JP2016190415A - Method for producing heavyweight concrete structure, and the heavyweight concrete structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a heavyweight concrete structure, in which the heavyweight concrete structure having sufficient weight can be produced.SOLUTION: The method for producing a heavyweight concrete structure comprises the steps of: preparing a heavyweight mixture which contains 0.1-5.0 vol% of a metal fiber, 40-80 vol% of aggregate having 2.5-5.0 g/cmdensity, cement and water; preparing a lightweight mixture which contains other aggregate, cement and water and has the weight per unit volume smaller than that of the prepared heavyweight mixture; transporting the prepared heavyweight mixture and the prepared lightweight mixture respectively to the vicinity of an execution site; and injecting the transported heavyweight mixture and the transported lightweight mixture respectively to the execution site.SELECTED DRAWING: None

Description

  The present invention relates to a method for manufacturing a heavy concrete structure and a heavy concrete structure manufactured by the method.

Concrete structures (heavy concrete structures) using concrete (heavy concrete) whose weight per unit volume is larger than normal concrete are, for example, ship ballasts, wave-dissipating blocks, revetment blocks, radiation shielding walls. It is used for bridge weights.
Such heavy concrete increases the weight per unit volume by, for example, replacing a part of the aggregate with a heavy aggregate having a density higher than that of a normal aggregate. For example, Patent Document 1 describes heavy concrete using a heavy aggregate made of a metal such as iron oxide such as FeO or Fe ₂ O ₃ .

  However, when such heavy aggregates are mixed with normal aggregates having different densities, separation from cement paste is likely to occur, for example, when heavy concrete before hardening is separated during transportation or when pumped May clog heavy aggregates inside a transfer device such as a hose. In particular, when manufacturing large-volume concrete structures such as marine ballasts, a large amount of heavy concrete is required. It is necessary to transport a relatively long distance. In this case, the cement paste and the aggregate are more likely to be separated. Further, in the production of a concrete structure having a large volume, if heavy concrete in a separated state is poured into a construction site, a gap is likely to occur after curing or the density is likely to be uneven. In particular, concrete structures such as marine ballasts that require uniform density in the horizontal direction have a high need to suppress such gaps and uneven density, and as a result, the amount of heavy aggregate is not separated. It is necessary to adjust to the extent, and it is difficult to sufficiently increase the weight per unit volume of the concrete.

JP 2009-179500 A

Then, this invention makes it a subject to provide the manufacturing method which can manufacture a heavy concrete structure with a large weight per unit volume, suppressing separation, in view of the above conventional problems.
It is another object of the present invention to provide a heavy concrete structure that is difficult to separate and has a large weight per unit volume.

The method for producing a heavy concrete structure according to the present invention includes a metal fiber of 0.1% by volume or more and 5.0% by volume or less and a density of 40% by volume or more and 80% by volume or less of 2.5 g / cm ³ or more and 5.0 g / cm. A weight mixture containing aggregate, cement, and water that is equal to or less than cm ³ , and a lightweight mixture that includes aggregate, cement, and water and has a weight per unit volume smaller than that of the weight mixture, respectively, and the weight A heavy concrete structure is manufactured by transferring the mixture and the lightweight mixture to the vicinity of the construction site and injecting the transferred weight mixture and the lightweight mixture to the construction site.

According to the present invention, 0.1% by volume to 5.0% by volume of metal fiber and 40% by volume to 80% by volume of density 2.5 g / cm ^{3 to} 5.0 g / cm ^{3 of} aggregate. And a light weight mixture containing aggregate, cement, and water, and a light weight mixture having a weight per unit volume smaller than that of the weight mixture, and the weight mixture and the light weight mixture. In order to transfer the weight mixture and the lightweight mixture to the same construction site, respectively, the cement paste, the metal fiber, and the aggregate are respectively used until the injection. Can be maintained in a state in which it is difficult to separate.
That is, separation is likely to occur when the metal fiber and an aggregate that is usually lower in density than the metal fiber are present in the cement paste in a mixed state, but the weight mixture of the present invention is a metal fiber. In addition, it is difficult to separate the aggregates having the density in the above range by mixing them in the content in the above range. In addition, by mixing the heavy mixture and the light mixture separately, and transporting each separately to the vicinity of the construction site, the metal fibers and aggregates are more difficult to separate in the heavy mixture and the lightweight mixture. Since the heavy concrete is manufactured by injecting the weight mixture and the light mixture into the construction site, the weight per unit volume of the manufactured heavy concrete can be easily increased.

In the present invention, a weight per unit volume of the weight mixture is 3.0 t / m ³ or more and 4.5 t / m ³ or less, and a weight per unit volume of the light mixture is 2.2 t / m ³ or more. It may be 9 t / m ³ or less.

  When the weight per unit of the weight mixture and the weight per unit of the light mixture are within the above ranges, the weight per unit volume of the heavy concrete can be easily increased while suppressing the separation in each mixture.

In the present invention, the metal fiber may have a density of 7.0 g / cm ³ or more and 8.0 g / cm ³ or less.

  When the metal fiber is in the density range, it is easy to increase the weight per unit volume of heavy concrete while suppressing separation.

  In the present invention, the light mixture may be prepared so that the metal fiber is contained in an amount of 0.1% by volume or more and 5.0% by volume or less.

  When the lightweight mixture is prepared so that the metal fiber is included in the above range, it is easy to increase the weight per unit volume of the heavy concrete while suppressing separation.

  The heavy concrete structure of the present invention is manufactured by the above-described manufacturing methods.

  As described above, according to the present invention, it is possible to provide a production method capable of producing a heavy concrete structure having a large weight per unit volume while suppressing separation. Further, it is possible to provide a heavy concrete structure that is difficult to separate and has a large weight per unit volume.

  Hereinafter, an embodiment of a method for producing a heavy concrete structure and a heavy concrete structure according to the present invention will be described.

The manufacturing method of the heavy concrete structure of the present embodiment includes a metal fiber of 0.1% by volume to 5.0% by volume and a density of 40% by volume to 80% by volume of 2.5 g / cm ^{3 to} 5.0 g / A weight mixture containing aggregate, cement, and water that is equal to or less than cm ³ , and a lightweight mixture that includes aggregate, cement, and water and has a weight per unit volume smaller than that of the weight mixture, respectively, and the weight It is a method of manufacturing a heavy concrete structure by transferring the mixture and the lightweight mixture to the vicinity of the construction site and injecting the transferred weight mixture and the lightweight mixture to the construction site. More specific description will be given below.
In addition, the heavy concrete as used in this embodiment means the concrete whose weight per unit volume is 2.4 t / m < ³ > or more.

(Weight mixture)
The manufacturing method of the heavy concrete structure of this embodiment includes the process of producing the weight mixture containing a metal fiber, an aggregate, cement, and water.
Although it does not specifically limit as a metal fiber, For example, a steel fiber, a stainless steel fiber, an alumina fiber, a titanium alloy fiber, an amorphous metal fiber etc. are mentioned.
In particular, steel fibers are preferable from the viewpoint of performance and versatility.

The density of the metal fiber is not particularly limited, but is, for example, 7.0 g / cm ³ or more and 8.0 g / cm ³ or less, preferably 7.5 g / cm ³ or more and 8.0 g / cm ³ or less. Is mentioned.
When the density of the metal fiber is within the above range, it is preferable because it is difficult to separate from the cement paste and the weight of the weight mixture can be increased.

Further, the size of the metal fiber is not particularly limited, and examples thereof include those having a diameter of 0.2 mm to 1.0 mm, preferably 0.5 mm to 1.0 mm. When the diameter of the metal fiber is within the above range, it is preferable because the fluidity is good and the weight of the weight mixture can be increased.
In addition, examples of the metal fiber include those having a length of 20 mm to 60 mm, preferably 20 mm to 40 mm. When the length of the metal fiber is within the above range, it is preferable because the fluidity is good and the weight of the weight mixture can be increased.

  The content of the metal fiber in the weight mixture is 0.1 volume% or more and 5.0 volume% or less, preferably 0.1 volume% or more and 3.0 volume% or less. When the content of the metal fiber is in the above range, it is preferable because the deterioration of the kneadability can be suppressed by the metal fiber and the fluidity of the weight mixture can be improved and the weight of the weight mixture can be increased.

The weight mixture contains aggregates along with metal fibers.
The aggregate is not particularly limited. As an aggregate, only one of a fine aggregate and a coarse aggregate may be sufficient, or a fine aggregate and a coarse aggregate may be included. When the weight mixture includes aggregate, a decrease in strength of heavy concrete can be suppressed.

The aggregate is not particularly limited. For example, natural aggregate such as river sand, mountain sand and sea sand, artificial fine aggregate such as crushed sand and blast furnace slag fine aggregate, and by-product lightweight fine aggregate. Ordinary fine aggregates such as, and heavy aggregates such as electric furnace oxidation slag aggregates.
Among them, a heavy aggregate having a relatively high density such as an electric furnace oxidation slag aggregate is preferable because the fluidity of the heavy mixture can be improved and the weight can be increased.
As the aggregate of the weight mixture, two or more kinds of the above aggregates may be mixed and used.

The aggregate has a density of 2.5 g / cm ³ or more and 5.0 g / cm ³ or less, preferably 3.0 g / cm ³ or more and 5.0 g / cm ³ or less.
When the density of the aggregate is in the above range, it is difficult to separate from the cement paste, and the weight of the heavy mixture and heavy concrete can be increased, which is preferable.

The aggregate content in the weight mixture is 40% by volume to 80% by volume, preferably 40% by volume to 70% by volume.
When the coarse aggregate is included as the aggregate, the content of the coarse aggregate is 20 volume% or more and 45 volume% or less, preferably 25 volume% or more and 35 volume% or less.
When the metal fiber and the aggregate are both contained in the cement paste, the cement paste, the metal fiber, and the aggregate are easily separated, but if the aggregate content is in the above range, the weight mixture Separation hardly occurs inside.

The cement of the weight mixture is not particularly limited, but for example, Portland cement such as ordinary Portland cement, early-strength Portland cement, ultra-high-strength Portland cement, Portland cement components such as white Portland, etc. Adjusted; mixed cement such as blast furnace cement, fly ash cement, silica cement;
Alumina cement, erwin cement, etc .; low heat cement, super fast cement, etc.
Of these, ordinary, early strong, moderately hot, and low heat Portland cements are preferred from the viewpoint of versatility.

The contents of cement and water in the weight mixture of the present embodiment are not particularly limited, and examples thereof include the following contents.
The cement is 10% by mass or more and 30% by mass or less, preferably 15% by mass or more and 20% by mass or less. When the cement content is in the above range, it is preferable because the fluidity of the heavy mixture can be improved and the strength of heavy concrete can be maintained.

  The water content is such that the water cement ratio is 25% by mass or more and 55% by mass or less, preferably 30% by mass or more and 45% by mass or less. When the water content is within the above water cement ratio, it is preferable because the fluidity of the heavy mixture can be improved and the strength of heavy concrete can be maintained.

  The weight mixture of this embodiment may contain other components as necessary.

  The method of preparing the weight mixture is not particularly limited, but for example, a powder material such as cement and metal fiber is first mixed, and a liquid material such as water is added, and a mixing device such as a mixer is added. 5 to 35 ° C. or less, and mixing under a mixing condition of 1 to 3 minutes.

The weight mixture prepared as described above has, for example, a weight per unit volume of 3.0 t / m ³ or more and 4.5 t / m ³ or less, preferably 3.0 t / m ³ or more and 4.0 t / m ^3. It is as follows.

  In addition, the weight mixture of the present embodiment has a metal fiber content as described above, and the aggregate of the density as described above is adjusted so as to have the above content, so that a sufficient unit volume can be obtained. The weight per hit can be increased, and a mixture that hardly separates during transfer can be obtained.

(Lightweight mixture)
The method for producing a heavy concrete structure according to this embodiment includes a step of producing a lightweight mixture containing aggregate, cement, and water and having a weight per unit volume smaller than that of the weight mixture.
In addition, the process of producing a heavy mixture and the process of producing a lightweight mixture may be performed simultaneously in parallel, and either one of the processes may be performed first.

  The aggregate of the lightweight mixture of the present embodiment is not particularly limited as long as it is an aggregate. As an aggregate, only one of a fine aggregate and a coarse aggregate may be sufficient, or a fine aggregate and a coarse aggregate may be included.

The aggregate is not particularly limited. For example, natural aggregate such as river sand, mountain sand, sea sand, artificial fine aggregate such as crushed sand, artificial lightweight aggregate, blast furnace slag fine aggregate, Examples include ordinary fine aggregates such as light-weight fine aggregates produced in the industry, and heavy aggregates such as electric furnace oxidation slag aggregates.
Among them, a heavy aggregate having a relatively high density such as an electric furnace oxidation slag aggregate is preferable because the fluidity of the light mixture can be improved and the weight can be increased.
As the aggregate of the lightweight mixture, two or more kinds of the above aggregates may be mixed and used.
Further, as the aggregate of the lightweight mixture, the same one as the aggregate of the weight mixture may be used, or a different one may be used.

Examples of the aggregate include a density of 2.5 g / cm ³ or more and 5.0 g / cm ³ or less, preferably 3.0 g / cm ³ or more and 5.0 g / cm ³ or less.
A density of the aggregate in the above range is preferable because it is difficult to separate from the cement paste and the weight of the lightweight mixture and heavy concrete can be increased.

  The aggregate content in the lightweight mixture is not particularly limited, but is, for example, 40% by volume to 80% by volume, and preferably 40% by volume to 70% by volume. When the aggregate content is in the above range, it is preferable because the fluidity of the lightweight mixture can be improved and the weight of the lightweight mixture and heavy concrete can be increased.

  Examples of the lightweight mixture cement include the same cement as the above-described heavy mixture cement. Of these, ordinary, early strong, moderately hot, and low heat Portland cements are preferred from the viewpoint of versatility.

The lightweight mixture may contain metal fibers along with the aggregate.
Examples of the metal fiber include the same metal fiber as that of the weight mixture.
The content of the aggregate in the light-weight mixture is not particularly limited, but when the metal fiber and the aggregate are both contained in the cement paste, the cement paste is separated from the metal fiber and the aggregate. Therefore, it is preferable to mix the light-weight mixture so that the content does not cause separation.
For example, it is 0.1 volume% or more and 5.0 volume% or less, preferably 0.1 volume% or more and 3.0 volume% or less.
Moreover, when metal fiber is contained in a lightweight mixture, it is preferable to mix | blend metal fiber so that it may become 20 volume% or less with respect to an aggregate, Preferably it is 15 volume% or less.

  The light-weight mixture may contain other components as necessary.

The contents of cement and water in the lightweight mixture of the present embodiment are not particularly limited, and examples thereof include the following contents.
Cement is 20% by mass or more and 40% by mass or less, preferably 25% by mass or more and 35% by mass or less. When the cement content is in the above range, it is preferable because the fluidity of the lightweight mixture can be improved and the strength of heavy concrete can be maintained.
The water content is such that the water cement ratio is 15% by mass or more and 55% by mass or less, preferably 20% by mass or more and 40% by mass or less. When the water content is in the range of the above water cement ratio, it is preferable because the fluidity of the lightweight mixture can be improved and the strength of heavy concrete can be maintained.

  The method for producing the lightweight mixture is not particularly limited. For example, cement and metal fiber are mixed, water is further added, and a mixing device such as a mixer or the like is used. Mixing under mixing conditions of not less than 3 minutes and not more than 3 minutes can be mentioned.

The lightweight mixture produced as described above is a mixture having a weight per unit volume smaller than that of the weight mixture. For example, the weight per unit volume is 2.2 t / m ³ or more and 2.9 t / m ³ or less, preferably 2.5 t / m ³ or more and 2.9 t / m ³ or less.

(transfer)
The method for manufacturing a heavy concrete structure according to the present embodiment includes a step of transferring the weight mixture and the light mixture separately produced as described above to a construction site.
Although a transfer means is not specifically limited, The pressure feed which transfers the inside of a hose with the pressure by a pump etc. is mentioned.
In the case of pumping, for example, using a hose having an inner diameter of 150 mm or more and 200 mm or less, a distance of about 10 m or more and 100 m or less may be pumped.
The heavy-weight mixture and the light-weight mixture of the present embodiment can be transported to a construction site while suppressing clogging and separation in the hose and the like even under the above-described pressure feeding conditions.

(Injection)
The manufacturing method of the heavy concrete structure of this embodiment includes the process of inject | pouring the said heavy mixture and the said lightweight mixture which were each separately transferred into the same construction location as mentioned above.
The method for injecting the weight mixture and the light mixture into the construction site is not particularly limited, and examples thereof include the following methods.

(1) A method of simultaneously injecting a heavy mixture and a light mixture into a construction site.
(2) First, the light mixture is injected into the construction site, and then the heavy mixture is injected into the upper part of the light mixture.
(3) First, the weight mixture is injected into the construction site, and then the light mixture is injected into the upper part of the weight mixture.

  When the heavy mixture and the light mixture are injected into the construction site at the same time, the heavy mixture and the light mixture can be injected while mixing. For example, the tip of the hose for injecting both is directed to one point of the construction site, and mixing is performed by the moment when the heavy mixture and the light mixture are injected. In this case, both can be mixed uniformly without using a mixing device or the like.

  When injecting the light mixture into the construction site and then injecting the heavy mixture into the upper portion of the light mixture, for example, the light mixture is injected into the construction site to form a layer made of the light mixture at the lower portion of the construction site. Next, a heavy mixture is poured onto the light mixture layer to form a heavy mixture layer above the light mixture layer.

When injecting the heavy mixture into the construction site and then injecting the light mixture into the upper part of the heavy mixture, for example, first, the heavy mixture is injected into the construction site to form a layer made of the heavy mixture at the lower part of the construction site. . At this time, it is preferable to form the layer of the weight mixture so as to be as uniform as possible in the horizontal direction, that is, to have a uniform thickness in the vertical direction. In addition, the light mixture is poured into a layer above the heavy mixture. According to this injection method, a heavy concrete structure in which a layer made of a heavy mixture and a layer made of a light mixture are laminated in the vertical direction can be produced.
In this case, the density of the heavy concrete structure is different in the vertical direction, but the density in the horizontal direction is a uniform heavy concrete structure. Therefore, it is suitable as a method for manufacturing a concrete structure that is required to have a uniform density in the horizontal direction, such as ballast for ships.

In this embodiment, the ratio of the weight mixture injected into the construction site and the light mixture is not particularly limited, and can be appropriately adjusted so that the heavy concrete structure to be manufactured has a target weight per volume.
For example, the weight per unit volume of the weight mixture is 3.0 t / m ³ or more and 4.5 t / m ³ or less, and the weight per unit volume of the light mixture is 2.2 t / m ³ or more and 2.9 t / m ^3. In the case of the following, the volume ratio of the lightweight mixture to the whole mixture of the heavy mixture and the lightweight mixture is 0.1 or more and 0.9 or less, preferably 0.2 or more and 0.8 or less.

In the manufacturing method of this embodiment, you may mix by vibrating the heavy mixture inject | poured into the construction location and the lightweight mixture.
Examples of the vibration means include a vibrator that is usually used for mixing mortar, concrete, and the like.
When mixing with a vibrator, a heavy mixture and a light mixture may be vibrated by simultaneously applying vibration to a plurality of locations using a plurality of vibrators.

The weight concrete structure of this embodiment manufactured by the manufacturing method of this embodiment as described above has a weight per unit volume of 2.4 t / m ³ or more, preferably 2.5 t / m ³ or more. .

The heavy concrete structure of this embodiment can suppress the separation of the cement paste, the metal fibers, and the aggregate during transfer and construction. Therefore, separation can be suppressed even when the ratio of metal fibers or aggregate is increased in the heavy mixture and the lightweight mixture. Therefore, heavy concrete having a sufficiently large weight per unit volume can be obtained.
Moreover, since a heavy concrete is manufactured by mixing a heavy mixture and a lightweight mixture in the vicinity of a construction site, it becomes easy to manufacture a heavy concrete structure having a desired weight per unit volume.
Furthermore, since it is easy to adjust the aggregate content in the heavy concrete structure to a desired content, the strength of the heavy concrete structure can be easily adjusted.

  The heavy concrete structure of this embodiment can be used as, for example, a ship ballast, a wave-dissipating block, a revetment block, a radiation blocking wall, a bridge weight, and the like. In particular, marine ballast is optimal because it can easily increase the weight per unit volume.

  In addition, although the manufacturing method and heavy concrete structure of a heavy concrete structure concerning this embodiment are as above, embodiment disclosed this time is an illustration and restrictive at no points. Should be considered. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  EXAMPLES Hereinafter, examples will be shown to describe the method for producing a heavy concrete structure according to the present invention more specifically, but the present invention is not limited to the following examples.

<< Test Example 1 >>
(Weight mixture)
Concrete was produced as a weight mixture.
The materials are as follows.
Cement: Trade name Ordinary Portland cement, manufactured by Sumitomo Osaka Cement Co., Ltd. Fine aggregate: Electric furnace oxidation slag aggregate, density 3.83 g / cm ³
Coarse aggregate: electric furnace oxidation slag aggregate, density 3.73 g / cm ³
Metal fiber: Steel fiber, diameter 0.6 mm, length 30 mm, density 7.85 g / cm ³

525 kg of cement, 1456 kg of fine aggregate, and 945 kg of coarse aggregate were mixed for 30 seconds using a horizontal biaxial forced kneading mixer, and water was added to a water cement ratio of 32.4% for another 1 minute. The mixture was mixed for 30 seconds, steel fiber was added to 1.0% by volume, and the mixture was further mixed for 2 minutes to prepare concrete.
The content of fine aggregate in the concrete is 38% by volume, and the content of coarse aggregate in the concrete is 25% by volume.

(Lightweight mixture)
Mortar was prepared as a lightweight mixture.
The materials are as follows.
Cement: Trade name Ordinary Portland cement, manufactured by Sumitomo Osaka Cement Co., Ltd. Fine aggregate: Electric furnace oxidation slag aggregate, density 3.83 g / cm ³
Metal fiber: Steel fiber, diameter 0.6 mm, length 30 mm, density 7.85 g / cm ³

Cement 766 kg and fine aggregate 1533 kg were mixed for 30 seconds using a mixing device horizontal biaxial forced kneading mixer, water was added to a water cement ratio of 40%, and further mixed for 1 minute 30 seconds. The fiber was added to 3.0% by volume and mixed for another 2 minutes to prepare a mortar.
In addition, content in the mortar of a fine aggregate is 40 volume%.

Example 1
Each of the following measurements performed using these weight mixture and light weight mixture alone was defined as Example 1.

(Comparative Example 1)
As Comparative Example 1, the weight mixture of Example 1 and the light mixture of Example were blended in advance so as to have the mixing ratio (volume ratio) shown in Table 1, and the mixing apparatus horizontal biaxial forced kneading mixer Concrete was produced using The mixing method was the same as in the previous example.

(Measurement of unit volume mass)
The mass per unit volume of the concrete, the mortar, and the concrete of the comparative example was measured according to the unit volume mass test method of JIS A 1116 fresh concrete and the test method (mass method) based on the mass of air.

(Slump measurement)
Slumps of the obtained mixture and cement composition were measured according to a JIS A 1101 concrete slump test method.
The results are shown in Table 1.

As shown in Table 1, the slump was high when each of the weight mixture (A) and the light mixture (B) of Example 1 was used alone. In the case of such a slump, the pumping performance is good.
On the other hand, Comparative Example 1 in which A and B were mixed had a low slump. In the case of such a slump, pumping with a pump is impossible.
In Comparative Example 1, it was difficult to uniformly knead with a mixer regardless of the ratio, and mortar, coarse aggregate, and metal fibers were separated.

<< Test Example 2 >>
(Weight mixture)
Concrete was produced as a weight mixture. Using the same materials as in Test Example 1 above, 567 kg of cement, 1402 kg of fine aggregate, and 910 kg of coarse aggregate were mixed for 30 seconds using a mixing device horizontal biaxial forced kneading mixer, and water was added to the water cement ratio. It added so that it might become 30%, and also mixed for 1 minute and 30 seconds, and added steel fiber so that it might become 2.0 volume%, and also mixed for 2 minutes, and produced concrete.
The content of fine aggregate in the concrete is 37% by volume, and the content of coarse aggregate in the concrete is 24% by volume.

(Lightweight mixture)
Mortar was prepared as a lightweight mixture. Using the same materials as in Test Example 1 above, 816 kg of cement and 1632 kg of fine aggregate are mixed for 30 seconds using a mixing device horizontal biaxial forced kneading mixer so that the water has a water cement ratio of 30%. And then mixed for 1 minute and 30 seconds, and steel fiber was added so as to be 5.0% by volume, and further mixed for 2 minutes to prepare a mortar.
In addition, content in the mortar of a fine aggregate is 43 volume%.

(Example 2)
The following measurements performed using these weight mixtures and light weight mixtures alone were taken as Example 2.

(Comparative Example 2)
As a comparative example, the weight mixture of Example 2 and the light mixture of Example 2 were previously blended so as to have the mixing ratio (volume ratio) shown in Table 2, and the mixing apparatus horizontal biaxial forced kneading mixer Concrete was produced using The mixing method was the same as in Example 2.

As shown in Table 2, the slump was high when each of the weight mixture (A) and the light mixture (B) of Example 2 was used in the same manner as in Test Example 1 above. In the case of such a slump, the pumping performance is good.
On the other hand, Comparative Example 2 in which A and B are mixed has a low slump, and pumping with a pump is impossible in such a slump.
In Comparative Example 2, it was difficult to uniformly knead with a mixer regardless of the ratio, and mortar, coarse aggregate, and metal fibers were separated.

Claims (5)

0.1% to 5.0% by volume of metal fiber, 40% to 80% by volume of density 2.5 g / cm ^{3 to} 5.0 g / cm ^{3 of} aggregate, cement, and water A weight mixture containing, an aggregate, cement, and water, and a light weight mixture having a weight per unit volume smaller than that of the weight mixture, and transferring the weight mixture and the light weight mixture to the vicinity of the construction site, respectively. And the manufacturing method of the heavy concrete structure which manufactures a heavy concrete structure by inject | pouring the said weight mixture and the said lightweight mixture which were transferred into a construction location, respectively. The weight per unit volume of the weight mixture is 3.0 t / m ³ or more and 4.5 t / m ³ or less, and the weight per unit volume of the light mixture is 2.2 t / m ³ or more and 2.9 t / m ^3. The method for producing a heavy concrete structure according to claim 1, wherein: The method for producing a heavy concrete structure according to claim 1, wherein the metal fiber has a density of 7.0 g / cm ³ or more and 8.0 g / cm ³ or less.   The manufacturing method of the heavy concrete structure as described in any one of Claims 1 thru | or 3 which produces the said lightweight mixture so that a metal fiber may be contained 0.1 volume% or more and 5.0 volume% or less.   The heavy concrete structure manufactured with the manufacturing method of the heavy concrete structure as described in any one of Claims 1 thru | or 4.