JP4405751B2 - Concrete block and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a concrete block in which ready-mixed concrete is poured into a mold and molded so that a concave portion is not formed on the surface due to air bubbles, and a method for manufacturing the same.
[0002]
[Prior art]
In recent years, concrete blocks used for civil engineering work have been diversified. For example, concrete blocks for various purposes are used, such as a side groove block installed on the side of a road, a retaining wall block that prevents an inclined slope from collapsing, and an L-shaped retaining wall block. These concrete blocks are standard products that are mass-produced in factories, and are transported to the site and installed at predetermined locations. Compared with the construction in which the formwork is assembled on site and the concrete is poured, the working time is greatly shortened, and the concrete block has an advantage that the strength is higher than the concrete member on the construction site.
[0003]
By the way, in manufacturing the concrete block, a mold is assembled and a release agent is applied to the inner surface of the mold. This is because when the formwork is removed, it does not adhere to the concrete surface. Then, the ready-mixed concrete is poured into (injected into) the formwork, and the formwork is vibrated so that the ready-made concrete spreads to every corner of the formwork and no bubbles remain inside. Or vibration is given to the ready-mixed concrete with a rod-shaped vibrator.
[0004]
Then, when the poured ready-mixed concrete is hardened and reaches a predetermined strength, demolding is performed and the molded concrete block is taken out. However, the surface of the molded concrete block is not a completely smooth surface, and depressions (concave portions) are formed on the surface due to the influence of air bubbles mixed in places. Therefore, the mortar must be repaired by embedding the recess.
[0005]
Fig. 4 shows the case where ready-mixed concrete (b) is poured into the formwork (b), and there are countless bubbles (c), (c) ... in the ready-mixed concrete (b). Although the bubbles (c), (c), etc. are slightly reduced by applying vibration to the frame (b), they are not completely eliminated. Bubbles (c), (c) attached to the inner surface of the mold (d) are difficult to remove even if vibration is applied, and many large bubbles (particularly in the part facing the bottom (f) of the inner mold (e)) C), (C) ... will be accumulated.
[0006]
If a recess is formed on the surface of the concrete block in this way, the distance from the bottom of the recess to the reinforcing steel bar becomes smaller than specified, and the durability (strength, water tightness, etc.) of the concrete block decreases. End up. Of course, the appearance is damaged by the recesses on the surface. For this reason, repair work for embedding mortar is necessary to repair the surfaced recesses, resulting in a decrease in efficiency in concrete block production.
[0007]
In addition, the bubbles (c), (c),... Accumulated in the part facing the bottom (f) may not be surfaced as a recess, and repairing is important because the hidden bubbles are crushed later. In this case, since a large load acts on the bottom of the concrete block, if the mortar is packed in the recess and repaired, the strength is insufficient. That is, the buried portion is peeled off and the concave portion is surfaced again.
[0008]
[Problems to be solved by the invention]
Thus, there are problems as described above in the production of concrete blocks. The problem to be solved by the present invention is this problem, and provides a concrete block that does not require the formation of recesses due to air bubbles on the concrete surface, that is, it is not necessary to repair the recesses after molding, and a method for manufacturing the same.
[0009]
[Means for solving the problems]
The concrete block manufacturing method according to the present invention is formed by pouring ready-mixed concrete into a mold, and the basic process is the same as the conventional one. However, the present invention is a manufacturing method in which a concave portion is not formed on the molded concrete surface, and for this purpose, a liquid in which a release agent and a mortar adhesive are mixed at an appropriate ratio is applied to the inner surface of the mold. Then, the transfer concrete material is kneaded, the kneaded transfer concrete is applied, the mortar adhesive is applied again, the mold is assembled, and the ready-mixed concrete is poured into the mold.
[0010]
In the present invention, concrete is applied to the inner surface of a formwork to make a transfer concrete layer in advance. In this state, ready-mixed concrete is poured into the formwork, but the entire surface of the concrete block becomes a transfer concrete layer. Here, a mortar layer may be formed instead of the above-mentioned transfer concrete in a portion where a large load does not act on the vertical surface of the concrete block.
[0011]
When the transfer concrete is applied to the inner surface of the mold, air bubbles are not confined between the inner surface of the mold and the transfer concrete layer is fixed to the poured ready concrete to form a concrete block. And this concrete block surface turns into a smooth surface, without a recessed part being formed.
[0012]
The above-mentioned transfer concrete is a mixture of water containing an adhesive for mortar, a super fast-hardening concrete repair material, and ready-mixed concrete (high-fluidity concrete), and is cured in a short time by being applied to the inner surface of the mold. Of course, if curing in a short time is not required, the water containing the adhesive for mortar and the super fast-hardening concrete repair material may not be used, or the blending amount may be reduced. Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.
[0013]
【Example】
FIG. 1 shows one step of a method for producing a concrete block according to the present invention. The shape of the mold 1 is the same as that shown in FIG. 4, and a concrete block having a square cross section is molded by the mold 1 and the inner mold 2. The manufacturing method of the present invention is constituted by the following steps.
[0014]
FIG. 2 is a flowchart showing main steps for producing a concrete block according to the present invention. This flow chart shows: (1) Application of mixed liquid of release agent and adhesive for mortar, (2) Mixing of concrete material for transfer, (3) Application of concrete for transfer, (4) Adhesion for mortar It consists of the following steps: spraying agent, (5) reversing and assembling the mold, (6) placing concrete, (7) disassembling the mold.
[0015]
(1) Application of liquid in which mold release agent and mortar adhesive are mixed A liquid in which a mold release agent and mortar adhesive are mixed is sprayed evenly onto the surface of the mold using a spray gun. And before spraying this liquid, the concrete piece adhering to a formwork surface is removed. Further, when a rust preventive agent or a release agent is applied, it is wiped off with a thinner or the like. And the liquid which mixed the mold release agent sprayed and the adhesive agent for mortar is dried. In this case, natural drying may be used, but a blower is used when drying in a short time. By applying a mixed liquid of a mold release agent and a mortar adhesive to the mold surface, the transfer concrete can be properly adhered to the mold surface and can be appropriately removed. Here, as the adhesive for mortar, for example, “High Mole Emulsion” manufactured by Showa Denko Construction Materials Co., Ltd. can be used.
[0016]
(2) Kneading the concrete material for transfer For example, water, super-hard hard concrete repair material, and ready-mixed concrete (high-fluidity concrete) are weighed in a ratio of 1: 2 to 3: 20-30. Here, a mortar adhesive is mixed in the water at a ratio of water: mortar adhesive = 3: 1. First, water containing an adhesive for mortar and a super fast hardened concrete repair material are kneaded. When an electric hand mixer is used during the kneading operation, it can be performed quickly. In this case, check for dumpling-like lumps, and if lumps are present, grind them. Further, ready-mixed concrete is kneaded with this.
[0017]
(3) Application of transfer concrete to formwork The transfer concrete kneaded in (2) is applied to the inside of the formwork surface partitioned. Here, the thickness of the concrete is 3 mm to 30 mm, and it is leveled with a trowel. In other words, cement paste and coarse aggregate are spread all over so that there are no junkers or thin parts, and the concrete is solidified.
[0018]
(4) Spraying the adhesive for mortar The adhesive surface for mortar is sprayed onto the concrete surface for transfer with a spray gun or the like, if necessary, to improve the adhesion to the ready-mixed concrete 7. Here, the mortar adhesive may be wet without being dried.
FIG. 3 shows a model of a cross section when a liquid 3 in which a release agent and a mortar adhesive are mixed, a transfer concrete 5, and a mortar adhesive 4 are applied to the inner surface 6 of the concrete mold 1.
[0019]
(5) Reversing and assembling the mold After the transfer concrete 5 is solidified, the mold is reversed and assembled. Here, the solidified state of the transfer concrete 5 refers to the extent that elasticity does not occur even when pressed with a finger. Moreover, you may solidify in a short time using an air blower.
[0020]
(6) Placing of ready-mixed concrete Ready-cast concrete 7 is poured into the mold 1. Here, although the properties of the ready-mixed concrete 7 are not limited, high-fluidity concrete is suitable because it has good adhesion to the transfer concrete 5. Then, vibration is applied so that the ready-mixed concrete 7 reaches every corner, and the frequency is adjusted by the solidification state of the transfer concrete 5.
[0021]
FIG. 1 shows a case where ready-mixed concrete 7 is poured into the mold 1. However, countless small bubbles 8, 8,... The ready-mixed concrete 7 poured by vibrating the formwork 1 is spread to every corner, and mixed bubbles 8, 8... Are discharged by vibration. In the ready-mixed concrete shown in (a), a large number of bubbles 8, 8,... are mixed, but in the state (b) in which vibration is applied, the number of bubbles 8, 8,. And even if there are bubbles 8, 8 ... between the poured concrete 7 and the transferred concrete 5, the bubbles 8, 8 ... do not appear on the surface of the molded concrete block.
[0022]
(7) When the ready-mixed concrete 7 is hardened, the mold 1 is removed.
The surface of the molded concrete block is covered with a transfer concrete layer, and there is no recess on the surface. Therefore, it is not necessary to repair the recess as in the prior art after removing the mold.
[0023]
By the way, the shape of the concrete block of this invention is free, and all kinds of concrete blocks are objects. As described above, the method for producing a concrete block of the present invention is to cast the ready-mixed concrete after applying and solidifying the transfer concrete on the inner surface of the mold, and obtain the following effects. I can do it.
[0024]
【The invention's effect】
The method for producing a concrete block according to the present invention is one in which the concrete for transfer is applied to the inner surface of the formwork and solidified, and then poured into the ready-mixed concrete and molded. Never formed. Therefore, it is not necessary to repair the concave portion after molding, and the productivity is greatly improved. The surface of the concrete block to be molded is covered with transfer concrete, and the appearance is smoother and more beautiful than the conventional concrete surface.
[0025]
In this way, by applying the transfer concrete to the inner surface of the mold, air bubbles do not intervene between the transfer concrete and the inner surface of the mold. Then, when the applied transfer concrete is in a dry state, the ready-mixed concrete is poured into a concrete block that is fixed and integrated with the transfer concrete. Further, if the ready-mixed concrete is poured and molded after applying an adhesive to the surface of the transfer concrete as required, the adhesion to the transfer concrete is further improved.
[Brief description of the drawings]
FIG. 1 shows one step in a method for producing a concrete block according to the present invention.
FIG. 2 shows a concrete block manufacturing process according to the present invention.
FIG. 3 is a concrete layer for transfer formed on the inner surface of the mold.
FIG. 4 shows one step in a conventional method for producing a concrete block.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Formwork 2 Inner formwork 3 Liquid which mixed release agent and adhesive for mortar 4 Adhesive for mortar 5 Concrete for transfer 6 Inner surface 7 Ready concrete 8 Air bubbles

Claims (5)

In a concrete block molded by pouring ready-mixed concrete into a mold, a concrete layer for transfer is formed on at least a part of the surface of the concrete block, and the concrete layer for transfer is composed of water mixed with an adhesive for mortar and super fast hardened concrete. A concrete block, which is made by mixing repair materials, adding fresh concrete, and kneading them.   In a manufacturing method in which ready-mixed concrete is poured into a mold to form a concrete block, a liquid mixed with a release agent and a mortar adhesive is applied to the inner surface of the mold, and after drying, the transfer concrete is applied and solidified. A method for producing a concrete block, comprising: assembling a mold, pouring the ready-mixed concrete into the mold, and demolding after curing.   The method for producing a concrete block according to claim 2, wherein an adhesive for mortar is applied to the solidified transfer concrete surface by applying.   4. The method for producing a concrete block according to claim 2, wherein the transfer concrete is formed by mixing water mixed with an adhesive for mortar and an ultra-high-hardness concrete repair material, and adding and mixing kneaded concrete. .   4. The method for producing a concrete block according to claim 2, wherein the concrete for transfer is made of ready-mixed concrete.

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