JP3085862B2 - Permanent formwork for concrete - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an improved permanent form for concrete.

[0002]

2. Description of the Related Art It has been proposed to use a permanent form for concrete work made of fiber reinforced cement in place of a conventional plywood form as a building form for a concrete wall (for example, JP-A-3-293473). Gazette). This type of concrete formwork is finally integrated with the concrete to be cast, and has the advantage that the formwork will be integrated with the walls or pillars of the building structure as it is, so that subsequent work of removing the formwork can be omitted. . By the way, in order to improve the adhesiveness with the concrete to be cast, the permanent form for concrete work is considered to provide a rectangular cross section or an inverted trapezoidal ridge on the back surface to improve the physical adhesiveness. Have been.

[0003]

However, these permanent forms for concrete work may be arranged not only vertically but also horizontally in accordance with the building structure such as walls and beams. There is a problem that the adhesiveness between the cast concrete and the permanent form for concrete work may be poor depending on the correlation between the concrete and the arrangement direction. That is, after the concrete is poured, the breathing water in the concrete, together with the air bubbles contained in the concrete, concentrates on the contact interface with the permanent form for concrete work, and tends to rise along this interface. Therefore, especially when the permanent form for concrete is arranged in the vertical direction, there is a problem that the adhesion to the cast concrete is significantly impaired despite the provision of the ridges.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made to improve the adhesiveness to concrete in a permanent form for concrete work.

[0005]

That is, the permanent form for concrete according to the present invention has a lengthwise direction on a surface 1B of a hollow or solid fiber-reinforced cement plate 1A which comes into contact with concrete to be cast. Multiple protruding ridges 2 ... 2
In the permanent form for concrete 1 provided with
On the surface 1B in contact with the concrete to be cast, a minute groove 3 continuous in the length direction and having a width and unevenness of 3 mm or less and 0.1 mm or more
.. 3 are continuously provided in the width direction.

According to another aspect of the present invention, minute concave grooves 3 ... 3 continuous in the length direction and having a width and unevenness difference of 3 mm or less and 0.1 mm or more are provided only on a mold surface 1B between a plurality of protrusions 2 ... 2. It is characterized by being performed. Further, in the first and second inventions, the cross-sectional shape of each of the minute concave grooves 3... 3 has a dovetail shape, and the sectional shape of the minute concave grooves 3.
It is characterized by comprising a combination of grooves having different heights and widths.

[0007]

According to the first aspect of the present invention, minute concave grooves 3... 3 having a width and an unevenness difference of 3 mm or less and 0.1 mm or more are continuously formed in the width direction on the surface 1B of the permanent form for concrete contacting the concrete. The purpose of this purpose is to prevent air bubbles and breathing water from stopping at the portion due to surface tension and capillary action, and prevent the bubbles and breathing water from moving upward. Therefore, it is possible to prevent water from being formed between the concrete and the permanent form for concrete, thereby improving the adhesion between the concrete and the permanent form for concrete.

The reason why the width and depth of the minute grooves 3 are set to 3 mm or less is that the diameter of bubbles contained in the breathing water of the concrete to be cast is generally about 3 mm or less. This is because bubbles rise along the grooves 3 and 3 and water is easily formed, so that the adhesion between the concrete and the permanent form for concrete cannot be improved. If it is 3 mm or less, it may be a fine groove, but if it is too small, it will be difficult to provide a fine concave groove, and it will not be possible to obtain the effect as substantially as a smooth surface. mm is appropriate. In addition,
The cross-sectional shape of the minute concave grooves 3 is not particularly limited as long as it is a shape capable of exhibiting the above-mentioned effects, such as a triangular shape, a square shape, and a semicircular shape.

In the second aspect of the present invention, the minute grooves 3.
Are provided only on the mold surface 1B between the plurality of ridges 2... 2 so that even when the concrete form 1 is stacked during transportation and storage, the minute grooves 3. 2 protects the object from being in contact with another object, and prevents the minute object groove 3... From damaging the object or abrasion disappearance or damage of the minute object groove 3.

In the third aspect of the present invention, the minute grooves 3.
The cross-sectional shape of each groove is made into a dovetail shape in order to further enhance the catching property of breathing water by capillary action. In the invention according to the fourth aspect, the sectional shape of the minute concave grooves 3... 3 is constituted by a combination of grooves having different heights and widths, even if the bubble diameter contained in the breathing water varies. This is to ensure the supplement.

[0011]

Next, an embodiment of the present invention will be described. FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a main part of the embodiment of FIG. 1, and FIGS. 3 to 6 are enlarged sectional views of a main part of another embodiment.

Embodiment 1 A fiber-reinforced cement plate 1A having a hollow or solid body (solid body in the illustrated example) as shown in FIG. In the concrete formwork 1 in which the parts 1D, 1D are provided and the plurality of ridges 2... 2 are provided on the surface 1B in contact with the concrete to be cast, the surface in contact with the concrete, ie, the ridges 2 2 and a plurality of ridges 2... 2 and a mold surface 1B.
Are provided with a plurality of minute concave grooves 3... The small grooves 3 were simultaneously extruded when the permanent mold 1 for concrete was extruded.

[Embodiment 2] Micro-groove 3 in Embodiment 1
A permanent mold 1 for concrete was formed in the same manner as in Example 1 except that the cross-sectional shape of... 3 was rectangular as shown in FIG.

[Embodiment 3] Micro-groove 3 in Embodiment 1
The permanent mold 1 for concrete was formed in the same manner as in Example 1 except that the cross-sectional shape of... 3 was a dovetail shape as shown in FIG.

[Embodiment 4] The minute concave groove 3 in Embodiment 1
The permanent mold 1 for concrete was formed in the same manner as in Example 1 except that the cross-sectional shape of... 3 was a combination of a triangular shape and a dovetail shape as shown in FIG.

[Embodiment 5] The minute concave groove 3 in the embodiment 1
As shown in FIG. 6, a large triangular ridge 3A having a height of 3 mm and a small triangular ridge 3 having a height of 1 mm are shown in FIG.
A permanent form 1 for concrete was formed in the same manner as in Example 1 except that B and B were combined at a ratio of 1: 3.

[Embodiments 6 to 10] A fiber-reinforced cement plate 1A having a hollow or solid body as shown in FIG. 1 (solid body in the illustrated example) is used for joining to end faces 1C and 1C. In the concrete formwork 1 provided with the engaging step portions 1D and 1D and provided with a plurality of ridges 2... 2 on the surface 1B in contact with the concrete to be cast, a plurality of ridges 2. 2B to 6B, a plurality of minute concave grooves 3 having a width B and a depth D of 1 mm and having a triangular cross section are provided on only the surface 1B.

Comparative Example A concrete permanent mold 1 was formed in the same manner as in Example 1 except that the minute concave grooves 3 were not provided in the permanent mold 1 for concrete.

Next, as shown in FIG. 7, for the examples 1 to 10 and the comparative example, the formwork 1 was assembled as the vertical arrangement X, the horizontal arrangement Y, and the bottom arrangement Z, and concrete was actually cast. After one week, formwork 1 with diamond cutter
Cut out 10cm square including concrete P
As shown in FIG. 8, jigs Q and Q were bonded to the concrete surface P and the formwork 1 surface with an epoxy resin adhesive, respectively, and the adhesion was tested using a tensile tester. The results are as shown in Table 1.

[0020]

[Table 1] * 1 in the table indicates that the concrete form 1 was broken on the surface concrete side. * 2 indicates that interface separation between concrete and formwork 1 occurred. Unmarked values indicate values when the concrete layer was broken.

As is clear from Table 1, in the case of the permanent mold for concrete 1 of the present invention, the adhesiveness to the concrete to be cast is extremely small even in the case of the X-direction arrangement where water supply is most easily performed. Approximately 2 to 4 times as compared with the comparative example without concave grooves
The adhesive strength was doubled, and it was found that the adhesive strength to concrete P was excellent. In the comparative example, interfacial peeling occurred, but in the example, there was no interfacial peeling, and it was confirmed that water supply with breathing water was not possible. still,
When the cross section of the sample of Example 6 was forcibly peeled off at the interface, it was confirmed that air bubbles of 1 to 2 mm had adhered.

[0022]

As described above, the permanent mold for concrete 1 according to the first aspect of the present invention has a small concave groove 3 so that it is difficult to supply water due to the surface tension or the capillary phenomenon of breathing water, and the concrete is accordingly reduced. It has excellent adhesiveness to the building and can build a strong building. Further, in the case of the invention of claim 2, since the minute concave grooves 3... 3 are not exposed on the back surface of the formwork, they do not come into contact with other objects and do not damage them, thereby facilitating the management of transportation and storage. Have. In the case of the third aspect of the present invention, since the dovetail-shaped micro-grooves 3... 3, the adhesiveness with concrete penetrating between the micro-grooves is improved, and an effect of obtaining more excellent adhesive strength is obtained. .
In the case of the invention of claim 4, there is an effect that a uniform adhesive force can be obtained even if the diameter of bubbles contained in the cast concrete varies.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the embodiment of FIG.

FIG. 3 is an enlarged sectional view of a main part of another embodiment.

FIG. 4 is an enlarged sectional view of a main part of another embodiment.

FIG. 5 is an enlarged sectional view of a main part of another embodiment.

FIG. 6 is an enlarged sectional view of a main part of another embodiment.

FIG. 7 is a perspective view showing a state where a mold is assembled.

FIG. 8 is an explanatory diagram of an adhesive strength test device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Permanent formwork for concrete 1A ... Plate-like body made of fiber reinforced cement 1B ... Surface which contacts concrete to be cast 1C ... End surface 1D ... Joining engagement stepped part 2 ... Multiple ridges 3 ... Minute groove P … Concreted concrete Q… Jig

Claims (4)

(57) [Claims] 1. A plurality of projecting ridges 2... 2 continuous in the length direction are provided on a surface 1B of a hollow or solid fiber-reinforced cement plate 1A in contact with concrete to be cast. In the permanent form 1 for concrete, minute grooves 3 ... 3 continuous in the length direction and having a width and irregularity difference of 3 mm or less and 0.1 mm or more are continuously provided in the width direction on the surface 1B in contact with the concrete to be cast. A permanent formwork for concrete, comprising: 2. Micro-grooves 3 ... 3 continuous in the length direction and having a width and unevenness difference of 3 mm or less and 0.1 mm or more are provided only on a mold surface 1B between a plurality of ridges 2 ... 2. The permanent form for concrete according to claim 1, characterized in that: 3. The permanent form for concrete according to claim 1, wherein the cross-sectional shape of each of the minute grooves 3 is a dovetail shape. 4. The permanent form for concrete according to claim 1, wherein the cross-sectional shape of each of the minute grooves 3 is constituted by a combination of grooves having different heights and widths. .