JP2601062B2 - 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 a joint portion of concrete.

[0008]

In the formwork of the above construction, the water-permeable material is provided with a water-impermeable portion corresponding to the joint portion of the concrete poured into the formwork. When the water flows down the water-permeable material, the water is prevented from flowing down below the water-impermeable portion.

[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 an embodiment of a water-permeable mold according to the present invention. A mold 10 shown in FIG. 1 includes upper and lower mold plates 12 and 14 and these mold plates 12 and 1.
No. 4, water-permeable material 16, 1 stuck to the concrete casting surface side
And 8.

The formwork 10 shown in this embodiment has a formwork plate 12, which has a size corresponding to almost one concrete casting height.
14 is used, and the water permeable materials 16 and 18 adhered to the respective form plates 12 and 14 are bent at the edges of the form plates 12 and 14, and the ends of the water permeable materials 16 and 18 are located on the upper and lower sides. It is installed so as to be sandwiched between the lower form plates 12 and 14.

The water-permeable material 18 adhered to the lower form plate 14 is provided with a water-impermeable portion 20 at a position corresponding to the joint portion A of the concrete to be cast. In this embodiment, the water-impermeable portion 20 is provided in the form of a strip near the upper end of the lower mold plate 14 over the entire length of the mold plate 14.
As a means for forming the water-impermeable portion 20, for example, the water-permeable material 18
However, if the combination of woven fabrics with different eye sizes or a combination of a nonwoven fabric and a water-impermeable porous film, the desired woven fabric or nonwoven fabric is impregnated with a synthetic resin or an adhesive. The band-shaped impermeable portion 20 having a width can be easily formed. Further, if the water-permeable material 18 is made of a synthetic resin, the water-impermeable portion 20 can be formed by heat fusion.

The impervious portion 20 is not only formed in a strip shape near the joint A of the concrete to be cast, but also, for example, covers the entire area of the water permeable material 18 above the joint. It is good.

When the installation of the formwork 10 configured as described above is completed, first, the lower concrete 22 is poured into the formwork 10. Lower concrete 2
When the concrete 2 is cast, 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 18, whereby The strength of the hardened concrete increases.

At this time, in this embodiment, since the belt-shaped water-impervious portion 20 is provided corresponding to the position of the top of the lower concrete 22, the concrete at the top of the lower concrete 22 is cast. The discharge of excess moisture contained therein is not promoted, but this does not cause any problem even if the water-impermeable portion 20 is not formed, because the condition is similar in the vicinity of the top of the poured concrete. .

Then, the upper concrete 24 is poured while the lower concrete 22 has hardened to some extent. When the upper concrete 24 is poured, the excess moisture contained in the concrete moves to the side and is discharged downward through the water permeable material 16 as in the case of the lower concrete 22. Then, the water flowing down along the water permeable material 16 reaches the water permeable material 18 of the lower form plate 14,
The water-permeable material 18 tries to flow down, but the water-permeable material 1
Since the water impervious part 20 is provided in 8, its flow is prevented at this part.

The water that has been prevented from flowing down in this way is:
In this embodiment, the water is discharged to the outside from the ends of the water permeable materials 16 and 18 sandwiched between the form plates 12 and 14, so that the water does not flow down the surface of the lower concrete 22.

[0017]

As described in detail in the above embodiments, according to the water-permeable formwork of the present invention, when concrete is cast 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 an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Formwork 12,14 Formwork board 16,18 Water permeable material 20 Impervious part 22 Lower concrete 24 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. A water-permeable formwork comprising: