JPH0633643B2 - Concrete panel - Google Patents

Description

TECHNICAL FIELD The present invention relates to a concrete panel. More specifically, the present invention relates to a concrete panel having stable strength without causing cracks because thermal expansion of a metal article during thermal drying and baking of a glaze is absorbed by a thermal expansion absorber provided at the periphery of the metal article. .

[Prior Art] Conventionally, since concrete panels are manufactured in advance in factories, there is no need to assemble concrete on the site to place concrete, and the quality is excellent, and the construction period can be drastically shortened. It is often used for curtain walls and floors of general buildings such as buildings, factories, and warehouses.

In such a concrete panel, various metal objects such as metal fittings for attaching the panel to a structure at the time of assembling, joints between panels, metal fittings for attaching accessories are embedded in the panel. However, when the surface of the concrete panel is glazed in order to improve the aesthetics of the concrete panel or to improve its durability, the embedded hardware will expand due to thermal expansion during heat drying and glaze baking, thus cracking the concrete panel. There is a problem that the strength of the produced panel is reduced.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a concrete panel in which the drawbacks of the conventional example are eliminated. That is, an object of the present invention is to provide a concrete panel having a stable strength by absorbing the thermal expansion of the metal article at the time of thermal drying and glaze baking by providing the thermal expansion absorbing portion on the periphery of the metal article.

[Means for Solving Problems] The concrete panel of the present invention is a concrete panel in which a glaze is baked on the surface and a metal object is embedded therein, and the concrete and the above-mentioned concrete during heat drying and baking of the glaze are included. In order to prevent the occurrence of cracks due to the difference in the coefficient of thermal expansion from the metal object, a thermal expansion absorbing portion is provided at the peripheral edge of the metal object.

[Operation] In the concrete panel of the present invention, since the metal product is provided with the thermal expansion absorbing portion on the periphery thereof, it is possible to prevent the thermal stress generated by the thermal expansion of the metal product during the glaze baking from being transmitted to the concrete. .

[Example] Next, the concrete panel of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of an embodiment of the concrete panel of the present invention, FIG. 2 is an enlarged sectional view taken along the line AA of FIG. 1, and FIG. 3 is a perspective view showing an example of a metal object.

1 to 3, (1) is a concrete panel, (2) is the concrete panel as reinforcement and anchor bar.
Reinforcing bars embedded in (1), and (3) are hardware. The hardware (3) is attached to the reinforcing bar (2) by welding or the like. Also (4)
Is a thermal expansion absorber provided on the periphery of the mounting hardware (3).

The hardware (3) is embedded in the concrete panel (1),
Thermal expansion occurs when baking glaze. That is, the baking of the glaze is usually performed at a high temperature of 600 to 1000 ° C, but when the metal is made of iron, the coefficient of thermal expansion at that high temperature is about 1.5 × 10 ^-5 / ° C.
Then, assuming that the temperature of the metal object during baking is 1000 ° C, it is about 0.15 mm / c.
Inflate at a rate of m. When the metal object is simply embedded in the concrete, the thermal expansion causes cracks in the panel, resulting in a decrease in the strength of the concrete panel.

The thermal expansion absorber (4) in the present invention is a metal object for preventing the occurrence of cracks during baking of the glaze as described above.
What is provided in the peripheral edge of (3), as long as it can absorb the thermal expansion of the metal (3) may be any, for example, at the time of firing the panel like an organic film. A substance that burns to create a clearance that absorbs expansion of the metal, a substance that absorbs expansion by creep deformation when the metal expands, such as an inorganic mortar, or an inorganic substance that melts at the temperature during firing. As described above, it is preferable to use one that is embedded in concrete by spraying on a metal object in advance, prevents cracks due to expansion of the metal object by melting at the time of firing, and resolidifies and fixes the metal object when returned to room temperature. it can.

The thermal expansion absorbing part (4) such as the mortar absorbs the thermal expansion of the metal product by partially breaking itself or by melting, and prevents the occurrence of cracks.

[Effects of the Invention] As described above, in the concrete panel of the present invention, in order to prevent the occurrence of cracks due to the difference in the coefficient of thermal expansion between the concrete and the metal object at the time of thermal drying and glaze baking on the periphery of the metal object. Since the thermal expansion absorbing part is provided, it is possible to reliably prevent the thermal expansion of the metal object during baking of the glaze and prevent the generation of cracks, and it is possible to obtain a concrete panel having stable strength.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the concrete panel of the present invention, FIG. 2 is an enlarged sectional view taken along the line AA of FIG. 1, and FIG. 3 is a perspective view showing an example of a metal object. (Main symbols in the drawing) (1): Concrete panel (3): Hardware (4): Thermal expansion absorber

Claims (1)

[Claims] 1. A concrete panel in which a glaze is baked on the surface and a metal object is embedded in the concrete panel, the crack being caused by a difference in thermal expansion coefficient between the concrete and the metal object when the concrete panel is thermally dried and when the glaze is baked. In order to prevent the occurrence of the above, the concrete panel is characterized in that a thermal expansion absorbing portion is provided on the peripheral edge of the metal object.