JP6063159B2 - Paste composition - Google Patents

Description

  The present invention relates to a paste composition and a mortar composition.

In recent years, ultra-high-strength concrete that exhibits a compressive strength of 150 N / mm ² or more and high bending strength has been proposed in accordance with demands for reducing the weight of structural members and reducing the amount of reinforcing bars used. In these concretes, cement, pozzolanic fine powder, aggregate, high-performance water reducing agent, and metal fiber are used, and ultrahigh strength is achieved by heat curing (see Patent Documents 1 and 2). Also proposed is a highly tough fiber-reinforced cement composite that exhibits pseudo-strain hardening under tensile stress (a behavior in which tensile stress increases after initial cracking) and has a function of suppressing crack width even when deformation increases. (See Patent Document 3). In this cement composite material, high toughness is achieved by organic short fibers such as polyvinyl alcohol.

JP 2001-181004 A JP 2006-298679 A JP 2007-126317 A

  However, when heat-curing ultra-high-strength concrete, it is necessary to transport the product to the construction site because it is manufactured using a formwork at the factory. Moreover, since the shape and size of the concrete product are restricted by the formwork used and the shape of the curing device, the degree of freedom in designing ultra-high-strength concrete is limited. On the other hand, a highly tough cement-based material exhibiting pseudo-strain hardening characteristics can be applied on-site, but its compressive and tensile strength is comparable to that of ordinary concrete. For this reason, there is a need for a highly tough and high strength material that does not require heat curing and can be applied on site. In addition, it is desirable that the shrinkage of the concrete is small from the viewpoint of the durability, long life, and high quality of the structure. Therefore, the material is required to reduce strain due to self-shrinkage.

  Then, this invention aims at providing the paste composition and mortar composition which can express high compressive strength at an early stage only by normal temperature curing, and can reduce self-shrinkage strain, while having high toughness. .

  As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention obtained a cement having a specific mineral composition and particle size distribution and an inorganic fine powder having a specific particle size by combining silica fume, water, a water reducing agent, an antifoaming agent, It has been found that by combining with an expansion material and high-tensile fibers, the strength of the paste composition and the mortar composition can be improved without self-curing while having high toughness, and the self-shrinkage strain can be reduced. It came to complete.

That is, the present invention includes cement, silica fume, water, water reducing agent, antifoaming agent, expansion material, inorganic fine powder, and high-tensile fiber, and the cement contains C ₃ S of 40.0 to 75.0% by mass and less than 2.7% by mass of C ₃ A, and 45 μm sieve residue is less than 25.0% by mass, and the fine inorganic powder is limestone powder, quartzite powder, crushed stone powder and slag When at least one kind of fine powder selected from the group consisting of powder is contained, and the inorganic fine powder is mixed, the mixture contains 86 to 100% by mass of a particle group having a particle size of 0.15 mm or less, and a particle size A paste composition containing 70% by mass or more of a particle group of 0.075 mm or less is provided. Such a paste composition has high toughness, can express high compressive strength at an early stage only by normal temperature curing, and can reduce self-shrinkage strain.

The fluidity | liquidity of a paste composition can be improved as the brane specific surface area of an inorganic fine powder is 3000-5000 cm < ² > / g. In addition, the paste composition of the present invention contains 10 to 60 parts by mass of inorganic fine powder with respect to 100 parts by mass of the total amount of cement and silica fume, so that the fluidity of the composition is further improved and the workability is excellent. It will be.

  The intensity | strength of a paste composition can further be improved as the average particle diameter of a silica fume is 0.05-2.0 micrometers. And it is preferable that the paste composition of this invention contains 3-30 mass% of silica fume on the basis of the total amount of a cement and a silica fume.

  The paste composition of the present invention preferably contains 10 to 25 parts by mass of water and 0.5 to 6.0 parts by mass of a water reducing agent with respect to 100 parts by mass of the total amount of cement and silica fume. Thereby, the intensity | strength of a paste composition improves further.

In the paste composition of the present invention, the high-tensile fiber has a tensile strength of 100 to 10000 N / mm ² , an aspect ratio of 40 to 250, and an external content of 0.3 to 5.0 volume with respect to the paste composition. %, It becomes easy to obtain high toughness and high compressive strength and tensile strength. Moreover, the said high tension fiber can further improve the intensity | strength of a paste composition as it is 1 or more types of fibers chosen from the group which consists of a metal fiber, carbon fiber, and an aramid fiber.

If content of an expansion | swelling material is 5-40 kg / m < ³ >, it will become easy to reduce the self contraction distortion of a paste composition.

  Moreover, this invention provides the mortar composition containing the paste composition mentioned above and a fine aggregate. Such a mortar composition also has high toughness, can exhibit high compressive strength at an early stage only by room temperature curing, and can reduce self-shrinkage strain.

  ADVANTAGE OF THE INVENTION According to this invention, it can provide the paste composition and mortar composition which can express high compressive strength at an early stage only by normal temperature curing, and can reduce a self-shrinkage strain, while having high toughness.

It is a graph showing the self-shrinkage distortion after 182 days of age of the compositions of Examples 3 , 6 and 9, Reference Examples 1, 2, 4, 5, 7, and 8, and Comparative Examples 1 to 3.

  Hereinafter, although suitable embodiment of the paste composition and mortar composition which concern on this invention is described, this invention is not limited to the following embodiment.

(Paste composition)
The paste composition of this embodiment contains cement, silica fume, water, a water reducing agent, an antifoaming agent, an expansion material, an inorganic fine powder, and high-tensile fiber.

As for the mineral composition of the cement, the amount of C ₃ S is 40.0 to 75.0% by mass, and the amount of C ₃ A is less than 2.7% by mass. The amount of C ₃ S in the cement is preferably 45.0 to 73.0% by mass, more preferably 48.0 to 70.0% by mass, and still more preferably 50.0 to 68.0% by mass. The amount of C ₃ A is preferably less than 2.3% by mass, more preferably less than 2.1% by mass, and even more preferably less than 1.9% by mass. If the amount of C ₃ S is less than 40.0% by mass, the compressive strength tends to be low, and if it exceeds 75.0% by mass, the cement itself tends to be difficult to fire. Further, when the amount of C ₃ A is 2.7% by mass or more, the fluidity is deteriorated. In addition, the lower limit of the amount of C ₃ A is not particularly limited, but is about 0.1% by mass.

The C ₂ S amount of the cement is preferably 9.5 to 40.0% by mass, more preferably 10.0 to 35.0% by mass, and still more preferably 12.0 to 30.0% by mass. It is. The amount of C ₄ AF is preferably 9.0 to 18.0% by mass, more preferably 10.0 to 15.0% by mass, and still more preferably 11.0 to 15.0% by mass. If it is the range of the mineral composition of such a cement, it will become easy to ensure the high compressive strength and high fluidity | liquidity of a paste composition.

  The upper limit of the 45 μm sieve residue of the cement particle size is less than 25.0% by mass, preferably 20.0% by mass, more preferably 18.0% by mass, and even more preferably 15. 0% by mass. The lower limit of the 45 μm sieve residue is 0.0% by mass, preferably 1.0% by mass, more preferably 2.0% by mass, and even more preferably 3.0% by mass. If the particle size of the cement is within this range, high compressive strength can be secured, and the slurry prepared using this cement has an appropriate viscosity, so that sufficient dispersibility is secured when fibers are added. it can.

The brane specific surface area of the cement is preferably 2500 to 4800 cm ² / g, more preferably 2800 to 4000 cm ² / g, still more preferably 3000 to 3600 cm ² / g, and particularly preferably 3200 to 3500 cm ² / g. When the brane specific surface area of the cement is less than 2500 cm ² / g, the strength of the paste composition tends to be low, and when it exceeds 4800 cm ² / g, the fluidity at a low water cement ratio tends to be lowered.

  In manufacturing the cement according to the present embodiment, it is not necessary to perform an operation different from that of normal cement. The cement is changed according to the target mineral composition such as limestone, silica, slag, coal ash, construction generated soil, blast furnace dust, etc., fired in the actual kiln, gypsum added to the obtained clinker And can be manufactured by pulverizing to a predetermined particle size. A general NSP kiln, SP kiln, or the like can be used for the kiln to be fired, and a general pulverizer such as a ball mill can be used for pulverization. Moreover, 2 or more types of cement can also be mixed as needed.

Silica fume is a by-product obtained by collecting dust in the exhaust gas generated when producing metal silicon, ferrosilicon, fused zirconia, etc., and the main component is amorphous SiO dissolved in an alkaline solution. ₂ . The average particle size of silica fume is preferably 0.05 to 2.0 μm, more preferably 0.10 to 1.5 μm, still more preferably 0.18 to 0.28 μm, and particularly preferably 0.20 to 0.28 μm. is there. By using such silica fume, it becomes easy to ensure high compressive strength and high fluidity of the paste composition.

In the paste composition of the present embodiment, the silica fume is preferably 3 to 30% by mass, more preferably 5 to 20% by mass, still more preferably 10 to 18% by mass, particularly preferably based on the total amount of cement and silica fume. 10 to 15% by mass. The unit amount of silica fume per 1 m ^{3 of} the paste composition is preferably 36 to 360 kg / m ³ , more preferably 61 to 242 kg / m ³ , and still more preferably 121 to 218 kg / m ³ .

As the water reducing agent, lignin-based, naphthalenesulfonic acid-based, aminosulfonic acid-based, polycarboxylic acid-based water reducing agents, high-performance water reducing agents, high-performance AE water reducing agents, and the like can be used. From the viewpoint of ensuring fluidity at a low water cement ratio, it is preferable to use a polycarboxylic acid-based water reducing agent, a high-performance water reducing agent or a high-performance AE water reducing agent as the water reducing agent, and a polycarboxylic acid-based high-performance water reducing agent. It is more preferable to use In the paste composition according to this embodiment, the water reducing agent is preferably 0.5 to 6.0 parts by mass, more preferably 1.0 to 4.0 parts by mass with respect to 100 parts by mass of the total amount of cement and silica fume. More preferably, it contains 1.8 to 3.0 parts by mass, particularly preferably 2.0 to 3.0 parts by mass. Moreover, the unit amount of the water reducing agent per 1 m ^{3 of} the paste composition is preferably 6 to 83 kg / m ³ , more preferably 13 to 55 kg / m ³ , and still more preferably 18 to 42 kg / m ³ .

Examples of antifoaming agents include special nonionic compounding surfactants, polyalkylene derivatives, hydrophobic silica, and polyethers. In this case, the antifoaming agent is preferably 0.01 to 2.0 parts by weight, more preferably 0.02 to 1.5 parts by weight, and still more preferably 0.000 parts by weight with respect to 100 parts by weight of the total amount of cement and silica fume. Including 03 to 1.0 parts by mass. The unit amount of the antifoaming agent per 1 m ^{3 of} the paste composition is preferably 0.10 to 28 kg / m ³ , more preferably 0.20 to 21 kg / m ³ , and still more preferably 0.40 to 14 kg / m. ³ .

  As the expansion material, metal powder, calcium sulfoaluminate (CSA type), and a lime type expansion material mainly composed of CaO can be used. An example of the calcium sulfoaluminate-based expansion material is Auin, and in particular, an expansion material that generates elintite is preferable. Examples of the lime-based expansion material include quick lime, quick lime-gypsum mixed system, and calcined dolomite, among which quick lime and / or quick lime-gypsum mixed system are preferable. These expanding materials can be used alone or in combination of two or more.

The content of the expansion material is preferably 5 to 40 kg, more preferably 10 to 35 kg, still more preferably 15 to 35 kg, and particularly preferably 20 to 35 kg per 1 m ^{3 of} the paste composition. When the content is small, it does not contribute to the expansibility, and when the content is large, it is excessively expanded, which is not preferable.

As the inorganic fine powder, fine powder such as limestone powder, quartzite powder, crushed stone powder, and slag powder can be used. The fine inorganic powder is a fine powder obtained by pulverizing or classifying limestone powder, silica powder, crushed stone powder, slag powder, etc. until the Blaine specific surface area is 2500 cm ² / g or more, and can improve the fluidity of the paste composition. . Preferably Blaine specific surface area of the powder inorganic fine powder is 3000~5000cm ² / g, more preferably 3200~4500cm ² / g, more preferably in a 3400~4300cm ² / g, 3600~4300cm ² / G is particularly preferable.

  When the inorganic fine powder according to the present embodiment is mixed, the mixture is composed of 86 to 100% by mass of a particle group having a particle size of 0.15 mm or less, and 70% by mass or more of a particle group having a particle size of 0.075 mm or less. contains. The particle group having a particle size of 0.15 mm or less is preferably contained in an amount of 88 to 100% by mass, more preferably 90 to 100% by mass, and still more preferably 92 to 100% by mass. If the particle group having a particle size of 0.15 mm or less is less than 85% by mass, the fibers are easily entangled, and are not uniformly dispersed, and the cured product may be non-uniform. Moreover, the particle group having a particle size of 0.075 mm or less is preferably contained by 75% by mass or more, more preferably 80% by mass or more, and further preferably 85% by mass or more. If the number of particles having a particle size of 0.075 mm or less is less than 70% by mass, fibers may be easily entangled and a fiber ball may be easily formed.

  The inorganic fine powder according to this embodiment preferably contains 10 to 60 parts by mass, more preferably 20 to 60 parts by mass, and still more preferably 30 to 60 parts by mass with respect to 100 parts by mass of the total amount of cement and silica fume. Especially preferably, it is 40-60 mass parts. When the amount of inorganic fine powder is less than 10 parts by mass or more than 60 parts by mass with respect to 100 parts by mass of the total amount of cement and silica fume, the fluidity tends to deteriorate.

Examples of the high-tensile fiber include metal fiber, carbon fiber, and aramid fiber. As the metal fiber, steel fiber, stainless steel fiber, amorphous alloy fiber, or the like can be used. The fiber diameter of the high-tensile fiber is preferably 0.05 to 1.20 mm, more preferably 0.08 to 0.70 mm, still more preferably 0.10 to 0.35 mm, and particularly preferably 0.12 to 0.20 mm. The fiber length of the high-tensile fiber is preferably 3 to 60 mm, more preferably 5 to 35 mm, still more preferably 7 to 20 mm, and particularly preferably 9 to 15 mm. The aspect ratio (fiber length / fiber diameter) of the high-tensile fiber is preferably 40 to 250, more preferably 50 to 200, still more preferably 60 to 170, and particularly preferably 70 to 140. The tensile strength of the high strength fiber is preferably 100~10000N / mm ^2, preferably from 500~5000N / mm ^2, more preferably ^{2000~3000N / mm 2, 1500~2500N / mm} 2 is particularly preferred. The density of high-tensile fibers, preferably from 1 to 20 g / cm ^3, more preferably 3 to 15 g / cm ^3, more preferably 5 to 10 g / cm ^3. By using such a high tension fiber, it becomes easy to impart high toughness, high compressive strength, high tensile strength and high fluidity to the paste composition.

The paste composition according to the present embodiment preferably has a high-strength fiber of 0.00% on an external basis with respect to the paste composition (that is, with respect to 100% by volume of the composition excluding the high-tensile fiber in the paste composition). By containing 3 to 5.0% by volume, more preferably 0.5 to 4.0% by volume, still more preferably 1.0 to 2.5% by volume, particularly preferably 1.5 to 2.5% by volume, High toughness is easily obtained. In addition, when it exceeds 5.0 volume%, kneading | mixing of a paste composition may become difficult. The amount of high-tensile fibers of the paste composition 1 m ³ is preferably 23～393Kg, more preferably 39～314Kg, more preferably 79～196Kg.

Moreover, the paste composition according to the present embodiment is preferably 10 to 25 parts by mass, more preferably 12 to 20 parts by mass, and still more preferably 13 to 18 parts by mass of water with respect to 100 parts by mass of the total amount of cement and silica fume. Part by mass, particularly preferably 15 to 18 parts by mass is included. The unit water amount per 1 m ^{3 of the} paste composition is preferably 137 to 344 kg / m ³ , more preferably 165 to 275 kg / m ³ , and still more preferably 178 to 248 kg / m ³ .

  The paste composition according to this embodiment includes one or more shrinkage reducing agents, setting accelerators, setting retarders, thickeners, glass fibers, synthetic resin powders, polymer emulsions, polymer dispersions, and the like as necessary. It may be added.

(Mortar composition)
The mortar composition of the present embodiment includes the paste composition of the present embodiment and the fine aggregate described above.

  The fine aggregate is not particularly limited, but river sand, land sand, sea sand, crushed sand, quartz sand, limestone aggregate, blast furnace slag fine aggregate, ferronickel slag fine aggregate, copper slag fine aggregate, electric furnace oxidation slag Fine aggregates can be used. The fine aggregate preferably has a particle size of passing through a 10 mm sieve and passing through a 5 mm sieve by 85% by mass or more.

  The mixture of fine aggregate and inorganic fine powder contains 40 to 80% by mass, preferably 45 to 80% by mass, and more preferably 50 to 75% by mass of a particle group having a particle size of 0.15 mm or less. Moreover, the said mixture contains 30-80 mass% of particle groups with a particle size of 0.075 mm or less, Preferably it contains 35-70 mass%, More preferably, it contains 40-65 mass%. When the content of the inorganic fine powder is 30% by mass or less, since the viscosity of the slurry is too low, the high tension fiber may not be sufficiently dispersed.

The mixture of fine aggregate and inorganic fine powder preferably contains 10 to 60 parts by mass of fine aggregate and 10 to 60 parts by mass of inorganic fine powder with respect to 100 parts by mass of the total amount of cement and silica fume. More preferably, the material contains 15-30 parts by mass, the inorganic fine powder 15-30 parts by mass, the fine aggregate 20-30 parts by mass, and the inorganic fine powder 20-30 parts by mass. The unit amount of the mixture of fine aggregate and inorganic fine powder per 1 m ^{3 of} the mortar composition is preferably 140 to 980 kg / m ³ , more preferably 300 to 900 kg / m ³ , still more preferably 600 to 900 kg / m. ³ .

  Furthermore, concrete may be prepared by combining an appropriate amount of coarse aggregate with the mortar composition according to the above embodiment. The amount of coarse aggregate and the amount of water may be changed as appropriate according to the target compressive strength, toughness, and target slump. As the coarse aggregate, gravel, crushed stone, limestone aggregate, blast furnace slag coarse aggregate, electric furnace oxidized slag coarse aggregate and the like can be used. Moreover, the coarse aggregate which stays 85 mass% or more on a 5 mm sieve is more preferable.

  Although the manufacturing method of the paste composition or mortar composition which concerns on this embodiment is not specifically limited, A part or all of materials other than water, a water reducing agent, and a high tension fiber (When an organic fiber is mix | blended also an organic fiber) It is preferable to prepare by mixing in advance and then adding water and a water reducing agent, mixing in a mixer. The fiber material is preferably added to the mixer after the paste composition or mortar composition is produced, and further kneaded. The mixer used for kneading the mortar composition is not particularly limited, and a mortar mixer, a biaxial forced kneading mixer, a pan-type mixer, a grout mixer, and the like can be used.

  The paste composition or mortar composition in the above embodiment is effective for PC beams, high durability panels, block earthquake resistant walls and the like that require high strength. Moreover, it becomes possible to reduce the amount of reinforcing bars, such as a bridge, by adding a high tension fiber. It is also effective for repairing and reinforcing bridges.

  As mentioned above, according to the paste composition and mortar composition of this embodiment, while having high toughness, high compressive strength can be expressed at an early stage only by normal temperature curing, and self-shrinkage strain can be reduced.

Hereinafter, the contents of the present invention will be described more specifically with reference to Examples , Reference Examples and Comparative Examples. In addition, this invention is not limited to the following Example.

[Preparation of materials used]
In order to prepare paste compositions or mortar compositions of Examples , Reference Examples and Comparative Examples, the following materials were prepared.

(1) Cement (C):
Portland cement was prepared by blending raw materials such as limestone, silica stone, slag, coal ash, construction generated soil, copper gravel, etc., calcining with kiln, adding gypsum and grinding. The chemical components of the obtained cement were measured according to JIS R 5202-2010 “Cement chemical analysis method”, and the mineral composition was calculated by the following Borg equation. The mineral composition of the obtained cement is shown in Table 1.
C ₃ S amount = (4.07 × CaO) − (7.60 × SiO ₂ ) − (6.72 × Al ₂ O ₃ ) − (1.43 × Fe ₂ O ₃ ) − (2.85 × SO ₃ )
C ₂ S amount = (2.87 × SiO ₂ ) − (0.754 × C ₃ S)
C ₃ A amount = (2.65 × Al ₂ O ₃ ) − (1.69 × Fe ₂ O ₃ )
C ₄ AF amount = 3.04 × Fe ₂ O ₃

  Moreover, the 45-micrometer sieve residue of the obtained cement was measured according to Cement Association standard test method JCAS K-02 "The test method of the fineness of the cement by a 45-micrometer mesh sieve". Further, the specific surface area of the brane was measured according to JIS R 5201-1997 “Physical Test Method for Cement”. The results are shown in Table 1.

(2) Silica fume (SF): average particle size 0.24 μm
The average particle size of silica fume is calculated from a particle size distribution measured using a laser diffraction / scattering particle size distribution measuring device (trade name “LA-950V2” manufactured by Horiba, Ltd.), and a particle size-passage integrated% curve is calculated. Then, the particle diameter at which the accumulated amount of the passage was 50% by volume was determined from the particle diameter-accumulated amount of passage% curve. A 0.2% sodium hexametaphosphate aqueous solution was used as a sample dispersion medium, and the sample was dispersed for 10 minutes with a homogenizer with an output of 600 W before measurement. The calculation of the particle size distribution followed Mie scattering theory. The particle refractive index was 1.45-0.00i, and the solvent refractive index was 1.333. Table 2 shows the accumulated amount (volume%) of each particle size.

(3) Inorganic fine powder (A) Silica powder: density 2.62 g / cm ³ , Blaine specific surface area 3820 cm ² / g
(B) Limestone fine powder: density 2.71 g / cm ³ , Blaine specific surface area 4280 cm ² / g

(4) Fine aggregate Crushed sand: density 2.62 g / cm ³ , coarse particle ratio 2.80

  The particle sizes of the inorganic fine powder and the fine aggregate were measured with reference to JIS A 1102-2006 “Aggregate Screening Test Method”. Subsequently, the inorganic fine powder, or the inorganic fine powder and the fine aggregate were mixed to adjust to a predetermined particle size. The results are shown in Table 3.

(5) Water reducing agent: polycarboxylic acid-based high-performance water reducing agent (solid content concentration 25% by mass)
(6) Antifoaming agent: special nonionic compounding type surfactant Table 4 shows the molar ratio of the structural units of POP, POE and alkyl chain in the antifoaming agent.

(7) Expansion material: Three commercially available brands (A, B, C) were used. Brand A is N-EX (trade name; manufactured by Taiheiyo Materials Co., Ltd., lime-based expansion material), Brand B is Hyper Expand (trade name; Taiheiyo Materials Co., Ltd., lime-based expansion material), and Brand C is Power CSA ( Product name; manufactured by Denki Kagaku Kogyo Co., Ltd., calcium sulfoaluminate-based expansion material).

(8) High tensile fiber: Steel fiber (trade name “CW9416”, manufactured by Tokyo Tsuna Co., Ltd.), density: 7.87 g / cm ³ , fiber diameter 0.16 mm, fiber length 13 mm, aspect ratio 81.25, tensile strength 2200 N / mm ²
(9) Mixing water (W): Tap water

[Preparation of paste composition or mortar composition]
Preparation of the paste composition or the mortar composition was performed as follows based on the formulation composition of Table 5.

Cement, expansion material, silica fume, antifoaming agent, fine inorganic powder and fine aggregate were added to the concrete biaxial mixer and stirred for 30 seconds. Next, mixing water containing a water reducing agent was put into the mixer and stirred for 10 minutes, and further, steel fibers were added and stirred for 3 minutes. Examples 3 and 6, Reference Examples 1, 2, 4, and 5 the paste composition of Comparative example 1-2, and was prepared in example 9, mortar compositions of reference examples 7, 8 and Comparative example 3.

[Evaluation of Paste Composition or Mortar Composition]
(1) Fresh properties (test method)
Using the paste compositions of Examples 3 and 6, Reference Examples 1, 2, 4 and 5, Comparative Examples 1 and 2, and the mortar compositions of Examples 9, Reference Examples 7, 8 and Comparative Example 3, The flow was measured. The slump flow was measured according to JIS A 1150-2007 “Concrete slump flow test method”.

(2) Strength Test Examples 3 and 6, Reference Examples 1, 2, 4 and 5, Paste compositions of Comparative Examples 1 and 2, and Mortar compositions of Example 9, Reference Examples 7, 8 and Comparative Example 3 A 5 cm × 10 cm cylindrical specimen is prepared according to JIS A 1132-2006 “How to make a specimen for concrete strength test”, and according to JIS A 1108-2006 “Concrete compressive strength test method”. A compressive strength test was performed. The specimen was cured in water at 20 ° C. until the test material age.

(3) Self-shrinking Examples 3 and 6, Reference Examples 1, 2, 4, and 5, paste compositions of Comparative Examples 1 and 2, and Mortar compositions of Example 9, Reference Examples 7, 8 and Comparative Example 3 Was placed in a 10 × 10 × 40 cm mold (made of steel) centered on an embedded gauge (manufactured by Tokyo Sokki Kenkyujo Co., Ltd.), and self-shrinkage strain was measured. In addition, a styrene board and a polytetrafluoroethylene sheet were arranged on the inner side of the mold surface, and measurement was performed in a state where the paste or mortar was not restrained, and the sealed state was maintained until the measurement was completed.

(Evaluation results)
Table 6 shows the results of the slump flow test, the compressive strength test, and the self-shrinkage measurement. Moreover, the age of the paste compositions of Examples 3 and 6, Reference Examples 1, 2, 4 and 5, Comparative Examples 1 and 2, and the mortar compositions of Example 9, Reference Examples 7, 8 and Comparative Example 3 The self-shrinkage strain after 182 days is shown in FIG.

As shown in Table 6, in Examples 3, 6 and 9, and Reference Examples 1, 2, 4, 5, 7 and 8 , the slump flow and compressive strength were good, and the self-shrinkage strain was also small.

  On the other hand, in Comparative Examples 1 to 3, the self-shrinkage strain was increased.

Claims (7)

A paste composition comprising cement, silica fume, water, a water reducing agent, an antifoaming agent, an expansion material, an inorganic fine powder, and a high-tensile fiber,
The cement contains 40.0-75.0% by mass of C ₃ S and less than 2.7% by mass of C ₃ A, and a 45 μm sieve residue is less than 25.0% by mass,
The expansion material contains a calcium sulfoaluminate-based expansion material,
The inorganic fine powder contains at least one fine powder selected from the group consisting of limestone powder, quartzite powder, crushed stone powder, and slag powder;
The inorganic fine powder has a Blaine specific surface area of 3000 to 5000 cm ² / g,
The inorganic fine powder contains a particle group having a particle size of 0.15 mm or less in an amount of 86 to 100% by mass and a particle group having a particle size of 0.075 mm or less in an amount of 70% by mass or more.
Wherein the total amount of 100 parts by weight of cement and the silica fume, 10-20 parts by weight of the water, including the water reducing agent 1.8-3.0 parts by weight, paste composition.   The paste composition according to claim 1, comprising 10 to 60 parts by mass of the inorganic fine powder with respect to 100 parts by mass of the total amount of the cement and the silica fume.   The paste composition of Claim 1 or 2 whose average particle diameter of the said silica fume is 0.05-2.0 micrometers.   The paste composition according to any one of claims 1 to 3, comprising 3 to 30% by mass of the silica fume based on a total amount of the cement and the silica fume. The high-strength fibers have a tensile strength of 100~10000N / mm ^2, the aspect ratio is 40 to 250, the content with respect to the paste composition is from 0.3 to 5.0% by volume, according to claim 1-4 The paste composition according to any one of the above. The paste composition according to any one of claims 1 to 5 , wherein the high-tensile fiber is one or more fibers selected from the group consisting of metal fibers, carbon fibers, and aramid fibers. The paste composition according to any one of claims 1 to 6 , wherein the content of the expansion material is 5 to 40 kg / m ³ .

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