JP2601063B2 - Water-permeable formwork - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water permeable form, and more particularly to a form suitable for casting concrete inside the form.

[0002]

2. Description of the Related Art Recently, attention has been paid to a technique for quickly discharging excess moisture in concrete poured into a formwork, densifying the structure of hardened concrete, and improving its strength. For example, it is disclosed in JP-A-52-137136. The form shown in this publication has a filter sheet, such as a nonwoven fabric or a woven cloth, which allows only moisture to pass through, on the concrete casting surface side of the form plate, and has water permeability. .

[0003] By the way, when casting concrete using such a formwork, not only the entire amount of concrete is cast at one time, but also the concrete is cast at several times.
For example, it is used in the construction of massive concrete structures. In the case where the concrete is cast a plurality of times, the concrete on the upper side is generally performed in a state where the concrete on the lower side is hardened to some extent.

[0004] Here, even when the concrete is cast in a plurality of times, the use of the above-mentioned mold having water permeability is expected to improve the strength of the hardened concrete. There were technical issues to explain.

[0005]

That is, in the above-mentioned formwork, since a water-permeable filter is stuck on the casting surface side, after the concrete on the lower side hardens, the concrete is re-applied on the upper side. When the concrete is poured, the water in the concrete that has been poured flows down through the filter. For this reason, there is a problem that a trace of discoloration due to the flow of moisture remains on the surface of the lower hardened concrete that has already hardened, and the appearance is impaired.

[0006] The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to reduce the number of times that concrete is cast using a water-permeable mold. An object of the present invention is to provide a formwork in which no trace of discoloration remains on the surface.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a water permeable form provided with a water permeable material on a concrete casting surface of a form plate, which is cast into the form. The water-permeable material is provided with a water-impermeable portion corresponding to the joint portion of the concrete, and a drain hole is provided near the upper portion of the water-impermeable portion and penetrates the form plate.

[0008]

In the formwork of the above construction, a water-permeable material is provided with a water-impermeable portion corresponding to a joint portion of concrete poured into the formwork, and the formwork plate is provided only in the vicinity of above the water-impermeable portion. Since the drainage hole that penetrates is provided, the water in the concrete poured on the upper side is prevented from flowing down by the impermeable part when flowing down the permeable material, and the blocked water is discharged from the drainage hole. It is discharged to the outside and is prevented from flowing downward.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a first embodiment of a water-permeable mold according to the present invention. The formwork 10 shown in FIG. 1 includes a formwork plate 12 and a water-permeable material 14 attached to the concrete casting surface side of the formwork plate 12. The formwork 10 shown in this embodiment uses a relatively long formwork plate 12 so that concrete can be poured a plurality of times.

The water-permeable material 14 is provided with a water-impermeable portion 16 at a position corresponding to the joint portion A of concrete. In this embodiment, the impermeable portion 16 is
1 in a direction perpendicular to the plane of the paper shown in FIG. As a means for forming the water-impermeable portion 16, for example, if the water-permeable material 14 is a combination of woven fabrics having different mesh sizes or a combination of a nonwoven fabric and a water-impermeable porous film, a woven fabric or By impregnating the nonwoven fabric with a synthetic resin or an adhesive, the band-like water-impermeable portion 16 having a desired width can be easily formed. If the water-permeable material 14 is a fiber made of a synthetic resin, the impermeable portion 16 can be formed by crushing the eyes by heat fusion.

Further, a drain hole 18 penetrating the form plate 12 is provided near the upper part of the water-impermeable portion 16. The drain holes 18 are provided only in this portion, and in this embodiment, the width of the form plate 12 is arranged in three rows at appropriate intervals in a direction orthogonal to the paper surface of FIG. It is provided over the entire length in the direction.

When the installation of the formwork 10 constructed as described above is completed, first, the lower concrete 20 is cast inside the formwork 10. Lower concrete 2
When 0 is poured, the excess moisture contained in the concrete moves sideways due to its own weight or vibration by a vibrator, and is discharged downward through the water permeable material 14, whereby The strength of the hardened concrete increases.

The upper concrete 22 is poured while the lower concrete 20 has hardened to some extent. When the upper concrete 22 is poured, the excess moisture contained in the concrete moves to the side and is discharged downward through the water permeable material 14, as in the case of the lower concrete 20. When the water flowing down the water-permeable material 14 reaches the portion where the water-impermeable portion 16 is provided, the water flowing-down is stopped, and the stopped water flows from the drain hole 18 to the outer surface of the form plate 12. Is discharged.

[0014] Accordingly, excess water accompanying the casting of the upper concrete 22 is discharged without passing through the surface of the lower concrete 20, and no trace of discoloration is generated on the surface of the lower concrete 20.

FIG. 2 shows a second embodiment of the present invention. In the embodiment shown in the figure, the upper and lower form plates 12 having a size corresponding to approximately one concrete casting height are shown.
a, 12b are used, and each form plate 12a, 12b
On the concrete casting surface side of the permeable material 14a,
14b is stuck. These water permeable materials 14a, 14b
Are bent at the edges of the form plates 12a and 12b, and the form plates 12a and 12b are
b.

An impermeable portion 16 is formed on the upper end side of the water permeable material 14b adhered to the lower form plate 12b so as to correspond to the joint A of the concrete to be cast. Further, a plurality of drain holes 18 are formed through the upper mold plate 12a so as to be located in the vicinity of the impermeable portion 16 above. With the thus configured mold, the same operation and effect as in the above embodiment can be obtained.

[0017]

As described in detail in the above embodiments, according to the water-permeable mold according to the present invention, when concrete is poured in a plurality of times, the concrete is cast on the previously cast concrete surface. In addition, the occurrence of discoloration due to the flow of moisture can be effectively prevented.

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Formwork 12 Formwork board 14 Water permeable material 16 Water impervious part 18 Drainage hole 20 Lower concrete 22 Upper concrete A Joint part

Claims (1)

(57) [Claims] 1. A water-permeable formwork having a water-permeable material provided on a concrete casting surface of a formwork plate, wherein the water-permeable material is provided with a water-impervious portion corresponding to a joint portion of concrete cast in the formwork. And a drain hole penetrating the form plate only near the upper part of the water-impermeable portion.