JP2001233652A - Concrete pole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a concrete pole not requiring maintenance of coating, etc., readily producible and not causing slag in molding. SOLUTION: This concrete pole comprises a hardened body of a mixture composed of at least cement, pozzolanic fine powder, a fine aggregate having <=2 mm particle diameter, a water reducing agent and water. Preferably the concrete pole further comprises a metal fiber and/or an organic fiber, inorganic powder having 3-20 μm average particle diameter, fibrous particles or flaky particles having <=1 mm average particle size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an ultra-high-strength concrete pole. The concrete pole of the present invention is used, for example, as a column for power transmission, power distribution, signal, outdoor light, road sign, carport, and the like.

[0002]

2. Description of the Related Art Conventionally, for signals, for street lights, for road signs,
For poles such as carports, iron poles are mainly used. As poles for power transmission and distribution (hereinafter referred to as power poles), concrete poles made of high-strength concrete with a compressive strength of about 80 MPa are mainly used.

[Problems to be solved by the invention]

[0003] In the case of iron poles used as posts for traffic lights, street lights, road signs, carports, etc., it is necessary to regularly paint the surface of the poles in order to prevent corrosion. There was a problem that it took. In addition, poles used as pillars such as road signs and carports have a relatively small cross-sectional area of about 10 cm in diameter and 2 m or more in length, making it difficult to manufacture with ordinary concrete. is there. On the other hand, concrete poles used as utility poles are manufactured by centrifugally molding concrete with a slump of about several centimeters, so it is difficult to put concrete into a formwork. In addition, there is also a problem of processing of slag generated after centrifugal molding.

[0004] Therefore, an object of the present invention is to provide a concrete pole which does not require maintenance such as painting and the like, is easy to mold, and does not generate loose during molding.

[0005]

Means for Solving the Problems The present inventor has made intensive studies to solve the above-mentioned problems, and as a result, has been able to solve the above-mentioned problems by manufacturing a concrete pole with a compounded material combining specific materials. The present inventors have found that they can do this, and have reached the present invention.

That is, the present invention provides at least cement,
A concrete pole (Claim 1) comprising a hardened product of a compound containing pozzolanic fine powder, fine aggregate having a particle size of 2 mm or less, a water reducing agent, and water, and further comprising a metal fiber and / or an organic material. The concrete pole preferably contains fibers (claim 2), inorganic powder having an average particle size of 3 to 20 μm (claim 5), and fibrous particles or flake particles having an average particle size of 1 mm or less (claim 6).

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The type of cement used in the present invention is not limited, and various types of Portland cement such as ordinary Portland cement, early-strength Portland cement, moderately heated Portland cement, low-heat Portland cement, etc. and mixed cements such as blast furnace cement and fly ash cement are used. can do. In the present invention, if it is intended to improve the early strength of the cured product, it is preferable to use an early-strength Portland cement, and if it is intended to improve the fluidity of the composition, a moderate heat Portland cement or a low heat Portland cement is used. It is preferred to use.

[0008] Pozzolanic fine powder includes silica fume, silica dust, fly ash, slag, volcanic ash,
Silica sol, precipitated silica and the like. Generally, silica fume and silica dust have an average particle size of 1.0
It is suitable for the pozzolanic fine powder of the present invention because it is not more than μm and does not need to be ground. The amount of pozzolanic fine powder depends on the strength of the concrete pole,
5 to 50 parts by weight per 100 parts by weight is preferred. When the amount of the pozzolanic fine powder is small, strength developability is reduced. When the amount of pozzolanic fine powder added is increased, the unit water amount is increased, so that the strength is also lowered.

In the present invention, fine aggregate having a particle size of 2 mm or less is used. Here, the particle size of the fine aggregate in the present invention is an 85% weight cumulative particle size. When the particle size of the fine aggregate exceeds 2 mm, the strength of the concrete pole decreases. In addition,
In the present invention, it is preferable to use fine aggregate having a maximum particle size of 2 mm or less, and it is more preferable to use fine aggregate having a maximum particle size of 1.5 mm or less. As fine aggregate, river sand, land sand, sea sand, crushed sand, silica sand, and a mixture thereof can be used. The amount of the fine aggregate is preferably 50 to 250 parts by weight, more preferably 80 to 180 parts by weight, based on 100 parts by weight of cement, from the strength of the concrete pole.

As the water reducing agent, a lignin-based, naphthalene-sulfonic acid-based, melamine-based, polycarboxylic acid-based water reducing agent, an AE water reducing agent, a high performance water reducing agent or a high performance AE water reducing agent can be used. Among these, it is preferable to use a high performance water reducing agent or a high performance AE water reducing agent having a large water reducing effect. The compounding amount of the water reducing agent is preferably 0.5 to 4.0 parts by weight in terms of solid content based on 100 parts by weight of cement. If the amount of the water reducing agent (in terms of solid content) is less than 0.5 part by weight with respect to 100 parts by weight of cement, kneading becomes difficult, and the fluidity of the composition is low, and work such as molding is also difficult. Cement 100
If the amount of the water reducing agent (in terms of solid content) exceeds 4.0 parts by weight, the strength is reduced. The water reducing agent can be used in either liquid or powder form.

The amount of water is 10 to 3 parts per 100 parts by weight of cement.
The amount is preferably 0 parts by weight, more preferably 15 to 25 parts by weight. If the amount of water is less than 10 parts by weight with respect to 100 parts by weight of cement, kneading becomes difficult, and the flowability of the composition is low, and work such as molding is also difficult. If the amount of water exceeds 30 parts by weight with respect to 100 parts by weight of cement, the strength is reduced.

In the present invention, from the viewpoint of greatly increasing the bending strength of the cured product and increasing the bending strength of the concrete pole, it is preferable that the composition contains metal fibers and / or organic fibers. Examples of the metal fiber include a steel fiber and an amorphous fiber. Among them, the steel fiber is excellent in strength, and is preferable from the viewpoint of cost and availability. Metal fiber has a diameter of 0.01 to 1.0 mm and a length of 2
の も の 30 mm is preferred. When the diameter is less than 0.01 mm, the strength of the fiber itself is insufficient, and the fiber tends to be cut when subjected to tension. If the diameter is more than 1.0 mm, the number of pieces with the same compounding amount decreases, and the effect of improving the bending strength decreases. Length 30mm
When it exceeds, fiber balls tend to be generated during kneading. If the length is less than 2 mm, the effect of improving the bending strength decreases. The blending amount of the metal fiber is preferably less than 4%, more preferably less than 3% of the volume of the blend. When the content of the metal fiber increases, the unit water amount also increases in order to ensure workability during kneading, and the like, so that the above-mentioned amount of the metal fiber is preferable.

Examples of the organic fiber include vinylon fiber, polypropylene fiber, polyethylene fiber, aramid fiber, carbon fiber and the like. Organic fibers are 0.005-1.0m in diameter
m and a length of 2 to 30 mm are preferred. The blending amount of the organic fiber is preferably less than 10% of the volume of the blend, more preferably less than 8%. In the present invention, it is possible to use metal fibers and organic fibers in combination.

In the present invention, from the viewpoint of increasing the packing density of the cured product and increasing the strength of the concrete pole, the composition should have an average particle size of 3 to 20 μm, more preferably an average particle size of 4 to 4 μm.
It is preferable to include a 10 μm inorganic powder. Examples of the inorganic powder include quartz powder, limestone powder, carbide, and nitride. Among them, quartz powder is preferable from the viewpoint of cost and the stability of the quality of the cured product. Examples of the quartz powder include quartz and amorphous quartz, and opal and cristobalite silica-containing powders. The amount of the inorganic powder depends on the strength of the concrete pole,
It is preferably 50 parts by weight or less with respect to 0 parts by weight, and more preferably 20 to 35 parts by weight.

In the present invention, the toughness of the cured product is increased,
From the viewpoint of increasing the toughness and strength of the concrete pole, it is preferable that the composition contains fibrous particles or flaky particles having an average particle size of 1 mm or less. Here, the particle size of a particle is the size of its maximum dimension (in particular, its length for fibrous particles). Examples of the fibrous particles include wollastonite, bauxite, and mullite, and examples of the flaky particles include mica flake, talc flake, vermiculite flake, and alumina flake. The compounding amount of the fibrous particles or flaky particles is preferably 35 parts by weight or less, more preferably 10 to 25 parts by weight, based on 100 parts by weight of cement in view of the strength and toughness of the concrete pole. In the case of fibrous particles, from the viewpoint of increasing the toughness of the concrete pole, the needleness represented by the length / diameter ratio is
It is preferable to use three or more.

In the present invention, the method of kneading the compound is not particularly limited. For example, 1) materials other than water and water reducing agent are previously mixed (premix), and the premix, water, water reducing The agent is put into a mixer and kneaded. 2) Materials other than water are mixed in advance (a premix, but a water reducing agent of a powder type is used), and the premix and water are charged into a mixer and kneaded. 3) Each material is individually charged into a mixer and kneaded. And the like.

The mixer used for kneading may be of any type used for kneading ordinary concrete, for example, an oscillating mixer, a pan-type mixer, a biaxial kneading mixer, or the like.

In the present invention, the method of forming the concrete pole is not particularly limited. For example: 1) Pour the formulation into a given mold. 2) In the case of manufacturing a hollow pole, a core is placed in a mold and a compound is poured between the mold and the core. 3) In the case of manufacturing a cylindrical hollow pole, the mixture is poured into a predetermined mold and centrifuged. And the like. In the casting of the above 1) and 2), no slag naturally occurs. Further, even when the centrifugal molding of 3) is performed, no sticking occurs in the present invention. The composition of the present invention has a JIS R
5201 (Physical test method of cement) 11. The flow value measured without performing the dropping motion 15 times in the method described in “11. It is easy to insert (pour), and for example, a pole having a relatively small cross-sectional area, such as a pole having a diameter of about 10 cm and a length of 2 m or more, is easily formed. In the present invention, the cross-sectional shape of the concrete pole is arbitrary. For example, the shape may be circular or square. Also,
Polygons such as hexagons and octagons are also acceptable.

In the present invention, curing conditions are not particularly limited, and steam curing or the like may be performed.

The cured product of the composition of the present invention exhibits a compressive strength exceeding 200 MPa and a bending strength exceeding 20 MPa.
For example, a pole having a relatively small cross-sectional area such as a diameter of about 10 cm and a length of 2 m or more does not cause any practical problem. Further, when used as a utility pole, the outer diameter can be made smaller and / or the concrete thickness can be made smaller than in a conventional utility pole. Further, the concrete pole of the present invention does not require maintenance such as repainting with a conventional iron pole.

[0021]

The present invention will be described below with reference to examples. 1. Materials used The following materials were used. 1) Cement; Low heat Portland cement (manufactured by Taiheiyo Cement Co., Ltd.) 2) Pozzolanic fine powder; silica fume (average particle size 0.7 μm) 3) Fine aggregate: 2: 1 of silica sand 4 and silica sand 5 (weight ratio) 4) Metal fiber; steel fiber (diameter: 0.2 mm, length: 15 mm) 5) High-performance AE water reducing agent; polycarboxylic acid-based high-performance AE water reducing agent 6) Water; tap water 7) inorganic powder; quartz Powder (average particle diameter 7μm) 8) Fibrous particles; wollastonite (average length 0.3mm, length / diameter ratio 4)

Example 1 Low heat Portland cement 100 parts by weight, silica fume 3
2.5 parts by weight, 120 parts by weight of fine aggregate, 1.0 part by weight of a high-performance AE water reducing agent (solid content with respect to cement), and 22 parts by weight of water were charged into a twin-screw mixer and kneaded. The flow value of the formulation
In the method described in "JIS R 5201 (Physical test method for cement) 11. Flow test", the measurement was carried out without performing the falling motion 15 times. As a result, the flow value was 270 mm. Further, the composition was poured into a mold of φ50 × 100 mm, placed at 20 ° C. for 48 hours, and then steam-cured at 90 ° C. for 48 hours.
The compressive strength (average value of three strands) of the cured product was 210 MPa. Further, the composition was poured into a 4 × 4 × 16 cm formwork, placed at 20 ° C. for 48 hours, and then steam-cured at 90 ° C. for 48 hours.
The bending strength (average value of three pieces) of the cured product was 25 MPa.

Example 2 100 parts by weight of low heat Portland cement, silica fume 3
2.5 parts by weight, fine aggregate 120 parts by weight, high-performance AE water reducing agent 1.0 part by weight (solid content with respect to cement), water 22 parts by weight, steel fiber
(2% of the volume in the formulation) was charged into a twin-screw kneading mixer and kneaded. The flow value of the formulation was measured as in Example 1. As a result, the flow value was 250 mm. Further, the compression strength and the bending strength were measured in the same manner as in Example 1. As a result, the compressive strength was 210 MPa and the bending strength was 47 MPa.

Example 3 100 parts by weight of low heat Portland cement, silica fume 3
2.5 parts by weight, fine aggregate 120 parts by weight, high-performance AE water reducing agent 1.0 part by weight (solid content with respect to cement), water 22 parts by weight, quartz powder
30 parts by weight, 24 parts by weight of wollastonite, and steel fiber (2% of the volume in the composition) were put into a twin-screw mixer and kneaded. The flow value of the formulation was measured as in Example 1.
As a result, the flow value was 250 mm. Further, the compression strength and the bending strength were measured in the same manner as in Example 1. As a result, the compression strength was 230 MPa and the bending strength was 47 MPa.

Example 4 The composition of Example 3 was poured into a transparent resin pipe having an inner diameter of 10 cm and a length of 2.5 m. As a result, the composition was filled to every corner of the pipe.

Example 5 Low heat Portland cement 100 parts by weight, silica fume 3
2.5 parts by weight, fine aggregate 180 parts by weight, high-performance AE water reducing agent 1.0 part by weight (solid content with respect to cement), water 22 parts by weight, quartz powder
30 parts by weight, 24 parts by weight of wollastonite, and steel fiber (2% of the volume in the composition) were put into a twin-screw mixer and kneaded. The compound is poured into a steel pipe with an inner diameter of 25 cm and a length of 5 m (amount of concrete with a thickness of 30 mm), and centrifugal molding (low speed 5G
× 5 minutes, medium speed 15G × 5 minutes, high speed 35G × 15 minutes). No slag was found after centrifugal molding.

[0027]

As described above, since the concrete pole of the present invention is manufactured using a compound having excellent fluidity, the work such as molding is easy. For example, the diameter is about 10 cm and the length is about 10 cm.
Even a pole with a relatively small cross section such as 2 m or more can be easily formed. Compressive strength is 200MPa, bending strength is manufactured using a compound exceeding 20MPa, for example, the diameter is about 10cm and the length is
There is no practical problem even with a pole having a relatively small cross section such as 2 m or more. In addition, when used as a power transmission or distribution pole (electric pole), the outer diameter can be made smaller and / or the concrete thickness can be made smaller than that of a conventional electric pole. Even when centrifugal molding is performed, no slag occurs. There is no need for maintenance such as repainting with conventional iron poles.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C04B 16:06) C04B 16:06) G 111: 56 111: 56 (72) Inventor Shigematsu Takahashi Tsukimi, Kumagaya-shi, Saitama 2-1-1 Taiheiyo Cement Co., Ltd. Cement and Concrete Technology Center (72) Inventor Kiyoshi Oshima 6276 Onoda, Onoda-shi, Yamaguchi Pref. Environmental Technology Center of Taiheiyo Cement Co., Ltd. (72) Inventor Kenji Ogawa Koto-ku, Tokyo 1-2-23 Kiyosumi F-term in Taiheiyo Cement Co., Ltd. Kiyosumi Research Laboratory 4G012 PA04 PA15 PA19 PA24 PB04 PB32

Claims (6)

[Claims] 1. A concrete pole comprising a hardened product of a compound containing at least cement, fine pozzolanic powder, fine aggregate having a particle diameter of 2 mm or less, a water reducing agent, and water. 2. The concrete pole according to claim 1, wherein the composition contains metal fibers and / or organic fibers. 3. The metal fiber has a diameter of 0.01 to 1.0 mm and a length of 2 to 30.
The concrete pole according to claim 2, which is a steel fiber of mm. 4. An organic fiber having a diameter of 0.005 to 1.0 mm and a length of 2
The concrete pole according to claim 2, wherein the concrete pole is at least one fiber selected from vinylon fiber, polypropylene fiber, polyethylene fiber, aramid fiber, and carbon fiber of up to 30 mm. 5. The concrete pole according to claim 1, wherein the composition contains an inorganic powder having an average particle size of 3 to 20 μm. 6. The concrete pole according to claim 1, wherein the mixture contains fibrous particles or flaky particles having an average particle size of 1 mm or less.