JPH0512545U - Formwork for concrete joints - Google Patents

Abstract

(57) [Abstract] [Purpose] It is easy to work on the surface of concrete 9 for the next concrete placement after demolding by devising the vertical joint formwork 1 used for concrete placement. To [Structure] A concrete setting retarder is present on the inner surface of a mold plate 3 constituting a mold 1 to easily form irregularities on the surface of unconsolidated concrete 9 after demolding. Alternatively, irregularities are formed on the inner surface of the template 3 and the irregularities are immediately obtained after the mold release.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a formwork used in a joint of each section when the concrete structure is divided into some sections and each section is successively concrete-placed.

[0002]

[Prior Art]

 Conventionally, when a concrete structure such as a dam is divided into a plurality of sections and concrete is placed in each section, a formwork for joints is used. Concrete is poured into the sections using this formwork, and the concrete is cured and then demolded. Next, concrete will be placed in the next section adjacent to this section.

In this case, it is necessary that the seam where the sections are in contact with each other should have good compatibility between the cast concrete and the concrete to be subsequently cast. Therefore, in the past, the concrete joining surface on the already placed side was roughened using methods such as chipping, sandblasting, and wire brushing to form fine irregularities, and washing with water etc. for finishing. Was cleaning.

[0004]

[Problems to be solved by the device]

 However, since a large number of reinforcing bars penetrate through the concrete jointing surface that causes roughening as described above, roughening work is troublesome and the amount of work is large, which increases the efficiency of concrete placing work. It was causing a decline.

Further, there is a problem in that noise and dust are generated when the roughening such as chipping is performed. The present invention has been made in view of the above circumstances, and an object thereof is to provide a concrete joint seam formwork that facilitates roughening work and eliminates the problems of noise and dust. ..

[0006]

[Means for Solving the Problems]

 The present invention has the following configuration in order to achieve the above object. That is, a concrete setting retarder for forming irregularities on the concrete joint surface is present on the inner surface of the template 3 that constitutes the joint frame 1 used for concrete placing. ..

[0007]

[Action]

 According to the present invention, the concrete set retarder on the inner surface of the mold plate 3 forming the form makes it easy to remove unconsolidated concrete from the surface of the concrete which the set retarder has acted on after the demolding to form recesses. Unevenness can be formed in the seam. These irregularities can be formed naturally during the demolding work, or can be more efficiently performed by washing the surface with a water jet 11 or the like.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. 1 is a cross-sectional side view of a concrete seam formwork of this embodiment, FIG. 2 is a perspective view of the inner side surface of the formwork of FIG. 1, FIG. 3 is an enlarged view showing work after demolding, and FIG. 3 is a view after the work, and FIG. 5 is an overall view of FIG.

In the concrete joint seam form of this embodiment, a relatively large concrete structure is divided into a plurality of staggered sections, and a vertical joint formwork 1 used at joints where the sections are in contact with each other. Is. The mold 1 is composed of, for example, a plurality of mold plates 3, that is, a mold plate 3 surrounding two or three sides of a section where the casting is performed. The template 3 is assembled by inserting the reinforcing bar 5 into the template 3. Then, for example, when two sides of the square section are surrounded by the template 3, the other two sides are in contact with the already placed concrete of the other section. Similarly, when surrounding three sides, the other one contacts the already cast concrete.

Inside the template 3 of this embodiment, a cloth 7 having a concrete set retarder absorbed therein is arranged at a predetermined interval. The thickness of the cloth 7 can be set according to the depth of the unevenness formed later. However, even with a thin cloth, it is possible to form sufficiently deep irregularities when the work of washing out the surface of the concrete that has not condensed with a water jet or the like after demolding.

Among such concrete setting retarders, NMB's NO. There are 89 products, such as "Distalite" (trade name) manufactured by Jikko Corporation. In addition, substances that generally have an effect of delaying the setting of concrete include carbohydrates such as glucose, fructose, sucrose, starch, cellulose, and their derivatives. Carboxylic acids such as acids and maleic acids Alcohols Phosphoric acid, boric acid, water-soluble fluorinated compounds, etc. can be used.

Further, as other commercially available products, Palic T, Pozzolith # 89, plastiment, Rital, hexaethyl cellulose and the like may be used. After the cloth 1 which has absorbed the concrete set retarder is assembled into the mold 1 constituted by the mold plates 3 arranged on the inner surface, concrete 9 is poured as shown in FIG.

After that, when the mold is removed after a certain curing period, as shown in FIG. 3, the cloth 7 in which the concrete setting retarder is absorbed is stuck to the exposed surface of the concrete 9. The worker removes the cloth 7 by hand or wash it off with a water jet 11. At this time, the surface of the concrete 9 that was in contact with the cloth 7 is not yet condensed, and the irregularities can be easily formed by the force of the water jet 11.

Further, during this work, it is possible to eliminate or reduce the generation of noise and dust because the concrete is not condensed as described above. After removing the cloth 7, the recess 13 shown in FIG. 4 is formed.

As described above, a large number of such recesses 13 are present on the joint surface of the concrete (FIG. 5), and it is compatible with the concrete to be placed next without performing the conventional roughening work. Can be improved sufficiently.

In the above examples, the concrete set retarder was present in the state of being absorbed by the cloth 7, but in other examples, for example, the concrete set retarder was formed into a jelly and was applied to the inner surface of the template 3. It can also be applied. The coating method can also be carried out by spraying with compressed air or the like.

As described above, the concrete setting retarder that has been allowed to exist without the cloth 7 can be easily removed by washing it off with a water jet or by scraping it off by an operator, so that the familiarity of concrete can be improved. The unevenness for improving can be easily formed.

In particular, when the concrete setting retarder is sufficiently working, the mold plate 3 is peeled off from the surface of the concrete 9 when the mold is removed, so that unevenness is automatically formed on the surface of the concrete 9. Can be expected.

When the concrete set retarder is used, as shown in FIG. 6 or 7, irregularities may be formed in advance on the inner surface of the template 3. That is, as shown in FIG. 6, the surface of the concrete 9 exposed after demolding is provided by providing a large number of short cylindrical projections (this shape can take any shape) 15 on the inner surface of the template 3. In addition, a short cylindrical recess is also formed, and together with the set retarder, many irregularities can be formed on the joining surface. In this case, it is also possible to make the template itself corrugated as shown in FIG.

In this way, the unevenness formed on the surface of the concrete is set to have the optimum shape and density, and further the depth and height depending on the magnitude and direction of the shearing force which is considered to work on the seam in design. It is desirable to do.

As described above, the concrete setting retarder delays the setting of the concrete surface, and the surface of the non-set concrete is treated with a water jet or other mechanical or physical method to form unevenness. Can be formed.

Further, by forming the unevenness on the inner surface of the template in advance, it is possible to automatically form the unevenness on the surface of the concrete without requiring a great deal of work after demolding. Become. In this case, the work corresponding to the conventional roughening work is unnecessary.

[0023]

[Effect of the device]

 As explained above, according to the concrete joint seam form of the present invention, the presence of the concrete setting retarder makes it possible to easily form irregularities on the surface of the concrete after demolding. Obtainable. Therefore, the work that replaces the conventional roughening work is extremely easy or unnecessary, and there is no need to perform chipping or sandblasting, so that the generation of noise and dust can be eliminated or reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional side view of a concrete seam formwork according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view showing an inner surface of the mold of FIG.

FIG. 3 is an enlarged perspective view showing a state where a predetermined work is performed on the surface of concrete that has been cast and cured by the formwork of FIG.

FIG. 4 is a perspective view showing a state where the work of FIG. 3 is finished.

5 is an overall perspective view of FIG.

FIG. 6 is an internal perspective view of a concrete joint seam form used in another embodiment.

FIG. 7 is a perspective view of the inside of a concrete joint seam form of another embodiment.

[Explanation of symbols]

 3 Template 5 Rebar 7 Cloth 9 Concrete 11 Water Jet 13 Recess

Claims (1)

[Scope of utility model registration request] 1. A concrete setting retarder for forming unevenness on a concrete joint surface is present on the inner side surface of a template 3 constituting a joint frame 1 used for concrete placing. Formwork for concrete joint seams.