JPH059053A - Manufacture of concrete product - Google Patents

Abstract

PURPOSE:To improve the fluidity, filling property, durability, quality stability and reduction of labor by filling into a specified space the raw concrete obtained by adding beta-1,3-glucan (beta-G), etc., to a cement hardener. CONSTITUTION:A mold frame 4 for a pillar body, etc., by assembling sheet bodies along an outer form of a desired structure, is obtained. Next, reinforced plates 5 of an iron sheet, etc., are attached in the inside of the frame 4 with a desired pitch and passing ports 6 are provided in the center of the sheets 5 and air passage holes 7 are opened in the four corners. Next, Portland cement is compounded with a high-performance water reducing agent such as a naphthalene sulfonic acid-formalin high condensate with the beta-G to obtain the raw concrete. Subsequently, the raw concrete is injected from a lower place of the frame 4 with a high pressure to harden it and the concrete is manufactured.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a concrete structure or a concrete product (structure) using a fresh concrete containing β-1,3 glucan and having high fluidity, high filling property and high separation resistance. And a product are referred to as "products" in this specification).

[0002]

2. Description of the Related Art As a method of constructing a concrete structure in which concrete is provided with high fluidity and high filling property without needing compaction at the time of placing, so-called "high performance" described in Civil Engineering Construction October 1989 issue. concrete"
(Developed by Professor Tsukasa Okamura, Faculty of Engineering, University of Tokyo), or those using the non-separable admixture used for water-separable concrete.

[0003]

Problems to be Solved by the Present Invention The above-mentioned conventional techniques have the following problems. <a> In the case of high-performance concrete, it is necessary to use materials that are carefully selected, have a very large amount of powder, and use a small amount of a thickening agent to secure the separation resistance when the concrete flows. Therefore, the quality control and the production control of the materials used are required to be very strict, and it is considerably difficult to use it for concrete which is mixed on site. <B> Concrete using the water-separable admixture has poor fluidity, and therefore it is difficult to fill the overcrowded member without compaction. In addition, since the unit water content increases, the watertightness decreases, the resistance to neutralization decreases, the drying shrinkage increases, and the large air bubbles cause the resistance to freeze-thawing and decrease the durability. 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 a fresh concrete having a high fluidity, a high filling property and a high resistance to separation. The purpose is to

[0005]

The present invention has been completed under the above circumstances. That is, the present invention is a method for producing a concrete product, which is carried out by filling a cement-based hardening material with β-1,3-glucan and raw concrete containing a high-performance water-reducing material in a certain space and hardening the same. . Next, the constituent materials of concrete used in the manufacturing method of the present invention will be described.

<Cement> Examples of the cement used in the present invention include silica stone, diatomaceous earth, blast furnace slag,
There can be mentioned various cements represented by Portland cement containing modifying materials such as fly ash and silica fume. The above-mentioned modifying material is an ultrafine powder, for example, a siliceous ultrafine powder (200,00).
0 cm ² / g or more) is used together to obtain a more preferable effect. That is, since such ultrafine powder has a large surface area because it is smaller than the size of commonly used cements by one order or more, it has an increased viscosity and is necessary for ensuring fluidity and filling property. It is possible to reduce the amount of the separation reducing agent used. As a result of the decrease in 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, and specifically, curdlan , Paramylon, pakiman, scleroglucan, laminaran, yeast glucan, and the like. In the present invention, curdlan is particularly preferably used. Curdlan is, for example, New Food Industry, Volume 20, Vol. 1
No. 0, pp. 49-57 (1978), a polysaccharide mainly composed of β-1,3-glucoside bonds and having heat coagulability, that is, heating in the presence of water. Is a polysaccharide having the property of coagulating (forming a gel).

Examples of such polysaccharides include polysaccharides produced by microorganisms of the genera Alcaligenes or Agrobacterium. Specifically, Alcaligenes fuecalis, Bur Myxogenes bacterium 10C3K
Polysaccharides produced by (Agricultural Biological Chemistry (Agricultural
Biological Chemistry), No. 3
Volume 0, page 196 (1966), or Alcaligenes fuecalis bar Myxogenes bacterium 10C3K
Polysaccharide produced by the mutant strain NTK-u (IFO 13140) (Japanese Patent Publication No. 48-32673), Agrobacterium radiobactor (IFO 13127) and its variant U-19 (IFO 12126). Sugars (Japanese Patent Publication No. 48-32674) and the like can be used. Curdlan, as described above, is a polysaccharide produced by a microorganism, but in the present invention, it may be used as it is in an unpurified state, or if necessary, highly purified before use. May be.

Paramylon also has β-
It is a kind of 1,3-glucan, and is a kind of a storage polysaccharide accumulated in cells by a microorganism, Euglena. Such paramylon can be obtained, 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 Japanese Patent No. 7297. However, unlike curdlan, the powder of paramylon does not have heat-coagulability, and therefore may be treated with an alkali, if necessary, in order to have heat-coagulability. Paramylon may also be used in the present invention in an unpurified form,
Alternatively, it may be highly purified before use. When β-1,3-glucan of microbial origin, especially curdlan or paramylon is treated with an alkali described below, a divalent or higher polyvalent metal ion such as calcium ion,
It is possible to obtain β-1,3-glucan having a property of forming a metal ion cross-linked gel in the presence of magnesium ions, copper ions, iron ions, cobalt ions and the like. A glucan having such metal ion cross-linking gel forming ability is
Microorganism-derived β-1,3-glucan is dissolved in an alkaline aqueous solution, and the alkaline aqueous 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 the metal ion-crosslinking 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 is precipitated and neutralized. The glucan thus obtained may be dehydrated and dried in powder form, if necessary. In the above method, the aqueous solution organic solvent for precipitating the glucan is preferably an alcohol such as methanol, and the alkaline aqueous solution for dissolving the glucan is, for example, sodium hydroxide, potassium hydroxide or water. An aqueous solution of ammonium oxide or the like is preferably used. The β-1,3-glucan thus obtained is, as described above,
For example, in the present invention, since it has the ability to form a metal ion cross-linked gel, it is particularly preferably used as a molding aid in a composition in which calcium ions are present. In the present invention, β-1,3-glucan acts as a separation reducing agent. That is, β-1,3-glucan increases the viscosity of concrete, and as a result, it is possible to prevent the fluidity of water and aggregate contained therein and the separation during pouring.

<High-performance water reducing agent> Examples of the high-performance water reducing agent used in the production method of the present invention include those that can be used in ordinary concrete. In the present specification, a high-performance AE water reducing agent and a superplasticizer are included. Let's assume. Specific examples include naphthalene-based compounds represented by a high-condensation product of naphthalenesulfonic acid formalin, and melamine-based, carboxylic acid-based and lignin-based compounds which are sulfonated melamine formalin condensates. These materials are used to improve the fluidity and filling properties of concrete having an increased viscosity, and can reduce the water content by about twice as much as 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 green concrete of the present invention is basically the same as the mixing method of conventional 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 and mixing can be more preferably adopted. This method itself may be carried out according to a generalized method as a divided kneading method. With 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 liquid medicine used for ensuring the predetermined fluidity, separation resistance, and filling property. In addition, after preparing a solid fresh concrete containing β-1,3-glucan,
A method of adding a high-performance water reducing agent just before pouring and kneading, a method of adding β-1,3-glucan to separated liquid concrete containing a high-performance water reducing agent, and kneading to obtain raw concrete or After preparing the fresh concrete, the β-1,3-glucan and the high-performance water reducing agent may be added simultaneously or sequentially and mixed, and any method may be used.

The method of filling the above-mentioned fresh concrete is the method of pouring into the concrete itself or the mold while giving a slight vibration, the method of press-fitting from the lower part of the form and pushing up the fresh concrete to the upper part, and filling the fresh concrete. Method of spraying down the vessel wall to flow down or dropping to fill the mold, flowing down fresh concrete along the wall of the mold, or flowing down directly from one opening or using a guide tube (Tremy tube) or Any method may be adopted as long as it is a method of filling a container with a fluid, such as a method of dropping and filling. Alternatively, a conventional filling method of green concrete, for example, a method of giving strong vibration to concrete or a form may be performed. Furthermore, when the method of pouring the fresh concrete of the present invention into the upper portion, the lower portion, the side portion, or the gap of the already hardened concrete is performed, even the uneven portions of the hardened concrete can be filled without any gap. The above-described method for filling fresh concrete according to the present invention can be performed in water as well. When the ready-mixed concrete of the present invention is filled in the form, it is desirable that the form is hermetically sealed so that air can escape partially in order to prevent leakage of the ready-mixed concrete.

<Mixing Example> A preferable composition of the concrete of the present invention is shown below. In the following description, the binding material refers to a mixture of cement and its modifying material. For the binding 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-
0.01 to 1.0% by weight of 1,3-glucan, more preferably 0.2 to 1.0% by weight, and 0.2 to 1.0% of a high-performance water reducing agent.
The amount is 6.0% by weight, more preferably 0.5 to 3.0% by weight. Further, when a silica-based ultrafine powder such as silica fume is used by substituting a part of the binder, it is preferable that the silica-based powder in the binder is about 6 to 30% by weight. For example, unit binding material (portland cement, fly ash, and blast furnace slag as a total amount of concrete per unit volume of 350 to 800 kg /
The unit amount of silica fume is 50 to 100 k with respect to m ³ ).
g / m ³ and β-1,3-glucan 0.02 to 1.
0% by weight, and the superplasticizer is in the range of 0.5 to 3% by weight.

[0015]

The concrete of the present invention does not separate as a whole and exhibits a property as a mud-like liquid, so that it does not require compaction by a vibrator when it is placed inside a certain space. As a result, concrete can be easily filled into every corner of the mold by only applying a vibrator fixed to the mold, without separating the aggregate in a short time. Therefore, the mold may have a complicated shape, the shape of the mold is not restricted by the fluidity of concrete, etc., and it is possible to place in a closed space or a wide space where the vibration device cannot reach. . Since no vibration is required, the health of workers and the preservation of the environment are greatly improved. In addition, since material separation such as breathing does not occur even after the completion of concrete pouring, it is possible to construct a concrete structure with high quality and high durability or to manufacture precast members even in a space with a complicated shape. . The "constant space" is a space formed by combining plate bodies (forms) so as to surround the outer shape of the structure. The volume thereof ranges from several cubic meters such as concrete members to huge ones such as buildings, dams and tanks, and can be a target of the "concrete product" of the present invention.

[0016]

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

[Table 1]

In order to test the characteristics, concrete 1 of the present invention was placed in a mold 2 having a large number of reinforcing bars 21 arranged at a minimum interval of 35 mm as shown in FIG. The formwork 2 has a height of 500 mm, a width of 825 mm, and a slope 22.
A part of the upper part of the heavens was covered by. According to this experiment, by simply pouring the concrete 1 into the form 2, it was possible to densely fill the form 1 with the concrete 1 after about 99 seconds without giving any vibration. (Figs. 1-4)

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 deterioration in durability is observed. The salt penetration resistance, seawater resistance, chemical resistance, neutralization resistance, etc. are sufficiently superior to those of ordinary concrete. <Comparison of compressive strength> The compressive strength of concrete products manufactured without vibration was compared with the compressive strength of general concrete products. The following two types of concrete were placed on the concrete wall formwork shown in FIG. 5, and after 28 days, core samples were taken from the positions shown in the figure and a compressive strength test was conducted. <1> Additives such as the above-mentioned separation reducing agent high-performance water reducing agent were added, and vibration was not given to the green concrete (concrete of the present invention). <2> The above additives were not added (concrete containing no separation reducing agent or the like, conventional concrete), but vibration was applied. The results are shown in FIG. 6, and in the case where the concrete of the present invention was used, there was no change in the compressive strength at all positions of the concrete product, and vibration was applied, even though no vibration was applied at all. It was found that the compressive strength was higher than the example.

[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 mixed mixing test of concrete was carried out for the five types of the above, and the slump flow was measured and the filling test was carried out. A U-shaped container as shown in FIG. 7 was used for the filling test. One side of this container is a concrete filling chamber A, the other side is a measuring chamber B, and communication windows are opened in the lower part of both chambers. Reinforcing bars are provided in the communication window at intervals of 35 mm and are closed by a shutter until the start of the test. During the test, fill the A filling chamber with the concrete to be tested, pull up the shutter, and press the B
The rising dimension H of the concrete to the measuring chamber is measured and used as a criterion for the filling property. In this test, the conventional ready-mixed concrete did not move from the A-filling chamber to the B-filling chamber because it was blocked by the reinforcing bars (35 mm intervals) in the communication window.

The results are shown in the lower right column of the following table. According to this evaluation test method for the combination of the binders having such particle sizes, the unit binder material for obtaining good fluidity and filling property is 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 rebar having a pure rebar spacing of 35 mm, but when the pure rebar spacing is larger than this, the minimum amount of the unit bonding material is 350 kg / m ^3. It can be reduced to a certain degree.

[Table 3]

[0021]

Example 3 The following table shows the composition and test results when silica fume was used instead of fly ash in Example 2. In this table, the formulation No. 1 is the standard formulation. On the other hand, No. 2 to No. In No. 5, fly ash was not used at all and silica fume was used as a substitute. As a result, the required amount of binder (C + B + SF) is 4
It was found that about 50 kg / m ³ is sufficient. This is because it has been found that with this level of bonding material, the fluidity indicated by 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 filling state test was performed when fresh concrete was poured from the lower part of the enclosed space, that is, near the bottom of the mold crushing. The space enclosed here is the inside of the mold formed by assembling the plate bodies along the outer shape of the target structure. Therefore, the size of this space changes depending on the shape of the target structure, and it can be applied to small buildings of several meters cubic to huge buildings, tanks, towers, and the like. <Test body> The test body is a formwork 4 of a column body having a height of 3.6 meters as shown in FIG. 8, and the cross section of the column is 600 mm × 60.
It is 0 mm. Inside the column form 4, an iron plate in the cutting direction 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 mix> The following concrete mixes were used.

[Table 5] <Press-fitting state> According to the amount of press-fitting from the lower part of the formwork, the ready-mixed concrete rose while maintaining a substantially horizontal surface, and the lower surface and the upper surface of the reinforcing plate 5 were sufficiently filled. (FIG. 9) The mold 4 was disassembled after the concrete was hardened. Then, the filling state of the 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 with no void. Next, in order to observe the filling state inside, each reinforcing plate 5
The concrete was cut at the top and bottom. As a result, to the bottom corners of the reinforcing plate 5, which is extremely difficult to fill,
It was found that the entire surface was filled with completely homogeneous concrete.

<Compressive Strength> Specimens were cut from the hardened concrete and tested for compressive strength. The results are shown in the table below, and it was found that the strength was sufficient.

[Table 6]

[0025]

[Embodiment 5] Using a steel plate form as shown in FIG.
A synthetic concrete product was produced. "Synthesis" is a structure in which concrete and a steel plate are integrally formed, and the compressive strength of the concrete and the tensile strength of the steel plate are effectively used. Therefore, the mold is not disassembled and becomes a part of the concrete product. Inner and outer molds 8 and 9 in order to configure both integrally
A large number of bolts are provided as a dowel 10 on the inside of the. Further, the inner and outer molds are connected by a large number of trusses 11. Fresh concrete of the above-mentioned composition is poured into such an enclosed space from below. Then, since the above-mentioned green concrete has extremely good fluidity, even if a large number of steel materials intersect inside, the fluidity is not obstructed and it is possible to sufficiently fill every corner. Further, since the separation resistance is high, the aggregate does not separate during the flow. Further, since breathing does not occur even after the completion of casting, it is possible to manufacture a synthetic product having uniform quality and high durability.

[0026]

[Sixth Embodiment] The fresh concrete as described above is sprayed onto a wall surface from a distance, or dropped into a mold of a concrete product so as to flow and be filled therein. Here, "blown" means
A method of making ready-mixed concrete collide with the surface of an object using compressed air and attaching it, "falling" is a method of freely dropping ready-mixed concrete inside a formwork etc. to fill the inside of the formwork, "downflow" Is a method of making a temporary passage, placing concrete on the passage, and pouring it into the target formwork. In the case of conventional concrete, with such a method, only the aggregate having a large specific gravity comes out before the mortar or collides with the formwork or the wall surface and scatters around. However, according to the manufacturing method of the present invention, such separation does not occur even when spraying from a distant place, flowing down from a high place, and dropping. <Comparison of scattering rates> For that purpose, the scattering rates were compared. 1 liter each of the concrete having high resistance to separation and the conventional concrete to which the separation reducing agent was not added was dropped onto the floor surface from a predetermined height. Then, the weight (W2) of the portion remaining in the center was measured without scattering to the surroundings. Then, the weight reduction from the initial weight (W1) was obtained, and the result was obtained as the scattering loss rate (%) = (W1-W2) / W1.

[Table 7]

As is clear from the results in the above table, it was found that when the concrete of the present invention was used, the scattering loss rate was extremely small even though it was allowed to fall freely.
Therefore, even a worker with little skill in the concrete spraying work can spray the wall surface in a substantially uniform state, like an expert. <Comparison of compressive strength> In a form as shown in FIG.
Drop concrete types from a height of 5 meters,
Alternatively, it was placed directly. (1) Concrete containing a separation reducing agent (high-fluidity concrete, concrete of the present invention) was dropped. (2) Concrete without adding a separation reducing agent (conventional concrete) was dropped. (3) Concrete without adding a separation reducing agent (conventional concrete) was carefully filled into the form, and was vibrated to be compacted. FIG. 12 shows the results of comparing the compressive strengths of the three types of concrete products described above, which were sampled 28 days after the placing. As a result, it was found that the compressive strength of the product produced by dropping the fresh concrete by the method of the present invention is almost the same as the compressive strength of the concrete product which is carefully filled with the fresh concrete and vibrated. On the other hand, it was also found that the concrete that did not contain the separation reducing agent was dropped from the viewpoint of compressive strength and could not be put to practical use. The same effect can be obtained even with a method of spraying fresh concrete onto the wall surface.

[0028]

Example 7 Concrete products are pour-joined using green concrete containing the above-mentioned separation reducing agent.
Pour splicing is a work in which fresh concrete that has not yet solidified is placed in contact with already hardened concrete and the two are integrated. Since concrete generally shrinks during or after hardening, it is most difficult to place new concrete under the hardened concrete to integrate the two. Therefore, as shown in FIG. 13, fresh concrete C2 is newly added below the already cured concrete C1.
The case of placing the will be described. Such a method, for example, when reinforcing the shaft while excavating,
It is used when pouring fresh concrete to the bottom of the previous concrete. Since the concrete used in the method of the present invention has good fluidity and excellent filling property, it is possible to sufficiently fill all the underside of already hardened concrete. In addition, since the concrete has a high resistance to separation, no breathing water is generated and the upper surface of the concrete C2 for splice is not lowered. Therefore, there is no defective portion on the boundary surface, and good integration can be obtained. <Punching strength test> Next, the results of the tensile strengths of the seams of the products manufactured by the method of the present invention and the seams manufactured using the conventional ready-mixed concrete were compared. As the already-hardened concrete C1, concrete of the age of 1 was used.

[Table 8] The above is a comparison of horizontal joints. The results obtained by comparing the tensile strength and the hydraulic conductivity of cores taken at vertical joints 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 has improved splice strength, but also has improved the hydraulic conductivity, which is a weak point of the seam, by one digit.

[0029]

[Embodiment 8] Immersion concrete is poured using green concrete to which the above-mentioned separation reducing agent is added. In this case, a special device is not required, and a method of using a tremie pipe and pouring fresh concrete from the upper end thereof can be adopted as in the conventional case. The tip of the tremie pipe is located at the bottom of the underwater form or the bottom of the excavated ditch. The concrete poured in this way first spreads in a plane. When the spread concrete reaches a certain thickness, it rises while maintaining its horizontal surface in the water. Therefore, the first cast part is always located at the uppermost part, and its upper surface is kept horizontal, so the slime and stabilizing liquid will rise while being placed on top of it. Never get involved. Therefore, it is possible to place underwater concrete of uniform quality and good quality. <Comparison of fluidity> Conventional concrete and concrete used in the method of the present invention were compared for fluidity in underwater pouring. For that purpose, a plurality of colored ready-mixed concretes were used and poured into the water with a tremie pipe. Then, after curing, a plurality of cores were sampled and the fluidity in the vertical direction was estimated.
The results are shown in FIG. 14, and the freshly poured concrete G that was initially poured is pushed upward while maintaining the horizontal layer, and blue B, red R, etc. are maintained as a substantially horizontal layer. all right.

[0030]

Example 9 First, general concrete, that is, ready-mixed concrete in which a separation reducing agent is not added, is manufactured in a concrete factory. Therefore, at this stage, the existing concrete factory can be used as it is without any modification. The ready-mixed concrete produced in this way will be transported to the site where it will be placed by a mixer truck. The above-mentioned separation reducing agent is added to the mixer truck that has arrived at the casting site immediately before the casting. Although the separation reducing agent is in a powder state, it has good dispersibility because it does not dissolve in water, and is sufficiently dispersed and mixed in the kneaded raw concrete. <Comparison of dispersibility> Next, a test was carried out to confirm that the effect was almost the same whether the separation reducing agent was added at the time of mixing the concrete or just before the placing.

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

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

[0031]

As described above, the present invention can achieve the following effects. <B> It is possible to manufacture a product having a complicated shape by using fresh concrete having high separation resistance, high fluidity, and high filling property. During the filling, concrete does not separate, and water and aggregate flow evenly in every corner of the space. Moreover, it does not shrink when cured. Therefore, it is possible to manufacture a product in which a complex shaped obstacle is projected inside the mold. <B> On top of that, it is possible to fill the formwork by simply pouring it without giving vibration to the ready-mixed concrete. Therefore, it is possible to easily manufacture a product that is not subjected to vibration. Also, the personnel required for compaction are no longer required,
Labor saving 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 be prevented. Therefore, it is possible to manufacture concrete products with high watertightness and durability and of uniform and stable quality. <D> Compared with other concretes with high separation resistance,
Since it is not necessary to carefully select the materials to be used, any material that meets the standards can be used. Therefore, excessive quality control is not required and it can be widely applied in general fields. <E> It can be used for manufacturing prestressed concrete members by vibration-free compaction.

<To> As shown in Examples 4 and 5, a method of pouring fresh concrete having the above-mentioned composition into the enclosed space from below can be adopted. Then, since the above-mentioned green concrete has extremely good fluidity,
Even if a large number of steel materials intersect each other, the fluidity is not impeded and filling can be performed in every corner. Further, since the separation resistance is high, the aggregate does not separate during the flow. Further, since breathing does not occur even after the completion of casting, it is possible to manufacture a synthetic product having uniform quality and high durability. <G> As shown in Example 6, a product can be manufactured by dropping from a high position or spraying from a distance.
It has been found that the method of the present invention has an extremely small scattering loss rate to the surroundings even though it is freely dropped from a high position. Therefore, even a worker with little skill in the concrete spraying work can spray the wall surface in a substantially uniform state, like an expert. <H> As shown in Example 7, a method of jointing concrete products can be adopted. In particular, this is not the case of placing fresh concrete on existing concrete, but the case of placing fresh concrete below the bottom surface of existing concrete. Such a method is used when placing ready-mixed concrete on the bottom of the previous concrete, for example, when reinforcing a vertical shaft while excavating it. Since the concrete used in the method of the present invention has good fluidity and excellent filling property, it is possible to sufficiently fill all the underside of already hardened concrete. Moreover, since the concrete has a high resistance to separation, no breathing water is generated, and the upper surface of the concrete C2 for piecing does not sink. Therefore, there is no defective portion on the boundary surface, and good integration can be obtained.

<R> As shown in Example 8, a method of casting a submerged concrete to manufacture a product can be adopted. The concrete poured in this way first spreads in a plane. When the spread concrete reaches a certain thickness, it rises while maintaining its horizontal surface in the water. Therefore, the first cast part is always located at the uppermost part, and its upper surface is kept horizontal, so the slime and stabilizing liquid will rise while being placed on top of it. Never get involved. Therefore, it is possible to place underwater concrete of uniform quality and good quality. <N> As shown in Example 9, first, a concrete having a normal mixture containing no separation reducing agent is produced, and the above-mentioned separation reducing agent is added to the mixer truck that arrives at the casting site immediately before the casting. Can be adopted. Although the separation reducing agent is in a powder state, it has good dispersibility because it does not dissolve in water, and is sufficiently dispersed and mixed in the kneaded raw concrete. As is apparent from Table 11, the slump flow and the air amount similar to the simultaneous addition method are obtained in the method of the present invention. Therefore, it is extremely practical that it can be manufactured without using special equipment, even though special ready-mixed concrete is used. Further, unless the concrete factory is rented out for one day, other types of ready-mixed concrete will be produced one after another, but can be produced by the usual method without considering the relation with other concrete.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram 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: Positional diagram of sample for compressive strength test

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

FIG. 7 is an explanatory diagram of a filling test device.

FIG. 8 is an explanatory diagram of an experiment for injecting concrete into the enclosed space.

[Fig. 9] An explanatory view of the rising state of concrete

FIG. 10 is an explanatory view of a synthetic structure.

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

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

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

FIG. 14 is an explanatory diagram of the distribution state of concrete poured in water.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display area C04B 24:00 2102-4G 24:38) C 2102-4G (31) Priority claim number Japanese Patent Application 2-165378 (32) Priority date 2 (1990) June 22 (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application 2-172814 (32) Priority date 2 (1990) ) July 2 (33) Priority claiming country Japan (JP) (31) Priority claiming number Japanese Patent Application No. 2-165379 (32) Priority Day 2 (1990) June 22 (33) Priority claiming country Japan (JP) (72) Inventor Takefumi Shindo 1-25-1 Nishishinjuku, Shinjuku-ku, Tokyo Taisei Construction Co., Ltd. (72) Inventor Jun Sakamoto 1-25-1 Nishishinjuku, Shinjuku-ku, Tokyo Taisei Construction Incorporated company (72) Inventor Somnutuku Tang Therm Sillicle 1-25, Nishishinjuku, Shinjuku-ku, Tokyo No. 1 Taisei Construction Co., Ltd.

Claims (7)

[Claims] 1. A method for producing a concrete product, which comprises filling a cement-based hardening material with β-1,3-glucan and a high-performance water-reducing agent in a fixed space and hardening it. 2. The method for producing a concrete product according to claim 1, wherein the shape of the structure is surrounded by a plate, and fresh concrete is poured from the lower part of the surrounding space. 3. The method for producing a concrete product according to claim 1, which is carried out by spraying green concrete. 4. Ready-mixed concrete is flowed down and dropped,
The method for manufacturing 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 spliced into already hardened concrete. 6. The method for producing a concrete product according to claim 1, wherein the fresh concrete is poured into 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 fresh concrete.