JPH0959961A - Concrete surface protection method and formwork structure - Google Patents

Abstract

(57) [Summary] (Corrected) [Problem] To protect the concrete surface from rainwater and dust until it is necessary at the time of completion, etc., and at the same time prevent concrete from shrinking due to drying and curing. A method for protecting a concrete surface (2) directly molded by a mold (10), in which a sheet material (12) is preliminarily peelably attached to a facing surface (11) of the mold facing the concrete surface. Including the step of placing concrete 1 on the formwork and the step of removing the formwork while leaving the sheet material on the concrete surface 2, the sheet material is stripped from the concrete surface 2 when necessary. Also,
The mold is formed by pasting a sheet material on the opposite surface in advance so that the sheet material can be separated from the opposite surface 11 at the time of demolding after concrete is cast into the mold and the sheet material 12 is integrated with the sheet material 12. It can be releasably left on the concrete surface through the protruding member 13 provided on the.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete surface protecting method and a formwork structure, and more particularly to protecting a concrete surface exposed to the outside by directly shaping a formwork in a concrete structure until necessary. The present invention relates to a formwork structure used for carrying out such a method.

[0002]

[Problems to be Solved by the Invention] In long-term construction such as concrete dams and construction such as bridges that are exposed to rain during construction, the concrete surface is contaminated by curing water during construction, rainwater, dust, etc. The current situation is that a great deal of labor is being cleaned.

In addition, the curing water may evaporate from the surface of the concrete, causing drying shrinkage and poor curing of the concrete.

Therefore, it is an object of the present invention to provide a concrete surface protecting method for protecting concrete surfaces from rainwater and dust not adhering until necessary such as at the time of completion of construction, and to provide a formwork structure for carrying out such a method. is there.

Another object of the present invention is to provide a formwork structure for carrying out such a concrete surface protecting method for preventing concrete from drying shrinkage and curing failure.

[0006]

A method for protecting a concrete surface according to the present invention is a method for protecting a concrete surface directly molded by a mold, and a facing surface of the mold facing the concrete surface. A step of preliminarily attaching a sheet material in a peelable manner, a step of placing concrete in the formwork, and a step of demolding the formwork while leaving the sheet material on the concrete surface, The sheet material is peeled off from the concrete surface when necessary.

Further, the formwork structure according to the present invention is a formwork structure for protecting a concrete surface directly molded by the formwork, and a sheet is previously formed on an opposite surface of the formwork facing the concrete surface. Characterized in that the sheet material is releasably attached, and the sheet material is peeled from the facing surface and is releasably left on the concrete surface at the time of demolding after the concrete is cast into the formwork. .

Here, the concrete surface directly molded by the mold is the surface of the concrete structure which is directly exposed to rain and dust after the mold is demolded,
Specific examples include the side surface of a concrete dam levee, the surface of a bridge, and a retaining wall.

Further, the sheet material is a sheet-like material having a non-water-permeable property and at least strong enough not to be broken at the time of pouring concrete or demolding. Examples of the material thereof include polyethylene and the like. be able to.

In the concrete surface protecting method of the present invention, a sheet material is preliminarily attached to the facing surface of the formwork facing the concrete surface to be protected, and the sheet material is cast on the concrete surface and removed from the mold to be applied to the concrete surface. Transfer
The sheet material is peeled off from the concrete surface at the time of completion, etc., and the formwork structure of the present invention is used in the above method.

Therefore, the adhesive force (a) between the sheet material and the form (opposing surface) is weaker than the adhesive force (b) between the sheet material and the concrete surface, and further, (b) can be easily by hand when necessary. It is necessary to make it so that it can be peeled off.

As specific means of (a), spray glue or the like may be applied between the mold and the sheet material, or an adhesive may be mentioned. As a specific means of (b) Can be an adhesive or the like.
Note that it is necessary to take into consideration that the sheet material and the concrete surface are gradually peeled off because the curing water flows to the concrete side after demolding.

Further, in order to further secure (b) and (c), in the present invention, the formwork structure is provided on the concrete surface through a projecting member integrally provided on the sheet material. It may remain peelable.
That is, by slightly embedding the projecting member in the cast concrete, the sheet material integrated with the projecting member is left on the concrete surface side.

The projecting member can be formed into a shape that can be integrally removed from the concrete surface side with the sheet material, or can be separated from the sheet material when the sheet material is peeled off and left on the concrete surface side to be buried. In the latter case, It is desirable that the material of the projecting member is plastic or the like so as not to affect concrete.

The sheet material remaining on the concrete surface not only protects the concrete surface from rain and dust, but also acts to prevent evaporation of free water inside the concrete.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 3 are explanatory views of the present invention. FIG. 1 shows a state in which the mold 10 is set, FIG. 2 shows a state in which the fillet 1 is placed on the mold 10, and FIG. 3 shows the form. 10 shows the state where 10 is removed.

In the formwork 10, a polyethylene sheet 12 as a sheet material is preliminarily provided on a facing surface 11 facing the concrete surface 2 (see FIGS. 2 and 3) to be covered with the sheet material via spray glue. A plurality of (only one is shown) adhesive jigs 13 as projecting members are provided in the vicinity of the periphery of the sheet 12 in the vicinity of the periphery of the sheet 12 with an adhesive having a stronger adhesive force than the spray glue.

As an example, the bonding jig 13 has a spherical shape in which the diameter is gradually reduced from the base end toward the top, and the diameter is increased at the top.

Concrete 1 is poured into the mold 10 constructed as described above (FIG. 2). Here, the sheet 2 remains on the facing surface 11 of the mold 10 without breaking, and the bonding jig 13 slightly enters the concrete 1.

Next, when the mold 10 is removed from the mold after a predetermined time has elapsed, the sheet 12 remains on the concrete surface 2 as shown in FIG. That is, the sheet 12 is the facing surface 1 of the mold 10.
While peeling off from the mold 1 along with the demolding, it remains on the concrete surface 2 due to the bonding force between the bonding jig 13 and the concrete 1.

In the state of FIG. 3, the sheet 12 covers the concrete surface 2 to protect it from rainwater and dust, and prevents free water of the concrete 1 from evaporating through the concrete surface 2.

After that, the sheet 12 is peeled off from the concrete surface 2 when necessary at the time of completion of construction. At this time, the sheet 12 is separated from the bonding jig 13, and the bonding jig 13 remains on the concrete 1 side, but the bonding jig 13 may adversely affect the concrete 1 by using a material such as plastic. There is no.

[0024]

As described above, according to the present invention, it is possible to cover the concrete surface of the concrete structure with a sheet material that can be peeled off when desired, while performing the usual work of attaching and detaching the formwork.

Therefore, the concrete surface can be protected from rainwater and dust adhering to it until it is needed, such as at the time of completion, so that it is not necessary to perform extensive cleaning as in the conventional case.

Further, since free water is prevented from evaporating through the concrete surface covered with the sheet material, it is possible to prevent drying shrinkage and insufficient hardening of the concrete.

[Brief description of drawings]

FIG. 1 is an explanatory view of the present invention showing a set state of a mold.

FIG. 2 is an explanatory view of the present invention showing a state in which concrete is placed in a mold.

FIG. 3 is an explanatory view of the present invention showing a state where the mold is demolded.

[Explanation of symbols]

 1 Concrete 2 Concrete surface 10 Formwork 11 Opposing surface 12 Polyethylene sheet 13 Bonding jig

Claims (3)

[Claims] 1. A method for protecting a concrete surface directly molded by a mold, wherein a sheet material is preliminarily peelably attached to a surface of the mold facing the concrete surface. Including the step of placing concrete in the formwork, and the step of removing the formwork while leaving the sheet material on the concrete surface, and peeling off the sheet material from the concrete surface when necessary A concrete surface protection method characterized by: 2. A formwork structure for protecting a concrete surface directly formed by a formwork, wherein a sheet material is pre-separably attached to an opposite surface of the formwork that faces the concrete surface, A formwork structure, wherein the sheet material is peeled off from the facing surface at the time of demolding after the concrete is poured into the formwork, and is releasably left on the concrete surface. 3. The formwork structure according to claim 2, wherein the sheet material remains releasably on the concrete surface through a projecting member provided integrally with the sheet material.