JPH02149484A - Production of glazed concrete panel - Google Patents

Abstract

PURPOSE:To obtain a desired large-sized concrete panel with simple facilities by charging a cement kneaded material having <=0.2 weight ratio of water to solid cement into a frame, molding the material into a desired shape by compaction and successively subjecting the molded body to drying, glazing, baking and rehydration. CONSTITUTION:A cement kneaded material having <=0.2 weight ratio of water to solid cement is charged into a frame and molded by compaction under 0.1-1kg/cm<2> pressure. The frame is dismantled and the molded body is dried at about 250-400 deg.C, glazed, baked, immersed in water for 30-60min and aged at 50-60 deg.C and 90-98% relative humidity for about 3 days.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing glazed concrete panels. More specifically, the present invention relates to a method for manufacturing a glazed concrete panel, which allows a large glazed concrete panel to be easily constructed using simple equipment.

[Conventional technology] Concrete panels have traditionally been manufactured in advance at a factory, so there is no need to assemble formwork and pour concrete on site, resulting in superior quality.They can also greatly shorten construction time, making them ideal for prefabricated houses and other applications. It is widely used for curtain walls and floors in general buildings such as buildings, factories, and warehouses.

In some cases, the surface of such concrete panels is glazed to improve the appearance or durability.

Special Publication in 1977 as a method for hanging glazed concrete panels
There is one described in Japanese Patent No.-48464. In the method described in this publication, a cement molded product having a water-solid ratio of 0.15 or less is produced by using a pressurizing machine such as a water pressure machine, a hydraulic machine, or a centrifugal separator, or a decompression device from a cement kneaded product. After the cement molded product is preliminarily hydrated and hardened, it is glazed and fired, and the resulting glazed fired product is hydrated and hardened again.

[Problem to be solved by the invention] However, in the method described in the above publication,
After pouring the cement mixture in liquid, slurry, or plastic form into a mold, dehydration is performed using the pressure machine or decompression device, which requires large-scale equipment and is difficult to dewater. There has been a problem in that the size of panels that can be manufactured is limited by the scale of the molding device, making it difficult to manufacture panels larger than a certain size.

In view of the above-mentioned problem, the present invention aims to provide a method for producing a glazed concrete panel that can produce a desired large panel using simple equipment.

[Means for Solving the Problems] The method for producing a glazed concrete panel of the present invention involves pouring a cement mixture in which the weight ratio of water to cement solids is 0.2 or less, compacting it and forming it into a desired shape. The resulting cement molded body is then dried, glazed, fired, and then rehydrated.

[Example] Hereinafter, a method for producing a glazed concrete panel of the present invention will be described in detail.

The cement mixture is a mixture of cement, aggregate, water, and admixtures or admixtures added as appropriate. As cement, portland cement and mixed cement are used, and as aggregate, magnetic chamotte, etc.
The present invention is not particularly limited in that it is sufficient to use commonly used materials such as anti-fire stones.

Further, an appropriate admixture or admixture may be used depending on the characteristics such as strength and water resistance required of the panel.

In the present invention, it is necessary to adjust the weight ratio of water to cement solids to be 0.2 or less. Here, cement solids refer to solid content other than water in cement mixtures such as cement, aggregate, and admixtures. When the ratio exceeds 0.2, problems such as peeling of the glaze and cracks occur after firing, which is not preferable.

The cement mixture is molded without a mold using a compaction machine with a compaction function, or is compacted using a compaction machine after being cast. This compaction can also be performed by compacting with a rod-shaped member or by beating with a spatula-shaped member. In this case, the compaction pressure (hereinafter referred to as pounding pressure) is preferably about 0.1 to 1 kg/ej. If it is less than 0.1 kg/cj, the compaction will be insufficient, leaving defects inside the panel, resulting in disadvantages such as a decrease in the strength of the panel.

On the other hand, if it exceeds 1 kg/cj, molding surfaces such as edges cannot be changed sufficiently in frameless molding, which is not preferable.

As described above, the cement mix according to the present invention has a smaller proportion of water than a normal cement mix that is normally poured into a formwork, and has a so-called loose feel, and cannot be compacted with a pouring machine or the like. This eliminates disappearance in the kneaded material and provides shape retention.

After molding the cement mixture, the mold is dismantled, and the resulting cement molded body is dried at 250 to 400°C for about 5 hours. Drying may be performed using a circulating dryer or the like.

After drying, a glaze such as raw glaze or frit glaze is applied to the desired surface of the cement molded body. The amount of coating is not particularly limited, but is approximately 0.5 to 2 kg/I, and can be applied by brushing,
Glaze is applied by spray painting, flow painting, etc.

The glazed cement molded body is fired in a firing furnace. The firing temperature and firing time are not particularly limited in the present invention, but are approximately 800 to 900°C for a holding time (8
The standard time is 0.5 to 2 hours (at 00 to 900°C).

The fired cement molded body is immersed in water for about 30 to 60 minutes to rehydrate, and then heated to 50 to 60°C.
It is cured for about 3 days under 90-98% R11.

Next, the manufacturing method of the present invention will be explained based on Examples, but the present invention is not limited to these Examples.

Examples 1 to 3 A cement mixture having the composition shown in Table 1 was prepared, and a wooden formwork (inner dimensions: length x width x height - 3000 cm x
900ca+X70c+n).

After shaping the cement mixture using a pounding machine at a pounding pressure of 0.2 kg/c-, the formwork was dismantled.

After drying the obtained cement molded body at 300°C for 5 hours, 1 kg/kg of glaze (), lit glaze) was applied to the surface of the molded body.
rr? It was applied to a thickness of . Then, for 1 hour in a firing furnace (
After firing (firing temperature: 850°C), it was immersed in water for 30 minutes and finally cured for 3 days at 60°C and 98% R1+ to rehydrate.

[Margin below] When the condition of the glazed surface of the obtained glazed concrete panel was visually observed, almost no cracks could be observed.

Comparative Example 1 A glazed concrete panel was produced in the same manner as in Example except that the formulation was changed to that shown in Table 1. When the condition of the glazed surface of the obtained panel was visually observed, it was observed that many fine racks were generated over the entire glazed surface.

[Effects of the Invention] According to the manufacturing method of the present invention, it is possible to produce an effect that a large glazed concrete panel can be easily fabricated using simple equipment, which has been difficult with conventional methods.

Claims (1)

[Claims] 1. Casting a cement mixture with a weight ratio of water to cement solids of 0.2 or less, compacting it and forming it into a desired shape, drying the obtained cement molded body, glazing it and firing it, A method for producing glazed concrete panels characterized by further rehydration.