JP2006290664A - Dry washout process and consolidating agent for use therein - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow removal of a surface layer of concrete placed without using water to facilitate washout finish and permit indoor application. <P>SOLUTION: A consolidating agent paste is obtained by adding a polyvinyl alcohol as a setting retarder, anhydrous gypsum as a hardening accelerator, silica sand as a fine aggregate, and water to aluminous cement and then kneading a resulting mixture. The paste is mixed with gravel, and a resulting mixture is applied to a concrete surface to form a decorative surface layer. When the inside is solidified and the surface looks dry after about 1 hour, the surface is brushed with a wire brush to scrape the surface layer to expose the gravel to the surface. A powder formed from the scraped surface layer is cleaned with a wet sponge. Since the inside is solidified, the gravel does not move and is exposed from the surface by approximately 2-3 mm, thus obtaining a decorative surface with the gravel. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for exposing a decorative material to a concrete surface, and to a method for exposing the decorative material to a concrete surface without using water.

As a method for improving the beauty by decorating an inorganic concrete surface, there is a washing finish. This is to delay the hardening of the cement paste on the finished surface after placing the concrete and wash it away to expose the decorative material such as aggregate on the concrete surface. Similar surface decoration methods include polishing finish and blast finish, but the wash-out finish has a merit that it does not require equipment and is low in cost and can be easily constructed.
This washing finish includes a method using a setting retarder that delays the setting and hardening of cement, a method of washing uncured concrete with water, and a method of pickling after setting the concrete.

The concrete method of delaying the hardening of concrete is to apply the setting retarder to the inner surface of the mold, place the concrete, remove the mold and wash away the uncured cement paste that touches the inner surface of the mold. There are a method for exposing the setting retarder, a method for attaching a paper soaked with a setting retarding agent to the inner surface of the mold or the concrete surface, and a method for directly spraying or applying the setting retarding agent to the cast concrete surface.
Common setting retarders are lignin sulfonate, oxycarboxylate, saccharide derivatives, starch ether, casein, cellulose, poval, citric acid, and so on. The main component is an acid salt, and the setting time can be arbitrarily controlled by the amount added.
In the case of normal concrete, the washout depth is set to 1/3 to 1/2 of the aggregate diameter to prevent the aggregate serving as a decorative material from falling off, so that the delay action is about a few millimeters from the concrete surface. In addition, the amount of setting retarder applied is determined and washed out.
Japanese Utility Model Publication No. 60-191405 Japanese Unexamined Patent Publication No. 53-136028 Japanese Patent Laid-Open No. 53-136029 JP 58-158206 A JP 62-003902 A JP-A 62-003903

The wash-out method that uses concrete added with setting retarder or casts concrete added with setting retarder and then applies a hardening accelerator removes it while the concrete surface is uncured. Then, the aggregate and other cosmetics are exposed on the surface, and the contaminated water containing cement particles and fine aggregate sand is generated by washing out, so it is necessary to dispose of the contaminated water and use water Therefore, it was difficult to construct indoors.
Therefore, the surface layer of the concrete placed without using water can be removed in a dry state, and the surface makeup corresponding to the washout finish can be easily applied even indoors.

A kneaded product of a caking additive with a setting retarder and a curing accelerator added to alumina cement is placed on the decorative surface, and when the inside of the placed paste is agglomerated, the surface is scraped with a brush or the like to remove the cosmetic material. This is an anhydrous washing method that is exposed on the concrete surface.
The decorative material may be placed by adding fine aggregate and water to the caking agent and kneading, or by placing or applying a kneaded mixture of caking agent and water. The surface layer may be rubbed off when the interior of the kneaded product is condensed and the cosmetic material is almost not moved to expose the cosmetic material to the surface.

Setting retarders include starch ether, casein, cellulose, polyvinyl alcohol (Poval), citric acid, sodium citrate, sodium gluconate, tartaric acid, boric acid, lignin sulfonate, oxycarboxylate, sugar, sugar Derivatives and the like can be used. Moreover, what has a silicofluoride, an oxycarboxylate, etc. as a main component can be used similarly.
The setting retarder is generally considered to delay the initial hydration reaction by temporarily blocking the contact between the cement and water by adsorbing itself or the reactants to the cement particle surface. The amount of the agent is determined in consideration of working time and the like.

As the hardening accelerator, gypsum, anhydrous gypsum, hemihydrate gypsum, slaked lime, sodium carbonate, lithium carbonate, calcium chloride, calcium nitrate and the like may be used alone or in combination. The addition amount of a hardening accelerator is 20-70 weight part in the case of anhydrous gypsum with respect to 100 weight part of alumina cements. The amount of the curing accelerator is also determined in consideration of the combination with the setting retarder and the working time.
By adding Portland cement, early-strength Portland cement, white Portland cement, blast furnace cement, fly ash cement, or silica cement, the effect is the same as adding a setting accelerator, so it is combined with a set retarder. The required amount of addition is determined in consideration of the setting time.

A brush is used as a tool for scraping the concrete surface after placing, and a wire brush or a deck brush is used. Further, when the area is not large, the surface layer of the cast concrete can be scraped off by a scrubber.
When the concrete surface is dry or semi-dry, the surface of the concrete is removed as a powder by rubbing the surface with a tool such as a brush, so clean the surface by suction with a vacuum suction device or include water. Wipe clean with a sponge.

  The anhydrous wash-out finishing method of the present invention exposes a decorative material such as aggregate to the surface by rubbing the surface layer of the concrete that has become dry or semi-dried with a brush or the like, while the inside is short due to the action of a hardening accelerator. High strength is developed over time, the cosmetic material does not leave the concrete during the surface scraping operation, only the surface layer can be removed anhydrously, and the washing finish can be easily performed.

Example 1
Supply high-pressure water with a high-pressure washing machine to the concrete surface that forms the decorative surface of the gravel, clean it with a deck brush and make the surface wet, preventing moisture from the makeup layer from being absorbed suddenly by the foundation Increase adhesion stability.
A paste in which an acrylic emulsion was mixed with a caking agent composed mainly of alumina cement on a wet surface was uniformly applied to the thickness of 1 to 2 mm with a trowel as an undercoat. On top of the undercoat is a solid cement composed of an alumina cement, a setting retarder, a curing accelerator, an additive such as a water reducing agent and a fluidizing improver, and an inorganic pigment for enriching the concrete surface. 30 to 40 parts by weight of water was mixed with 100 parts by weight of powder obtained by mixing the binder and silica sand as an aggregate, and kneaded with a hand mixer. The particle size of the silica sand is appropriately selected from Nos. 5 to 7 according to the finished surface.

100 to 200 parts by weight of gravel having a particle size of 1 to 15 mm as a cosmetic material was added to and mixed with the binder paste. Small particles and cobblestones with a flat shape are not suitable as decorative materials for concrete surfaces, and are eliminated.
A mixture of boulder and grazing paste was applied on the undercoat with a trowel, and the surface was leveled to a thickness of 11 mm.

After about 1 hour, it was confirmed that the interior had condensed and did not move even when force was applied to the gravel. The surface of the caking additive paste is in a freshly dried state (semi-dry), but the gravel does not move, so the surface can be scraped without peeling off the gravel. When the surface was rubbed with a wire brush, the caking agent on the surface was removed as a powder or a lump of powder, and the gravel was exposed. Therefore, rubbing was continued until about 2 to 5 mm was exposed.
When the sponge was soaked in water and the powder that floated on the surface was cleaned, the concrete surface was in a wash-finished state with boulders and gravel. It is also possible to scrape the surface with a sponge soaked in water while the surface is dry. Further, the powdery substance floating on the surface may be removed by suction with a vacuum cleaner capable of sucking water.

Example 2
A paste in which an acrylic emulsion was mixed with a caking agent composed mainly of alumina cement on a wet surface was uniformly applied to the thickness of 1 to 2 mm with a trowel as an undercoat. On the undercoat, add 25 to 50 parts by weight of water to 100 parts by weight of a mixture of alumina cement, setting retarder, curing accelerator, and inorganic pigment to enrich the concrete surface as shown in FIG. Kneaded to form a paste. If necessary, mix 5-7 silica sand to increase weight. In addition to silica sand, fly ash, calcium carbonate, bentonite, low refractory earth, blast furnace slag, clay minerals such as Kibushi clay and Sasame clay, talc and the like can be used as the filler.

This paste of caking agent was troweled on the undercoat to form a 9 mm thick layer. Even if the undercoat is not dried, it may be coated with a caking paste.
As a decorative material, gravel with a diameter of about 10 to 30 mm is laid on the surface so that the gravel does not contact or overlap each other within 15 to 30 minutes after applying the decorative layer. When you push boulder into the makeup layer with a wooden mallet or a wood board, the cement mortar in the makeup layer will rise, so push it until the mortar surface is the same as the mortar.
The setting start of the caking agent is checked in advance, and the pressing of the cosmetic material is completed before the setting starts.

  If you want to finish the joints of the decorative material deeply, level the cement paste of the raised makeup layer between the gravel with a brush, and if you want to finish the joints shallowly, level the cement paste raised by the rubber jar, Make it a flat surface.

After about 1 hour, it was confirmed that the interior had condensed and did not move even when force was applied to the gravel. The surface state of the binder paste is a freshly dried state (semi-dry), but the gravel does not move, so the surface can be scraped without peeling off the gravel. When the surface was rubbed with a wire brush, the caking agent on the surface was removed as a powder or a lump of powder, and the gravel was exposed. Therefore, rubbing was continued until about 2 to 5 mm was exposed.
When the sponge was soaked in water and the powder that floated on the surface was cleaned, the concrete surface was washed and finished with boulders and gravel.

As shown in FIG. 1, the caking agent of the present invention starts to condense in about 30 minutes after kneading, completes in a short time of 3 to 4 hours, and has sufficient bending strength in about 4 hours. And compressive strength can be obtained. Since the surface layer is powdered to the extent that a person rubs it with a brush, the decorative material can be exposed to the surface in a dry manner.
Silica sand, fly ash, and the like are blended while increasing or decreasing depending on the required strength of the portion to which the caking agent is applied. In places where a load is not always applied, such as a wall surface, the strength of the caking agent is not so required, so even if a large amount of silica sand or the like is added, no problem occurs.

  The wash-out finishing method of the present invention exposes a cosmetic material such as an aggregate to the surface by scraping the cement paste on the surface of the concrete that has become dry or semi-dried with a brush, etc. The surface layer part can be removed with a brush, but the cosmetic material does not leave the concrete, only the surface layer can be removed anhydrously, and the washing finish should be carried out easily. Can do.

The recipe of the Example of this invention.

Claims (7)

A cosmetic agent is added to an agglomerate containing a set retarder and a curing accelerator in alumina cement, kneaded and placed on the decorative surface. When the interior has set, the surface is scraped to expose the cosmetic material to the concrete surface. An anhydrous washing-out method. A kneading agent with a setting retarder and a curing accelerator added to alumina cement is kneaded and placed on the decorative surface. The decorative material is pushed into the casting surface, and when the interior is condensed, the surface is rubbed off to obtain the cosmetic material. An anhydrous washing method that exposes the concrete surface. 3. The anhydrous washing-out method according to claim 1 or 2, wherein the curing accelerator is gypsum, anhydrous gypsum, hemihydrate gypsum, slaked lime, sodium carbonate, Portland cement, or a combination thereof. An anhydrous washing-out caking agent comprising alumina cement, a setting retarder, and a curing accelerator. 5. The anhydrous washing-out caking agent according to claim 4, wherein the curing accelerator is gypsum, anhydrous gypsum, hemihydrate gypsum, slaked lime, sodium carbonate, Portland cement, or a combination thereof. An anhydrous washing caking agent comprising 100 parts by weight of alumina cement, 20 to 70 parts by weight of anhydrous gypsum, and 0.1 part by weight of a setting retarder. 7. The caulking for anhydrous washing according to any one of claims 4 to 6, further comprising any one of bentonite, fly ash, calcium carbonate, blast furnace slag, silica sand, talc, clay mineral, or a mixture thereof. Agent.

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