KR20010007852A - Composition reducing earth resistance and molding manufactured therewith - Google Patents

Abstract

PURPOSE: A grounding resistance-reduced composition containing water adsorbing mineral and water absorbing polymer is provided which has excellent grounding effect and no annual variation of grounding resistance, and forms grounding electrodes with high electric conductivity. CONSTITUTION: The composition comprises 18-57wt.% of at least one water adsorbing mineral selected from zeolite, bentonite and kaolin and 0.1-5wt.% of water absorbing polymer, 0.1-5wt.% of at least two PAN-based carbon fiber selected from carbon fibers having 1, 3, 6, 9 and 12mm of length, as an electric conductivity material, 38-77wt.% of binder, 0.1-2wt.% of high plasticizer, 0.1-4wt.% of setting agent. The hardened product comprises 100pts.wt. of resultant composition and 30-50pts.wt. of water.

Description

Composition for reducing earth resistance and a cured product manufactured using the same

The present invention relates to a grounding resistance reducing material composition and a cured product manufactured using the same, and more particularly, a water-absorbing mineral and a water-absorbing polymer are contained, so that constant moisture is always maintained around the ground electrode, and the particle size of carbon fiber, which is an electrically conductive material, is used. The present invention relates to a grounding resistance reducing material composition having a control effect that is doubled and a hardening body manufactured by using the same.

Conventionally, as a grounding 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 embedded around the ground electrode, the chemical reducing agent is present in a gel state containing moisture. Although the chemical reducing agent shows an immediate effect in lowering the ground resistance, after about 6 months to 1 year has passed. Loss of rain or groundwater has led to the problem of losing grounding resistance and contaminating soil.

In addition, the cement-based high-strength reducing material has a problem that it forms a solid ground electrode after construction, in which case it takes a certain time to lower the ground resistance, and the ground resistance reduction ability depends only on the conductivity of the carbon material in the cement hardened body.

Patent Application No. 91-70062 discloses, in order to improve the above problems, "In the conductive cement composition composed of portland cement, silica sand and carbon fiber, the silica sand in an amount of 1 to 90 parts by weight 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. There was a problem that the ability to reduce the ground resistance depends only on the conductivity of the carbon material, and there was a limit in improving the ground 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, excellent grounding resistance reducing ability, there is no secular variation of the grounding resistance, forming a grounding electrode having excellent electrical conductivity, and using the grounding resistance reducing material composition It aims at providing the hardened | cured material manufactured by this.

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, and the grounding resistance reducing material composition which is doubled the grounding effect by effectively controlling the particle size of the carbon fiber, an electrically conductive material, and It is achieved by providing a hardened body manufactured by using the grounding resistance reducing material composition and the hardened body manufactured by using the excellent grounding resistance reducing effect, such as lightning protection equipment, hospital equipment, power transmission line equipment, substation equipment, distribution line equipment, railway, road It can be used in a variety of grounding, such as electrical equipment, computer equipment, electrostatic shielding equipment, electromagnetic shielding equipment.

The present invention is 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, It relates to a grounding resistance reducing material composition comprising 0.1 to 4% by weight of a regulator and a cured product produced using the same.

Hereinafter, the composition and manufacturing method of the grounding resistance reducing material composition of the present invention and a cured product manufactured using the same will be described in more detail.

The earth resistance reducing material composition of the present invention comprises a water absorbent mineral, an absorbent polymer, carbon fibers, 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 wide 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 soil at all times, and it can be used as a soil improving material because it has good ion exchange ability to adsorb heavy metals in soil well. It is an environmentally friendly material.

The absorbent polymer has a property of absorbing and retaining water of about 50 g per 1 g without being dissolved in water, and since the pH thereof is neutral, there is no fear of environmental pollution such as soil.

That is, water is absorbed between the molecular chains constituting the polymer at a much finer level than the pores of the absorber, so it absorbs tens to hundreds of times its own weight, and the absorbed water and the polymer form a hydrogel, such as 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 ground 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 of different lengths, and a fan system having a length of 6 mm and 12 mm, respectively. The combination of carbon 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, as a binder, 38 to 77 wt% of Portland cement, mixed cement, special cement, etc. are used, and the strength is lowered when a large amount of water is added. In order to impart fluidity, 0.1 to 2% by weight of a lignin-based, naphthalene-based, and melamine-based high fluidizing agent is used.

Moreover, 0.1-4 weight% of alkali metal carbonates, such as sodium carbonate, are added as a coagulation regulator for adjusting the coagulation time (hardening time) of a hardened | cured material.

As another preferred embodiment of the present invention can be prepared a cured body excellent in the resistance to ground resistance consisting of 100 parts by weight of the grounding resistance reducing material composition configured as described above and 30 to 50 parts by weight of the blended water.

The method for producing a cured product having excellent grounding resistance reduction may include mixing 100 parts by weight of the grounding 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 step of polishing.

In the practice 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.

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, and 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, the surface of the surface was cleaned of moisture, 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

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

The earth resistivity was analyzed as 330Ω-m by using a 4-point measuring instrument for the test.

Then, a trench of 0.4 m in width, 1 m in depth, and 3 m in length was carried out, and then, the BC100 mm 2 wire 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 (Kgf / ㎠) 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 a battery resistivity of less than 0.05? Excellent physical properties were 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, bending strength, and compressive strength were excellent, and the battery resistivity and grounding resistance were low, thereby reducing the grounding resistance.

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 and the cured product manufactured using the same may maintain a constant moisture around the grounding electrode formed in the soil by the action of the mineral water absorbent and the absorbent polymer and form a grounding electrode having excellent electrical conductivity, thereby reducing grounding resistance. This is excellent.

In addition, there is no secular change in ground resistance because the mineral water absorbent and the absorbent polymer that maintain the function of adsorbing and discharging water through fine pores according to the surrounding environment are always maintained.

Therefore, it can be variously used for 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)

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 It comprises a 4% by weight, earth resistance reducing material composition. The method of claim 1, wherein the water absorbent mineral is zeolite (Zeolite), bentonite (Bentonite), kaolin (Kaolin), characterized in that at least one member selected from the group consisting of, earth resistance reducing material composition. The method of claim 1, wherein the carbon fiber is a combination of two or more selected from the group consisting of Pan-based carbon fibers having a length of 1mm, 3mm, 6mm, 9mm, 12mm. Ground resistance reducing material composition. The grounding resistance reducing material composition according to claim 1 or 3, wherein the carbon fiber is a combination of fan-based carbon fibers having a length of 6 mm and 12 mm, respectively, in a ratio of 2: 1. Hardened | cured material comprised from 100 weight part of grounding resistance reduction material compositions of Claims 1-3, and 30-50 weight part of compounding numbers. The cured product according to claim 5, wherein the cured product has a battery resistivity of less than 0.05? · M, a bending strength of 45 Kgf / cm 2 or more, and a compressive strength of 200 Kgf / cm 2 or more.