JPH09184247A - Lightweight concrete roof tile and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily manufacture a durable lightweight concrete roof tile by specifying the material, shape and specific gravity of mixed aggregate, and pressure, etc., at the time of pressure molding in manufacturing the lightweight concrete roof tile. SOLUTION: This lightweight concrete roof tile with a specific gravity of 1.6 to 2.0 is manufactured by molding using synthetic-resin foam as aggregate. For the aggregate, the synthetic-resin foam with a specific gravity of about 0.07 to 0.12, comprising beadlike particles made from a polystyrene and having an average particle size of about 2mm or less, is about 10 to 30vol%, and fine aggregate such as sand is about 10 to 40vol%, a total content of both being about 40 to 50vol%. Further, about 0.2 to 0.6vol% fiber reinforcement such as alkali-resistant glass fiber is mixed, fly ash or blast-furnace slag is mixed by about 10 to 35wt.% of cement weight, and the mixture is press-die molded at a pressure of about 50kgf/cm<2> or more. Thus the lightweight concrete roof tile can be manufactured into a durable one with good machinability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightweight concrete roof tile formed by molding lightweight concrete and a method for producing the same.

[0002]

2. Description of the Related Art Conventional cement-based roof tiles are generally obtained by kneading cement, water and fine aggregates such as sand, and molding and curing, as shown in JIS A 5402 as thick slate. However, since it is heavy, difficult to cut, and poor in heat insulation, it has been recently attempted to eliminate these drawbacks, for example, Japanese Patent Publication No. 61-310.
For the purpose of heat insulation and weight reduction as shown in No. 75,
Lightweight concrete roof tiles mixed with inorganic foam aggregates have been proposed.

[0003]

However, since the lightweight concrete roof tile uses the inorganic foam aggregate,
There is a problem that elastic deformation is small, and when the inorganic foam aggregate and cement are kneaded or crushed during press molding, a predetermined product size cannot be obtained, and a large weight reduction cannot be achieved. Further, since water-permeable bubbles are present, there is a problem that watertightness and freeze-thaw resistance are poor and durability is lowered. In addition, there are problems that it is difficult to control the water-cement ratio and that the bending strength becomes low.

The present invention is intended to solve the above problems, and to provide a lightweight concrete roof tile which is lightweight, durable and easy to manufacture, and a method for manufacturing the same.

[0005]

According to the first aspect of the present invention, a specific gravity is about 1.6 to 2 which is obtained by molding a hydraulic binder composition containing a synthetic resin foam as an aggregate. ．
It is characterized by being a lightweight concrete roof tile of 0.

The means of claim 2 is characterized in that the aggregate of the synthetic resin foam is a lightweight concrete roof tile made of beads having an average particle diameter of about 2 mm or less.

The means of claim 3 is characterized in that the synthetic resin foam is a lightweight concrete roof tile made of polystyrene.

A fourth aspect of the present invention is characterized in that the synthetic resin foam is a lightweight concrete roof tile having a specific gravity of 0.07 to 0.12.

A fifth aspect of the invention is characterized in that the obtained lightweight concrete roof tile is a lightweight concrete roof tile containing a synthetic resin foam in a volume of approximately 10 to 30%.

The means of claim 6 is characterized in that the obtained lightweight concrete tile contains a fine aggregate such as sand having a volume of about 10 to 40%.

The means of claim 7 is a lightweight concrete roof tile in which the hydraulic binder is cement.

The means of claim 8 is characterized in that it is a lightweight concrete roof tile containing a fiber reinforcing material in an absolute volume of approximately 0.2 to 0.6%.

The means of claim 9 is characterized in that it is a lightweight concrete roof tile mixed with alkali resistant glass fibers as a fiber reinforcing material.

According to a tenth aspect of the present invention, the fly ash and / or the blast furnace slag is approximately 10 to 35 times the cement weight.
It is characterized in that it is a lightweight concrete roof tile with a mixture of wt%.

The means of claim 11 forms a lightweight concrete aggregate in which a plurality of synthetic resin foams are solidified with a hydraulic binder to form an integral body, water, a hydraulic binder, and a lightweight concrete in which the synthetic resin foam is kneaded. It is characterized in that it is a lightweight concrete roof tile that is processed.

According to a twelfth aspect of the present invention, in the production of the lightweight concrete roof tile according to any one of the first to eleventh aspects, the lightweight concrete roof tile is produced by pressure molding. To do.

According to a thirteenth aspect of the present invention, there is provided a method for producing a lightweight concrete roof tile, wherein the pressure forming process is a press form forming process in which the pressure applied during the forming process is approximately 50 kgf / cm ² or more. .

[0018]

Embodiments of the present invention will be described below. First, the lightweight concrete roof tile of claim 1 will be described. Various known materials can be used as the raw material of the synthetic resin foam used here, and are not particularly limited. Further, the synthetic resin foam may be a crushed product obtained by crushing a foamed synthetic resin or an irregular shape, but a spherical or substantially spherical so-called bead, which has a weight and volume measurement error. It is preferable that the amount of the light-weight concrete roof tile containing this is small, and the variation in the specific gravity is small, and a roof tile with stable quality can be obtained. Further, when stress is applied to the lightweight concrete roof tile mixed with the synthetic resin foam, it can be dispersed if it is a bead,
Although high-strength concrete tiles can be obtained, in the case of a crushed product or a deformed shape, stress concentration is applied and the strength is weakened.

Regardless of whether the synthetic resin foam is a pulverized product, a deformed product, or a bead, the average diameter of the synthetic resin foam is 0.1 to 2.0.
The range is preferably 0 mm, more preferably 0.1 to 1.5 mm. If it is 0.1 mm or less, it becomes too small, and when kneading with water and a hydraulic binder, the fluidity of the kneaded material tends to decrease, and it is difficult to sufficiently secure the mixing amount of the synthetic resin foam. However, it is likely that it is difficult to sufficiently reduce the weight of the roof tile containing this. In addition, the average diameter is 2.0
If it is more than mm, the number of synthetic resin foams per unit volume of roof tile tends to be limited, and the strength tends to be weakened, which is not preferable. The average diameter when the synthetic resin foam is a pulverized product or an irregular shape is represented as an average value of a maximum length and a minimum length.

Examples of the synthetic resin as a raw material of the synthetic resin foam include various styrene resins such as polystyrene, olefin resins such as polypropylene and polyethylene, various copolymers such as acrylonitrile-styrene copolymer and styrene-ethylene copolymer. Polymer (of course, random, block,
Grafts, etc.), polyvinyl chloride, polyvinyl chloride resins such as polyvinylidene chloride, etc.
Among them, when polystyrene is used, the strength is strong,
It is most desirable because of its low cost.

A tile having a specific gravity of 1.6 is obtained by using such a synthetic resin foam as an aggregate, mixing at least cement and water, and molding the resulting hydraulic binder composition.
To 2.0. If the specific gravity is less than 1.6, it is extremely preferable from the viewpoints of weight reduction and heat insulation, but since the mixing ratio of the synthetic resin foam increases, the flame retardancy (incombustibility) decreases and The roof tile tends to be low in strength and expensive in price, and when the specific gravity exceeds 2.0, it tends to be unfavorable from the viewpoints of weight reduction, cutting property and heat insulating property.

Examples of hydraulic binders that harden synthetic resin foams as aggregates include cement, lime, gypsum, and adhesives. Among them, cement has high strength, excellent water resistance, and relatively high strength. Most desirable because it is cheap. As the cement, ordinary Portland cement, early strength Portland cement, super early strength Portland cement, portland cement such as moderate heat Portland cement, or mixed cement such as blast furnace cement, silica cement, fly ash cement, or ultra early strength cement. ,
Expandable cement, special cement such as cosmetic cement (white cement, color cement, etc.), or alumina cement can be used, and it is preferable to use properly depending on the application.

[0023] Such a synthetic resin foam, a hydraulic binder composition obtained by adding water to a hydraulic binder, etc., is dehydrated and molded into a predetermined roof tile shape and cured, and its specific gravity is substantially the same. The range was 1.6 to 2.0. The water binder ratio (W / C) of the hydraulic binder composition is preferably about 40% or less, and is preferably about 25% after dehydration molding. The amount of the hydraulic binder such as cement is 20 to 35% by volume, preferably 2% by volume in the hydraulic binder composition.
2 to 32% by volume, more preferably 24 to 29% by volume
It is preferably used.

A lightweight concrete roof tile is obtained by molding the above hydraulic binder composition in an uncured state. The molding process in this case is usually pressure molding, and specifically, There are a press form forming process and an extrusion forming process using an extruder, and which is adopted is appropriately selected mainly depending on the shape of a desired product. In addition to the above-mentioned press form molding processing, various processing methods such as papermaking molding processing and casting molding processing may be used. After the molding, the product is used as a product by being subjected to a usual curing process for a normal concrete product, for example, an air curing, an underwater curing, a steam curing or an autoclave curing.

The lightweight concrete roof tile according to claim 2 brings about the above advantages by forming the synthetic resin foam into a spherical or substantially spherical bead-like particle shape, and further has an average particle diameter of about 2 mm or less, More preferably about 1.5 mm
Below, it is most preferably about 1 mm or less. The reason is that the buoyancy of the synthetic resin foam can be reduced by making the average particle diameter into a small particle shape of about 2 mm or less.
The floating of the synthetic resin foam can be effectively prevented, and as a result, the synthetic resin foam is uniformly dispersed in the mixture of cement and water to obtain a product having an average density, and the cement, water and the synthetic resin foam. That is, the fluidity of the mixed product is excellent. The synthetic resin foam has an average particle size of 0.
It is preferably 1 to 1 mm from the viewpoint of fluidity and dispersibility.

The lightweight concrete roof tile according to claim 3 is made of polystyrene (EPS: expanded polystyrene) as a raw material of the synthetic resin foam. In this case, it is most desirable because it has high strength and is inexpensive. Will be things.

In the lightweight concrete roof tile according to claim 4, the true specific gravity of the synthetic resin foam is in the range of 0.07 to 0.12. The reason is that, in addition to obtaining appropriate strength, This is because it is economically suitable. When this is converted into an expansion ratio, it is in the range of about 8 to 15 times. If the specific gravity is less than 0.07, the strength of the finished product tends to be weak. On the contrary, if the specific gravity exceeds 0.12, it is excellent from the viewpoint of strength, but it is flame retardant (incombustible).
And the material cost tends to increase.

According to a fifth aspect of the present invention, when the synthetic resin foam is contained in the obtained lightweight concrete roof tile, the mixing amount of the synthetic resin foam is in the range of about 10 to 30%, more preferably about 10 to 20%. Range, most preferably about 14 to 1
The range is 8%. If it is less than 10%, it tends to have an unfavorable tendency from the viewpoints of weight reduction, cutting property and heat insulating property. On the other hand, if it exceeds 30%, it is extremely preferable from the viewpoints of weight reduction and heat insulation, but since the mixing ratio of the synthetic resin foam increases, the flame retardance (noncombustibility) decreases and the roof tile The strength tends to decrease, and the price tends to be high.

The lightweight concrete roof tile according to claim 6 has sand mixed therein in order to improve the shape-retaining function of the hydraulic binder composition during molding. In addition to its normal function as a fine aggregate, this sand plays a role of reducing the amount of deformation that occurs when the synthetic resin foam is compressed inside the hydraulic binder composition during pressure molding. When the synthetic resin foam is pressed and deforms more than a certain amount, it buckles, and after the pressure is released, it has the effect of restoring, so small irregularities or microcracks are likely to form on the surface of the product, but it is added from the outside due to the inclusion of sand. The applied pressure is absorbed, the synthetic resin foam deforms,
The use of sand is preferred as it reduces buckling resulting in the prevention of shape changes after pressure release and the advantage of a smooth surface. The sand may have a particle size of 5 mm or less, which is usually used as a fine aggregate for concrete, and a specific gravity in the range of, for example, about 2.6, and the type thereof is not particularly limited. Also, instead of sand, JIS A
As specified in 5012, blast furnace slag fine aggregate (grain size 5 mm or less, specific gravity, for example, about 2.0 to 2.6)
Or fine aggregate of structural lightweight concrete aggregate specified in JIS A 5002 (grain size 5 mm or less, specific gravity is, for example,
Those of about 1.3 to 2.3) can be used.

The content of sand in the lightweight concrete roof tile is preferably in the range of approximately 10 to 40%, more preferably 20 to 35%, more preferably 27 to 3 in terms of the absolute volume of the obtained roof tile.
The range of 1% is most preferable. If the sand content is less than 10%, the aggregate of the synthetic resin foam tends to buckle during the molding process, and the restoring force of the buckled synthetic resin foam causes microcracks on the surface or inside of the roof tile. In some cases, the bending strength and the surface property are deteriorated. On the other hand, when the content of sand exceeds 40%, it is not desirable from the viewpoints of weight reduction, cuttability and heat insulation.

Furthermore, in the lightweight concrete roof tile of the present invention, a preferable result is obtained when the total amount of the sand and the synthetic resin foam mixed is 40 to 50% in terms of the absolute volume of the roof tile to be obtained. can get. The reason for this is that if it is less than 40%, the dehydration amount tends to increase during pressure molding, and the thickness of the product may become thin. This is because if the total amount of the above-mentioned mixed amount exceeds 50%, the flowability tends to decrease, the pressure molding time may take a long time, and the filling property may deteriorate. In the present invention, the specific gravity of the hydraulic binder composition and the specific gravity of the lightweight concrete roof tile obtained by molding and curing this composition are substantially the same. The reason is that the composition (eg, water binder ratio (W /
The water in (C) is 40%) is partially removed by dehydration molding (the above (W / C) is reduced to about 25%, for example). The specific gravity of the roof tile is higher than that of the above composition by, for example, about 0.1 because it is larger than that of the above composition. Is released from the roof tile (during which the volume of the roof tile hardly changes), and as a result, the specific gravity of the roof tile decreases by about 0.1 during curing and drying. Therefore, the specific gravity of the hydraulic binder composition and the obtained roof tile Is almost equal to the specific gravity of.

The lightweight concrete roof tile according to claim 7 uses cement as a hydraulic binder. As described above, cement has high strength, excellent water resistance, and is relatively inexpensive. Most suitable as a binder.

The lightweight concrete tile according to claim 8 is a mixture of a fiber reinforcing material in an absolute volume of 0.2 to 0.6%, which makes it possible to obtain a lightweight concrete tile having toughness and high bending strength. . Examples of the fiber reinforcing material include alkali glass fiber, vinylon fiber, nylon fiber, polypropylene fiber and the like. The lightweight concrete roof tile according to claim 9 uses an alkali resistant glass fiber as a fiber reinforcing material, and the alkali resistant glass fiber is particularly preferable because it has high bending strength and resistance to alkali. used.

The length of the alkali-resistant glass fiber is preferably about 10 mm to 20 mm on average, but is not particularly limited. If the mixing ratio of the fiber reinforcing material such as alkali resistant glass fiber is less than 0.2% in absolute volume, the bending strength is weak, and if it exceeds 0.6%, the fluidity of the mortar tends to be lowered, The pressure forming time may be long, and the filling property may be poor and the manufacturing cost may be high. Therefore, the above range is suitable and preferable.

The lightweight concrete roof tile of claim 10 is one in which fly ash and / or blast furnace slag or the like is mixed to reduce the alkalinity of the cement so that the cement is kept weakly alkaline in order to prevent alkali. Therefore, it is preferable. Further, when fly ash or the like is mixed in the cement, the fluidity is improved, the surface is made beautiful, and the synthetic resin foam is less likely to appear on the surface of the roof tile. Further, the long-term strength is improved, and a strong roof tile is obtained. The content of fly ash and / or blast furnace slag is preferably about 10 to 35%, more preferably 15 to 35%, based on the weight of cement.
20 to 27% is the most preferable. If the mixing ratio exceeds 35% by weight, the initial strength tends to decrease, and conversely, if the mixing ratio is less than 10% by weight, the effect of mixing is poor. These fly ash have a specific surface area of about 240.
0 cm ² / g or more, blast furnace slag specific surface area of about 3000 cm ² /
Powders of g or more are used.

The lightweight concrete roof tile according to claim 11 is characterized in that, in addition to the aggregate of synthetic resin foam, a plurality of synthetic resin foams are hardened with a hydraulic binder so that an integral lightweight concrete aggregate is present. , The synthetic resin foam is protected from being crushed even when pressure is applied during press molding, so that it may shrink during pressure molding or bulge after pressure release after pressure molding. It almost disappears and a product with a clean roof surface can be obtained. As this lightweight concrete aggregate,
Those described in the specification of Japanese Patent Application No. 6-71031 previously proposed by the present applicants may be mentioned.

As the synthetic resin foam or hydraulic binder used for the lightweight concrete aggregate, the same ones as described above can be used. Water is added to such a synthetic resin foam or a hydraulic binder to adjust the water binder ratio (W / C) so that the water absorption rate is low, the expansion rate due to water absorption is low, and the strength is high. Is formed into a substantially spherical shape with a diameter of 5 mm or less, more preferably 3 mm or less (for example,
A pan-type granulator or the like is used: see Japanese Patent Application No. 8-12085) and cured so that the true specific gravity thereof falls within the range of 0.8 to 1.5.

The proportion of the lightweight concrete aggregate can be appropriately selected according to the degree of lightness of the desired product, but may be in the range of about 15 to 50% by volume. The water binder ratio (W / C) is also appropriately selected depending on the type of product, but it is preferably 40% or less from the viewpoint of strength.

In producing the above-mentioned lightweight concrete roof tile, various admixtures such as an AE agent and a water reducing agent are further added to the hydraulic binder, the synthetic resin foam and the hydraulic binder composition containing water as a main component. , AE water reducing agent, high-performance AE water reducing agent, etc. are mixed, the bending strength is improved by, for example, about 10%, quality can be stabilized, and more preferable results can be obtained. Further, the obtained lightweight concrete roof tile may be subjected to acrylic coating or the like in order to improve the appearance of the surface.

According to a twelfth aspect of the present invention, the method for producing a lightweight concrete roof tile comprises producing the lightweight concrete roof tile according to any one of the first to eleventh aspects by pressure molding.

In the method for manufacturing a lightweight concrete roof tile according to claim 13, the pressure forming process requires a pressing force of about 50 kgf /
This is performed by a press form forming process with a cm ² or more. If it is less than 50 kgf / cm ² , the pressing time tends to be long and the molding tends to occur smoothly, which tends to cause trouble. The press form forming process has an advantage that a product having a complicated shape, which cannot be formed by extrusion forming process, can be easily formed. Further, in order to obtain the roof tile of the present invention favorably, adjustment of the pressing force at the time of molding is often significant.

[0042]

Embodiments of the present invention will be described below.
First, Tables 1 and 2 show formulation examples. Incidentally, EPS represents expanded polystyrene. Also, beads represent granular materials, but EP
It may be abbreviated as EPS instead of S bead.

[0043]

[Table 1]

[0044]

[Table 2]

In the compounding examples of the lightweight concrete roof tiles of the above-mentioned comparative examples and examples, as the synthetic resin foam, specific gravity of polystyrene foamed 0.06, 0.10, 0.
15 beads (EPS beads) having an average diameter of 0.9 mm were used. As the cement, ordinary Portland cement was used. Further, as the fiber reinforcing material, 13 mm of alkali resistant glass fiber was used. 2.5mm in diameter for sand
The following river sand was used. As the lightweight concrete aggregate, a synthetic resin foam, ordinary Portland cement and water similar to those described above are kneaded and hardened at a water binder ratio of about 25% and cured to have a substantially spherical shape with an average diameter of about 3 mm. A true specific gravity of 1.5 was used. The lightweight concrete compounded as described above was pressed into a roof tile by pressing with a pressure of 70 kgf / cm ² and then cured by steam to be cured.

Tables 3 and 4 show the results of comparison of the characteristics of the roof tiles of Examples 1 to 6 with Comparative Examples 1 to 7.

[0047]

[Table 3]

[0048]

[Table 4]

As is clear from Tables 3 and 4, the lightweight concrete roof tiles of the examples of the present invention have a smaller density than the conventional concrete roof tiles and are useful. Although the bending strength is a little low, it is a sufficient strength with no practical problems. In Example 3, the surface property is improved by mixing the fly ash, and in Example 4, the bending strength is maximized by mixing the alkali resistant glass fiber. On the other hand, Comparative Example 4 does not use sand, and Comparative Example 5 has a low specific gravity of EPS, so that cracks easily occur on the surface of the roof tile, and the bending strength is low.

An experiment was conducted only by changing the average particle size of the EPS beads to 1.2 mm, 1.7 mm, and 2 mm in the formulation of Example 3 except for three types. As a result, it is preferable that the one having a thickness of 1.2 mm has a good surface property and has few surface irregularities. In addition, a product having a diameter of 1.7 mm can be mixed as a hydraulic binder composition and a product can be easily manufactured, but some surface irregularities were observed. If it exceeds 2 mm, the composition tends to be easily separated, so that attention must be paid to mixing. In addition, when the sand content was high, as in Comparative Example 1 and Comparative Example 7, the cutting properties and nailing properties tended to decrease.

[0051]

Since the lightweight concrete roof tile of claim 1 uses a light synthetic resin foam, the roof tile strength is not reduced and the roof tile weight is reduced.
As a result, the work of transporting, unloading, and holding the roof tiles becomes easier and the work efficiency is improved. Further, since the load applied to the structure such as a house is reduced, not only the size of the rafters that directly support the roof tiles can be reduced, but also all the structural members such as columns, beams, and foundations can be reduced. . This is especially useful when you want to make a large eaves.

Further, since the synthetic resin foam having almost no water absorption is used, it is easy to control the water cement ratio during the production. In addition, since the synthetic resin foam is included, it is possible to reduce the heat transfer to the inside of the building due to the heat insulation effect, and the heating and cooling costs can be reduced accordingly.

Furthermore, since the cutting can be easily performed with a saw or the like, the working operation when cutting the roof tile in conformity with the shape at the corner can be extremely facilitated. Further, since it is hard to break even when nailed, it is not necessary to previously provide a through hole for the nail, so that the molding process is easy.

According to the lightweight concrete roof tile of claim 2,
In particular, since the synthetic resin foam is substantially spherical, that is, in the form of beads, it is difficult for the synthetic resin foam to be crushed during kneading or press molding, so that the product size as designed can be obtained. Further, since the particle size is small, it is well mixed with cement and a product having a uniform density can be obtained.

According to the lightweight concrete roof tile of claim 3,
An economical and strong product can be obtained.

According to the lightweight concrete roof tile of claim 4,
It is possible to obtain a tough and most economical lightweight concrete roof tile.

According to the lightweight concrete roof tile of claim 5,
By containing the synthetic resin foam in a predetermined amount, it is possible to reduce the weight while maintaining the toughness.

According to the lightweight concrete roof tile of claim 6,
The presence of fine aggregate such as sand plays a role as a normal fine aggregate, and can effectively alleviate or prevent external pressure from being directly transmitted to the synthetic resin foam during pressure molding. As a result, it is possible to prevent the synthetic resin foam from compressing and shrinking, to eliminate the expansion of the synthetic resin foam after releasing the pressure, and to obtain a product with a clean surface.

According to the lightweight concrete roof tile of claim 7,
Since cement is used as the hydraulic binder, the product has high strength, excellent water resistance, and is relatively inexpensive.

According to the lightweight concrete roof tile of claim 8,
Since the fiber reinforcing material is contained, it is possible to obtain a lightweight concrete roof tile that is tough and has high bending strength.

According to the lightweight concrete roof tile of claim 9,
Since alkali-resistant glass fiber is used as the fiber reinforcement,
There is an advantage that high bending strength can be obtained and resistance to alkali such as cement is rich.

According to the lightweight concrete roof tile of claim 10, since fly ash and / or blast furnace slag are contained for the purpose of alkali resistance against the alkalinity of cement, and for improving the surface property and improving the long-term strength, Cement can be weakly alkaline,
This makes it possible to obtain a lightweight concrete roof tile having good surface properties, toughness, and high bending strength.

According to the lightweight concrete roof tile of claim 11, a lightweight concrete aggregate in which a plurality of synthetic resin foams are solidified by a hydraulic binder is used in combination with the synthetic resin foam to obtain a synthetic resin foam. Even if the content is increased to reduce the weight, the decrease in nonflammability can be suppressed and a good roof tile can be obtained.

According to the method of manufacturing a lightweight concrete tile of claim 12, the lightweight concrete tile of claims 1 to 11 is manufactured by pressure molding, so that the molding can be performed smoothly.

According to the method for manufacturing a lightweight concrete roof tile of claim 13, the pressure forming process requires a pressing force of about 5 during the forming process.
Since the press form forming process of 0 kgf / cm ² or more is used, there is an advantage that the pressing time can be relatively short and that a product having a complicated shape, which cannot be obtained by the extrusion forming process, can be easily formed.

Claims (13)

[Claims] 1. A specific gravity of about 1.6 obtained by molding a hydraulic binder composition containing a synthetic resin foam as an aggregate.
Lightweight concrete roof tiles from 2.0 to 2.0. 2. The lightweight concrete roof tile according to claim 1, wherein the aggregate of the synthetic resin foam is beads having an average particle diameter of about 2 mm or less. 3. The lightweight concrete roof tile according to claim 1, wherein polystyrene is used as the synthetic resin foam. 4. The lightweight concrete roof tile according to claim 1, wherein the specific gravity of the synthetic resin foam is approximately 0.07 to 0.12. 5. A synthetic resin foam is contained in the obtained lightweight concrete roof tile in a volume of approximately 10 to 30%.
Lightweight concrete tile of any one of 4 to 4. 6. The obtained lightweight concrete roof tile contains approximately 10
The lightweight concrete tile according to any one of claims 1 to 5, which contains fine aggregate such as sand having a volume of 40% to 40%. 7. The hydraulic binder is cement.
Lightweight concrete tile of any one of to 6. 8. The lightweight concrete roof tile according to claim 1, wherein the fiber reinforcing material is mixed in an absolute volume of approximately 0.2 to 0.6%. 9. The lightweight concrete roof tile according to claim 8, wherein alkali resistant glass fibers are mixed as the fiber reinforcing material. 10. The lightweight concrete roof tile according to claim 1, wherein fly ash and / or blast furnace slag is mixed in approximately 10 to 35% by weight of the cement weight. 11. A lightweight concrete roof tile according to any one of claims 1 to 10, wherein a lightweight concrete aggregate in which a plurality of synthetic resin foams are solidified by a hydraulic binder is used together with the synthetic resin foams. 12. The method for producing a lightweight concrete tile according to claim 1, wherein the lightweight concrete tile is produced by pressure molding. 13. The method for producing a lightweight concrete roof tile according to claim 12, wherein the pressure forming process is a press form forming process in which a pressure applied during the forming process is approximately 50 kgf / cm ² or more.