JPS63120606A - Manufacture of concrete product, surface of which has washing section - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention forms a friction-enhancing vibration part on a concrete pile, and forms a decorative pattern on the surface of a concrete pillar, beam, gate post, ball, etc. This relates to the manufacturing method of concrete products made by centrifugal forming, and belongs to the industrial field that deals with concrete products made by centrifugal forming.

(Prior Art) Conventionally, a washing method has been known in which when the surface of a concrete product is in a green hardened state, a part of the cement mortar on the surface is removed to expose aggregate on the surface.

This cleaning method involves applying a hardening retardant to the inner surface of the formwork in which concrete is to be formed, pouring the concrete, and after removing the mold, the semi-hardened cement mortar on the cement surface is washed out with water to expose the aggregate. A method is adopted in which the surface of concrete after hardening is dissolved and removed using an acid such as hydrochloric acid or sulfuric acid.

It is possible to use these washing methods to expose aggregate at desired locations on the surface of concrete piles. In other words, the strength of a pile buried underground increases as the frictional force with the stratum increases. However, geological formations are made up of multiple layers with different properties, and while it is desirable to increase the friction with layers such as gravel, it is not desirable to increase the friction with soft layers. , it is necessary to selectively expose aggregate at desired locations in the concrete layer.

(Problems to be Solved by the Invention) However, when manufacturing concrete products by centrifugal molding, according to the former of the conventional washing methods,
There is a problem in that the hardening retardant applied to the formwork diffuses on the inner surface of the formwork due to centrifugal force, making it difficult to accurately form the desired aggregate exposed surface.

In addition, the latter of the conventional cleaning methods is dangerous due to the handling of acids, requires specialized workers, and even specialized workers do not clean concrete based on the use of acids.
There is a problem in that it is not easy to accurately form the surface of 1-1 according to a desired shape, and the work efficiency is also not good.

(Means for Solving the Problems) The basic purpose of the present invention is to solve the above-mentioned problems. It provides law.

That is, in this invention, concrete is poured into a centrifugal molding form with a predetermined shape of curing retarder paper pasted on the inner wall,
After the concrete product is centrifugally formed by a conventional method, the surface of the concrete product that is in contact with the hardening retardant paper is washed out and the cement mortar near the surface is removed to expose the aggregate. .

The hardening retarder paper can be coated with or impregnated with both a release agent and a cement hardening retarder, or just a cement hardening retarder, or can be coated with or impregnated with other chemicals if desired. It is also possible to use an impregnated one.

The cement hardening retarders used here include lignins, sugar oxides such as gluconic acid, sugars such as sugar,
Fluorine compounds such as magnesium silicofluoride can be mentioned as an example.

This curing retarder paper is cut into a predetermined shape according to the shape to be added to the surface of the concrete product. The predetermined shape can be arbitrarily determined, and it can also be shaped so as not to represent a famous air volume or a famous person's image, such as forming a pattern on the surface of a concrete product. Any figure can also be represented.

For example, when cutting curing retarder paper into a predetermined shape, curing retarder paper of the same shape can be easily manufactured using NC-controlled (numerically controlled) cutting, and curing retarder paper of various shapes can be easily manufactured. It is also possible to efficiently cut curing retarder paper.

An adhesive layer made of adhesive, pressure-sensitive adhesive, etc. is provided on the surface of the curing retarder paper formed into a predetermined shape, and the paper is pasted to a predetermined location on the inner wall of a centrifugal molding form via this adhesive layer. For example, taking into consideration the depth of the pile to be driven into the ground and the geological condition,
Affix it to the inner surface of the formwork at the location of the concrete pile where you want to expose the aggregate. When adding a pattern to the surface of a concrete product, the pattern is attached to the inner surface of the formwork so as to match the part of the concrete product to be patterned.

This centrifugal forming form is not limited to a specific shape, and can be applied to various forming forms used for manufacturing concrete products of various shapes to be formed. Using a formwork with this curing retarder paper attached to the inner wall, the concrete content is centrifugally formed, compacted, and hardened. The washing and removal of cement mortar on the surface of the concrete 1 to product after demolding can be carried out by simple and inexpensive washing with water. It is also possible to use a solution in which various chemical solutions are dissolved as desired.

In addition, the depth of washing mentioned above is based on the amount applied to the curing retarder paper.
It can be set freely by adjusting the nature and type of the impregnated chemical and the curing time of the concrete.

(Operation of the invention) That is, according to the present invention, the hardening retarder paper attached to the inner wall of the centrifugal molding form comes into contact with the surface of the concrete where the aggregate is to be exposed, and the hardening retarder paper is coated or impregnated. The chemical applied penetrates into the concrete surface. This agent contains either a release agent, a concrete hardening retarder, or only a cement hardening retarder, which inhibits the hardening of the concrete in contact with the spreading agent paper.

After compacting with a centrifugal molding machine, the concrete is then cured at room temperature or by steam curing, and after being removed from the mold, the concrete surface where the hardening retardant paper contacts is washed away, since the concrete in this area is in a semi-hardened state. Cement and sand are easily washed out and removed, and the unevenness of the aggregate is formed on the surface of the concrete product precisely following the shape of the hardening retarder paper, dramatically improving the coefficient of friction.

In addition, concrete is a mixture of aggregates with various particle sizes, and due to the centrifugal force during centrifugal forming, large-diameter aggregates, that is, coarse aggregates, are scattered more on the surface side, making the unevenness more noticeable. , the friction coefficient is significantly improved, and the appearance is also improved.

Therefore, even when it is desired to add a pattern to the surface of a concrete product, a highly decorative pattern can be accurately formed using the curing retarder paper.

(Example) An example of the present invention will be described below based on FIGS. 1 to 4.

The curing retarder paper 1 used in this example has a multilayer structure as shown in FIG.

That is, a waterproof protective layer 3 is provided on the other side (lower layer in the figure) of the base paper 2, which has a chemical layer 1a coated with a release agent and a cement hardening retarder. An adhesive layer 4 is further formed in the lower layer, and a separator 5 is provided on the surface of the adhesive layer 4.

The hardening retardant paper 1 is cut into a predetermined shape corresponding to the shape desired to be added to the surface of the concrete pile, and then used to form the inner wall 6a of the centrifugal forming form 6 for forming a cylindrical concrete product. The curing retarder paper 1 from which the separator 5 has been removed is attached to a predetermined location via the adhesive layer 4 (FIG. 2).

With the chemical layer 1a of the hardening retardant paper 1 exposed inward, concrete 7 mixed with cement, aggregate, and water is poured into the mold 6 using a conventional method, and the mold is molded using a centrifugal molding machine (not shown). 6 to perform centrifugal molding (Fig. 3). At this time, it is also possible to increase the strength by arranging reinforcing bars as necessary.

A cylindrical concrete pile 8 is obtained by this centrifugal forming machine.

Next, at least the part of the concrete pile 8 that was in contact with the hardening retarder paper 1 is washed with water to remove the semi-hardened cement mortar on the surface part.

Next, on the removed surface area, an uneven part having the same shape as the hardening retardant paper 1 is formed by washing out the cement mortar, and coarse aggregate with a relatively large diameter is exposed in an orderly manner, so that the aggregate exposed surface 9 is formed. It is formed.

This concrete pile 8 is embedded in the ground, and the exposed aggregate surface 9 comes into contact with a desired stratum 10, increasing friction and improving strength.

FIG. 5 shows another embodiment, in which a pattern 12 is formed on the surface of a concrete product 11 by using curing retarder paper in a predetermined shape.

In this example, the hardening retarder paper is cut into a predetermined shape corresponding to the pattern desired to be added to the surface of the concrete product 110, and then washed out in the same manner as in the previous example to form the pattern 12. It is. On the surface where the aggregate is exposed by washing out, relatively large-diameter coarse aggregate is exposed in an orderly manner, and the exposure of this aggregate has the effect of greatly improving the decorative effect.

The shape of these curing retarder papers is arbitrary, and they can be shaped as appropriate to match the pattern desired on the surface of the concrete product. It is also possible to display patterns in multiple locations.

Further, the shape and use of the concrete product to which the pattern is added are not particularly limited, and the present invention can be applied to various concrete products formed by centrifugal molding.

In these examples, a paper coated with both a release agent and a cement hardening retardant was used as the hardening retarder paper. Any drug that delays the hardening of cement 1- by the action of the drug may be used.

It is also possible to impregnate the curing retarder paper with the agent. Furthermore, in the above two embodiments, the curing retarder paper has an adhesive layer 4 on one side of the base paper, and a separator 5 on the surface thereof. It is not necessarily necessary to provide a curing retarder paper as shown in Figure 6, and it is also possible to apply adhesive or adhesive to the curing retarder paper or the formwork when pasting it to the formwork. be. Note that 13 in the figure is a chemical layer having both a release agent and a cement hardening retardant applied to its surface.

(Effects of the Invention) As explained above, according to the present invention, concrete is poured into a centrifugal molding form with hardening retarder paper of a predetermined shape pasted on the inner wall, and concrete 1 to product are formed by a conventional method. After centrifugal forming, the surface of the concrete product in contact with the hardening retarder paper is washed out to remove the cement mortar. It is possible to efficiently provide an uneven aggregate exposed surface, and the centrifugal effect allows the coarse aggregate to be exposed in an orderly and close manner, resulting in an extremely beautiful and excellent decorative effect.

[Brief explanation of the drawing]

Fig. 1 is an enlarged cross-sectional view of a release paper used in a sub-example of this invention, Fig. 2 is a partial cross-sectional view of the formwork, and Fig. 3 is a case in which concrete is poured into the formwork and centrifugally formed. FIG. 4 is a cross-sectional view showing the state of use of a concrete product obtained by implementing the present invention, FIG. 5 is a perspective view of a concrete product obtained by another example, and FIG. FIG. 7 is an enlarged cross-sectional view showing a modified example of the curing retarder paper. 1... Curing retarder paper 1a, 13... Drug layer 3
... Protective layer 6 ... Formwork 6a ... Inner wall 8 ... Concrete pile 9 ... Aggregate exposed surface 11 ... Concrete product 12 ... Decorative pattern patent applicant Mitani Seksan Co., Ltd. Furukawa Co., Ltd.

Claims (1)

[Scope of Claims] 1. Concrete is poured into a centrifugal molding form with a predetermined shape of hardening retarder paper pasted on the inner wall, and a concrete product is centrifugally molded by a conventional method. Method 2 for manufacturing a concrete product having a washed-out portion on the surface, characterized in that aggregate is exposed by washing out the surface of the concrete product in contact and removing cement mortar near the surface. and cement set retarder or only cement set retarder applied to the surface;
or a method for manufacturing a concrete product having a washed-out portion on the surface according to claim 1, characterized in that the concrete product is impregnated with water.