JPH0656497A - Alumina cement composite material - Google Patents

Abstract

PURPOSE:To improve incombustibility, heat shock resistance, heat insulating properties, mechanical strength, etc., by mixing a fry ash wool and a light aggregate. CONSTITUTION:A fry ash wool (A) is obtained by spinning a low-silica and high-alumina fry ash into a fiber having 5 to 10mum diameter according to the electric furnace method, etc., and a cement mixture (B) is then prepared by blending alumina cement water and 20 to 80wt.% light aggregate such as pumiceous balloon. Both the components (A) and (B) are subsequently blended so that the amount of the component (A) may be 1 to 40wt.% based on the total weight of (A) and (B). The resultant mixture (C) is then molded and cured in an autoclave, etc., so as to produce an alumina cement composite material (D) exhibiting about 0.8g/cm<3> bulk density, 0.19Kcal/m.hr. deg.C thermal conductivity, etc. As necessary, one or more kinds of a foaming agent (e.g. Al or Fe) and a frothing agent (e.g. saponin or gelatin) are added to the component (D), thus producing the objective alumina cement composite material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alumina cement composite material having excellent non-combustibility and heat insulating properties, and more particularly to a lightweight alumina cement composite material.

[0002]

2. Description of the Related Art A very important condition for building materials is
It is nonflammable. In particular, it is very important that it can maintain its mechanical strength even if it is kept at a high temperature such as 800 ° C. to 1000 ° C. for a long time, and can retain its shape, shape and specific function without expanding or contracting. Is. However, there are few materials that are completely non-combustible in the present building materials. It is made of wood, paper, plastic, organic adhesives, etc. to retain various functions as building materials.
This is because there is no choice but to combine polymer materials such as various organic fibers or inorganic fibers that do not have heat resistance at high temperatures.

Further, although the building material composed mainly of Portland cement is nonflammable,
When heated above 00 ° C, dehydration occurs and the mechanical strength cannot be maintained. In order to solve such a point, various attempts have been made under the present circumstances, but in reality, a quasi-incombustible or flame-retardant sign is attached to a building construction and it is unavoidably used during the construction construction.

Further, with the recent rise in land prices, houses are becoming collective and high-rise in place of conventional wooden houses, and concrete houses and prefabricated houses are increasing. The building materials used for this purpose are required not only to be non-combustible but also to have other functions. One of them is adiabatic. In the case of concrete houses and prefabricated houses,
Air-conditioning equipment is indispensable, and a building material that maintains a comfortable living environment, reduces energy costs, and has a high heat insulating property is required. That is, a material that is not only nonflammable but also has low thermal conductivity is required.

In addition, due to the aggregation of concrete houses, the building materials are required to have sound insulation and sound absorption. In the modern society of the future, it is especially required to cut off the sound from adjacent rooms and absorb it to create a comfortable living space.

The problem of dew condensation is also important in the case of concrete houses. Further, heat resistance and moisture resistance are also required. Recently, allergic diseases caused by microorganisms such as mites have become a problem. It is also required for building materials that these microorganisms are difficult to reproduce. Therefore, the building materials from now on are required to have a low water absorption property, a small dimensional change that does not cause a decrease in strength even under moisture absorption, and high workability and workability. Not only is it easy to cut and siding, but it is also necessary for construction materials in the future to have joint treatment and good fit in details. Other,
The surface strength of building materials is also required. That is, even if the surface of the building material comes into contact with other materials, they do not peel off or fall off, and the powder does not scatter. As a matter of course, it is required that the durability can be maintained for a long time.

The building materials having the above-mentioned properties have hitherto been called fireproof heat insulating materials or heat insulating materials. Both the fireproof heat insulating material and the heat insulating material have low thermal conductivity.
Although there is no clear distinction between the two, the heat insulating material is used at a low temperature of up to about 500 ° C, and the refractory material is generally a material capable of withstanding 800 ° C or higher. Commonly used refractory insulation materials include calcium silicate, perlite, vermiculite, ceramic foam,
Such as metal foam. Table 1 shows their specific gravity, bending strength, safe operating temperature and thermal conductivity.

[0008]

[Table 1]

[0009] Magnesium carbonate type heat insulating material, foam glass type heat insulating material and the like have a safe use temperature of up to about 430 ° C and cannot be said to be fireproof and noncombustible materials.

As a non-combustible building material, a large amount of calcium silicate type heat insulating material is used as a siliceous raw material such as diatomaceous earth and quartz powder, and inorganic fiber to calcareous material such as quick lime and slaked lime. It is cured at room temperature or high temperature and high pressure. In addition, quick lime and silica stone powder are autoclaved while stirring in a slurry state to synthesize tobermorite or zonotolite and dehydration press-molded to produce a light material having a specific gravity of about 0.15. Table-2 shows the standard of the calcium silicate heat insulating material described in JIS A9510.

[0011]

[Table 2]

A material having a bulk specific gravity of 0.13, a bending strength of 3 kg / cm ² and a compressive strength of 6 kg / cm ² can be used up to about 850 ° C. However, in any case, the bending strength is about ² to 3 kg / cm ² , and it cannot be used in a place where mechanical strength is required. In addition, there are many problems in workability such as cracking during work. In addition, asbestos calcium silicate board is also used for fireproof coating of steel frame subjected to anticorrosion treatment.

The vermiculous heat insulating material is a heat insulating material of vermiculite (aluminum-iron-magnesium hydrous silicate, which is a clay mineral having a three-layer structure and mica-like) and heated rapidly to about 1000.degree. It evaporates and expands 20 to 30 times. Vermiculite is obtained by adding cement, water glass, etc. to this and heating and sintering it.
It has a density of g / cm ³ and a thermal conductivity of 0.12 kcal / m · hr · ° C, and is used for high-temperature heat insulating materials and lightweight aggregates. However, this material also has low mechanical strength and its use range is limited.

The pearlite heat insulating material is 8 when crushed from natural glassy rocks such as obsidian, pearlite, and shale and rapidly heated.
It foams rapidly at a temperature of from 00 to 900 ° C or higher and has a specific gravity of 0.04 to
It becomes a hollow body of 0.20. An insulating material is obtained by adding an adhesive such as water glass and inorganic fibers to this and press-molding. Since the maximum operating temperature of this heat insulating material is only 600 ° C, a temperature range higher than that, that is, 800 to 10
Obviously, it cannot be used at a temperature of about 00 ° C.

Therefore, this pearlite heat insulating material is
It is used to keep cold in G and LNG tanks, liquid nitrogen, liquid oxygen tanks, air separators, and freezers. But,
This pearlite heat insulating material has a problem of water absorption, and a water repellent is usually applied to the surface thereof. The standard of the water repellent perlite heat insulating material to which the water repellent is added is specified in JIS A9512, which is shown in Table-3.

[0016]

[Table 3]

The ceramic foam heat insulating material is a foam fired body produced by adding a small amount of iron oxide to aluminum silicate, and has a heat insulating property 18 times that of concrete and 2 times that of gypsum board, and is -200 to + 700 ° C. It can be used in the temperature range of. The feature is that it is inexpensive and has high sound absorption. Other,
Porous ceramic-based heat insulating materials made from silica, alumina, etc. are also made. Table 4 shows various properties of these porous ceramics. However, the raw material itself is expensive, the range of use is limited, and there is a problem as a general building material.

[0018]

[Table 4]

The metal foam heat insulating material is a foamed material such as aluminum and is manufactured by the development of a metal foam manufacturing technique. It is a foamed aluminum having irregular polyhedral closed cells with a porosity of about 90% and a bulk specific gravity of 0.2 to 0.3. The specific gravity of this heat insulating material is 1/10 of that of aluminum, its heat resistance is 500 ° C., and its heat insulating property is comparable to that of marble. In addition, it is nonflammable, has a large sound absorbing and sound insulating effect, and is easily processed and constructed. Because of these properties, they are used as multifunctional materials such as heat insulating materials, soundproofing materials, building materials, and electromagnetic wave shielding materials. However, the price is higher than that of the ceramic foam type, the range of use is limited, and it is often used in places where acoustic effects are strongly required. Further, since it is a metal type, it cannot be used in the presence of corrosive gas such as acid or alkali.

Light-weight aerated concrete (ALC) is obtained by crushing calcareous raw material (lime or cement) and siliceous raw material (silica stone, silica sand, blast furnace slag, etc.) into a water-foaming material (metal powder, surfactant). Etc.), an admixture, etc. are added and mixed to make it porous. Since this lightweight concrete is lightweight, nonflammable, and has a high heat insulating property, it is used as an outer wall material for building materials such as prefabricated houses. However, it has problems such as high water absorption and weak freeze-thaw. In addition, the mechanical strength is low, and the range of use must be limited. JIS A5416 (lightweight cellular concrete panel) specifies for outer walls, partitions, roofs, etc.

A heat insulating material is used at a temperature slightly lower than that of the heat insulating material. As a heat insulating material, the thermal conductivity is 0.1
The target is kcal / m · hr · ° C or less. Many of the heat insulating materials are porous and lightweight, and most of them are common with the sound absorbing material. The heat insulating material has been used for industrial purposes for a long time, and the water-mixed material containing asbestos, diatomaceous earth, and magnesium carbonate was used, but thereafter, organic materials such as corks, felts, and expanded polystyrene are also used. It became so. However, organic heat insulation materials have low heat resistance,
Light weight calcium silicate these days, because it is flammable
Ceramic fiber products such as glass wool and rock wool have come into wide use. Short fiber glass wool has a bulk specific gravity of 0.15 or less, thermal conductivity of 0.045 kcal
/ M · hr · ° C, operating temperature below 300 ° C, heat insulating material,
It is used as a sound absorbing material. However, both of them have low operating temperatures and cannot be used as non-combustible building materials.

Further, various types of building interior and exterior materials having excellent heat insulation, water resistance, fire resistance, etc. are manufactured.
One of them is a building material (made by Toyobo) made mainly of rock wool. The characteristics of this material are as follows. (1) It has a low thermal conductivity of 0.045 kcal / m · hr · ° C and is excellent in heat insulation and dew resistance. (2) Low water absorption,
Little decrease in strength and dimensional change when absorbing water and moisture. (3) It is semi-combustible. (4) Easy workability.

The main uses of this building material are as an interior / exterior base material for a general house, an interior / exterior base material for a reinforced concrete structure, and an eaves ceiling. However, since the main material is rock wool, it is not a noncombustible material but a quasi-noncombustible material. The maximum safe use temperature of rock wool is 600 ° C., and as long as it is used, it cannot be a non-combustible material that can maintain fire resistance even at a high temperature of 800 ° C. to 1000 ° C.

In addition, it is often attempted to spray a nonflammable material on a steel sheet used as a metal-based building material in order to impart sound absorption, sound insulation, heat insulation, dew condensation prevention, and the like. There is. This is the so-called spraying method. The spray material used is spray rock wool (manufactured by the Rock Wool Industry Association). This spray material is mainly composed of rock wool, and its characteristics are as follows. (1) Since it is made of granular rock wool, cement and water, it is lightweight and has excellent fire resistance. (2) Since it is a spraying process, it can be easily applied to complex shapes and creates a seamless coating layer.
(3) The construction and drying are fast, and it can be pumped to higher floors, which shortens the construction period and is economical. (4) The work environment is good due to the safety of rock wool and the development of dust prevention construction. (5) It has a fire resistance certification.

Applications of this fire resistant coating material are columns, walls, ceilings, roofs, floors and the like. Although this spray material has excellent properties, it has a low surface strength, and when it comes into contact with another material, the surface is easily peeled off and powder is scattered. for that reason,
It has drawbacks such as high surface contamination.

[0026]

As described above, a large number of non-combustible or quasi-incombustible building materials have been produced conventionally, but in each case, there are some problems, and these problems have been solved. The development of new noncombustible building materials is strongly desired.

In view of such a social situation in building materials, the present invention is a non-combustible building material, particularly 800 ° C to 1
Non-flammable even at high temperature of 000 ° C, and mechanical strength,
It is intended to provide a building material capable of maintaining other functions such as lightness, heat insulation, surface robustness, durability, water resistance, and condensation resistance.

That is, the object of the invention of claim 1 is to provide a building material which is non-combustible, maintains mechanical strength particularly at high temperatures, and has excellent heat insulating properties. In addition to the purpose described in Item 1, it is another object to provide a lightweight building material having high surface strength.

[0029]

As a result of intensive studies on these problems, the present inventor has succeeded in solving the above problems and has reached the present invention. It was found that the first object of the present invention can be achieved by an alumina cement composite material characterized by containing fly ash wool and lightweight aggregate as described in claim 1.

That is, the present invention has found that fly ash wool, which is a refractory inorganic fiber, is used as a reinforcing material for building materials, and it is combined with alumina cement having high fire resistance as a base material to further reduce the weight. When a lightweight aggregate is used, it has excellent mechanical strength even under an extremely high temperature of 800 ° C. to 1000 ° C., has thermal shock resistance, and has low thermal conductivity and excellent heat insulation. It was possible to obtain such a building material very easily.

As described above, since ordinary Portland cement undergoes dehydration at a temperature of 300 ° C. or higher, it cannot maintain mechanical strength at high temperature even if it is combined with any reinforcing material. The present invention, as described above, uses a combination of highly fire-resistant alumina cement and fly ash wool, which is a non-combustible material, to obtain a temperature of 800 ° C to 1 ° C.
It was possible to secure excellent mechanical strength even under an extremely high temperature of 000 ° C. Further, since alumina cement has a smaller particle size than ordinary Portland cement, the reinforcing effect of fly ash wool is more sufficiently exhibited, and the surface fastness is also increased. Furthermore, by using lightweight aggregate such as shirasu balloon together, weight reduction,
Low thermal conductivity and heat insulation can be achieved.

Further, the fly ash wool / alumina cement composite material according to the present invention is very excellent in that the production time is short and the productivity is high. That is, each raw material can be weighed, mixed, stirred, poured, and cured in a simple autoclave in about 3 to 5 hours.

In the present invention, as described in claim 2, by further containing at least one of a foaming agent and a foaming agent, it is possible to achieve further weight reduction and low thermal conductivity of the building material, Succeeded in increasing strength. According to the present invention, nonflammability, light weight, heat insulation, sound insulation, sound absorption, fire resistance, mechanical strength, surface hardness, durability,
It is possible to satisfy the necessary conditions of various building materials such as water resistance, moisture resistance, condensation resistance, durability, and thermal shock resistance. Furthermore, the manufacturing process is extremely simple.

The present invention will be described in more detail below. The fly ash wool used in the present invention is a coal ash (fly ash) produced as a by-product when coal is burned at 1400 ° C to 17 ° C.
It is melted at a high temperature of 00 ° C, and it is made into fibers by centrifugal force,
Alternatively, it is made into fibers or cotton by blowing compressed air.

The fly ash as a raw material has a chemical composition similar to that of basalt, andesite, blast furnace slag, etc., which is a raw material for rock wool, and it has been found that fibers having almost the same performance as rock wool can be produced. . It has been found that fly ash wool is advantageous in terms of heat insulation because it can relatively lengthen the fiber length as compared with rock wool, and has excellent heat resistance because of its high melting temperature. Further, fly ash, which is an unused resource, can be effectively used as a raw material, and it is excellent in economic efficiency.

The heat resistance of fly ash wool was examined by heating to 1300 ° C. in air using a thermal analyzer.
As a result, there was no change in the thermogravimetric curve and there was no increase in weight. Also, in the differential heat curve, 1000 ° C
There was no clear endothermic or exothermic peak below, but 105
An exothermic peak near 0 ° C. and an endothermic peak near 1150 ° C. were observed. The former exotherm was due to the crystallization of vitreous fly ash wool, and the latter endotherm was due to the melting of fly ash wool. Therefore, the operating temperature of the composite material using this fly ash wool is preferably a temperature at which crystallization does not occur, that is, 1050 ° C. or less. However, if it is a short time, it can be used up to around the melting point of 1150 ° C.

The high heat resistance of fly ash wool can be supported by the following simple experiment. That is, even if the fly ash wool was heated to a red hot state in the gas burner and put into water at once, no change was observed in the fly ash wool itself.

The diameter of fly ash wool was about 5 to 10 μm when observed with a scanning electron microscope. The mechanical strength of fly ash wool is 4120MPa, tensile modulus is 200GPa when diameter is 6μm.
Is. These properties were far higher than those of other inorganic fibers such as alumina fiber, glass fiber, carbon fiber and the like. Moreover, it had excellent heat resistance and mechanical properties that were incomparable to those of rock wool and glass wool made from slag from steel mills.

The composition of fly ash as a raw material differs depending on the place of production of coal, but the main ones are silicon dioxide (silica) and alumina.
It accounts for 60 to 80% of the whole. In addition, it contains a small amount of ferric oxide, calcium oxide, magnesium oxide and the like. In order to maintain the quality of fly ash wool, it is preferable that the components of fly ash as a raw material are stable. Further, fly ash having a content of silicon dioxide as low as possible and a content of alumina as high as possible is preferable because it has a low viscosity at a high temperature and can be melted at a low temperature.
Further, in order to approximate the composition and solubility of fly ash wool to those of rock wool, auxiliary materials such as limestone can be added to fly ash.

Fly ash wool can be manufactured by a conventional mineral wool manufacturing method. For example, a batch system method (cupola method) using a cupola in which a powdery raw material is solidified and charged, the raw material in a powder state is used. An electric furnace method (for example, Geotech method by Geotech) using an electric furnace that is directly charged can be used. In particular, the electric furnace method is preferable because it has advantages such as a low power consumption rate, a high yield, a low shot sphere (non-fibrous particle) mixing ratio, and a long fiber length can be expected. The fly ash wool may optionally have the shot spheres at the ends of the fibers removed by a sprinkling operation. Fiberization of the high-temperature melt requires melting at a temperature at which an appropriate viscosity is obtained, and depending on the composition of the raw material coal ash, 1100-1
Temperatures of 900 ° C, especially 1400 to 1700 ° C, are suitable.

Alumina cement is an inorganic hydraulic cement whose main component is calcium aluminate. The properties of alumina cement differ depending on the composition and particle size of CaO, Al ₂ O _3, etc. It is preferable to increase the proportion of CaO when the main purpose is to have early strength and mechanical strength, and to increase the proportion of Al ₂ O ₃ when aiming for fire resistance.

In the present invention, the lightweight aggregate contained in the alumina cement composite may be any non-combustible lightweight aggregate usually used in building materials, and among them, to achieve low thermal conductivity. Those that generate closed cells are preferred. It may be any of natural lightweight aggregate, artificial lightweight aggregate, and by-product lightweight aggregate, for example, shirasu balloon, ceramic balloon, fly ash balloon, perlite, expanded shale, expanded clay, gravel, expanded slag, flint, coal coal. , Diatomaceous earth, and the like.

Particularly, a shirasu balloon can be preferably used. Shirasu balloon is made from Shirasu, which is a volcanic ejecta deposited in Kagoshima prefecture, Hokkaido, Akita prefecture, etc., as a raw material, and is foamed at high temperature. It has a spherical shape, and there are various types such as density and diameter.
Since this shirasu balloon is lightweight and excellent in fire resistance, it is used as a lightweight building material for curtain walls and the like. If necessary, other additives commonly used in this field, for example, other aggregates, stabilizers, fluidizing agents and the like can be appropriately added.

The alumina cement composite material of the present invention can be manufactured very simply, for example, as follows. A predetermined amount of alumina cement, shirasu balloon and water are weighed and mixed in a mixer. Fly ash wool is added little by little to this and mixed.
It can be easily manufactured by putting it in a mold and curing it in water for a predetermined period, or by putting it in a simple autoclave and performing steam curing. The manufacturing time for this can be 3 to 5 hours.

The fly ash wool / alumina cement composite material according to the present invention has extremely high heat resistance. Specifically, the prepared fly ash wool / alumina cement composite material is placed in an electric furnace and heated to 10
Hold at 00 ° C for 3 hours. After heating, the red-hot sample was immediately put into water. When the fly ash wool was not included, a small crack was generated on the surface, but when the fly ash wool was included, no change was observed. Therefore, it was found that the alumina cement composite material containing fly ash wool has not only high heat resistance but also high thermal shock resistance.

The alumina cement composite material of the present invention can be blended in various ways depending on the mixing ratio of fly ash wool or lightweight aggregate to alumina cement and the water ratio to alumina cement. Therefore, a building material having excellent performance can be easily obtained.

Alumina cement water / cement (W /
The C) ratio is a range that is usually used, and is not particularly limited, but the smaller the W / C ratio, the higher the strength of the material obtained, but the poorer the fluidity and the lower the workability.

The amount of fly ash wool that can be contained in the alumina cement composite material can be appropriately set depending on the water / cement (W / C) ratio of the alumina cement used, the amount of lightweight aggregate, and the like. By adding fly ash wool, various excellent effects such as strengthening strength, maintaining high temperature strength, preventing explosion at high temperature heating, securing thermal shock strength, securing / strengthening toughness, securing surface robustness, etc. are achieved. Expressed. However, considering the dispersibility of fly ash wool, the content of fly ash wool in the alumina cement composite is usually 1 to 40% by weight.
The range is about 10 to 25% by weight.

Generally, it is preferable to use about 20 to 80% of the weight of the alumina cement as the lightweight aggregate, but the bulk density and the thermal conductivity can be reduced as the added amount is increased. The content can be set appropriately. For example, the thermal conductivity of non-combustible heat insulating building material is 0.1-0.2kcal
For the purpose of about / m · hr · ° C, the lightweight aggregate / cement ratio is preferably 0.5 or more. On the other hand, if the amount of the lightweight aggregate is too large, the surface hardness (surface robustness) decreases, so the lightweight aggregate / cement ratio is preferably 1.0 or less.

For example, a large amount of lightweight aggregate is added, and
The cement material according to the present invention produced with a high water / cement ratio can have a bulk density as low as 0.5 g / cm ³ and has excellent properties. Here, as a reference, Table 5 shows the values of thermal conductivity and mechanical strength of various commercially available heat insulating materials.

[0051]

[Table 5]

However, it has been found that the surface strength is weak and the powder drops when the surface is rubbed. Therefore, when the surface strength is weak, it is preferable to separately coat the surface of the material with an inorganic coating film. Further, the material has a problem that it takes a long time to start setting hardening. Therefore, when a foaming agent or a foaming agent is further contained in the alumina cement composite material to form voids in the base material, it is possible to achieve weight reduction and heat insulation without lowering the surface strength. did it. That is, by further forming voids in the base material, the bulk density and the thermal conductivity can be further reduced while maintaining the surface robustness.

The foaming agent is composed of two kinds of substances which react with each other in water in the alumina cement paste to generate gas (for example, hydrogen peroxide and calcium hypochlorite, hydrochloric acid and sodium bicarbonate). , A single substance (for example, metal powder such as aluminum, iron, magnesium, zinc, calcium carbide, etc.) that reacts with water in alumina cement paste to generate gas, and heat is generated by the heat of hydration reaction of alumina cement A single substance (eg yeast etc.) can be mentioned. From the viewpoint of practicality, aluminum powder is particularly preferable.

If necessary, it is preferable to add a foaming accelerator such as caustic soda and a foam stabilizer such as asphalt emulsion, water glass, saponin, and resin as an auxiliary agent together with the foaming agent.

Examples of the foaming agent include detergents (for example, sodium lauryl sulfate, alkylallyl sulfonic acid, etc.), resin soaps, vegetable or animal colloids, saponins, naphthalene alkyl sulfonates, sodium isopropyl sulfonate, colloid butyl. In addition to naphthalene sulfonate, calcium chloride, protein derivatives (eg gelatin, casein, etc.), so-called surfactant AE agents can be mentioned.

To form voids inside the sample, for example, a metal powder such as an aluminum powder may be added, and hydrogen generated from the powder may be used to construct bubbles. Also,
Bubbles and voids can be formed in the cement sample by adding a surface-active agent, stirring it sufficiently, and performing bubbling, thereby achieving weight reduction and low thermal conductivity. The method using the surfactant can be easily performed by applying the method used for manufacturing ALC.

Further, thermoplastic plastic beads such as Styrofoam are dispersed in cement paste, and after curing, those plastics are melted and removed by heating, or in an organic solvent such as benzene, toluene or ketone. Voids can also be created by dipping and melting and removing the plastic.

Further, as the steel sheet, a non-combustible material, which is lined with a non-combustible, lightweight, low-conductivity material by spraying, has been put into practical use. The lightweight, non-flammable, low thermal conductivity material obtained by the present invention can also be used as the backing material. In order to reduce the weight in such applications, it is difficult to add aluminum powder and foam, and a method using a surfactant is preferable.

The addition amount of the foaming agent or foaming agent can be appropriately set depending on the amounts of other alumina cement, fly ash wool and lightweight aggregate. Generally, the larger the addition amount of these, the larger the voids. Therefore, the bulk density is lowered, and the thermal conductivity can be reduced.

For example, when the addition amount of the lightweight aggregate and the water / cement ratio are suppressed to some extent and a foaming agent or a foaming agent is added instead, the bulk density is about 0.6 to 0.7 g / cm ³ ,
The thermal conductivity can be reduced to about 0.2 kcal / m · hr · ° C, and we have succeeded in realizing a non-combustible building material with excellent lightness and heat insulation. However, if the addition amount is too large, the strength is lowered, which is not preferable. For example, the addition amount of aluminum powder is 0.0 in terms of ratio to cement.
1 to 0.4, particularly 0.05 to 0.3 is preferable.

As described above, the alumina cement composite material of the present invention has, in addition to the mixing ratio of fly ash wool and lightweight aggregate to alumina cement and the water ratio to alumina cement, a mixing ratio of a foaming agent or a foaming agent. According to the above, various blending is possible, which makes it possible to easily obtain a building material having excellent performance for various purposes.

The water / cement ratio, the amount of the lightweight aggregate, and the amount and method of addition of the foaming agent or foaming agent were variously studied, and the bulk density was about 0.5 to 0.6 g / cm ^3. And the thermal conductivity is 0.17 kcal / m ・ hr ・
It was found that the temperature was lowered to about ℃. Comparing with the thermal conductivity of the commercially available heat insulating material shown in Table 5 above, it can be seen that this value is sufficiently practical. Also, bending strength 10 kg / cm
^2. It was also possible to produce a material having an excellent mechanical strength such as a compressive strength of 58 kg / cm ² . Furthermore, the surface strength of the sample is increased by adding a foaming agent or a foaming agent,
No powder was produced or scattered.

Further, when the foaming agent or the foaming agent was added, the mechanical strength and the thermal conductivity of the composite material were examined by increasing the addition amount of fly ash wool. The amount of water / cement, lightweight aggregate / cement, and blowing agent or foaming agent added was kept constant, and the amount of fly ash wool to be filled was varied. As a result, by including fly ash wool, the bulk density and thermal conductivity are increased, but since lightweight aggregates and foaming agents / foaming agents are added, it is practically sufficiently lightweight and has low thermal conductivity. It has been found that a material with a high rate can be obtained, and yet extremely excellent mechanical strength and nonflammability can be achieved.

As described above, in the present invention, by studying various amounts of addition of each material, it is possible to easily obtain an extremely practical building material. For example, when shirasu balloon is used as the lightweight aggregate and aluminum powder is used as the foaming agent, respectively, water / cement ratio 1.1, shirasu balloon / cement ratio 0.7, fly ash wool / cement ratio 0.1, aluminum powder /
The specimen prepared with the cement ratio of 0.2 had a bulk density of 0.80 g / cm ³ and a thermal conductivity of 0.19 kcal / m · hr ·
℃, bending strength 10.5kg / cm ² and compressive strength 58kg / cm ²
Each had excellent characteristics. These values were superior to the refractory bricks shown in Table-5.
Moreover, although the refractory brick has a weak surface strength, the specimen according to the present invention did not have such a phenomenon.

When fly ash wool is added at 25% of the cement weight, the bulk density is 0.60 g / c.
m ^3, the thermal conductivity of 0.176kcal / m · hr · ℃, bending strength 8.5 kg / cm ^2, a compressive strength 15.8 kg / cm ^2, a very low non-combustible building materials in thermal conductivity is obtained.

These test pieces were excellent in terms of heat and mechanical strength and were highly practical building materials. It has been found that the fly ash wool / alumina cement composite material according to the present invention is placed in an electric furnace, heated to 1000 ° C., and even if it is put into water at once, it is not broken and has excellent heat resistance. Further, even when the sample was dipped in water and dried or exposed as it was, no occurrence of cracks was observed. Also, putting the sample in water,
Even if it was taken out, drained to some extent, and put in the refrigerator, it did not crack. As described above, it was also found to have durability, water resistance, moisture resistance, and freeze resistance.

Further, the fly ash wool / alumina cement composite material according to the present invention, particularly the composite material containing a foaming agent or a foaming agent, has many voids on the surface,
Compared to a flat concrete wall, dew is less likely to be generated, and even if it is generated, it is easy to volatilize from another void due to the complicated surface shape.

From the above, the fly ash wool / alumina cement composite material according to the present invention is not only lightweight, but also excellent in low thermal conductivity, heat resistance, durability, water resistance and dew resistance. It was found to exhibit characteristics. Further, by controlling the foaming / foaming method, temperature, etc. with a foaming agent or a foaming agent, it is possible to further reduce the weight and achieve heat insulation.

[0069]

EXAMPLES The present invention will be illustrated below with reference to examples, but the present invention is not limited thereto.

Example 1 Alumina cement (manufactured by Denki Kagaku Kogyo, the same applies hereinafter) 100
50 g of water is added to g to give the specified water / cement ratio (W / C
= 0.5) cement paste was prepared. To this, a predetermined amount of shirasu balloon was added all at once so that a predetermined shirasu balloon / cement (S / C) ratio was obtained, and the mixture was stirred by a motor for 1 minute. Then, in this, fly ash wool (made in China, see Reference Examples 1 and 2 described later for characteristics, the same applies hereinafter) 1
0 g {fly ash wool / cement (FAW / C)
Ratio = 0.1} was finely torn and added in 10 batches with stirring (3 minutes). This mixture was placed in a plastic container (length 14.5 cm, width 8 cm, height 2 cm). The next day, it was demolded and cured in a simple autoclave (121 ° C) for 1 hour. Table 6 shows the production conditions, thermal conductivity, bulk density and compressive strength of the produced fly ash wool / alumina cement composite material. Table 6 also shows the results of the alumina cement composite material obtained in exactly the same manner except that fly ash wool was not included.

[0071]

[Table 6]

The bulk density of the obtained composite material is 1.3 to
It was about 1.7 g / cm ³ , and it was difficult to call it a lightweight building material. However, when the thermal conductivity of these is measured by the probe method, it is 0.5 to 0.9 kcal / m · hr · ° C, which means that ordinary concrete or mortar (thermal conductivity of 0.8 to 1.6 kcal /
m ・ hr ・ ℃). Also, the thermal conductivity of what is commonly called lightweight concrete is 0.6-
The value was about 0.8 kcal / m · hr · ° C, and the value obtained by the present invention was about the same. The bulk density and thermal conductivity decreased as the amount of shirasu balloon increased. In addition, the addition of fly ash wool tended to increase the bulk density and decrease the thermal conductivity.

The prepared fly ash wool / alumina cement composite material was placed in an electric furnace and heated to 1000
After being kept at ℃ for 3 hours, the red-hot sample was immediately put into water. When the fly ash wool was not included, small cracks were generated on the surface, but when the fly ash wool was included, no change was observed. Therefore, it was found that the alumina cement composite material containing fly ash wool has not only high heat resistance but also high thermal shock resistance.

Example 2 100 g of alumina cement was mixed with a predetermined amount (4) so that a predetermined water / cement ratio (W / C = 4.0 or 4.5) was obtained.
00 g or 450 g) of water was added to make a cement paste. To this, a predetermined amount of Shirasu balloon was added at once so as to obtain a predetermined S / C ratio, and the mixture was stirred for 8 minutes. A predetermined amount of fly ash wool was finely torn into a predetermined FAW / C ratio, and the mixture was added in 10 batches with stirring (3 minutes). This mixture was placed in a plastic container (length 14.5 cm, width 8 cm, height 2 cm).
After 2 days, the mold was removed and cured in a simple autoclave (121 ° C) for 1 hour. Table 7 shows the production conditions, thermal conductivity, bulk density and compressive strength of the produced fly ash wool / alumina cement composite material.

[0075]

[Table 7]

A higher water / cement ratio than in Example 1,
By increasing the amount of shirasu balloon further,
The bulk density was around 0.5, which was extremely lightweight. Further, the thermal conductivity was 0.13 kcal / m · hr · ° C, which was about the same value as the commercially available product. Further, in this case, even if the amount of fly ash wool was increased, the bulk density and the thermal conductivity were hardly increased, and the one having high mechanical strength was obtained. However, this lightweight heat insulating material had a weak surface strength, and white powder was peeled off when the surface was rubbed with a finger. Further, this sample has a problem that it takes a long time to start setting hardening.

Example 3 The amount of shirasu balloon was reduced to the level used in Example 1, aluminum powder was added as a foaming agent, and the influence on the lightness and thermal conductivity was examined. Cement paste was prepared by adding 100 g of alumina cement with water having a predetermined water / cement ratio. To this, 60 g of Shirasu balloon having a predetermined S / C amount was added at once and stirred for 8 minutes.
To this, 10 g of fly ash wool was finely torn and added in 10 batches with stirring (2 minutes).
Finally, 5 g or 10 g of aluminum powder was added at once and stirred for 2 minutes. This mixture was placed in a plastic container (length 14.5 cm, width 8 cm, height 2 cm). After 1 day, the mold was removed, and it was cured in a simple autoclave (121 ° C) for 1 hour. Table 8 shows the production conditions, thermal conductivity, bulk density and compressive strength of the produced fly ash wool / alumina cement composite material.

In order to facilitate the comparison, a strict comparison cannot be made because the manufacturing conditions are different, but the case where the aluminum powder measured in the above-mentioned examples is not added is also described. By adding aluminum powder and foaming, the bulk density was reduced to 1/2 and the thermal conductivity was reduced from about 1/3 to about 1/4. Moreover, even if the surface of this sample was rubbed with a finger, neither powder nor peeling occurred.
Materials that are almost as required, such as lightness, thermal conductivity, and surface strength, were obtained.

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[Table 8]

Example 4 Further, the influence of the addition amount of aluminum powder was examined. Water (110 g, 120) of a predetermined water / cement ratio (W / C = 1.1 to 1.5) on 100 g of alumina cement.
g, 150 g) was added to make a cement paste. A certain amount of shirasu balloon (60g, 70g, 80
g, 100 g) were added at once and stirred for 4 minutes. While tearing 10 g of fly ash wool into small pieces,
The mixture was added in 10 batches with stirring (2 minutes). Finally, 20 g of aluminum powder was added at once and stirred for 2 minutes. Add this mixture to a plastic container (vertical 14.5c
m, width 8 cm, height 2 cm). About 50 ~
It was floated in warm water of 80 ° C. and heated for 30 minutes. This heat treatment accelerated the reaction, and the generation of hydrogen and water vapor became remarkable. After 1 day, the mold was removed, and it was cured in a simple autoclave (121 ° C) for 1 hour. Table 9 shows the production conditions, thermal conductivity, bulk density and compressive strength of the produced fly ash wool / alumina cement composite material.

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[Table 9]

When the amount of aluminum powder added was increased, the bulk density and thermal conductivity seemed to decrease. However, since the amount of shirasu balloon also fluctuated, it seemed that it had an effect. Particularly, in the case of sample C3, the bulk density was 0.60 g / cm ³ and the thermal conductivity was 0.19 kcal / m · hr ·
A non-combustible building material having a bending strength of 10.5 kg / cm ² and a compressive strength of 58 kg / cm ² was obtained. These were building materials with high practicality in terms of both thermal and mechanical strength.

Example 5 The effect of the addition amount of fly ash wool was examined. A cement paste was prepared by adding 150 g of water having a predetermined water / cement ratio (W / C = 1.5) to 100 g of alumina cement. A certain amount of shirasu balloon 80g
Was added at once and stirred for 4 minutes. A predetermined amount (FA
W / C = 0, 0.1, 0.15, 0.20, 0.25,
0.30) fly ash wool (0g, 10g, 1
(5 g, 20 g, 25 g, 30 g) was finely torn and added in several tens of times with stirring (2 to 8 minutes). Finally, add 30g of aluminum powder at once,
Stir for 4 minutes. This mixture was placed in a plastic container (length 14.5 cm, width 8 cm, height 2 cm). The container was floated in warm water of about 50 to 80 ° C. and heated for 30 minutes.
This heat treatment accelerated the reaction, and the generation of hydrogen and water vapor became remarkable. After 1 day, the mold was removed, and it was cured in a simple autoclave (121 ° C) for 1 hour. Manufacturing conditions of the manufactured fly ash wool / alumina cement composite,
The thermal conductivity, bulk density and compressive strength are shown in Table-10.

[0084]

[Table 10]

When the fly ash wool was added, the bulk density and the thermal conductivity increased irrespective of the amount added, but the practicability was sufficiently high and the bending strength and the compression strength increased. Above all, when fly ash wool is added at 25% of the cement weight, the bulk density is 0.60 g / cm ³ , and the thermal conductivity is 0.176 kcal / m · h.
r · ° C, bending strength 8.5 kg / cm ² , compressive strength 15.8 kg /
A non-combustible building material of cm ² was obtained. These values were extremely highly practical. Furthermore, even when the surface of each of these specimens was strongly rubbed with a finger, neither peeling off nor white powder on the belly of the finger was observed. Therefore, high surface hardness,
A non-combustible building material having surface fastness was obtained.

Reference Example 1 The chemical composition of the fly ash wool raw material (fly ash) used in Examples 1 to 5 and the fiber characteristics of the fly ash wool were compared with those of glass wool and rock wool, respectively. It shows in Table-12.

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[Table 11]

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[Table 12]

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INDUSTRIAL APPLICABILITY According to the present invention, fly ash wool, which is a refractory inorganic fiber, is used as a reinforcing material, alumina fire cement having high fire resistance is used as a base material, and light aggregate such as shirasu balloon is used. In addition, a building material excellent in nonflammability, thermal shock resistance, heat insulation and mechanical strength can be obtained very easily. In addition, it is excellent in economic efficiency and can effectively utilize the conventional problem of coal ash.

Furthermore, by adding a foaming agent or a foaming agent, the base material can be foamed to achieve further weight reduction and surface strength can be increased, and surface hardness, durability, water resistance and moisture resistance can be increased. It is possible to satisfy the requirements for durability, dew condensation resistance and durability.

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Claims (2)

[Claims] 1. An alumina cement composite material comprising fly ash wool and lightweight aggregate. 2. The alumina cement composite material according to claim 1, further containing at least one of a foaming agent and a foaming agent.