KR100391159B1 - Composition reducing earth resistance - Google Patents

Abstract

According to the present invention, 18 to 57% by weight of water-absorbing minerals, 0.1 to 5% by weight of absorbent polymer, and carbon fiber 0.1 to form a grounding electrode having excellent grounding resistance reducing ability, no secular change in grounding resistance, and excellent electrical conductivity. In the grounding resistance reducing material composition comprising -5% by weight, 38-77% by weight of the binder, 0.1-2% by weight of the high fluidizing agent, and 0.1-4% by weight of the coagulation controlling agent, wherein the carbon fiber has a length It relates to a ground resistance reducing material composition characterized in that the fan-based carbon fibers of 6 mm and 12 mm, respectively, combined at a ratio of 2: 1.

The grounding resistance reducing material composition of the present invention maintains a constant moisture around the grounding electrode formed in the soil by the action of the mineral-based water absorbent and the absorbent polymer, thereby forming a grounding electrode having excellent electrical conductivity, and thus has excellent grounding resistance reduction capability.

Description

Composition reducing earth resistance

The present invention relates to a grounding resistance reducing material composition, and more particularly, a water-absorbing mineral and an absorbent polymer are contained so that constant moisture is always maintained around the ground electrode, and the particle size of the carbon conductive fiber, which is an electrically conductive material, is efficiently controlled. The present invention relates to a grounding resistance reducing material composition in which the grounding effect is doubled.

Conventionally, as a ground resistance reducing material, a chemical reducing agent containing an inorganic material and an electrolyte, and a cement-based high strength reducing material containing cement, aggregate, and carbon fiber have been used.

However, when the chemical reducing agent is mixed with water and buried around the ground electrode, it is present in a gel state containing moisture. Although the chemical reducing agent shows an immediate effect in lowering the ground resistance, after about six months to one year has elapsed. Loss of rain or groundwater has led to the problem of losing ground resistance and contaminating soil.

In addition, although the cement-based high-strength reducing material forms a hard ground electrode after construction, in this case, it takes a certain time to lower the ground resistance, and the ground resistance reduction ability is dependent only on the conductivity of the carbon material in the cement hardened body.

In order to remedy the above problems in Korean Patent Application No. 91-70062, "In the conductive cement composition composed of portland cement, silica sand and carbon fiber, the amount of 1 to 90 parts by weight of silica sand relative to 100 parts by weight of the portland cement And the carbon fiber is contained in an amount of 0.6 to 1.7 parts by weight based on 100 parts by weight of the total amount of the portland cement and silica sand. In addition, there was a problem in that the grounding resistance reduction ability depends only on the conductivity of the carbon material, and there was a limit to the enhancement of the grounding resistance reduction effect because constant moisture was not always maintained around the ground electrode.

The present invention has been made to solve the above problems in the prior art, an object of the present invention is excellent grounding resistance reduction, there is no secular variation of the grounding resistance, the grounding resistance can form a grounding electrode excellent in electrical conductivity It is providing a reducing material composition.

The object of the present invention is to contain a water-absorbing mineral and an absorbent polymer to maintain a constant moisture around the ground electrode at all times, to provide a grounding resistance reducing material composition which is effectively controlled by the particle size of the carbon fiber which is an electrically conductive material is effectively controlled This ground resistance is effectively reduced, and it is excellent in grounding such as lightning protection equipment, hospital equipment, power transmission line equipment, substation equipment, distribution line equipment, railway and road electrical equipment, computer equipment, electrostatic shielding equipment, and electromagnetic shielding equipment. Can be used.

Features of the present invention for achieving the above object, 18 to 57% by weight of the water-absorbent mineral, 0.1 to 5% by weight of the absorbent polymer, 0.1 to 5% by weight of carbon fiber, 38 to 77% by weight of the binder and In the ground resistance reducing material composition comprising 0.1 to 2% by weight of a high fluidizing agent and 0.1 to 4% by weight of a coagulation control agent, wherein the carbon fiber has a length of 6 mm and 12 mm, respectively. It is in combination by the ratio of 1.

Hereinafter, an embodiment of the earth resistance reduction material composition of the present invention will be described in detail.

The ground resistance reducing material composition of the present invention comprises a water absorbent mineral, an absorbent polymer, carbon fiber, a binder, a high fluidizing agent, and a coagulation control agent.

Zeolite, Bentonite, Kaolin, and the like are used as the water-adsorbable minerals, and in particular, zeolite has a function of adsorbing and releasing water with a large pore area of 1,000 m 2 / g. As it can maintain constant temperature and humidity at all times regardless of season, it can maintain constant grounding resistance in the soil at all times. As it has good ion exchange ability, it adsorbs heavy metals in the soil so it can be used as soil improving material. Possible environmentally friendly materials.

In addition, the absorbent polymer has a property of absorbing and maintaining about 50 g of water per 1 g without being dissolved in water, and has an advantage that the pH thereof is neutral so that the environment such as soil may not be contaminated. As the absorbent polymer, conventionally known starch-based, cellulose-based and synthetic polymer-based polymers are not particularly limited and may be variously used.

That is, because water is absorbed between the molecular chains constituting the polymer at a much finer level than the pores of the absorbent material, the water absorbs tens to hundreds of times its own weight, and the absorbed water and the polymer form a hydrogel to form a pressure. It has excellent water-retaining property without moisture escape by external force.

In addition, as the electrically conductive material of the present invention, 0.1 to 5% by weight of a pan-based carbon fiber having a length of 1 mm, 3 mm, 6 mm, 9 mm, and 12 mm is used. In the resistance reducing agent, only one type (length) of carbon fiber was used, but in the present invention, an optimal network was formed by combining two or more kinds of carbon fibers having different lengths, and the fan-based carbon having a length of 6 mm and 12 mm, respectively. Combining the fibers in a ratio of 2: 1 showed the best physical properties and appeared to be the most desirable.

In the ground resistance reducing material composition of the present invention, the binder is 38 to 77% by weight of portland cement, mixed cement, special cement, etc., and the strength is lowered when a large amount of water is added. In order to impart fluidity to the mixture, 0.1 to 2% by weight of a lignin-based, naphthalene-based, and melamine-based high leveling agent is used.

Further, 0.1 to 4% by weight of an alkali metal carbonate such as sodium carbonate is added as a coagulation regulator for controlling the coagulation time (solidification time) of the cured product.

As another preferred embodiment of the present invention, a cured product having excellent earth resistance reduction properties composed of 100 parts by weight of the earth resistance reduction material composition configured as described above and 30 to 50 parts by weight of the blended water may be manufactured.

The method for producing a cured product having excellent earth resistance reduction properties includes mixing 100 parts by weight of the earth resistance reducing material composition and 30 to 50 parts by weight of the blended water, pouring the mixture into a mold, and general molding the pours. Shaping to a certain shape and size by vibrating, pressing, extruding or centrifugal molding, and curing the molding to atmospheric curing, constant temperature curing, heating curing, steam curing or autoclave curing, and the surface of the curing body. It is composed of the steps of polishing.

In the embodiment of the present invention, molding and curing of the molded body are performed by a conventionally known method and are not particularly limited.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the described embodiments.

Examples 1-5 and Comparative Examples 1-3

The compositions and contents of Examples 1 to 5 and Comparative Examples 1 to 3 are shown in Table 1 below, after mixing zeolite, an absorbent polymer, carbon fiber, Portland cement, a high fluidizing agent, and sodium carbonate in advance. Water was added and mixed according to the "physical test method for cement" specified in JIS R 5201. As the absorbent polymer in the above example, Stocksorb manufactured by STOCKHAUSEN, Germany was used.

(Unit: weight%) Example Comparative example One 2 3 4 5 One 2 3 Zeolite 32 43 20 34 26 0 10 75 Absorbent polymer One 0.5 3 0.9 0.4 0 0 0 Carbon fiber 3 mm 0 0 0 0.7 0 0 0 0 6 mm 0.6 0.4 2 0 0.4 0.9 0 0.8 12 mm 0.3 0.2 One 0 0 0 0.6 0 15 mm 0 0 0 0.2 0 0 0 0 18 mm 0 0 0 0 0.2 0 0 0 Portland cement 65 55 73 63 72 98 88 24 A high fluidizer 0.5 0.4 0.3 0.5 0.5 0.2 0.5 0.1 Sodium carbonate 0.6 0.5 0.7 0.7 0.5 0.9 0.9 0.1 Sum 100 100 100 100 100 100 100 100 Water (parts by weight) 40 40 40 40 40 40 40 40

100 parts by weight of the composition prepared in Examples 1 to 5 and Comparative Examples 1 to 3 were mixed with 40 parts by weight of water, and molded into a 4 × 4 × 16 cm mold according to JIS R 5201 "Physical Test Method for Cement". After preparing, curing in a thermo-hygrostat with a temperature of 20 ± 1 ° C. and a relative humidity of 90% or more, after 24 hours, the cured cured product was demolded to measure physical properties.

Hereinafter, the physical property measurement method of the cured product produced by the present invention will be described in detail.

1. Water absorption rate

In order to measure the water absorption of the demolded cured product, the cured product was dried in a drier at 105 ° C for 24 hours.

The weight (W ₁ ) of the dried cured product was measured and then immersed in water at 23 ° C. again. After 24 hours, the cured product immersed in water was taken out, and the surface water was wiped, and the weight (W ₂ ) was measured to determine the water absorption rate in the following formula.

2. Electric resistivity

After leaving the demolded cured body in the air for about 1 hour, silver electrodes were applied to both ends of the cured body, and then the resistance was measured using a resistance meter.

The electrical resistivity was calculated by substituting the measured resistance value into the following equation.

3. Flexural strength and compressive strength

After curing the demolded cured body for 6 days, the bending strength and the compressive strength were measured.

The bending strength was measured according to JIS R 5201 "Physical test method of cement" and the compressive strength was measured using the cut specimen.

4. Earth resistance test

The ground resistance test was conducted to test the ground resistance reduction effect of the ground resistance reducing material composition according to the present invention according to the adhesion to the soil.

For the test, the earth resistivity was measured using a four-point measuring instrument, and the earth resistivity was analyzed as 330 Ω · m.

Then, a trench of 0.4 m in width, 1 m in depth, and 3 m in length was carried out, and then, the electric wire of BC 100 mm2 was fixed to the floor, 10 kg of material per m was mixed with water, laid, and backfilled with soil.

The ground resistance measuring instrument was a four-point measuring instrument, DET2 / 2 manufactured by BIDDLE, and the measuring method was measured by a fall of potential method.

Property measurement result Example Comparative example One 2 3 4 5 One 2 3 Water absorption rate (%) 23 25 20 26 21 8 11 33 Electric resistivity (Ωm) 0.04 0.05 0.03 0.07 0.04 0.25 0.31 0.38 Strength (kgf / ㎠) 48 45 52 40 41 21 16 8 Compressive strength (㎏f / ㎠) 234 211 250 202 205 170 140 65 Earth resistance (Ω) 91 82 105 97 87 210 192 170

As a result of measuring the physical properties, the specimens prepared in Examples 1 to 5 had an electrical resistivity of less than 0.05 Ω · m, a bending strength of 45 kgf / cm 2 or more, and a compressive strength of 200 kgf / cm 2 or more, thus reducing ground resistance. As the hardened | cured material which existed, the physical property superior to the past was shown.

In addition, as shown in Table 2, the specimen of the present invention composed of a water-absorbent polymer excellent in water absorption and water retention properties and two or more different (length) carbon fibers as shown in Table 2 does not contain an absorbent polymer. Compared to Comparative Examples 1 to 3 using only carbon fiber, the water absorption rate, the bending strength and the compressive strength were excellent, and the electric resistance and the ground resistance were low, and thus the ground resistance reduction effect was excellent.

This is because the specimen prepared by the present invention always maintains a constant moisture around the ground electrode, and the particle size of the carbon fiber, which is an electrically conductive material, is efficiently controlled to double the grounding effect.

In addition, the performance of Example 4 with the addition of carbon fibers having a length of 3 mm and 15 mm, respectively, was excellent, but the electrical resistivity was higher and the strength was lower than those of Examples 1 to 3 with the addition of 6 mm and 12 mm carbon fiber. , Example 6 with the addition of 6 mm and 18 mm is excellent in performance, but it is difficult to mix materials, so Examples 1 to 3 in which the fan-based carbon fibers of 6 mm and 12 mm are combined at a ratio of 2: 1 It has been shown to be desirable.

The grounding resistance reducing material composition of the present invention maintains a constant moisture around the grounding electrode formed in the soil by the action of the mineral water absorbent and the absorbent polymer, thereby forming a grounding electrode having excellent electrical conductivity, and has excellent grounding resistance reduction capability.

In addition, there is no secular change in ground resistance because the water-based mineral adsorbent and the absorbent polymer always maintain a constant resistance value through the fine pores according to the surrounding environment.

Therefore, it can be variously used for the grounding of lightning protection equipment, hospital equipment, power transmission line equipment, substation equipment, distribution line equipment, electric equipment such as railroad and road, computer equipment, broadcasting station equipment, electrostatic shielding equipment and electromagnetic shielding equipment.

Claims (6)

delete delete delete 18 to 57% by weight of water absorbent mineral, 0.1 to 5% by weight of absorbent polymer, 0.1 to 5% by weight of carbon fiber, 38 to 77% by weight of binder, 0.1 to 2% by weight of high fluidizing agent, and 0.1 to 2% of coagulation modifier In the ground resistance reducing material composition comprising 4% by weight, The carbon fiber is ground resistance reducing material composition, characterized in that the combination of the length of the fan-based carbon fiber of 6 mm and 12 mm in the ratio of 2: 1, respectively. delete delete