JP5875189B2 - Method for forming concrete structure - Google Patents

Description

  The present invention relates to a method for forming a concrete structure, and more particularly to a method for forming a concrete structure in which the surface of the concrete structure is smooth and beautifully finished.

Conventionally, in the formation of a concrete structure, normally, the ready-mixed concrete is placed in a mold and cured, and then the mold is removed.
However, in general, a concrete structure formed with this formwork can cause air bubbles or air accumulation between the formwork and the concrete inside the cast concrete.
Many of these causes are caused by the fluidity of the ready-mixed concrete. For this reason, bubble holes, junkers, flapping, etc. are generated on the surface of the concrete structure, and the surface of the concrete structure is remarkably deteriorated.
Furthermore, fine letters and figures cannot be clearly formed due to the size and type of the aggregate, and in any case, it is difficult to finish the surface of the concrete structure to be smooth and clean.

In order to prevent these problems, conventionally, the surface of a concrete structure is finished finely with resin mortar or painting later, or in JP-A 64-18603 (Patent Document 1), resin mortar is formed on the inner surface of a mold. And concrete concrete was formed by placing resin mortar on the concrete surface.
Furthermore, for the one using an improved formwork, for example, JP-A-7-252933 (Patent Document 2), using a metal concrete formwork coated with a polyarylene sulfide resin composition, It is disclosed that the concrete surface is smooth, free from bubbles and traces of bubbles, and is capable of forming a concrete having an excellent aesthetic appearance without any spots.
Japanese Patent Laid-Open No. 11-21995 (Patent Document 3) discloses that a surface plate made of a cement-based material is assembled in a formwork, and an adhesive is applied to the back surface of the surface plate. There is disclosed a method for forming a concrete structure in which concrete and a surface plate are integrated by interposing an adhesive layer to form a concrete structure by curing the concrete that has been placed.

JP-A 64-18603 Japanese Patent Laid-Open No. 7-252933 Japanese Patent Laid-Open No. 11-21995

However, in the forming method of Patent Document 1, resin mortar or the like is applied to the inside of the mold. Therefore, in the case of the on-site mold, since it is vertically long and a large number of reinforcing bars, separators, and the like are incorporated therein, these are obstructive. Next, it is difficult to apply resin mortar etc. to the entire inner surface of the formwork panel, and it takes time and effort. Since it has a low viscosity and high fluidity, when it is applied in a longitudinal mold, the applied resin mortar hangs down and is not uniformly applied to a predetermined thickness, and uneven coating tends to occur.
For this reason, the thickness of the formed resin mortar layer on the concrete surface becomes non-uniform, and it becomes difficult to hide the cover or jumper on the concrete surface with the resin mortar layer.

On the other hand, in the metal concrete formwork of Patent Document 2, the formwork itself is heavy, and if it is made of aluminum in order to reduce the weight, it becomes expensive and is not suitable for use in large quantities.
Moreover, when manufacturing products such as concrete blocks that have a fixed shape, the shape of the formwork is constant, so there is no need to prepare various formwork. Since a formwork having a shape is required, a special metal concrete formwork coated with a polyarylene sulfide resin composition has a problem in preparing a formwork having a corresponding shape.

  Furthermore, in the method for forming a concrete structure of Patent Document 3, since a surface plate is used, it takes time and money to produce the surface plate, the cost of the structure increases, and an adhesive is applied to the surface plate. However, similarly to the above-mentioned Patent Document 1, it is difficult to apply the adhesive because the reinforcing bars and separators in the mold are obstructed by the on-site casting, and it is difficult to apply the adhesive between the surface plate and the concrete. The integration had problems such as deterioration of the adhesive over the long term and the possibility of the surface plate falling off due to the difference in shrinkage between the surface plate and concrete.

  The present invention eliminates the trouble of applying the grout material to the inner surface of the formwork, and the grout material injected into one place in the formwork turns uniformly to the surface of the placed concrete, smoothly forming the concrete surface, and the surface finish An object is to provide a method for forming a concrete structure that is in good condition and can be constructed at a low construction cost.

The present invention has been made to solve the above-mentioned problems. An appropriate amount of the grout material (2) is injected into the lower part of the framed mold (1), and then the raw material is grown on the grout material (2). After placing concrete (3) at a height of 0.3 m to 0.5 m , vibration is applied to the ready-mixed concrete (3), and the grout material (2) is moved along the inner peripheral surface of the mold (1). The mold is raised to at least the height of the ready-mixed concrete (3), cured and cured with the grout material (2) covering at least the outer peripheral side surface of the ready-mixed concrete (3), and then the mold (1) is released from the mold. And, when applying vibration to the ready-mixed concrete (3), the fluidity of the grout material (2) injected into the mold (1) is in the range of 4 to 8 seconds in terms of the J14 funnel flow-down value. It is characterized by that.

Also, an appropriate amount of grout material (2) is poured into the lower part of the framed mold (1), and then an appropriate amount of ready-mixed concrete (3) is placed on the grout material (2) at a height of 0.3 to 0.5 m. Then, the ready-mixed concrete (3) is vibrated, and the grouting material (2) is raised along the inner peripheral surface of the formwork (1) to at least the height of the ready-mixed concrete (3), Further, after pouring a suitable amount of grout material (2) onto the ready-mixed concrete (3), and placing the ready-mixed concrete (3) on the grout material (2) to a height of 0.3 to 0.5 m. Then, vibration is applied to the ready-mixed concrete (3), the grout material (2) is raised to the height of the ready-mixed concrete (3), and the same process is repeated thereafter, so that the grout material (2) and the ready-mixed concrete are repeated. (3) is driven to the specified height, and the front After curing cured state grout (2) is coated with at least an outer peripheral side surface of the raw concrete (3), said mold (1) is allowed to release, and, when applying vibration to the raw concrete (3) The fluidity of the grout material (2) injected into the mold (1) is in the range of 4 to 8 seconds in terms of J14 funnel flow value .

  Further, it is preferable that the grout material (2) is cement-based and has at least non-shrinkage and fluidity, and has a fluidity of 4 seconds to 8 seconds as a J14 funnel flow value. Good.

  In addition, the grout material (2) is poured and the ready-mixed concrete (3) is placed in the mold (1) in a state where the frame is high and at least a large number of rebars (4) are placed. It is good.

  The ready-mixed concrete as used in the present invention includes those obtained by adding water, sand, gravel or the like to cement and kneaded, or mortar in which water or sand is added to cement.

  Furthermore, the grout material (2) of the present invention is a thriller-like material that is usually injected to fill gaps such as cavities and gaps, and is a cement-based material having properties such as no shrinkage, non-breeding, and high fluidity. In particular, the fluidity is preferably from 4 to 8 seconds, and preferably from 5 to 7 seconds as the J14 funnel flow value.

  In the present invention, the grout material (2) is simply poured into the tip of the lower part of the ready-mixed concrete (3) to be placed in the mold (1) without applying it to the inner surface of the mold (1). The grout material (2) is extremely easy to use, and in particular, the inside of the formwork (1) is complicated due to irregularities or the like, and a large number of reinforcing bars (4), separators (5), etc. are provided. However, it can be easily injected without being influenced by the use of the grout material (2).

Moreover, using the difference in specific gravity between the grout material (2) and the ready-mixed concrete (3), the light weight grout material (2) arranged below the ready-mixed concrete (3) is combined with its fluidity, It rises automatically due to vibration and goes well around the outer periphery of the ready-mixed concrete (3), and the grout material (2) is formed on the outer periphery of the concrete without shrinkage.
Therefore, the surface of the formed concrete structure is formed very smoothly, there is no air bubbles or junkers, etc., it is possible to form a bare concrete skin with a good surface finish, and construction can be performed at a low construction cost. .
Moreover, even if there is an uneven pattern on the surface of the concrete structure, the uneven pattern can be clearly formed due to the non-shrinkage and fluidity of the grout material (2).

It is explanatory drawing which shows the formation method of this invention. It is explanatory drawing which shows the other formation method of this invention. It is explanatory drawing which shows the formwork state which framed on-site strike of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, as shown in FIG. 1A, an appropriate amount of grout material (2) is injected into the lower part of the mold (1). The standard of the injection amount of the grout material (2) is such an amount that it is formed to a thickness of about 0.5 mm to 3 mm over at least the entire side surface of the concrete structure to be formed.
As the grout material (2), a cement-based non-shrinkable and highly fluid material is used. Particularly, the fluidity is important, and the J14 funnel flow value is preferably 4 to 8 seconds, preferably Is preferably 5-7 seconds. For example, Denka Pretuscon manufactured by Denki Kagaku Kogyo Co., Ltd. is used, and the consistency after kneading with water is the J14 funnel flow down value If it is used in a range, good fluidity is secured, and it is easy to lift when vibration described later is applied.

  Next, as shown in FIG. 1 (b), ready-mixed concrete (3) is placed on the poured grout material (2).

And as shown in FIG.1 (c), a vibration is added to the said ready-mixed concrete (3) with a vibrator (6).
The vibrator (6) for applying vibration is preferably a rod-like vibrator in that direct vibration can be applied to the ready-mixed concrete (3), but other vibrators may be used depending on the type of concrete structure, and the entire formwork (1). May be vibrated.
The reason for directly applying vibration to the ready-mixed concrete (3) is to prevent the grout material (2) and the ready-mixed concrete (3) from being mixed during the vibration.
Due to this vibration, the lower grout material (2) having a lighter specific gravity and better fluidity than the upper ready-mixed concrete (3) is pushed by the ready-mixed concrete (3) with a higher specific gravity, just like a liquefaction phenomenon. ) And ready-mixed concrete (3), it floats at a certain thickness.
Due to this phenomenon, the grout material (2) that floats along the inner peripheral surface of the mold (1) is vibrated until it rises at least to the height of the ready-mixed concrete (3), and the grout material (2) After curing and curing in a state where at least the outer peripheral side surface of the ready-mixed concrete (3) is covered, the mold (1) is released, and the grout material (2) is coated on the concrete surface as shown in FIG. 1 (d). A concrete structure is formed.

Further, the forming method when the concrete structure is about 0.5 m or higher when cast on site will be described with reference to FIG. 2. First, as shown in FIG. 2 (a), a mold framed high on the foundation concrete (A). An appropriate amount of grout material (2) is injected into the lower part of the frame (1).
In this case, the amount of the grout material (2) to be injected is approximately 0.5 mm to 3 mm thick at least on the entire side surface as described above with respect to the ready-mixed concrete (3) to be input next. It is the amount to be done.

Next, as shown in FIG. 2B, an appropriate amount of ready-mixed concrete (3) is placed on the grout material (2).
If the amount of the ready-mixed concrete (3) to be placed is too large, the grout material (2) will not rise to the desired height due to vibration. A range of .5 m is preferred.

  Then, as shown in FIG. 2 (c), the ready-mixed concrete (3) was vibrated with a vibrator (6), and the grout material (2) was placed at least along the inner peripheral surface of the mold (1). Raise to the height of the ready-mixed concrete (3).

Further, as shown in FIG. 2 (d), an appropriate amount of grout material (2) is poured onto the ready-mixed concrete (3), and an appropriate amount of the ready-mixed concrete (3) is poured onto the grout material (2) as in the previous time. After placing, as shown in FIG. 2 (e), the ready-mixed concrete (3) is vibrated to raise the grout material (2) to the height of the ready-mixed concrete (3), and thereafter the same steps are repeated. Then, after setting and curing the grout material (2) and the ready-mixed concrete (3) to a predetermined height, the grout material (2) covers at least the outer peripheral side surface of the ready-mixed concrete (3), The mold (1) is released to form a concrete structure.
In addition, when the formwork (1) framed in this way is high, when the grout material (2) is poured into the formwork (1), the grout material (2) is the vertical formwork (1). In order not to cover the inner surface, the tip of the hose for injecting the grout material (2) is preferably extended to the lower part of the mold (1).
That is, when the grout material (2) to be poured is applied to the inner surface of the mold (1) above the height of the ready-mixed concrete (3) to be placed next, the ready-mixed concrete (3 This is because the grout material (2) in this portion is likely to be hardened, and there is a risk of causing spots on the surface of the concrete structure.

Thus, even in the formation of a high concrete structure, the grout material (2) can be reliably formed on the surface of the concrete structure, so that the surface of the concrete structure can be finished in a smooth state free of bubbles and jumpers. It becomes possible.
Moreover, it is possible to make a concrete surface with a beautiful appearance even when it is desired to show a bare concrete surface with a concrete structure made in the field.

  Moreover, in the formation method of this invention, as shown in FIG. 3, when constructing the concrete structure etc. of construction on the spot, many rebars (4) and separators ( 5) etc. are arranged, but even in this state, since the use of the grout material (2) is only injected into the mold (1), there are reinforcing bars (4), separators (5), etc. Can be installed without getting in the way.

  In addition, the forming method of the present invention is used for precast concrete products, concrete art works, etc., in addition to the case of constructing a concrete structure of a building on the spot, and a grout material to which various color pigments are added (2) may be used to color the concrete structure.

1 Formwork 2 Grout material 3 Ready-mixed concrete 4 Rebar

Claims (2)

An appropriate amount of grout material (2) is poured into the lower part of the framed mold (1), and then ready-mixed concrete (3) is placed on the grout material (2) at a height of 0.3 to 0.5 m. Then, vibration is applied to the ready-mixed concrete (3), the grout material (2) is raised along the inner peripheral surface of the formwork (1) to at least the height of the ready-mixed concrete (3), and the grout material ( 2) after curing and curing in a state where at least the outer peripheral side surface of the ready-mixed concrete (3) is covered, the mold (1) is released, and when the vibration is applied to the ready-mixed concrete (3), the mold A method for forming a concrete structure, wherein the flowability of the grout material (2) injected into the frame (1) is in the range of 4 seconds to 8 seconds in terms of the flow down value of J14 funnel . An appropriate amount of grout material (2) is poured into the lower part of the framed mold (1), and then an appropriate amount of ready-mixed concrete (3) is placed on the grout material (2) to a height of 0.3 to 0.5 m. After placing, vibration is applied to the ready-mixed concrete (3), the grout material (2) is raised along the inner peripheral surface of the formwork (1) to at least the height of the ready-mixed concrete (3), An appropriate amount of grout material (2) is poured onto the ready-mixed concrete (3), and after placing the ready-mixed concrete (3) on the grout material (2) to a height of 0.3 to 0.5 m , Vibration is applied to the ready-mixed concrete (3), the grout material (2) is raised to the height of the ready-mixed concrete (3), and thereafter the same process is repeated to repeat the grout material (2) and the ready-mixed concrete (3 ) To a predetermined height, After curing cured state preparative material (2) is coated with at least an outer peripheral side surface of the raw concrete (3), said mold (1) is allowed to release, and, when applying vibration to the raw concrete (3) The method for forming a concrete product, wherein the flowability of the grout material (2) injected into the mold (1) is in the range of 4 seconds to 8 seconds in terms of the flow down value of J14 funnel .