 27.1 31.9 0:55 27.9 32.7 1:00 28.6 33.1 1:05 29.2 33.8 1:10 29.4 33.8 1:15 29.6 34.1 1:20 29.8 34.0 1:25 29.9 33.9 1:30 29.2 32.5

As can be seen in Table 6 and Figure 4, it can be seen that the surface temperature of the concrete prepared by replacing the oxidized slag with electricity compared to the general concrete is measured about 5, and the surface temperature rise slope is also compared to the general concrete It appears more steep that the heat conduction effect inside the concrete is excellent according to the oxidation of the slag of electricity.

On the other hand, Table 7 and Figure 5 shows the dry shrinkage strain of the oxide concrete slag of the general concrete and the present invention, the concrete using the composition of the present invention due to the reduction of cement content than the conventional fast-rigid polymer concrete It was confirmed that the concrete drying shrinkage is significantly reduced, this reduction of the drying shrinkage is a major point that can suppress the early cracking of the concrete.

division General Concrete Example 1 Example 2 Dry Strain Strain (%) 0.094 0.02 0.015

On the other hand, the waterproofness of concrete is evaluated by chlorine ion permeation test, and the electrode container is fixed on both sides of the concrete during the test, the circuit is composed of the electrodes from these containers as terminals and the electrolyte is passed through the electrolyte solution. As a method of evaluating the degree of permeability, the measured voltage is converted into a current value, and the total amount of electric charge passed is expressed as Coulomb.

Table 8 below is a table evaluating the permeability characteristics according to the amount of passing charge measured through the chlorine ion permeation test described above, Table 9 shows the measured values of the waterproofness of the Comparative Examples and Examples 1, 2 composition, the cement content of Due to the decrease and increase in the slag content, it can be seen that the concrete using the composition of the present invention has a much higher water resistance than conventional fast-hard polymer concrete.

coulomb Permeability Rating More than 4000 High permeability 2000-4000 usually 1000-2000 lowness 100-1000 Very low 100 or less Impervious

division Plain concrete Example 1 Example 2 Waterproof measurement (Coulomb) 1,106 116 352

As described above, in the present invention, by replacing most of the aggregates with oxidized slag with electricity having a uniform density than natural aggregates, and using concrete that has significantly reduced the expensive concrete content, tensile stress and cracking are generated with high thermal conductivity. Almost no, it is possible to realize the snow melting system that can maximize the snow effect with little power, improve the overall strength of concrete, expand the use of industrial waste, and achieve the economic effect of cost reduction. .

The present invention is not limited to the above-described specific embodiments and descriptions, and various modifications can be made to those skilled in the art without departing from the gist of the present invention claimed in the claims. And such modifications are within the scope of protection of the present invention.

Claims (10)

Iii) 8 to 16% by weight of cement, 3 to 6% by weight of water, 28 to 59% by weight of fine aggregate, 30 to 50% by weight of coarse aggregate, and 30 to 100% by weight of the fine aggregate is oxidized slag by electricity. Road melting snow system characterized in that it comprises a concrete having a particle size of the electric furnace oxidized slag is 1.2 ~ 5.0mm, and ii) a heat wire embedded in the concrete to generate heat as power is applied.
The road snow melting system according to claim 1, further comprising a control device for adjusting an amount of power or current applied to the hot wire.
delete The road snow melting system according to claim 1 or 2, wherein the concrete further comprises 5 to 35% of the polymer by weight of the cement.
The method of claim 4, wherein the polymer is selected from the group consisting of SB (60 to 70% by weight, butadiene 30 to 40% by weight) latex, PAE emulsion, EVA emulsion, epoxy resin, acrylic resin, polyester, water-soluble MMA Road snow melting system, characterized in that the water-soluble liquid polymer consisting of any one or a mixture thereof.
The road snow melting system according to claim 1 or 2, wherein the concrete has a daily strength of 300 kgf / cm 2 or more.
Iii) excising the heating wire after cutting the road front; And
Ii) 8 to 16% by weight of cement, 3 to 6% by weight of water, 28 to 59% by weight of fine aggregates, 30 to 50% by weight of coarse aggregates, 30 to 100% by weight of the fine aggregates Paving concrete having an oxide slag and a particle size of 1.2 to 5.0 mm of the oxide slag;
Road snow packaging method comprising a.
delete 8. The method of claim 7 wherein the concrete further comprises 5 to 35% polymer by weight of cement.
The method of claim 9, wherein the polymer is selected from the group consisting of SB (60 to 70% by weight, butadiene 30 to 40% by weight) latex, PAE emulsion, EVA emulsion, epoxy resin, acrylic resin, polyester, water-soluble MMA Road melting snow packaging method characterized in that the water-soluble liquid polymer consisting of any one or a mixture thereof.

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