JP3074576B2 - Method of manufacturing concrete products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete structure or a concrete product (structure) using ready-mixed concrete containing β-1,3 glucan and having high fluidity, high filling property and high separation resistance. In this specification, it includes a product and a product.

[0002]

2. Description of the Related Art As a method of constructing a concrete structure in a state where compaction is not required at the time of casting by imparting high fluidity and high filling property to concrete, a so-called "high performance" described in the civil engineering work October 1989 issue is known. concrete"
(Developed by Prof. Okamura, Faculty of Engineering, The University of Tokyo), or those using non-separable admixtures for underwater non-separable concrete have been developed.

[0003]

[Problems to be solved by the present invention] The above-mentioned prior art has the following problems. <B> In the case of high-performance concrete, it is necessary to use carefully selected materials, to keep the amount of powder very large, and to secure the separation resistance of concrete during flow by using a small amount of thickener. For this reason, very strict requirements are placed on the quality control and production control of the materials used, and it is extremely difficult to use concrete for compounding on site. <B> In the case of concrete using a water-immiscible admixture, the fluidity is poor, so that it is difficult to fill a densely arranged bar without compaction. In addition, a large amount of water reduces the watertightness, decreases the resistance to neutralization, increases the drying shrinkage, and reduces the resistance to freezing and thawing due to large air bubbles. There is.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a method for producing a concrete product using ready-mixed concrete having high fluidity, high filling property and high separation resistance. The purpose is to:

[0005]

SUMMARY OF THE INVENTION The present invention has been completed under the above circumstances. That is, the present invention is a method for producing a concrete product in which a ready-mixed concrete obtained by adding β-1,3-glucan and a high-performance water reducing material to a cement-based hardening material is filled in a certain space and hardened. . Next, the constituent material of the concrete used in the production method of the present invention will be described.

<Cement> Examples of cement used in the present invention include silica stone, diatomaceous earth, blast furnace slag,
Examples include various cements represented by Portland cement containing a modifying material such as fly ash or silica fume. The above-mentioned modifying material is an ultrafine powder, for example, a silica ultrafine powder such as silica fume (200,00
0 cm ² / g or more), a more favorable effect can be obtained. In other words, such an ultrafine powder has a large surface area because it is at least one order of magnitude smaller than the size of commonly used cements, and therefore has an increased viscosity and is necessary to ensure fluidity and filling properties. It is possible to reduce the use amount of the separation reducing agent. As a result of reducing the amount of the separation reducing agent used, it is possible to improve the compressive strength of the finished concrete.

<Β-1,3-glucan> β-1,3-glucan is a polysaccharide in which glucose is mainly bound by β-1,3-bonds. , Paramylon, pakiman, scleroglucan, laminaran, yeast glucan and the like. In the present invention, a curd run is particularly preferably used. As described in, for example, New Food Industry, Vol. 20, No. 49, pp. 49-57 (1978), curdlan is mainly composed of a β-1,3-glucoside bond, Usually, it is a polysaccharide having heat coagulability, that is, a polysaccharide having a property of coagulating (forming a gel) when heated in the presence of moisture.

[0008] Examples of such polysaccharides include polysaccharides produced by microorganisms of the genus Alcaligenes or Agrobacterium. Specifically, Alcaligenes fuecalis var myxogenes cells 10C3K
Polysaccharides produced by Agricultural Biological Chemistry (Agricultural
Biological Chemistry), 3rd
0, p. 196 (1966), or Alcaligenes eucalys var Myxogenes 10C3K
Polysaccharides (JP-B-48-32773) produced by the mutant strain NTK-u (IFO 13140), Agrobacterium radiobacter (IFO 13127)
And polysaccharides (JP-B-48-32674) produced by its strain U-19 (IFO 12126) and the like can be used. Card Run, as mentioned above,
Although it is a polysaccharide produced by a microorganism, in the present invention, it may be used without purification, or may be used after being highly purified, if necessary.

[0009] Paramylon also has a β-
It is a kind of 1,3-glucan, and a kind of storage polysaccharide that Euglena, a microorganism, accumulates in cells. Such paramylons are available, for example, from Carbohydrate Research (Carbohydrate).
Research), 25 , 231-242 (197).
9), JP-A 64-37297 or JP-A 1-3
It is already known from US Pat. However, unlike curdlan, the powder of paramylon does not have heat coagulability, so that it may be subjected to an alkali treatment if necessary in order to have heat coagulability. Paramylon may also be used in the present invention as it is without purification,
Alternatively, if necessary, it may be used after being highly purified. If β-1,3-glucan of microbial origin, in particular, curdlan or paramylon is treated with an alkali described below, a divalent or higher polyvalent metal ion such as calcium ion,
Β-1,3-glucan having a property of forming a metal ion crosslinked gel in the presence of magnesium ion, copper ion, iron ion, cobalt ion and the like can be obtained. Glucan having such a metal ion cross-linking gel forming ability,
A β-1,3-glucan of microbial origin is dissolved in an aqueous alkali solution, and the aqueous alkali solution is brought into contact with a water-soluble organic solvent to precipitate β-1,3-glucan, preferably neutralized to pH 6 to 7. Can be obtained by:

As another method for obtaining a metal ion crosslinked gel-forming β-1,3-glucan, an alkaline aqueous solution of the above β-1,3-glucan is frozen, and the frozen product is brought into contact with a water-soluble organic solvent. , Β-1,3-glucan by precipitation and neutralization. The glucan thus obtained may be dehydrated and dried into a powder, if necessary. In the above method, as a water-soluble organic solvent for precipitating glucan, an alcohol such as methanol is preferably used, and as an aqueous alkali solution for dissolving glucan, for example, sodium hydroxide, potassium hydroxide, An aqueous solution such as ammonium hydroxide is preferably used. The β-1,3-glucan thus obtained is, as described above,
For example, in the present invention, it is particularly preferably used as a molding aid in a composition in which calcium ions are present since it has a metal ion crosslinked gel forming ability. In the present invention, β-1,3-glucan acts as a separation reducing agent. That is, β-1,3-glucan increases the viscosity of the concrete, and as a result, can prevent the water and the aggregate contained therein from flowing and separating during the casting.

<High-performance water reducing agent> Examples of the high-performance water reducing agent used in the production method of the present invention include those which can be used for ordinary concrete. In the present specification, the high-performance AE water reducing agent and the superplasticizer are included. Shall be considered. Specific examples include naphthalene-based phthalamine-based formalin polycondensates and melamine-based, carboxylic acid-based, and lignin-based sulfonated melamine-formalin condensates. These materials are used to improve the fluidity and filling property of concrete with increased viscosity, and can reduce the water content by about twice that of a normal water reducing agent. Further, the ready-mixed concrete used in the production method of the present invention may contain various admixtures for the purpose of simply reducing the amount of water, entraining an appropriate amount of air, and the like. For example, AE
Agents, AE water reducing agents, water reducing agents, etc., and those for ordinary concrete can be used.

<Mixing method> The mixing method of the ready-mixed concrete of the present invention is basically the same as the conventional mixing method of concrete. This mixing can be carried out according to the usual method of adding water. In particular, a method of adding water in two portions and kneading the mixture can be more preferably employed. This method itself may be performed according to a method that is generalized as a split kneading method. Using this split kneading method,
The separation resistance of concrete is further improved. As a result, it is possible to reduce the amount of the separation reducing agent and the high-performance water reducing agent required to secure a predetermined fluidity, separation resistance and filling property. In addition, a method in which a solid ready-mixed concrete containing β-1,3-glucan is prepared, and a high-performance water reducing agent is added and kneaded immediately before casting, and a separated liquid containing the high-performance water reducing agent is mixed. A method in which β-1,3-glucan is added to concrete and kneaded and mixed to prepare ready-mixed concrete, or after preparing ordinary ready-mixed concrete, β-1,3-glucan and a high-performance water reducing agent are added simultaneously or sequentially. Any method such as a kneading method may be used.

The above-mentioned method for filling the ready-mixed concrete includes a method of pouring the concrete itself or the form while applying light vibration, a method of pressing the form from the bottom of the form and filling the ready-mixed concrete to the upper part, and a method of filling the ready-mixed concrete. The method of filling the formwork by spraying down or falling down on the wall of the container, flowing down the ready-mixed concrete along the wall of the formwork, or flowing down directly from one opening or using a guide tube (tremy tube) or Any method may be adopted as long as the method fills the container with a fluid, such as a method of dropping and filling. Further, a conventional method of filling ready-mixed concrete, for example, a method of giving strong vibration to concrete or a formwork may be used. Furthermore, when the method of pouring the ready-mixed concrete of the present invention into the upper part, the lower part, the side part or the gap of the already hardened concrete is carried out, the unevenness of the hardened concrete can be filled without gaps. The method of filling the ready-mixed concrete of the present invention described above can be similarly performed in water. When filling the ready-mixed concrete of the present invention into a formwork, it is desirable that the formwork be hermetically sealed so that air can partially escape so as to prevent leakage of the ready-mixed concrete.

<Examples of Formulation> Preferred compositions of the concrete of the present invention will be described below. In the following description, the binding material refers to a mixture of cement and its modifying material. For the binder material (250-700 kg / m ³ per unit volume of concrete as the total amount of Portland cement, fly ash and blast furnace slag), β-
1,3-glucan is contained in an amount of 0.01 to 1.0% by weight, more preferably 0.2 to 1.0% by weight, and a high-performance water reducing agent of 0.2 to 1.0%.
6.0 wt%, more preferably in the range of 0.5 to 3.0 wt%. In the case where a silica-based ultrafine powder such as silica fume is used in place of a part of the binder, it is preferable that the silica-based powder in the binder be about 6 to 30% by weight. For example, a unit binding material (a total amount of Portland cement, fly ash and blast furnace slag is 350 to 800 kg / unit volume of concrete).
m ³ ) The unit amount of silica fume is 50 to 100 k
g / m ^3, and 0.02-1.
0% by weight and the high-performance water reducing agent in the range of 0.5 to 3% by weight.

[0015]

The concrete of the present invention does not need to be compacted by a vibrator when poured into a certain space because it does not separate as a whole and exhibits the properties of a muddy liquid. Even if a vibrator fixed to the form is slightly applied, the concrete can be easily filled into every corner of the form without separating the aggregate in a short time. Therefore, the form may have a complicated shape, the form of the form is not limited by the fluidity of the concrete, and the casting can be performed in a closed space or a wide space where the vibration device cannot reach. . Since no vibration is required, the maintenance of worker's health and the preservation of the environment are greatly improved. Also, since material separation such as breathing does not occur even after completion of concrete casting, it is possible to construct a uniform and highly durable concrete structure or manufacture a precast member or the like even in a space having a complicated shape. . The “constant space” is a space configured by combining plate bodies (forms) in a state surrounding the outer shape of the structure. The "concrete product" of the present invention can have a volume ranging from a few cubic meters such as a concrete member to a huge one such as a building, a dam or a tank.

[0016]

Example 1 Using the concrete of the present invention having the following composition, tests of fluidity, filling property and separation resistance were carried out.

[Table 1]

For testing the characteristics, concrete 1 of the present invention was poured into a formwork 2 having a plurality of reinforcing bars 21 arranged at a minimum interval of 35 mm as shown in FIG. The mold 2 has a height of 500 mm, a width of 825 mm, and a slope 22.
A part of the top of which was covered with a varnish was used. According to this experiment, the concrete 1 could be densely filled into the form after about 99 seconds without any vibration by simply pouring the concrete 1 into the form 2. (FIGS. 1 to 4)

Next, a test was conducted to examine the strength and durability of the same composition. The resulting data is shown in the following table.

[Table 2] The above values are equivalent to ordinary concrete, and no decrease in durability is observed. The salt penetration resistance, seawater resistance, chemical resistance, neutralization resistance, etc. are sufficiently superior to ordinary concrete. <Comparison of compressive strength> The compressive strength of a concrete product manufactured without giving a vibration was compared with the compressive strength of a general concrete product. The following two types of concrete were poured into the concrete wall form shown in FIG. 5, and after 28 days, a core sample was taken from the position shown in the figure to conduct a compressive strength test. <1> Additives such as the above-mentioned separation reducing agent and high-performance water reducing agent were added, and no vibration was given to the ready-mixed concrete (the concrete of the present invention). <2> The above additives were not added (concrete without addition of separation reducing agent, conventional concrete), but vibration was applied. The results are shown in FIG. 6. When the concrete of the present invention was used, no change was observed in the compressive strength at all positions of the concrete product even when no vibration was applied, and the vibration was applied. It was found that the compressive strength was higher than in the examples.

[0019]

(About fineness 3250Cm ² / g) Example 2] In general commercially available ordinary portland cement, the following table with different ground granulated blast furnace slag (4300Cm about ² / g) and fly ash (3000 cm about ² / g) weight The kneading test of concrete was performed for the five types of blends, and the slump flow was measured and the filling test was performed. For the filling test, a U-shaped container as shown in FIG. 7 was used. One side of this container is a concrete filling room A and the other side is a measurement room B, and a communication window is opened at the lower part of both rooms. Reinforcing bars are provided at intervals of 35 mm in the communication window, and are closed by a shutter until the start of the test. At the time of the test, fill the A filling room with the concrete to be tested, lift the shutter, and
The height dimension H of the concrete into the measuring chamber is measured and used as a criterion for determining the filling property. In this test, the conventional ready-mixed concrete did not move from the A filling room to the B filling room because it was blocked by the reinforcing bars (35 mm intervals) of the communication window.

The results are as shown in the lower right column of the following table. According to this evaluation test method for a combination of binders having such a particle size, a unit binder material for obtaining good fluidity and filling property was obtained. The minimum amount of (cement + blast furnace slag fine powder + fly ash) is 400 kg / m ³ (2
00 + 200 + 0) or more. This is intended for the filling property in the case of a multi-stage arrangement of reinforcing bars having a net spacing of 35 mm. When the net spacing of the reinforcing bars is larger than this, the minimum amount of the unit binding material is 350 kg / m ^3. It can be reduced to the extent.

[Table 3]

[0021]

Example 3 The following table shows the composition and test results when silica fume was used in place of fly ash in Example 2. In this table, the formulation No. 1 is a reference composition. On the other hand, No. 2-No. No. 5 is a case where fly ash is not used at all and is replaced with silica fume. As a result, the necessary amount of the binder (C + B + SF) is 4
It turned out that about 50 kg / m ³ is sufficient. The reason for this is that with such a binder material, the fluidity exhibited by the slump flow is slightly reduced, but on the other hand, the filling property is extremely good, and the filling height is sufficiently maintained.

[Table 4]

[0022]

EXAMPLE 4 A test was conducted on the filling state when fresh concrete was poured from the lower part of the enclosed space, that is, near the bottom of the mold. Here, the enclosed space is the inside of a mold formed by assembling a plate along the outer shape of a target structure. Therefore, the size of this space varies depending on the shape of the target structure, and it can cover a small building of several meters cubic to a huge building, tank, tower, or the like. <Specimen> As shown in FIG. 8, the specimen was a column-shaped formwork 4 having a height of 3.6 m, and the column had a cross section of 600 mm × 60 mm.
0 mm. Inside the column formwork 4, an iron plate in the direction of the cross section was attached as a reinforcing plate 5 at 900 mm pitch. At the center of the reinforcing plate 5, a passage opening 6 having a diameter of 180 mm is provided.
An air vent hole 7 having a diameter of 30 mm was opened in the corner.

<Concrete Mixing> Concrete having the following mixing ratio was used.

[Table 5] <Press-fitting condition> According to the press-fitting amount from the lower portion of the formwork, the ready-mixed concrete rose while maintaining a substantially horizontal surface, and was sufficiently filled in the lower surface and the upper surface of the reinforcing plate 5. (FIG. 9) After hardening of the concrete, the mold 4 was dismantled. Then, the state of filling of concrete above and below the reinforcing plate 5 was observed from the outside. As a result, it was found that the surface of the mold 4 farthest from the passage opening 6 was sufficiently filled, and that no gap was present. next,
Concrete was cut at the upper and lower parts of each reinforcing plate 5 to observe the state of filling inside. As a result, it was found that completely uniform concrete was filled over the entire surface up to the lower corners of the reinforcing plate 5 which were extremely difficult to fill.

<Compressive Strength> A test specimen was cut from the hardened concrete, and a test for compressive strength was performed. The results are as shown in the following table, and it was found that the strength was sufficient.

[Table 6]

[0025]

Embodiment 5 Using a steel plate form as shown in FIG.
Synthetic concrete products were manufactured. “Synthesis” is a structure in which concrete and a steel plate are integrally formed, and effectively utilizes the compressive strength of the concrete and the tensile strength of the steel plate. Therefore, the formwork is not dismantled but becomes a part of the concrete product. Inner / outer formwork 8, 9
A number of bolts are protrudingly provided as dowels 10 on the inner side. Further, the inner and outer forms are connected by a number of trusses 11. The ready-mixed concrete having the above-described composition is poured into the surrounding space from below. Then, since the above-mentioned ready-mixed concrete has extremely good fluidity, even if many steel materials intersect inside, it can be sufficiently filled to every corner without obstructing the fluidity. Further, since the separation resistance is high, the aggregate does not separate during the flow. Furthermore, since breathing does not occur even after the completion of the casting, a synthetic product having uniform quality and high durability can be manufactured.

[0026]

Embodiment 6 The ready-mixed concrete as described above is sprayed onto a wall surface from a distance or dropped, dropped, and filled into a concrete product form. Here "spray"
The method of colliding ready-mixed concrete against the surface of the object using compressed air and attaching it, "falling" is a method of filling the inside of the form by freely dropping the ready-mixed concrete inside the formwork, etc. Is a method of making a temporary passage, placing concrete in the passage, and pouring it into the target formwork. In the case of conventional concrete, in this method, only the aggregate having a large specific gravity jumps out of the mortar or collides with a formwork or a wall surface and scatters around. However, according to the production method of the present invention, such separation does not occur even when spraying from a distance or flowing down or dropping from a high place. <Comparison of scattering rates> For that purpose, comparison of the scattering rates was performed. One liter of each of the concrete having high separation resistance and the conventional concrete to which the separation reducing agent was not added was dropped on the floor from a predetermined height. Then, the weight (W2) of the portion remaining at the center without being scattered around was measured. Then, the weight reduced from the initial weight (W1) was obtained, and the result was obtained as the scattering loss rate (%) = (W1−W2) / W1.

[Table 7]

As is evident from the results in the above table, it was found that the use of the concrete of the present invention resulted in a very small scattering loss rate despite the free fall.
Therefore, even a worker with little skill in spraying concrete can spray the wall surface in a substantially uniform state, similarly to a skilled worker. <Comparison of compressive strength>
Types of concrete are dropped from a height of 5 meters,
Or it was cast directly. (1) Concrete (high-fluidity concrete, concrete of the present invention) to which a separation reducing agent was added was dropped. (2) Concrete (conventional concrete) to which no separation reducing agent was added was dropped. (3) Concrete to which no separation reducing agent was added (conventional concrete) was carefully filled in a formwork and vibrated to compact it. FIG. 12 shows the results of comparing the compressive strengths of the above three types of concrete products by taking samples 28 days after the casting. As a result, it was found that the compressive strength of a product manufactured by dropping ready-mixed concrete according to the method of the present invention was almost the same as the compressive strength of a concrete product vigorously filled with fresh concrete and subjected to vibration. On the other hand, it was also found that the concrete dropped without the separation reducing agent was not practically practical, judging from the compressive strength. A similar effect can be obtained even by a method of spraying ready-mixed concrete onto a wall surface.

[0028]

Embodiment 7 Concrete products are joined by using ready-mixed concrete to which the above-mentioned separation reducing agent is added.
Jointing is the work of placing ready-mixed concrete in contact with hardened concrete and combining them. Since concrete generally shrinks during or after hardening, it is most difficult to cast new concrete under the hardened concrete to integrate them. Therefore, as shown in FIG. 13, a fresh concrete C2 is newly placed under the already hardened concrete C1.
Will be described. Such a method is, for example, when excavating a shaft and reinforcing it.
It is used when placing fresh concrete below the previous concrete. Since the concrete used in the method of the present invention has good fluidity and excellent filling properties, it can be sufficiently filled into every corner of the lower surface of the already hardened concrete. In addition, since the separation resistance of the concrete is large, no breathing water is generated, and the upper surface of the jointed concrete C2 does not lower. Therefore, there is no defective portion on the boundary surface, and good integrity can be obtained. <Splice strength test> Next, the results of the tensile strength of the seam of the product manufactured by the method of the present invention and the seam manufactured by using the conventional ready-mixed concrete were compared. As the already hardened concrete C1, a one year old concrete was used.

[Table 8] The above is a comparison at the horizontal seam, and the results obtained by comparing the tensile strength and the hydraulic conductivity of the core sampled at the vertical seam are as follows.

[Table 9] As is clear from the above results, it was found that the product manufactured by the manufacturing method of the present invention not only improved the joint strength but also improved the permeability, which is a weak point of the joint, by one digit.

[0029]

Embodiment 8 Underwater concrete is cast using fresh concrete to which the above-mentioned separation reducing agent is added. In this case, no special device is required, and a method can be employed in which a tremy pipe is used as in the conventional case, and ready-mixed concrete is charged from the upper end thereof. The tip of the tremy pipe should be located at the bottom of the underwater formwork or at the bottom of the excavated trench. The concrete poured in this way spreads out gradually in a plane. When the spread concrete reaches a certain thickness, it rises while keeping its horizontal surface underwater. Therefore, the first part cast is always located at the top, and the top surface is kept horizontal, so the slime and stabilizing liquid will rise with it placed on it, No involvement. Therefore, it is possible to cast uniform and high quality underwater concrete. <Comparison of fluidity> The fluidity of conventional concrete and the concrete used in the method of the present invention in underwater casting were compared. For this purpose, a plurality of colored ready-mixed concretes were used and poured underwater with a tremy pipe. Then, after curing, a plurality of cores were collected, and the fluidity in the vertical direction was estimated.
The results are shown in FIG. 14. It is clear that the freshly poured concrete G initially cast is pushed upward while maintaining the horizontal layer as it is, and the blue B, red R, etc. are maintained as substantially horizontal layers hereinafter. all right.

[0030]

Embodiment 9 First, general concrete, that is, ready-mixed concrete in which no separation reducing agent is added, is manufactured in a concrete factory. Therefore, at this stage, the conventional concrete factory can be used without any modification. The ready-mixed concrete produced in this way is transported to the site where it is poured by a mixer truck. The above-described separation reducing agent is injected into the mixer truck that has arrived at the casting site immediately before casting. Although the separation reducing agent is in the form of a powder, it does not dissolve in water and thus has good dispersibility, and is sufficiently dispersed and mixed in the kneaded ready-mixed concrete. <Comparison of dispersibility> Next, a test was conducted to confirm that the effect of the separation reducing agent was substantially the same whether added at the time of mixing the concrete or immediately before casting.

[Table 10] In producing the above concrete, the separation reducing agent was added at the same time as the kneading and the addition at the casting site, and the results were compared.

[Table 11] As is clear from this table, the slump flow and air amount similar to the simultaneous addition method are obtained in the method of the present invention. Therefore, despite the use of special ready-mixed concrete, it is extremely practical that it can be manufactured without requiring special equipment. Further, unless concrete concrete plants are rented out for one day, other types of ready-mixed concrete will be produced one after another, but they can be produced by a usual method without considering the relationship with other concrete.

[0031]

According to the present invention, the following effects can be achieved as described above. <A> It is possible to manufacture products with complicated shapes by using ready-mixed concrete with high separation resistance, high fluidity and high filling properties. During the filling, the concrete does not separate, but flows to every corner of the space while holding water and aggregate uniformly. further,
Does not shrink when cured. Therefore, it is possible to manufacture a product in which a complicated shaped obstacle protrudes inside the mold. <B> The concrete can be filled to the end of the form only by pouring it without giving any vibration to the ready-mixed concrete. Therefore, it is possible to easily manufacture a product that is not subjected to vibration. In addition, the personnel required for compaction is no longer necessary,
Labor saving of work is possible. Since human intervention can be omitted that much, concrete mechanization and robotization of concrete work become possible. <C> Separation of materials due to insufficient compaction can be prevented, and material separation due to excessive compaction can also be prevented. Therefore, it is possible to produce concrete products having high water tightness and durability, and uniform and stable quality. <D> Compared to other concretes having high separation resistance, there is no need to carefully select materials to be used, so any material that meets the standard can be used. Therefore, excessive quality control is not required, and it can be widely applied in general fields. <E> Can be used for the production of prestressed concrete members by compaction without vibration.

<F> As shown in Examples 4 and 5, a method of injecting ready-mixed concrete having the above-described composition into the enclosed space from below can be adopted. Then, because the above-mentioned ready-mixed concrete has extremely good fluidity,
Even if a large number of steel materials intersect inside, it can be filled to every corner without impairing the fluidity. Further, since the separation resistance is high, the aggregate does not separate during the flow. Furthermore, since breathing does not occur even after the completion of the casting, a synthetic product having uniform quality and high durability can be manufactured. <G> As shown in Embodiment 6, the product can be manufactured by dropping from a high position or spraying from a distance.
In the method of the present invention, it was found that the scatter loss rate to the surroundings was extremely low despite the free fall from a high position. Therefore, even a worker with little skill in spraying concrete can spray the wall surface in a substantially uniform state, similarly to a skilled worker. <H> As shown in Embodiment 7, a method of joining concrete products can be adopted. In particular, this is not the case where the ready-mixed concrete is placed on the existing concrete, but the case where the ready-mixed concrete is cast below the lower surface of the existing concrete. Such a method is used, for example, when fresh concrete is poured into the lower part of the previous concrete, such as when reinforcing a shaft while excavating a shaft. Since the concrete used in the method of the present invention has good fluidity and excellent filling properties, it can be sufficiently filled into every corner of the lower surface of the already hardened concrete. In addition, since the concrete has high separation resistance, no breathing water is generated, and the upper surface of the jointed concrete C2 does not sink. Therefore, there is no defective portion on the boundary surface, and good integrity can be obtained.

<I> As shown in Embodiment 8, a method of casting a submerged concrete to produce a product can be adopted. The concrete poured in this way spreads out gradually in a plane. When the spread concrete reaches a certain thickness, it rises while keeping its horizontal surface underwater. Therefore, the first part cast is always located at the top, and the top surface is kept horizontal, so the slime and stabilizing liquid will rise with it placed on it, No involvement. Therefore, it is possible to cast uniform and high quality underwater concrete. <N> As shown in Example 9, first, a concrete with a normal composition containing no separation reducing agent was manufactured, and the above-described separation reducing agent was injected into a mixer truck that had arrived at the casting site immediately before casting. Can be adopted. Although the separation reducing agent is in the form of a powder, it does not dissolve in water and thus has good dispersibility, and is sufficiently dispersed and mixed in the kneaded ready-mixed concrete. As is clear from Table 11, the slump flow and air amount similar to those of the simultaneous addition method are obtained in the method of the present invention. Therefore, despite the use of special ready-mixed concrete, it is very practical to be able to manufacture without the need for special equipment. Unless the concrete factory is rented out for one day, other types of ready-mixed concrete will be manufactured one after another, but can be manufactured in a usual manner without considering the relation with other concrete.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a fluidity test of concrete used in the production method of the present invention.

FIG. 2 is an explanatory view of a fluidity test of concrete used in the production method of the present invention.

FIG. 3 is an explanatory view of a fluidity test of concrete used in the production method of the present invention.

FIG. 4 is an explanatory view of a fluidity test of concrete used in the production method of the present invention.

FIG. 5 is a location diagram of a sample for a compressive strength test.

FIG. 6 is a comparison diagram of a compressive strength test.

FIG. 7 is an explanatory view of a filling test apparatus.

FIG. 8 is an explanatory diagram of an experiment of pouring concrete into an enclosed space.

FIG. 9 is an explanatory view of a rising state of concrete.

FIG. 10 is an explanatory diagram of a composite structure.

FIG. 11 is an explanatory view of an experiment in which concrete is dropped from a high place.

FIG. 12 is an explanatory diagram of a comparison of compressive strength of dropped concrete.

FIG. 13 is an explanatory diagram of a joint test of concrete.

FIG. 14 is an explanatory view of a distribution state of concrete poured into water.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification code FI C04B 14:38) 111: 72 111: 74 (31) Priority claim number Japanese Patent Application No. 2-165378 (32) Priority date 1990 June 22 (1990.6.22) (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 2-172814 (32) Priority date July 2, 1990 (1990. 7.2) (33) Priority claim country Japan (JP) (31) Priority claim number Japanese Patent Application No. 2-165379 (32) Priority date June 22, 1990 (1990.6.22) (33) Priority claim country Japan (JP) (72) Inventor Takefumi Shindo 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Inside Taisei Corporation (72) Inventor Jun Sakamoto 1--25, Nishishinjuku, Shinjuku-ku, Tokyo No. 1 Taisei Construction Co., Ltd. (72) Inventor Somnouk Tang Therm Siricle 1-25-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo (56) References JP-A-1-12345 (JP, A) JP-A-2-217345 (JP, A) JP-A-5-32447 (JP, A) JP-A-4-367550 ( JP, A) JP-A-3-285857 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C04B 28/02 C04B 24/38 C04B 111: 72 C04B 111: 74

Claims (7)

(57) [Claims] (1) A method for producing a concrete product, comprising: filling a predetermined space with a ready-mixed concrete obtained by adding a β-1,3-glucan and a high-performance water reducing agent to a cement-based hardening material and curing the mixture. 2. The method for producing a concrete product according to claim 1, wherein the shape of the structure is surrounded by a plate body, and ready-mixed concrete is poured from a lower portion of the surrounding space. 3. The method for producing a concrete product according to claim 1, wherein the fresh concrete is sprayed. 4. A method in which the ready-mixed concrete is dropped and dropped.
A method for producing a concrete product according to claim 1. 5. The method for producing a concrete product according to claim 1, wherein the ready-mixed concrete is transferred to hardened concrete. 6. The method for producing a concrete product according to claim 1, wherein the ready-mixed concrete is cast in water. 7. The method for producing a concrete product according to claim 1, wherein β-1,3-glucan or a high-performance water reducing agent is added to the cement-based hardening material after the production of the ready-mixed concrete.