JP2002193655A - Hydraulic composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic composition which, before hardening, excels in flowability and material separation resistance and has self-filling ability and, after hardening, has a compressive strength of 130 MPa or larger a flexural strength of 20 MPa or larger and large fracture energy. SOLUTION: The hydraulic composition includes a cement 100 pts.wt., a pozzolanic fine powder 5 to 50 pts.wt., a fine aggregate (grain size of 2 mm or less) 50 to 250 pts.wt., a dispersant 0.5 to 4.0 pts.wt. (in terms of solid contents), an organic fiber and/or an inorganic fiber 0.1 to 10% by volume ratio in the hydraulic composition, water 10 to 35 pts.wt. and an acicular grain and/or a thin piece grain (mean grain size of 1 mm or less) 4.5% or less by volume ratio per the total amount of the cement and the pozzolanic fine powder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a self-filling property (excellent fluidity and material separation resistance) before curing, has excellent workability, and has mechanical properties (compression strength, bending strength) after curing. The present invention relates to a cement-based hydraulic composition having excellent strength and breaking energy.

[0002]

2. Description of the Related Art Hitherto, hydraulic compositions having excellent mechanical properties (compression strength, bending strength, breaking energy, etc.) have been developed. For example, the claims of Japanese Patent Publication No. 60-59182 disclose inorganic solid particles A (for example, silica dust particles) having a particle size of 50 to 0.5 μm and a particle size of 0.5 to 100 μm.
And solid particles B at least one order of magnitude larger than particles A
(For example, at least 20% by weight of Portland cement), a surface active dispersant (for example, a concrete superplasticizer such as a highly condensed naphthalene sulfonic acid / formaldehyde condensate) and an additional material C
(A material selected from the group consisting of sand, stone, fibers such as polypropylene fibers, whiskers, etc.). The hydraulic composite material described in this publication has a compressive strength of 100 MPa or more after curing and is excellent in mechanical properties (Table 32, page 32, column 1, Table 1).

[0003]

Generally, concrete having excellent mechanical properties (compression strength, bending strength, breaking energy, etc.) has the following advantages. First, when constructing a building or the like by cast-in-place, the thickness of the concrete layer can be reduced, which reduces the amount of concrete to be poured, reducing labor, reducing costs, and reducing the space used. Increase can be achieved. Second, in the case of manufacturing a precast member, the thickness of the precast member can be reduced, so that the weight can be reduced, and as a result, transportation and construction can be facilitated. Third, abrasion resistance, durability to neutralization, creep and the like are improved. For this reason, there is a demand for the development of a hydraulic composition having better mechanical properties than the hydraulic composite material described in the above-mentioned publication.

On the other hand, when constructing a building or the like by cast-in-place or manufacturing a precast member, the time required for placing a hydraulic composition (concrete or the like) is shortened, or the concrete or the like after casting is used. It is advantageous to use a hydraulic composition having excellent fluidity and resistance to material separation (in other words, a hydraulic composition having self-filling properties) from the viewpoint of shortening the time required for vibration to be applied.

However, in the hydraulic composite material described in the above-mentioned publication (Japanese Patent Publication No. 60-59182), the fluidity and the material separation resistance before curing and the mechanical properties (compression strength, bending strength) after curing are improved. It is difficult to achieve both improvement in strength and breaking energy. For example, when fibers are blended to improve the bending strength, the fluidity is reduced and the workability is poor. On the other hand, when the fibers are mixed and the mixing ratio of the kneading water and the admixture is increased,
While good fluidity can be ensured, the resistance to material separation decreases.

Therefore, the present invention provides a liquid composition which is excellent in fluidity and resistance to material separation before curing, has self-filling properties, and has a conventional hydraulic composition after curing (for example, a water-based composition described in the above publication). It is an object of the present invention to provide a hydraulic composition having more excellent mechanical properties (compression strength, bending strength, breaking energy, etc.) than a hard composite material.

[0007]

Means for Solving the Problems The present inventor has made intensive studies to achieve the above object, and as a result, obtained the finding that the above object can be achieved by combining specific materials. Reached. That is, claim 1 of the present application
Is a cement, a pozzolanic fine powder, a fine aggregate having a particle size of 2 mm or less, a dispersant (for example, high performance A
E water reducing agent such as a water reducing agent), an organic fiber and / or an inorganic fiber, water, a hydraulic composition containing needle-like particles and / or flaky particles having an average particle size of 1 mm or less, wherein the needle-like particles and / or
Alternatively, the composition is such that the compounding amount of the flaky particles is 4.5% or less by volume ratio with respect to the total amount of the cement and the pozzolanic fine powder. The hydraulic composition thus configured is excellent in fluidity and material separation resistance before curing, has self-filling properties, and after curing, has excellent mechanical properties compared to conventional hydraulic compositions. Has characteristics (compression strength, bending strength, breaking energy, etc.). The hydraulic composition has an average particle size of 3 to 20 in order to increase the packing density after curing.
It may contain a μm inorganic powder (for example, quartz powder) (claim 2).

[0008] The hydraulic composition preferably comprises the following compounding ratio. That is, the hydraulic composition according to claim 3 of the present application comprises 100 parts by weight of cement, 5 to 50 parts by weight of fine pozzolanic powder, and 50 to 25 fine aggregate having a particle size of 2 mm or less.
0 parts by weight, a dispersant (water reducing agent) 0.5 to 4.0 parts by weight (in terms of solid content), organic fibers and / or inorganic fibers, water 10 to 35 parts by weight,
A hydraulic composition containing needle-like particles and / or flaky particles having an average particle size of 1 mm or less, wherein the compounding amount of the organic fiber and / or the inorganic fiber is 0.1 to 1 by volume ratio in the hydraulic composition.
0%, and the compounding amount of the acicular particles and / or flaky particles is 0.05 to 4.5% by volume relative to the total amount of the cement and the pozzolanic fine powder. You. The hydraulic composition is an inorganic powder having an average particle size of 3 to 20 μm in an amount of 50 parts by weight or less per 100 parts by weight of the cement in order to increase the packing density after curing.
(Quartz powder) (claim 4).

The organic fibers and / or inorganic fibers have, for example, a size of 0.005 to 1.0 mm in diameter and 2 to 30 mm in length (claim 5). The organic fiber and / or the inorganic fiber can be configured to be, for example, at least one selected from the group consisting of vinylon fiber, polypropylene fiber, polyethylene fiber, aramid fiber, and carbon fiber (Claim 6). The hydraulic composition usually has a compressive strength of 130 MPa or more and a bending strength of 20 MPa or more (Claim 7).

[0010]

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 particularly limited, for example, various Portland cements such as ordinary Portland cement, early-strength Portland cement, moderate heat Portland cement, low heat Portland cement, blast furnace cement, fly ash cement Etc. can be used. In the present invention, in order to improve the early strength after hardening of the hydraulic composition, it is preferable to use early-strength Portland cement. In order to improve the fluidity of the hydraulic composition, it is preferable to use a medium heat Portland cement or a low heat Portland cement.

As the pozzolanic fine powder, silica fume, silica dust, fly ash, slag, volcanic ash,
Silica sol, precipitated silica and the like. In general, silica fume and silica dust have an average particle size of 1.0 μm or less and do not need to be subjected to a treatment such as pulverization. Therefore, they are suitable as the pozzolanic fine powder used in the present invention. The blending amount of the pozzolanic fine powder is 5 to 50 per 100 parts by weight of cement.
Part by weight is preferred, and 10 to 45 parts by weight is more preferred. If the blending amount of the pozzolanic fine powder is too small, the material separation resistance of the hydraulic composition is lowered, and the mechanical properties after curing are undesirably lowered. If the amount of the pozzolanic fine powder is too large, the amount of water increases, and the mechanical properties after curing 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 is an 85% weight cumulative particle size. If the particle size of the fine aggregate exceeds 2 mm, the strength of the hydraulic composition after curing is 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, or a mixture 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. If the blending amount of the fine aggregate is too small, the self-shrinkage in the initial stage of hardening (coagulation stage) increases, and the heat of hydration also increases. If the amount of fine aggregate is too large,
It is not preferable because the mechanical properties (particularly, bending strength) after curing are reduced.

Examples of the dispersing agent include various water reducing agents such as lignin, naphthalenesulfonic acid, melamine and polycarboxylic acid (water reducing agent, AE water reducing agent, high performance water reducing agent, high performance A
E 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 amount of the dispersant is 10
The amount is preferably 0.5 to 4.0 parts by weight in terms of solid content based on 0 parts by weight. If the blending amount (solid content) of the dispersant 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 hydraulic composition decreases, which is not preferable. If the amount of the dispersant (in terms of solid content) exceeds 4.0 parts by weight with respect to 100 parts by weight of cement, the mechanical properties after curing are undesirably reduced. The dispersant can be used in either liquid or powder form.

The amount of water used in the hydraulic composition of the present invention is preferably from 10 to 35 parts by weight, more preferably from 15 to 30 parts by weight, based on 100 parts by weight of cement. 10 water
If the amount is less than part by weight, kneading becomes difficult, and the fluidity of the hydraulic composition is undesirably reduced. 35 water
Exceeding the weight part is not preferred because the mechanical properties after curing deteriorate.

The hydraulic composition of the present invention comprises an organic fiber and / or
Or it contains an inorganic fiber. By including organic fibers and / or inorganic fibers, the bending strength and the breaking energy are improved, and micro cracks (several hundred μm to several mm
Cracks) can be suppressed and structural defects can be prevented from occurring. Examples of the organic fiber include vinylon fiber (polyvinyl alcohol-based synthetic fiber), polypropylene fiber, polyethylene fiber, aramid fiber, polyamide fiber (nylon fiber), polyester fiber, and acrylic fiber. Examples of the inorganic fiber include a carbon fiber and a glass fiber. Among organic fibers and / or inorganic fibers, vinylon fiber, polypropylene fiber, polyethylene fiber, aramid fiber, carbon fiber, etc.
It is preferable in terms of excellent strength, cost, and availability. The organic fiber and / or the inorganic fiber may use either the organic fiber or the inorganic fiber alone,
You may use together. One type of organic fiber may be used alone, or two or more types may be used in combination. The same applies to inorganic fibers.

The organic fibers and / or inorganic fibers have a diameter of 0.00
5 ~ 1.0mm, length 2 ~ 30mm is preferable, diameter 0.01 ~
0.9 mm, more preferably a length of 4 to 25 mm, a diameter of 0.05 to
0.8 mm and a length of 6 to 20 mm are particularly preferred. 0.00 in diameter
If it is less than 5 mm, the strength of the fiber itself is insufficient, and the fiber is liable to break when subjected to tension. When the diameter is more than 1.0 mm, the number of pieces with the same compounding amount decreases, and the effect of improving bending strength, fracture energy and toughness decreases. When the length is less than 2 mm, the effect of improving the bending strength, the breaking energy and the toughness decreases. If the length exceeds 30 mm, fiber balls tend to be formed during kneading. The compounding amount of the organic fiber and / or the inorganic fiber (however, when used together, the total amount thereof) is preferably 10% or less by volume ratio (volume ratio) in the hydraulic composition, and more preferably 0.1 to 10%. , 2.0-6.0%
Is particularly preferred. If the compounding amount of the organic fibers and / or the inorganic fibers exceeds 10%, the unit water amount increases in order to ensure workability during kneading, and the mechanical properties after curing deteriorate, which is not preferable.

The hydraulic composition of the present invention has an average particle size of 1 mm
It contains the following needle-like particles and / or flaky particles. Here, the “particle size” of the acicular particles and / or the flaky particles
Is the size of the largest dimension of these particles (especially the length of acicular particles). Examples of the acicular particles (fibrous particles; fine acicular materials) include wollastonite, bauxite, and mullite. Examples of the flaky particles (fine flakes) include mica flakes, talc flakes, vermiculite flakes, and alumina flakes. As the acicular particles and / or flaky particles, either the acicular particles and the flaky particles may be used alone or in combination. In addition, one kind of the acicular particles may be used alone, or two or more kinds may be used in combination. The same applies to flaky particles. The blending amount of the acicular particles and / or flaky particles (however, when used together, the total amount of cement and pozzolanic fine powder (100%) is not more than 4.5% by volume, Preferably it is 0.05-4.5%, more preferably 0.1-4.0%, particularly preferably 0.5-3.5%. If the needle-like particles and / or the flaky particles are not blended, the organic fibers and / or the inorganic fibers are easily separated, and the resistance to material separation is undesirably reduced. If the compounding amount of the acicular particles and / or flaky particles exceeds 4.5% by volume relative to the total amount of the cement and the pozzolanic fine powder, the viscosity of the hydraulic composition increases and the fluidity decreases. However, the time required for the casting into the mold or the like becomes long, which is not preferable. From the viewpoint of enhancing the toughness after curing, it is preferable to use needle-like particles having a needle-likeness expressed by a length / diameter ratio of 2 or more.

In the present invention, from the viewpoint of increasing the packing density after curing, the hydraulic composition preferably contains an inorganic powder having an average particle size of 3 to 20 μm, more preferably 4 to 10 μm. Examples of the inorganic powder include quartz powder, limestone powder, carbide powder, nitride powder and the like. Among them,
Quartz powder is preferable in terms of cost and quality stability after curing. Examples of the quartz powder include quartz, amorphous quartz, opal and cristobalite silica-containing powder, and the like. The amount of the inorganic powder may be selected from the viewpoints of fluidity before curing, strength after curing, durability, etc.
It is preferably 50 parts by weight or less, more preferably 20 to 35 parts by weight based on parts by weight.

In the present invention, the method of kneading the hydraulic composition is not particularly limited, and for example, the following (1)
To (3). (1) Water and materials other than the dispersant (water reducing agent) are mixed in advance,
After preparing a mixture (premix material), the premix material, water, and a dispersant are charged into a mixer and kneaded. (2) Materials other than water (however, a powder type dispersant is used) are preliminarily mixed to prepare a mixture (premix material), and then the premix material and water are charged into a mixer. Knead. (3) Each material is individually charged into a mixer and kneaded.

The mixer used for kneading may be of any type used for kneading ordinary concrete, such as an oscillating mixer, a pan-type mixer, or a twin-shaft mixer.

The method for molding the hydraulic composition of the present invention is not particularly limited, and any method such as casting may be employed. Also, the curing method is not particularly limited, and air curing, steam curing, autoclave curing, and the like can be performed.

[0022] The hydraulic composition of the present invention may be prepared as described in "JIS R 5201".
(Physical test method of cement) 11. The flow value measured in the method described in “11. Flow test” without performing the falling motion 15 times is 200 mm or more, and is excellent in fluidity. Further, the hydraulic composition of the present invention is also excellent in material separation resistance. Therefore, when constructing a building or the like by cast-in-place, or when manufacturing a precast member, if the hydraulic composition of the present invention is used,
Shortening the time for setting hydraulic composition (concrete),
It is possible to shorten the time required for vibration applied to the cast hydraulic composition and the like.

Furthermore, the hydraulic composition of the present invention exhibits a compressive strength of 130 MPa or more, preferably 140 MPa or more, more preferably 150 MPa or more, and particularly preferably 170 MPa or more.
MPa or more, preferably 22 MPa or more, more preferably 23 MPa
Above, particularly preferably exhibit a bending strength of 25 MPa or more, 1
8 kJ / m ² or more, preferably 21kJ / m ² or more, particularly preferably 2
It has a breaking energy of ⁴ kJ / m ² or more and has excellent mechanical properties. Therefore, when constructing a building or the like by cast-in-place, or in the case of manufacturing a precast member, the amount of the hydraulic composition used is reduced, reducing costs, reducing labor in construction and transportation, increasing the use space, Improvements in durability and the like can be realized.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. 1. Materials used The following materials were used. (1) Cement; Low heat Portland cement (manufactured by Taiheiyo Cement Corporation) (2) Pozzolanic fine powder; silica fume (average particle size: 0.7 μm) (3) Fine aggregate: silica sand No. 5 (maximum particle size: 0.6 mm or less) (4) Organic fiber; vinylon fiber (diameter: 0.3 mm, length: 12 mm); aramid fiber (diameter: 0.4 mm, length: 12 mm); polypropylene fiber (diameter: 0.2 mm, length: 9 mm) (5) Dispersant: Polycarboxylic acid-based high-performance AE water reducing agent (6) Water: Tap water (7) Inorganic powder; Quartz powder (average particle size: 7 μm) (8) Acicular particles; Wollastonite (average length: 0.3) mm, length / diameter ratio: 4)

2. Mixing and kneading [Examples 1-3, Comparative Examples 1-2] 100 parts by weight of low heat Portland cement, 32.5 parts by weight of silica fume, fine aggregate 120
Parts by weight, 1.0 part by weight of high-performance AE water reducing agent (in terms of solid content),
22 parts by weight of water, 4% of vinylon fiber (volume ratio in the hydraulic composition), 35 parts by weight of quartz powder, and wollastonite in the amounts shown in Table 1 were put into a twin-screw kneading mixer and kneaded. In addition,
Wollastonite was used in such a manner that part of the quartz powder was replaced, so that the total amount of the wollastonite and the quartz powder was constant (35 parts by weight). Examples 4-6, Comparative Examples 3-4 Low heat Portland cement 100 parts by weight, silica fume 32.5 parts by weight, fine aggregate 120
Parts by weight, 1.0 part by weight of high-performance AE water reducing agent (in terms of solid content),
22 parts by weight of water, 4% of aramid fiber (volume ratio in the hydraulic composition), 35 parts by weight of quartz powder, and wollastonite in the amounts shown in Table 1 were put into a twin-screw kneading mixer and kneaded. The wollastonite was used in such a manner that part of the quartz powder was replaced, and the total amount of the wollastonite and the quartz powder was kept constant (35 parts by weight).

Examples 7 to 9, Comparative Examples 5 to 6 100 parts by weight of low heat Portland cement, 32.5 parts by weight of silica fume, 120 parts by weight of fine aggregate, 1.0 part by weight of high-performance AE water reducing agent (in terms of solid content), water 22 parts by weight, 4% of polypropylene fiber (volume ratio in the hydraulic composition), 35 parts by weight of quartz powder, and wollastonite in the amounts shown in Table 1 were charged into a twin-screw kneading mixer and kneaded. The wollastonite was used in such a manner that part of the quartz powder was replaced, and the total amount of the wollastonite and the quartz powder was kept constant (35 parts by weight).

Comparative Example 7 Low Heat Portland Cement 10
0 parts by weight, silica fume 32.5 parts by weight, fine aggregate 120 parts by weight, high-performance AE water reducing agent 1.0 part by weight (solid content conversion), water 22
Parts by weight, 35 parts by weight of quartz powder are charged into a twin-screw kneading mixer,
Kneaded.

3. Evaluation (1) Flow value The flow value of each hydraulic composition was measured in accordance with the method described in “JIS R 5201 (Physical test method for cement) 11. Flow test” without performing 15 falling movements. . (2) Presence or absence of material separation During the measurement of the flow value in the above (1), each spread hydraulic composition was visually observed, and the presence or absence of material separation was observed. (3) Falling time of mortar V funnel The falling time of each hydraulic composition was measured using a mortar V funnel. If the falling time is 10 to 30 seconds, the fluidity is good. (4) Workability In the following tests (5) to (7), the work time and ease of pouring each workable hydraulic composition into the mold (workability)
Therefore, the workability was evaluated as “○: good” and “×: poor”. (5) Compressive strength Each hydraulic composition is poured into a φ50 × 100 mm mold, and the temperature is 20 ° C.
And then steam-cured at 90 ° C. for 48 hours. The compressive strength of the obtained cured product was measured according to “JIS A 1108 (Method of testing compressive strength of concrete)”. (6) Flexural strength Each hydraulic composition is poured into a 10 × 10 × 40 cm formwork, and the temperature is 20 ° C.
And then steam-cured at 90 ° C. for 48 hours. The bending strength of the obtained cured product was measured according to “JIS R 5201 (physical test method for cement)”. (7) Breaking energy Each hydraulic composition is poured into a mold of 10 × 10 × 40 cm, and the temperature is 20 ° C.
And then steam-cured at 90 ° C. for 48 hours. The fracture energy of the obtained cured product was measured according to "Measurement of fracture energy of mortar and concrete by three-point bending test of RILEM notched beam (draft)". Table 1 shows the test results of "3. Evaluations (1) to (7)".

[0029]

[Table 1]

In Table 1, Comparative Examples 1, 3, and 5 do not contain needle-like particles (wollastonite), so that material separation occurs. In Comparative Examples 2, 4, and 6, since the compounding ratio of the acicular particles (wollastonite) exceeds the numerical range specified in the present invention, the fluidity is reduced and the workability is poor. Comparative Example 7 does not include organic fibers and needle-like particles (wollastonite), and thus has a small value of breaking energy.

[0031]

EFFECT OF THE INVENTION The hydraulic composition of the present invention, before curing,
It has excellent fluidity and resistance to material separation, and has self-filling properties, making it easy to apply. After curing, it has excellent mechanical properties (compressive strength of 130MPa or more, bending strength of 20MPa or more, large breaking energy). Have.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C04B 16:06 C04B 16:06 A 14:38 14:38 AC 14:06) 14:06) Z 103 : 32 103: 32 103: 40 103: 40 111: 20 111: 20 (72) Inventor Makoto Katagiri 2-4-2 Daisaku, Sakura City, Chiba Pref. Pacific Research Institute F-term (reference) 4G012 PA04 PA15 PA20 PA24 PB03 PB31 PC03 PC12

Claims (7)

[Claims] 1. Cement, pozzolanic fine powder, particle size 2mm
The following fine aggregate, dispersant, organic fibers and / or inorganic fibers,
Water, a hydraulic composition containing needle-like particles and / or flaky particles having an average particle size of 1 mm or less, wherein the compounding amount of the needle-like particles and / or flaky particles is the same as that of the cement and the pozzolanic fine powder. A hydraulic composition having a volume ratio of 4.5% or less based on the total amount. 2. The hydraulic composition according to claim 1, comprising an inorganic powder having an average particle size of 3 to 20 μm. 3. 100 parts by weight of cement, fine pozzolanic powder 5
50 to 250 parts by weight, fine aggregate having a particle diameter of 2 mm or less 50 to 250 parts by weight, dispersant 0.5 to 4.0 parts by weight (in terms of solid content), organic fibers and / or inorganic fibers, water 10 to 35 parts by weight, average particle size 1 mm A hydraulic composition containing the following needle-like particles and / or flaky particles, wherein the blending amount of the organic fibers and / or inorganic fibers is 0.1 to 10% by volume in the hydraulic composition. And, the compounding amount of the acicular particles and / or flaky particles is a volume ratio with respect to the total amount of the cement and the pozzolanic fine powder.
A hydraulic composition that is between 0.05 and 4.5%. 4. The hydraulic composition according to claim 3, wherein the composition contains inorganic powder having an average particle size of 3 to 20 μm in an amount of 50 parts by weight or less per 100 parts by weight of the cement. 5. The organic fiber and / or the inorganic fiber have a diameter of 0.005 to 1.0 mm and a length of 2 to 30 mm.
5. The hydraulic composition according to any one of items 1 to 4. 6. The organic fiber and / or the inorganic fiber are vinylon fiber, polypropylene fiber, polyethylene fiber,
The hydraulic composition according to any one of claims 1 to 5, comprising at least one selected from the group consisting of aramid fibers and carbon fibers. 7. The hydraulic composition according to claim 1, which has a compressive strength of 130 MPa or more and a bending strength of 20 MPa or more.