WO1998002397A1

WO1998002397A1 - Lightweight-concrete roofing tile and process for producing the same

Info

Publication number: WO1998002397A1
Application number: PCT/JP1996/002005
Authority: WO
Inventors: Ichiro Nakajima; Kumiko Osugi
Original assignee: Kanegafuchi Kagaku Kogyo Kabushiki Kaisha
Priority date: 1996-01-30
Filing date: 1996-07-17
Publication date: 1998-01-22

Abstract

Lightweight-concrete roofing tiles made by molding a hydraulic binder composition containing synthetic resin foams as the aggregate and having a specific gravity of about 1.6 to 2. A preferably example of the aggregate is beads of the resin foams having an average particle size of about 2 mm or less, while a suitable example of the foams is polystyrene foams.

Description

Description Lightweight concrete roof tile and method of manufacturing the same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to light concrete tiles formed by processing lightweight concrete and a method for producing the same. Background art

Conventional cement-based roof tiles are generally formed by kneading and hardening fine aggregates such as cement, water and sand as shown in JIS A 5402 as a thick slate. However, it was heavy and difficult to cut, but it had poor heat insulation properties. Therefore, to solve these drawbacks, we came close to solving the problem. For example, Japanese Patent Publication No. Sho 61-3-075 Lightweight concrete roof tiles mixed with inorganic foamed aggregates have been proposed for the purpose of heat insulation and weight reduction as shown in (1).

However, since the above lightweight concrete tile uses an inorganic foam aggregate, the elastic deformation of the aggregate is small, and the lightweight concrete roof tile is formed at the time of kneading the inorganic foam aggregate and the cement or at the time of press molding, and a predetermined product is produced. There are problems that dimensions cannot be obtained and that a large reduction in weight cannot be achieved. Furthermore, due to the presence of air bubbles, there is a point that watertightness is inferior in freeze-thaw resistance and durability is reduced. In addition, since the water absorption of the inorganic foam aggregate is high, it is difficult to control the water cement ratio, and there is a problem that the bending strength is low. It is an object of the present invention to provide a lightweight concrete roof tile which solves such a problem, is lightweight and durable and can be manufactured easily, and a method for manufacturing the same. DISCLOSURE OF THE INVENTION The lightweight concrete roof tile of the present invention is obtained by molding and processing a hydraulic binder composition containing a synthetic resin foam as an aggregate, and has a specific gravity of approximately 1.6 to 2.0. It is characterized by.

Various known materials can be used as the raw material of the synthetic resin foam used here, and it is not particularly limited. Also, synthetic resin foams can be made of crushed foamed synthetic resin or of irregular shape! In the case of a so-called bead, which has a spherical shape or a substantially spherical shape, the weight and volume measurement errors are smaller, and the specific gravity of the light-weight concrete tile mixed with this is reduced and the quality is stable. It is preferable because a broken roof tile can be obtained. Further, when stress is applied to the lightweight concrete tile mixed with the synthetic resin foam, if a bead is used, this can be dispersed, and a high-strength concrete tile can be obtained. In the case of a crushed product or an irregular shape, stress concentration occurs and the strength is reduced. Therefore, it is desirable to use beads as much as possible.

[-The synthetic resin foam may have a mean diameter of about 0.1 to 2 mm [11, preferably about 0.1 to 1. A range of 5 mm is good. If it is less than about 0.1 mm, 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. Therefore, it is likely that it is difficult to sufficiently reduce the weight of the roof tile containing this. Further, if the average diameter is about 2 mm or more, the number of synthetic resin foams per unit volume of the tile becomes small, and the strength tends to be weak. The average diameter in the case where the synthetic resin foam is a pulverized product or a rectangular shape is represented as an average value of the maximum length and the minimum length.

The synthetic resin foam is used as aggregate and mixed with at least cement and water. The specific gravity of the roof tile obtained by molding and processing the obtained hydraulic binder composition is set to be approximately 1.6 to 2.0. When the specific gravity is less than about 1.6, it is extremely preferable from the viewpoint of weight reduction and heat insulation. However, since the mixing ratio of the synthetic resin foam increases, the flame retardancy (nonflammability) decreases. In both cases, the strength of the tiles tends to decrease, and the price tends to be expensive. If the specific gravity exceeds approximately 2.0, the tendency of the tiles becoming unfavorable from the viewpoint of weight reduction, cutting properties and heat insulation properties tends to be reduced. Have.

Hydraulically bonded trj material obtained by adding water to a synthetic resin foam, hydraulic binder, etc., as described above, is dehydrated and formed into a specified roof tile shape and cured, and the ratio ffi is substantially reduced. The range was 1.6 to 2.0. The water binder ratio (WZ C) of the hydraulic binder composite is preferably about 40% or less, and is preferably about 25% after dehydration molding. The hydraulic binder such as cement is contained in the hydraulic binder composition at a volume ratio of about 20 to 35% by volume, preferably about 22 to 32% by volume, more preferably about 24 to 2% by volume. It is preferable to use 9% by volume.

The above-mentioned hydraulic binder composition is molded before curing to obtain a lightweight concrete roof tile. In this case, the molding process is usually pressure molding, and specifically, a press mold. There are frame forming processing and extrusion forming processing using an extruder. Which method to use is appropriately selected mainly depending on the desired product shape. In addition, in addition to the above-described press mold forming process, various processing methods such as sheet forming process and casting forming process may be used.

After molding, the concrete is cured by a normal curing process performed on a normal concrete product, for example, by curing in the air, underwater, or steam, or in an autoclave, and used as a product. Since this lightweight concrete roof uses a light synthetic resin foam, the strength of the roof is reduced. Without it, roof tiles—the effect of reducing the amount can be obtained. This facilitates the work of transporting, unloading, and holding the roof tiles, and improves work efficiency. In addition, in order to reduce the load on buildings such as houses, we will not only reduce the size of the rafters that support the tiles at the ii'i junction, but also reduce the size of all structural members such as columns, beams, and foundations be able to. It is especially useful for eaves that require a large eave.

In addition, since a synthetic resin foam having almost no water absorption is used, the ratio of water to the hydraulic binder at the time of manufacture is also acceptable. In addition, since it contains a synthetic resin foam, a heat insulation effect is generated, and it is possible to reduce the transfer of heat to the inside of the building, thereby reducing the cost of cooling and heating.

In the past, since cutting by tsutsu, etc. can be easily performed, the work of cutting a tile in a corner or the like according to the shape can be extremely easily performed. Also, since it is difficult to break even when nailed, there is no need to provide a through hole for the nail in advance, so molding is easy.

Another lightweight concrete roof tile according to the present invention is characterized in that the synthetic resin foamed aggregate has an average particle diameter of about 2 mra or less as beads and is a lightweight concrete roof tile. That is, when the synthetic resin foam is formed into a spherical or substantially spherical bead-like particle shape, the synthetic resin foam hardly collapses at the time of kneading or press molding, so that the designed product dimensions can be obtained. Also, since the particle size is small, it can be mixed well with cement to obtain a product with uniform density. The average particle size is about 2 咖 or less, more preferably about 1.5 πππ or less, and most preferably about 1 ram or less. The reason is that the buoyancy of the synthetic resin foam can be reduced by setting the average particle size to a small particle size of about 2 iniD or less, so that the lift of the synthetic resin foam in the hydraulic binder composition is effective. As a result, the synthetic resin foam is evenly mixed with cement and water And a product having an average density is obtained, and the fluidity of the hydraulic binder composition is excellent. The synthetic resin foam preferably has a mean particle size of about 0.1 to from the viewpoint of fluidity and dispersibility.

In the present invention, another lightweight concrete roof tile is a lightweight concrete roof tile using expanded particles of expandable polystyrene (EPS) as the synthetic resin foam. . That is, synthetic resins used as raw materials for synthetic resin foams include styrene resins such as polystyrene, olefin resins such as polypropylene and polyethylene, acrylnitrile-styrene copolymer, styrene-ethylene copolymer, and the like. (Including random, block, graft, etc.), polyvinyl chloride, polyvinyl chloride resin such as polyvinylidene chloride, etc. Power, especially if foamed EPS particles are ffl, bead It is the most desirable because it is strong and cheap.

Another lightweight concrete roof tile according to the present invention is characterized in that the true specific gravity (hereinafter, simply referred to as specific gravity) of the synthetic resin foam is approximately 0.07 to 0.12. That is, if the specific gravity is in the range of about 0.07 to 0.12,

In addition to obtaining appropriate strength, it can be manufactured economically at a low cost. When this is converted into the expansion ratio, it is in the range of about 8 to 15 times. If the ratio is less than about 0.07, the strength of the finished product tends to be weak. Conversely, if it exceeds about 0.12, the strength of the finished product is excellent, but the flame retardancy ( (Incombustibility) and material costs tend to increase.

Another lightweight concrete roof tile according to the present invention is characterized in that the obtained lightweight concrete roof tile contains a synthetic resin foam at a capacity of approximately 10 to 30%. The mixing amount of the synthetic resin foam is more preferably in the range of about 0 to 20%, and more preferably in the range of about 14 to 18%. At less than about 10% It tends to have an unfavorable tendency from the viewpoints of weight reduction, cutability and heat insulation. On the other hand, if it exceeds about 30%, it is extremely preferable from the viewpoint of weight reduction and heat insulation, but the flame retardancy (non-combustibility) decreases as the mixing ratio of synthetic resin foam increases. However, the strength of the tiles tends to decrease and the price tends to be high.

Still another lightweight concrete roof tile according to the present invention is characterized in that the obtained lightweight concrete roof tile contains fine aggregate such as sand in a volume of approximately 10 to 40%. Here, at the time of molding, fine aggregate is mixed in order to improve the shape retention function of the hydraulic binder composition. This fine aggregate, in addition to the normal Sakugawa as a fine aggregate, also reduces the amount of deformation caused by the shrinkage of the synthetic resin foam inside / out of the hydraulic binder during molding. Play a role. The synthetic tree foam is tt 'shrunk-it buckles if it deforms beyond a certain ffi, but it has the effect of restoring after pressure release, so small irregularities or micro-mouth cracks are likely to occur on the surface of the product, The mixing of fine aggregate absorbs the pressure applied from the outside and reduces the deformation and buckling of the synthetic resin foam, thereby preventing the shape from changing after the pressure is released and providing the advantage of a smooth surface. It is preferable to use fine aggregate.

In the case where sand is used as the fine aggregate, the particle diameter of ffl usually used as a fine aggregate for concrete is 5 mm or less, and the specific gravity may be, for example, in a range of about 2.6, and the type thereof may be different. There is no particular limitation. In place of azai and sand, A furnace slag fine aggregate (grain size of about 5 mm or less, specific gravity of about 2.0 to 2.6, for example) or JIS as specified in JIS A 5012, or JIS A lightweight fine concrete aggregate for structural use specified in A5002 (particle size of about 5ππη or less, specific gravity of, for example, about 1,3 to 2.3) can be used.

The content of fine aggregate in the lightweight concrete tile is The absolute volume is preferably in the range of about 10 to 40%, more preferably in the range of about 20 to 35%, and most preferably in the range of about 27 to 31%. If the fine aggregate content ffi is less than about 10%, the synthetic resin foam will buckle and tilt during the molding process. In some cases, micro cracks are generated, and the llfl strength / metaphysical property is reduced. On the other hand, if the content of fine aggregate exceeds about 40%, it becomes less desirable from the viewpoint of lightening, cutting properties and heat insulation.

Furthermore, in the lightweight concrete roof tile of the present invention, the total amount of the fine aggregate and the synthetic resin foam mixed is about 40 to 50% in absolute volume in the obtained tile. A good result is obtained. The reason for this is that if it is less than about 40%, the amount of dewatering tends to increase during pressure molding, and the thickness of the product may be reduced. If the total of the above-mentioned mixed S exceeds about 50%, the fluidity tends to decrease.As a result, when adding: it takes a long time during molding, or when the filling of the mold becomes poor. Because it can happen. 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 compact are almost the same. The reason is that the water in the composition (for example, water binder ratio (WZ C) is 40%) is partially removed by dehydration molding (the (W / C) is, for example, 25% At this time, since the rate of decrease in volume due to dehydration is greater than the rate of decrease in weight, the specific gravity of the tile is increased by, for example, 0.1 mm, compared to the composition, Due to the hardening and drying of the tile after dehydration molding, about 5 to 6% of water is discharged from the tile in an Itffi ratio of 5 to 6% (in this case, the volume of the tile hardly changes). Is reduced by about 0.1 mm, the specific gravity of the hydraulic binder composition is substantially equal to the specific gravity of the obtained tile.

In another lightweight concrete roof tile according to the present invention, the hydraulic binder is cement. It is characterized by the following. That is, cement, lime, gypsum, adhesives, etc. can be cited as the hydraulic binder that solidifies the synthetic resin foam as an aggregate, but the cement among them is strong, has excellent water resistance, and is relatively Most desirable because it is inexpensive. Portland cement such as ordinary Portland cement, single strength Portland cement, ultra-high strength Portland cement, medium heat Portland cement, etc., or a mixture of blast furnace cement, silica cement, fly ash cement, etc. Special cement such as cement or ultra-high-strength cement, expansion cement, cosmetic cement (white cement, power cement, etc.), or alumina cement can be used, and it is preferable to use properly depending on the application. .

Still another lightweight concrete roof tile according to the present invention is characterized in that it is a light concrete tile in which a fiber reinforcing material is mixed in an absolute volume of approximately 0.2 to 0.6%. By mixing a predetermined amount of the fiber reinforcing material, a tough and light-weight concrete roof tile having high bending strength can be obtained. Examples of the fiber reinforcing material include alkali-resistant glass fiber, vinylon fiber, nylon fiber, and polypropylene fiber.

Another lightweight concrete roof tile according to the present invention is characterized in that alkali-resistant glass fibers are mixed as a fiber reinforcing material. That is, the alkali-resistant glass fiber is particularly preferably used because it has a high bending strength and is resistant to alkali.

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 approximately 0.2% in absolute volume, the bending strength is weak, and if it exceeds approximately 0.6%, the mortar fluidity tends to decrease. However, the press molding time may be longer, and the filling cost may be worse and the production cost may be higher. It is.

Another lightweight concrete roof tile according to the present invention is characterized in that fly ash and / or blast furnace slag are mixed with approximately 10 to 35% by weight of the amount of cement bacteria. That is, by mixing fly ash, Z or blast furnace slag, etc., the alkalinity of the cement is reduced, which is expected to have the effect of increasing the durability of fiber reinforcing materials including glass fibers. . Also, if fly ash or the like is mixed into the cement, the fluidity is improved, the surface becomes more beautiful, and there is an advantage that synthetic resin foam is less likely to appear on the tile surface. Further, the long-term strength is improved, and a strong roof tile can be obtained.

The mixing amount of fly ash and Z or blast furnace slag is preferably about 10 to 35%, preferably about 15 to 35% with respect to the weight of cement, and preferably about 20 to 27%. Is most preferred. If the mixing ratio exceeds approximately 35% by weight, the initial strength tends to decrease. Conversely, if the mixing ratio is lower than approximately 10% by weight, the effect of mixed people is poor. These fly ash powders have a specific surface area of about 240 OcmVg or more, and the blast furnace slag has a specific surface area of about 300 on ² / g.

Another lightweight concrete roof tile according to the present invention comprises a lightweight concrete aggregate obtained by solidifying a plurality of synthetic resin foam particles with a hydraulic binder, water, a hydraulic binder, and a synthetic resin foam. It is characterized by being molded from a lightweight concrete. In other words, in addition to the synthetic resin foam aggregate, a plurality of synthetic resin foams are hardened with a hydraulic binder to form an integrated lightweight concrete aggregate, so that pressure is applied during press forming. Also protects the synthetic resin foam from crushing, so that it hardly shrinks during pressure molding or swells after pressure is released after pressure molding. '' Getting the goods Can be done. Examples of the lightweight concrete aggregate include those described in Japanese Patent Application No. 6-71031 proposed by the present applicant earlier.

As the synthetic resin foam or hydraulic binder used for the lightweight concrete aggregate, the same ones as described above can be used. Water was added to such a synthetic resin foam and hydraulic binder, and the water binder ratio (WZ C) was adjusted so that the water absorption was small, the expansion due to water absorption was small, and the strength was strong. Are formed in a substantially spherical shape such that ίίί is less than or equal to 5 and more preferably less than or equal to 3 (for example, using a bread-type granulator: see Japanese Patent Application No. 8-12085). Then, it is cured so that the true ratio is in the range of 0.8 to 1.5.

The proportion of light concrete aggregate can be selected as appropriate depending on the desired product weight reduction β, but it is sufficient if the volume ratio is about 15 to 50%. . The water binder ratio (W / C) is preferably 40% or less, which is appropriately selected depending on the type of product, from the viewpoint of strength.

When manufacturing lightweight concrete roof tiles with Ikl before, in the hydraulic binder composition, synthetic resin foam and hydraulic binder composition mainly composed of water, various admixtures such as AE agent, water reducing agent , AE water reducing agent, high-performance AE water reducing agent, etc., can improve the llll strength, for example, by about 10%, stabilize the product K, and obtain more favorable results. . Further, the obtained lightweight concrete tile may be subjected to an acrylic coating or the like in order to improve the surface appearance.

A method of manufacturing a lightweight concrete roof tile according to the present invention is characterized in that the lightweight concrete roof tile is manufactured by press forming. Thereby, molding can be performed smoothly.

In this case, the pressure molding process has a pressing force of approximately 5 O kgf / cm ² It is preferable to use the press mold forming process described above. That is, if the pressing force is less than about 5 Okgf / cm ² , the pressing time is likely to be long, and there is a tendency that trouble is likely to occur in smooth forming, which is not preferable. The press mold forming process has an advantage that a product having a complicated shape which cannot be formed by an extrusion forming process can be easily formed. In addition, in order to obtain the wooden tile of the present invention in a favorable manner, adjustment of the pressing force at the time of molding often has a great significance.

For example, in the forming of a normal thick slate, the pressing force is formed at approximately 120 to 150 kίcm ² , and when the pressing force is 120 kgf Z cm ² or less, the strength is reduced. On the other hand, in the molding of the present invention, molding can be performed in a range of about 50 kgf / cm ² or more, more preferably about 70 kgf / cm ² or more, so that molding can be performed even with a press machine having a small press capacity. Industrially preferred. BEST MODE FOR CARRYING OUT THE INVENTION

In order to explain the present invention in more detail, Tables 1 to 3 below show examples which are examples of blending of the hydraulic binder composition used as the material of the lightweight concrete roof tile of the present invention. Shown together. Incidentally, EPS or EPS beads represent expanded particles of expandable polystyrene beads.

Mixing example table of lightweight concrete tile A (per £)

The values in parentheses in Tables 1 to 3 indicate the volume ratio when the entire hydraulic binder composition is set to 1. Mixing example of lightweight concrete tile B (per £) Example Example Comparative example Comparative example 1 2 5 6 Hydraulic binder

Ratio of alleged substances Si: 1.6 1.8 1.8 1.8 ijfi portra: 'set 7 16 w5e 765e 765B [specific gravity 3.14] (0 · 24) (0 · 24) (0.24) (0 · 24)

1 z 1

[Comparative IB2.10]

water

[Specific gravity 1.00] (0.31) (0.31) (0.31) (0.31) — Light

[Specific gravity 0.10]

E P S beads 26g 18g llg 27g

CO 26 C VO 1 _18 o) CO 18) V «. JLO [specific gravity〗 [0.10] [0.10] [0.06] [0.15] Sand 503g 711g 718g 702g

[Specific gravity 2.60] (0.19) (0.27) (0.27) (0.27) Alkali resistant lath fiber

[Specific gravity 2.50〗

Lightweight] concrete

[Specific gravity 1.20]

E P S E P S

Mixing characteristics Specific gravity Specific gravity Small Large

Table 3

Mixing example table of lightweight concrete tiles C (per £)

In the blending examples of the lightweight concrete roof tiles of the above Comparative Examples and Examples, the synthetic resin foam had an average diameter of 0.06, 0.10, and 0.15 obtained by expanding polystyrene. 9 mm beads (EPS beads

) It was used. As the cement, Portland cement was used. Also

A 13 mm alkali-resistant glass fiber was used as a fiber reinforcing material. River sand with a diameter of 2.5 mm or less was used as the sand. As the lightweight concrete aggregate, the same synthetic resin foam, ordinary Portland cement and water as described above are kneaded at a water binder ratio of about 25% and hardened. The shape and the true specific gravity of 1.5 were used. It cured by steam curing after molding tiles applying a pressure of lightweight concrete Ichiboku press mold molding at 7 0 kgf / ciD ² which was formulated as above.

Tables 4 to 6 show the characteristics of the roof tiles of the above Examples 6 to 6 compared with Comparative Examples 1 to 7.

Table 4 Ratio of features ί ^ Α

Then:

Ratio Example Ratio! X Example Ratio Example Ratio IX Example

1 2 3 4

2.2 2.0 1.1.5.6

X Λ

Bending strength (kgi / sheet) 280 180 210 130

(JIS A 5402) Δ X Water absorption (wtx) 7 20 Π 10

(JIS A 5402) Cloud X-Flammability Pass Pass Fail Pass (JIS A 1321) X

Difficult to cut

X

Nailing 瞧 i¾

X

Small Small Small Small Formability Density Variation Density Variation Large

X X

Surface good good good good

X

Table 5 Comparison of characteristics B

^ // US V LP ■ = Example

1 2 5 6

1 β 1 1 .ϋ 1 R Flexural strength (kgf / sheet) 230 250 180 250 (JIS A 5402) △

Water absorption (Wt%) 10 9 9 9 (JIS A 5402)

Non-combustibility Passed Passed Passed Fail (JIS A 1321) X Cutability Good Good Good Good Nailability Good Good Good Small thickness Formability Good Good Density variation Good Tsukidai

X

Good surface good Good

X

Table 6 Characteristics comparison table C

As is evident from Tables 4 to 6, the lightweight concrete roof tile of the embodiment of the present invention is smaller in size than the conventional concrete roof tile which is a comparative example, Yes It is ffl. Although the flexural strength has a slightly lower value, it is sufficient for practical use. In Example 3, the surface property was reduced due to the mixture of fly ash, and in Example 4, the bending strength was maximized due to the mixing of Al-resistant glass fiber. On the other hand, in Comparative Example 4, no sand was used, and in Comparative Example 5, cracks tended to occur on the surface of the tile, and the flexural strength was low due to the low EPS efficiency. .

| V.'j. In Example 3, the EPS beads were reduced to 1.2 mm. 7 mm. An experiment was performed in which the size exceeded 2 mm but was changed to class 3 only. As a result, the one having a thickness of 1.2 mm is preferable because the surface properties are good and the surface unevenness is small. Also, the one with 1.7 mm can be mixed as a hydraulic binder composition, and the product can be easily manufactured, but some surface irregularities were observed. When the thickness exceeds 2 mm, the composition tends to be easily separated, and it is necessary to pay attention to the mixing. In addition, those having a large amount of S containing sand, such as Comparative Example I and Comparative Example 7, tended to decrease the cutting properties and nailing properties. In addition, a tile having good nailing property means a tile in which nails can easily pass through the tile and the tile is not easily cracked by nailing. Industrial applicability

As described above, the lightweight concrete tile according to the present invention can be suitably used as a roof tile of a house or the like, particularly at a site where a reduction in weight is required.

Claims

The scope of the claims

1. A lightweight concrete tile having a ratio Φ: of approximately 1.6 to 2.0, which is formed by molding a hydraulic binder composition containing a synthetic resin foam as an aggregate.

2. An aggregate of synthetic resin foam made of beads with an average particle size of about 2 IDID or less.

3. The light mixing concrete tile according to claim 1 or 2, wherein a polystyrene foam is used as the synthetic resin foam.

4. The lightweight concrete tile according to claim 1 or 2, wherein the specific gravity of the synthetic resin foam is approximately 0.07 to 0.12.

5. Synthetic resin foam is included in the obtained lightweight concrete roof at about 10 to 30%. The range of if request is as follows. .

6. The lightweight concrete roof tile described in item 1 or 2 above, which contains approximately 100% to 0% of fine aggregate such as sand, etc. .

7. The lightweight concrete roof tile according to claim 1, wherein the hydraulic binder is a cement.

8. The lightweight concrete tile according to claim 1 or 2, wherein a fiber reinforcing material is mixed in an absolute volume of approximately 0.2 to 0.6%.

9. The range of gradations obtained by mixing shochu liquor glass fiber as a fiber reinforcing material.

10 0. Light-weight concrete roof tile according to claim 7 in which fly ash and Ζ or blast furnace slag are mixed in an amount of about 10 to 35% by weight of cement weight o

1 1. Lightweight core made by integrating a plurality of synthetic resin foam with hydraulic binder 3. The lightweight concrete roof tile according to claim 1, wherein the concrete aggregate is used together with the synthetic resin foam.

12. The method for manufacturing a lightweight concrete roof tile according to claim 1 or 2, wherein the lightweight concrete roof tile is manufactured by pressure molding.

1 3. Method for producing lightweight concrete roof tiles ranging first 2 Para claimed according pressing process is press-mold molding was approximately 5 O kgf / cm ² or less applied pressure during molding.