JPH0659534U - Concrete formwork board - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a concrete formwork board that is lightweight and has good cutting properties, as well as excellent releasability and durability. [Structure] Laminated paper is used as a board material 1.
On one surface, a pattern-shaped release agent layer 2 having a large number of a part to which the release agent was attached and a part where the paper surface was exposed was printed in a pattern.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a formwork used when pouring concrete.

[0002]

[Prior art]

 Generally, wooden plywood is used as the concrete formwork, but recently, a paper form made of this has been proposed. For example, the one described in JP-A-2-128068 shows a concrete formwork board composed of a plurality of paper layers. This has the advantage of being lightweight, easy to cut on site, and excellent in workability.

[0003] Also, it is necessary to secure the mold releasability of the mold from concrete, and there is a method described in JP-A-59-102053 as a method for improving the mold releasability. This is a paper in which a paper is adhered to the surface of plywood with an adhesive and a release layer is formed on this paper with a synthetic resin or a release agent.

[0004]

[Problems to be solved by the device]

 By the way, when the concrete surface was observed when the concrete was cured and the form was removed, it was found that there were so-called avatars because fine air bubbles remained. This is a result of insufficient air bubbles being discharged between the formwork and concrete. In addition, it is desirable that the breathing water, which is excess water, be promptly discharged during the curing process. This is because this breathing water rises along the weirs of the formwork, increasing the water-cement ratio of the concrete surface layer and making the durability of the concrete surface layer lower than that of the inside.

From the above viewpoint, when the above-mentioned mold is examined, in the invention described in JP-A-2-128068, since the entire surface is made of paper, breathability and water permeability are good and air bubbles are not generated. It is also excellent in terms of water discharge. However, since the paper and the concrete are in direct contact with each other, there is a problem that the mold releasability is insufficient and the durability is not expected because the whole becomes water absorbing state.

Further, in the invention described in JP-A-59-102053, mold releasability and water resistance are good, but air permeability and water permeability are almost lost, so that air bubbles remain on the concrete surface or breathing Problems such as not draining water will remain.

The present invention has been made in view of the above matters, and an object thereof is to provide a concrete formwork board that is lightweight, has excellent cutting properties, and has excellent releasability and durability. .

[0008]

[Means for Solving the Problems]

 The present invention has the following configuration in order to solve the above technical problems. That is, paper is laminated to form a board material 1. On one surface of the board material 1, a pattern-shaped release agent layer 2 composed of a large number of areas where the release agent is attached and areas where the paper surface is exposed is printed in pattern. Printed.

As the pattern, vertical stripes, horizontal stripes, grids, diamonds, polka dots, etc. In short, it is preferable that parts where the paper is exposed and the release agent layer 2 are interleaved.

[0010]

[Action]

 Since the whole is a board material laminated with paper, it is lightweight and has good cutting properties, and can be easily cut with a knife-type cutter. Further, since the release agent layer 2 is formed in a pattern including a large number of portions where the release agent is attached and portions where the surface of the paper is exposed, releasability is secured in the portion where the release agent layer 2 is formed, and the paper is Ventilation and water permeability are secured in the exposed parts. Further, since the release agent layer 2 appropriately suppresses the water absorption, the durability is good as compared with the case where only the paper is used.

[0011]

【Example】

 An embodiment of the present invention will be described with reference to FIGS. The board material 1 is obtained by impregnating a paper material with a water resistant adhesive and curing it with pressure. Examples of the water resistant adhesive include urea-vinyl chloride resin, phenol resin, melamine resin, resorcinol resin, α -Olefin maleic anhydride resins are preferred. The pressurization may be either heating or normal temperature.

Then, the release agent layer 2 is printed on one surface of the board material 1. As the release agent layer 2, a release agent dispersed in a synthetic resin solution can be used. Examples of the release agent include emulsion type, paraffin type and silicone type. Further, ceramic such as hexagonal boron nitride or solid lubricant such as Teflon may be dispersed and contained in the synthetic resin solution. Further, as the synthetic resin solution, melamine resin system, phenol resin system, epoxy resin system, urethane resin system and the like are preferable.

The printing is not performed on the entire surface of the board material 1, but as shown in FIGS. 2 to 4, a pattern having a large number of portions where the release agent is attached and portions where the paper surface is exposed, that is, The printed portion and the non-printed portion are formed to have a pattern.

In the pattern shown in FIG. 2 as this pattern, printing portions and non-printing portions are alternately arranged to form a vertical stripe. Further, the one shown in FIG. 3 is printed in a grid pattern. Printing can be by roller or spray.

Further, in the one shown in FIG. 4, a rhombus is formed by intersecting diagonal lines. Of course, any pattern such as a checker pattern or a honeycomb pattern can be used.

In the above-mentioned configuration, the printing portion has no air permeability, but has good releasability. On the other hand, the non-printing portion has low releasability, but moisture and air pass therethrough as shown by arrow F. Aeration and water permeability will be good. Therefore, the bubbles 4 in the concrete 3 are discharged to the outside from the non-printing portion, that is, the portion where the paper is exposed, and the breathing water is also discharged from here. On the other hand, after curing the concrete, the board material 1 is released from the mold, but the part of the release agent layer 2 has a low affinity with the concrete and can be easily released.

In some cases, water in concrete flows out directly, and in others, it is once absorbed by the board material 1 and then evaporated. The ratio of the printed part to the non-printed part is preferably about 3 to 7 to 7 to 3, and it depends on whether the mold release property or the air permeability is important, and it is also appropriately selected depending on the concrete to be placed. There is a need.

In addition, if necessary, the paper laminated material 2 is manufactured using waterproofed paper, or a water resistant treatment such as forming a waterproof film on the paper laminated material 2 is applied to obtain sufficient water resistance. You can get sex.

As described above, according to the concrete formwork using this formwork board, since a concrete structure with less patter can be formed, the surface area of the concrete structure is minimized after completion. In addition to being able to do so, it is possible to make it more compact. This will greatly improve the resistance to acid rain, freezing, and salt damage in coastal areas.

The amount of dehydration according to the present invention can be expected to be about 1 to 2 liters per cubic rice depending on the conditions. Since this dehydration is mainly performed in the part near the concrete surface with a thickness of about 10 cm, it is considered that the amount of dehydration in the part reaches more than 10% of the mixed water. Therefore, it is possible to greatly improve the strength and watertightness on the concrete surface where the strength is most needed. Further, since the concrete surface solidifies early after pouring the concrete, it is possible to remove the formwork relatively early, which can contribute to the progress of various processes.

[0021]

[Effect of device]

 According to the present invention, not only is it lightweight and has good cutting properties, but it is also possible to achieve both releasability and ventilation / water permeability. Further, since the water absorption is appropriately suppressed, the durability is good as compared with the one composed of only paper. Moreover, since the material is paper, it has water absorbability and is low cost.

[Brief description of drawings]

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

FIG. 2 is a plan view showing a release agent layer in a stripe shape according to an embodiment of the present invention.

FIG. 3 is a plan view showing a release agent layer in a grid pattern according to an embodiment of the present invention.

FIG. 4 is a plan view showing a release agent layer having a diamond shape according to an embodiment of the present invention.

[Explanation of symbols]

 1 ... Board material, 2 ... Release agent layer.

Claims (1)

[Scope of utility model registration request] 1. A paper material is laminated to form a board material, and a pattern-shaped release agent layer comprising a large number of a part to which a release agent is attached and a part where the paper surface is exposed is printed on one surface of the board material. Characteristic concrete formwork board.