JPH0337632B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides concrete structures with a predetermined shape,
It relates to a pouring formwork that is temporarily installed to make it to a certain size.

[Conventional technology and its problems]

Conventionally, molds made of steel, plywood, etc. were often used as pouring formwork, but in order to improve the release from the concrete when dismantling the formwork after a predetermined number of days have passed after concrete pouring, molds made of steel or plywood were often used. A release agent was applied. If the release material was not sufficiently applied at this time, concrete would adhere to the surface of the pouring form and had to be removed. In addition, in order to completely perform this coating work, depending on the concrete structure, the extra process of assembling and dismantling is required after the large-scale casting form is moved with a retoucher etc. in the assembled state. In short, painting work had to be carried out in spaces too narrow for people to enter, and work such as tunnel construction was extremely dangerous.

On the slab surface where the pouring formwork is placed in the form of a horizontal flat plate, there have been frequent falls due to workers slipping due to the applied release agent.

An object of the present invention is to provide a casting formwork in which the above-mentioned problems are solved.

[Means for solving problems]

The present invention involves forming a film-like base layer of polyolefin resin or the like on the surface of the substrate of the casting form body for ready-mixed concrete, and further forming a film-like base layer of polyolefin resin or the like on the surface of the base layer with a large number of micro pinholes. forming a coating layer, and on the surface of the coating layer,
By sliding a solid or semi-solid release agent with a coefficient of thermal expansion larger than that of the coating layer while pressing the release agent, the micro pinholes are impregnated with the release agent. , solves the above problems.

[Effect]

When concrete is poured into the pouring form, the fresh concrete generates heat of hydration reaction inside the coating layer. The heat of the hydration reaction thermally expands the coating layer and the release agent in the tiny pinholes, and the release agent with a large coefficient of thermal expansion leaches out, forming a thin film of release agent between the coating layer and the concrete. The covering layer and the poured concrete do not come into direct contact, and the poured concrete does not adhere to the covering layer. Therefore, the work of removing the casting frame body can be easily performed.

〔Example〕

To explain the present invention in detail based on the drawings, in FIGS. 1 and 2, 1 is a pouring formwork temporarily installed when pouring concrete 2, and 3 constitutes the formwork 1. This is the formwork body. Substrate 3 of the form body 3
A base layer 4 made of thermoplastic polyolefin resin or the like is provided on the a surface 3b, and a covering layer 5 similarly made of polyolefin resin or the like is provided on the surface of the base layer 4. Further, a large number of minute pinholes 7 are formed in the coating layer 5 and are impregnated with a release agent 6 to improve the release (separation) of the pouring formwork 1 from the poured concrete 2. The substrate 3a of the form body 3 may be made of wood, steel, aluminum, or the like.

Therefore, the manufacturing method of the form body 3 will be explained with reference to FIG. is placed. The receiving plate 8 on which the substrate 3a is placed is first heated to a high temperature in a furnace with an atmosphere of about 200°C to 250°C in a high-temperature heating process. In the next initial electrostatic coating step (), a high voltage is applied between the paint spraying device 9, which is a cathode, and the receiving plate 8, which is an anode. The powdered paint P that is sprayed is electrically charged during scattering, is attracted to the surface of the substrate 3a, and starts fusing. As the powder coating P, polyethylene and polypropylene, which are collectively referred to as polyolefin resins, are preferable.

Next, in the medium temperature heating step (), the receiving plate 8 and the substrate 3a are heated at 150°C to 200°C, preferably 180°C, in a heating furnace (not shown) in order to maintain the temperature necessary for fusing the powdered paint P. It is heated and dried in an atmosphere of ~190°C for about 20 minutes. In this way, the layer thickness is 100μ~
In the liquid spraying process (), a liquid injection device 1 is applied to the surface of the base layer 4 formed in a film shape of about 200μ.
1, spray a liquid agent W such as water or thinner. Next, after cooling these to about room temperature,
In the latter electrostatic coating step (), before the liquid agent W has dried, the powdered paint P is sprayed onto the surface of the base layer 4 from the paint spraying device 10 to perform electrostatic coating. In this case as well, the powdered paint P charged during scattering is attracted to the surface of the base layer 4 in the same manner as described above. In the subsequent high-temperature heating step (), heating is performed for about 20 minutes in an atmosphere with a furnace temperature of 180°C to 220°C, preferably 200°C to 210°C, during which time the powdered paint P is fused. However, the layer thickness is 300~400μ
A film-like covering layer 5 is formed, and a base layer 4 is formed.
In the process of adhering to the powder coating material P, the liquid agent W evaporates upwardly inside the powdered coating material P where fusion is progressing. At this time, minute pinholes 7 are formed in the coating layer 5 due to the locus of movement of the liquid agent W particles within the fused powder paint P.
The form body 3 is then taken out from the receiving plate 8 outside the furnace. Note that the surfaces of the base layer 4 and the coating layer 5 are formed into coated surfaces that are uniform throughout and have an excellent surface finish. As shown in Figure 3 (),
The micro pinholes 7 of the coating layer 5 are impregnated with the release agent 6 by sliding the solid or semi-solid release agent 6 onto the surface of the coating layer 5 while being pressed. In this way, the formwork main body 3 formed by fixing the base layer 4 to the surface 3b of the substrate 3a and the coating layer 5 having minute pinholes 7 to the surface of the base layer 4 is placed inside the casting form 1. concrete 2
When concrete is poured, the following phenomenon occurs inside the coating layer 5 due to the heat generated by the hydration reaction of the fresh concrete. That is, the temperature of the coating layer 5 and the release agent 6 in the pinholes 7 rise at the same time due to the heat of hydration reaction, which is generally said to be within 80°C, but the temperature of the release agent 6 in the coating layer 5 and the polyolefin resin constituting the coating layer 5 are increased at the same time. Due to the difference in thermal expansion coefficient with agent 6,
Release agent 6 oozes out from pinhole 7. To explain the leaching process of the release agent 6 from the pinholes 7 at this time, in response to the heat generated from the poured concrete 2, the release agent 6 in some of the pinholes 7 separates from the concrete 2 and the coating layer 5. The release agent 6 in the remaining pinholes 7 exudes the release agent 6 after the contact, respectively. The release agent 6 also oozes out from the pinholes 7 when the elastic coating layer 5 is compressed by the lateral pressure of the poured concrete 2. The release agent 6 leached out in this way diffuses onto the surface of the coating layer 5 to form a molecular film (not shown) or a thin film 12 having a thickness close to it. The above coating layer 5
Microscopically, the poured concrete 2 and the cast concrete 2 do not directly contact each other, but the thin film 12 exists between them. Therefore, the poured concrete 2 and the form body 3 can be released from the mold very easily. Since only a predetermined amount of the release agent 6 impregnated into the pinholes 7 is leached out of each pinhole 7 when the concrete 2 is placed once, the number of times the release agent 6 is placed is approximately 5 to 6 times. diversion is possible.
Therefore, it is only necessary to impregnate the release agent 6 once every 5 to 6 times of pouring, and there is no need to apply it every time concrete is poured as in conventional pouring forms.

As another example, as shown in FIG. 4 and FIG. A pinhole 7 may also be formed. In addition, in this case, the base layer 4 and the covering layer 5 are
After the film formed of the powdered paint P is thermocompressed onto the surface of the substrate 3a of the form body 3, or is fixed using an adhesive or the like, or the base layer 4 is formed, Furthermore, a film of the powdered paint P may be fixed to the surface of the base layer by a similar method.

In the present invention, as mentioned above, thermoplastic resin such as polypropylene or polyethylene is used as the base layer 4.
and were respectively adopted as the material of the coating layer 5,
This is because the resin is extremely stable against alkalis and acids, has a high surface hardness and is difficult to scratch, has excellent mold releasability at low temperatures, or has no pinholes. This is also based on properties such as the fact that the modulus of elasticity does not decrease.

〔Effect of the invention〕

As described above, in the present invention, the release agent 6 in the micro pinholes 7 leaches out due to the heat and pressure generated by the hydration reaction of fresh concrete, and the coating layer 5
Since the surface of is covered with a thin film 12 of the release agent 6, there is no microscopic contact between the coating layer 5 and the poured concrete 2, and the concrete 2 and the formwork when the poured formwork 1 is dismantled. The mold release from the main body 3 is easily performed. Therefore, in addition to the inherent properties of the synthetic resin, which has fairly good peelability from concrete 2 compared to other formwork materials, the above effects work synergistically, making it extremely easy to remove formwork 1. There are benefits to be gained.

Further, since the casting form 1 of the present invention can be used continuously many times, there is no need to apply a release agent each time the form is assembled, unlike the conventional method.

Furthermore, conventionally, after the release agent is applied to the formwork 3 installed horizontally on the floor slab, the release agent floats on the surface of the pouring formwork 1, making it easy for workers to slip. Working on such a formwork 1 was extremely dangerous, but in the present invention, separation from the concrete 2 is achieved by a thin film 12 of release agent 6 formed on the surface of the formwork body 3 as the concrete 2 is poured. Since it is decided to do this by holding the mold, the worker will not slip even if he or she walks on it, and an accident of falling from the pouring formwork 1 can be prevented. Furthermore, since the coating layer 5 is formed on the surface of the film-like base layer 4, the release agent 6 in the minute pinholes 7 can be prevented from seeping out to the substrate 3a side.

As described above, the present invention has extremely significant effects in terms of labor saving and safety management in the construction industry.

[Brief explanation of drawings]

FIG. 1 is an enlarged sectional view showing an embodiment of the present invention;
Fig. 2 is a vertical cross-sectional view showing concrete poured inside the pouring form, Fig. 3 is a cross-sectional view showing the method of manufacturing the casting form according to the present invention in the order of steps, and Fig. 4 is a vertical cross-sectional view showing concrete poured inside the pouring form. FIG. 5 is an enlarged cross-sectional view showing an example, and FIG. 5 is a cross-sectional view showing a method of forming minute pinholes in the manufacturing method. 3...Form body, 3a...Substrate, 3b...Surface, 4...
Base layer, 5... Covering layer, 6... Release agent, 7... Minute pinhole.

Claims (1)

[Claims] 1 Substrate 3a of pouring form body 3 for fresh concrete
A film-like base layer 4 made of a polyolefin resin or the like is formed on the surface 3b of the base layer 4, and a coating layer 5 made of a polyolefin resin or the like having a large number of micro pinholes 7 is formed on the surface of the base layer 4. The release agent 6, which is solid or semi-solid and has a coefficient of thermal expansion larger than that of the coating layer 5, is pressed and slid onto the surface of the coating layer 5, thereby impregnating the micro pinholes 7 with the release agent 6. A pouring formwork characterized by being constructed with.