JP2001323436A - Wave-dissipating block - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wave-dissipating block being easy to manufacture (particularly for molding work) and excellent in durability. SOLUTION: The wave-dissipating block is formed of a hardened blend including at least cement, pozzolanic fine particles, fine aggregate having a grain diameter of 2 mm or less, a water reducing agent, and water. Preferably, the block further includes metallic fibers and/or organic fibers, inorganic powders having an average powder size of 3 to 20 μm, and fibrous or flaked grains having an average grain size of 1 mm or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for a breakwater in a harbor, a breakwater covering work, a breakwater foundation covering work, a seawall covering work, a seawall foundation covering work, and a sand shore breakwater, a runway breakwater, etc. Regarding wave-dissipating blocks.

[0002]

2. Description of the Related Art In Japan, which is surrounded by the sea, many coastal and harbor structures are subject to repeated damage by waves. Therefore, in Japan, tetrapods,
By installing wave-dissipating blocks such as shake blocks, joint blocks, and three-pillar blocks in harbors and seashores, damage from waves is prevented. FIGS. 1 to 4 show the above-described tetrapot, shake block, joint block, and three-post block. These wave-dissipating blocks are slump 8cm
It is manufactured by filling a form of concrete into a mold, curing and hardening.

[Problems to be solved by the invention]

[0003] As shown in the above figures, the wave-eliminating block has a complicated shape. Therefore, in the production of the wave-dissipating block, the molding operation is particularly difficult.

[0004] Further, since the wave-dissipating block is used in combination with a breakwater or the like at a construction site such as a breakwater, it is troublesome to stack the work. Therefore, it is required that the breakwater once constructed can be used for a long period of time, that is, the durability of the wave breaking block is further improved.

Therefore, an object of the present invention is to provide a wave-eliminating block which is easy to manufacture (particularly, a molding operation) and has excellent durability.

[0006]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, the above-mentioned problems have been solved by manufacturing a wave-dissipating block by using a cured product of a combination of specific materials. Gained the knowledge that it could be solved,
The present invention has been reached.

That is, the present invention provides at least a cement,
A wave-dissipating block comprising a cured 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 (claim 1). Further, the composition contains metal fibers and / or organic fibers (claim 2),
It preferably contains inorganic powder of up to 20 μm (claim 5), fibrous particles or flaky particles having an average particle size of 1 mm or less (claim 6).

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The present invention is a wave-dissipating block comprising a cured product of a compound containing at least cement, fine pozzolanic powder, fine aggregate having a particle size of 2 mm or less, a water reducing agent, and water. In the present invention, the type of wave-dissipating block is not particularly limited, and examples thereof include those conventionally used as wave-dissipating blocks, such as a tetrapod, a shake block, a joint block, and a three-pillar block.

In the present invention, the type of cement is not limited, and various types of Portland cement such as ordinary Portland cement, early-strength Portland cement, medium-heat Portland cement, low-heat Portland cement, and mixed cements such as blast furnace cement and fly ash cement are used. Can be used. In the present invention, when it is intended to improve the early strength of the wave-breaking block, it is preferable to use an early-strength Portland cement. It is preferred to use

[0010] 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 blending amount of the pozzolanic fine powder is preferably 5 to 50 parts by weight based on 100 parts by weight of cement. When the amount of pozzolanic fine powder is small, the fluidity of the blend is reduced and molding is difficult. Further, the strength of the cured product is reduced, which is not preferable. If the amount of the pozzolanic fine powder is increased, the unit water amount is increased, so that the strength and durability of the cured product are undesirably reduced.

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. If the particle size of the fine aggregate exceeds 2 mm, the strength of the cured product is undesirably reduced. 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, quartz sand and mixtures thereof can be used. The blending 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 viewpoint of the fluidity of the composition, the strength of the cured product, durability and the like.

As the water reducing agent, a lignin type, naphthalene sulfonic acid type, melamine type or polycarboxylic acid type 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 flowability of the composition becomes low, which makes molding and other operations difficult. If the amount of water reducing agent (in terms of solid content) exceeds 4.0 parts by weight with respect to 100 parts by weight of cement, the strength and durability of the cured product are undesirably 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 fluidity of the composition becomes low, so that operations such as molding become unfavorable. When the amount of water exceeds 30 parts by weight for 100 parts by weight of cement,
It is not preferable because the strength and durability of the cured product decrease.

In the present invention, from the viewpoint of greatly increasing the bending strength of the cured product, 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
~ 1.0mm, length 2 ~ 30mm 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. If the length exceeds 30 mm, fiber balls tend to be formed 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.

The organic fibers 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 improving the durability, the compound has an average particle size of 3%.
It is preferable to include an inorganic powder having an average particle size of 4 to 10 µm. Examples of the inorganic powder include quartz powder, limestone powder, carbide, and nitride.
Above all, quartz powder is preferable from the viewpoint of cost and the quality stability 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 may be adjusted according to the fluidity of the compound and the strength and durability of the cured product.
The amount is preferably 50 parts by weight or less, more preferably 20 to 35 parts by weight with respect to parts by weight.

In the present invention, from the viewpoint of increasing the toughness of the cured product, 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 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, from the viewpoint of the fluidity of the composition, the strength after curing and the durability. From the viewpoint of increasing the toughness of the wave-absorbing block, it is preferable to use fibrous particles having a needleiness expressed by a length / diameter ratio of 3 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 ordinary kneading of concrete, for example, an oscillating mixer, a pan-type mixer, a twin-shaft mixer, or the like.

After kneading, the compound is put into a predetermined mold and molded, then cured and cured. The composition of the present invention has a flowability of 200 mm or more as measured by a method described in "JIS R 5201 (Physical test method for cement) 11. Flow test" without performing 15 falling movements. And the work such as loading into a mold is easy. In addition, in this invention, what is necessary is just to perform air curing, steam curing, etc. for curing.

The cured product of the composition of the present invention exhibits a compressive strength exceeding 200 MPa and a bending strength exceeding 20 MPa. The cured product of the composition of the present invention is dense and has excellent durability.

In the wave-breaking block of the present invention, a space is provided inside the wave-breaking block within a range where a required weight can be obtained, and ready-mixed concrete, sand, gravel, clay, fluidized soil, Furnace slag, blast furnace slag, electric furnace slag, non-ferrous metal refining slags such as copper slag, metal powder, construction waste such as concrete lumps, casting waste sand, ceramic waste, ceramic waste,
One or more selected from catalyst carrier waste material and refractory waste material may be filled. Such a wave-eliminating block is preferable because the cost can be reduced. When a space is provided inside the wave-dissipating block, the thickness of the cured body is 5
cm or more is preferable. The cured product of the composition of the present invention exhibits high compressive strength exceeding 200 MPa and high bending strength exceeding 20 MPa as described above. Even if the space is provided, there is no problem in the strength, durability and the like of the wave-dissipating block.

[0023]

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 1 100 parts by weight of low heat Portland cement, 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. The above 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. 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 water permeability of the cured product was measured by a variable water permeability test method in accordance with "Japan Geotechnical Society Standard JGS 0231 (Soil permeability test method)". As a result, no permeation of water was recognized, and the permeation depth was zero.

Example 2 Low heat Portland cement 100 parts by weight, 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. Further, the water permeability was measured in the same manner as in Example 1. As a result, no permeation of water was recognized, and the permeation depth was zero.

Example 3 The formulation of Example 2 was charged into a mold for producing a tetrapod (type 2.0) without vibration. After demolding after curing and observing the cured product (tetrapot), there was no problem such as insufficient filling.

[0027]

As described above, since the wave breaking block of the present invention is manufactured using a compound having excellent fluidity,
Work such as molding is easy. Moreover, the wave-eliminating block of the present invention is excellent in durability and can be used for a long time.

[Brief description of the drawings]

FIG. 1 is an example of a wave canceling block (tetrapot).

FIG. 2 is an example of a wave cancel block (shake block).

FIG. 3 is an example of a wave-eliminating block (a joint block).

FIG. 4 is an example of a wave-eliminating block (a three-pillar block).

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Claims (7)

[Claims] 1. A wave-eliminating block comprising a hardened product of a compound containing at least cement, fine pozzolanic powder, fine aggregate having a particle size of 2 mm or less, a water reducing agent, and water. 2. The wave-absorbing block 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 wave-dissipating block 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 wave-damping block according to claim 2, which is at least one kind of fiber selected from vinylon fiber, polypropylene fiber, polyethylene fiber, aramid fiber, and carbon fiber of up to 30 mm. 5. The wave-eliminating block according to claim 1, wherein the composition contains an inorganic powder having an average particle size of 3 to 20 μm. 6. The wave breaking block according to claim 1, wherein the composition contains fibrous particles or flaky particles having an average particle size of 1 mm or less. 7. A space is provided in the interior, and ready-mixed concrete, sand, gravel, clay, fluidized soil, converter slag,
Blast furnace slag, electric furnace slag, non-ferrous metal refining slag, metal powder,
The wave-eliminating block according to any one of claims 1 to 6, wherein the wave-eliminating block is filled with at least one selected from construction waste, foundry sand, ceramic waste, ceramic waste, catalyst carrier waste, and refractory waste.