JP2002308659A - Cement hardened body and its production process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cement hardened body which can be produced by a production process that involves mixing, as a substitute for cement, a large amount of incineration ash into cement, in a cement mix for forming a cement formed body, and also to provide the production process of the cement hardened body. SOLUTION: The production process involves mixing a cement mix containing cement (C) and incineration ash (F), then forming the mixed cement mix into a cement formed body and hardening the cement formed body, wherein, in the cement mix, the ratio (F/(F+C)) of the content of the incineration ash (F) to the total content of the cement (C) and the incineration ash (F) is >=10 mass %, also, the cement mix contains a fibrous reinforcing material in a 2-10 vol.% ratio of the fibrous reinforcing material to the mixture (F+C) of the incineration ash (F) and the cement (C), and further, in the cement mix, water- powder ratio (S) meets the relational expression 0<=(S-S0)<=5% (S0 is an optimum water content).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hardened cement body using incinerated ash (fly ash and the like) and a method for producing the same, and more particularly, to a fiber material and a water content in an optimum ratio. The present invention also relates to a hardened cement body having excellent bending strength and the like, which is manufactured by performing optimal kneading, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Although incinerated ash such as coal generated by coal-fired power generation is partially used for purposes such as cement raw materials or admixtures for concrete, most of the incinerated ash is disposed of in landfills, thus protecting the environment. From the viewpoint of resource utilization and resource utilization, expansion of utilization is required. Similarly, incineration ash such as sludge generated after purifying sewage water is also required to be used for purposes other than landfill disposal. In addition, utilization of incineration slag and the like generated in the hot metal treatment process in ironworks is also required.

Various types of hardened cement bodies in which the above-mentioned incinerated ash is mixed with cement have been conventionally proposed. In general, it is desired to mix as much of the above-mentioned incinerated ash into cement as possible. It is also required that the body has a strength close to that of a general hardened concrete body made of gravel, sand, or the like mainly composed of a conventional cement raw material. In addition, since such a cured body (block) containing incinerated ash is often used for a marine block or the like, it is required to have abrasion resistance, non-alkali elution, and the like.

[0004] Conventionally, such a hardened material is made of cement and dry fine powder (coal ash, blast furnace slag, sludge incineration ash).
A water-curable material containing, as far as possible, water is added and kneaded in a range as close to the optimum water content ratio as possible, and a method for producing a cured body in which the material is poured into a mold and vibrated to compact the mold is proposed. (JP-A-9-12348). In such a production method, the amount of water contained is reduced as much as possible, and the dispersibility of each component is increased by vibration treatment, whereby cement hardened without heat, cracks, and breathing without heat generation during the production of the cured product. It provides the body.

Further, the cement, a large amount of fine powder,
In order to produce a cured product made of a material containing water having a water powder ratio of about the optimum water content ratio, a method for determining the blending ratio of each material has been proposed (Japanese Patent Laid-Open No. 10-323820). A kneaded product is produced by kneading and mixing cement, fine powder, and water, and a flow test is performed on the kneaded product to determine a water powder ratio showing a predetermined flow value. An estimated value of the water powder ratio (optimal water powder ratio) at which the strength is maximized is calculated, an estimated value of the compression strength of the cured body is calculated from the estimated value of the water powder ratio, and the estimated value of the compression strength is calculated. The cement addition rate is obtained by calculation from the estimated value and the required compressive strength of the hardened body.

[0006] Such a production method comprises the steps of:
Calculate the compressive strength of the hardened cement and the value of the cement addition rate, seek the optimum cement addition rate for the material such as fine powder while repeating the feedback, and aim to improve the compressive strength of the hardened cement. Is what it is.
Furthermore, in order to improve the strength of the hardened cement, for example, tensile strength and resistance to cracks, various concretes and the like to which a glass fiber reinforcing material or the like is added have been proposed (Japanese Patent Publication No. 1-54163). In such a hardened cement body, concrete molding is performed while applying vibrations from above the working form by a vibration plate in order to sufficiently disperse the glass fiber reinforcing material in the cement material.

[0007] Incidentally, it is desired that the hardened cement body containing incinerated ash contains incinerated ash as much as possible, that is, the amount of cement is reduced as much as possible to maintain high mechanical strength such as bending strength and compressive strength. ing. For this reason, it has been considered to add a fiber reinforcing material or the like to the hardened cement body. However, there is a problem with a cured body containing incinerated ash simply by adding a fiber reinforcing material and vibrating with a diaphragm as in the prior art. That is, in the cured body containing incinerated ash, fibers are formed in the fiber reinforcing material, particularly fly ash fiber, and not only the mixing is limited, but also the dispersibility becomes extremely poor. In particular, such a phenomenon particularly occurs because the consistency becomes considerably high due to fiber mixing. In view of the above, there is a demand for a hardened cement body capable of mixing a large amount of fly ash and fiber reinforcing material as a substitute material for cement and maintaining excellent mechanical strength, and a method for producing the same.

[0008]

SUMMARY OF THE INVENTION In view of the above-mentioned conventional hardened cement containing incinerated ash, the present invention provides a cement hardened material having a high mechanical strength, in which a large amount of incinerated ash can be mixed as a substitute for cement. It is an object to provide a body and a method for producing the same.

[0009]

Means for Solving the Problems The present inventor has conducted intensive studies to solve the above-mentioned problems. As a result, the fiber reinforcing material, particularly the fiber reinforcing material such as fly ash fiber is thin and easily broken. Mixing and mixing fly ash and cement will break the fiber reinforcement, but if you use the premix and the compaction method using vertical vibration,
The fiber reinforcement is not broken and can be easily mixed and fluidized, and if the water and cement ratio is mixed at a normal ratio, the fiber reinforcement, especially the fiber reinforced material such as fly ash fiber, easily becomes lump. Although it becomes impossible to mix sufficiently, it is possible to increase the limit mixing ratio of the fiber reinforcement by appropriately restricting the moisture, and the mixing ratio of the fiber reinforcement within a predetermined range increases the mechanical strength of the hardened cement. The present invention has solved the above problem.

That is, the hardened cement body and the method for producing the same according to the present invention are described in the following (1) to (8). (1) In a cement hardened body formed by kneading and molding cement (C) containing incinerated ash (F), the mixing ratio (F) of the incinerated ash in the incinerated ash (F) and the cement (C)
/ F + C) is in the range of 10% by mass or more, and a mixture (F + C) comprising the incinerated ash (F) and the cement (C)
The fiber reinforcement in the range of 2 to 10% by volume,
And the water powder ratio (S) is 0 ≦ with respect to the optimum water content ratio (S0).
(C) A hardened cement, characterized by being formed from a kneaded mixture obtained by adding water and kneading so as to be in a range of (S) − (S0) ≦ 5%.

(2) The hardened cement according to (1), wherein the incinerated ash is fly ash or sludge incinerated ash generated by thermal power generation. (3) The fiber reinforcing material is fly ash fiber,
The cured cement according to the above (1) or (2), which is a glass fiber, a carbon fiber, or a resin fiber. (4) The hardened cement according to (3), wherein the fiber reinforcing material is fly ash fiber obtained by melting and spinning coal ash at a high temperature.

(5) In the method for producing a hardened cement according to any one of the above (1) to (4), at least the fiber reinforcing material, incinerated ash and cement are premixed.
A method for producing a hardened cement, comprising mixing, mixing, and then fluidizing by vibrating and compacting.

(6) The method for producing a hardened cement according to the above (5), wherein vibration is applied from above and below the kneaded mixture. (7) The method for producing a hardened cement according to the above (5) or (6), wherein the premix is a backflow high-speed mixing method. (8) The method for producing a hardened cement according to any one of the above (5) to (7), wherein the vibration acceleration is set to 3 G or more when the vibration is applied and fluidized.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments and examples of a cured cement body and a method for producing the same according to the present invention will be described in detail with reference to the drawings. The hardened cement body and the method for producing the same according to the present invention are not limited to the following embodiments and examples.

FIGS. 1 (a) and 1 (b) are schematic views of an apparatus for imparting vibration when producing a hardened cement body according to the present invention. FIG. 2 and FIG. 3 are graphs showing the relationship between the mixing ratio of fly ash fiber and the bending strength of the hardened cement according to the present invention at the ages of 7 days and 28 days.
FIG. 4 is a relation diagram showing a dry density when a high-performance water reducing agent is added to the hardened cement according to the present invention. FIG.
6 and FIG. 6 show the results of the comparative cement hardened material of 7 days and 28 days in age.
FIG. 4 is a graph showing the relationship between the mixing ratio of fly ash fiber and the flexural strength of a hardened cement body on a day.

The hardened cement according to the present invention is formed from at least incinerated ash (F) and cement (C). Examples of the incinerated ash (F) include fly ash, volcanic ash and the like from flue gas such as coal ash, furnace slag, and combustion ash of dried sludge, and particularly generated from a thermal power plant or a blast furnace. Fly ash is preferred, and more preferably, so-called EP ash obtained by collecting dust generated by pulverized coal combustion with an electrostatic precipitator, or preformed ash obtained by coarsening the same. Among them, the fly ash and the like are easy to handle because the water content is constant, and can sufficiently disperse a fly ash fiber described later.

The above cement (C) includes various portland cements such as ordinary portland cement, early-strength portland cement, ultra-high-strength portland cement, moderately heated portland cement; alumina cement such as alumina cement and lime alumina cement; blast furnace slag mixing Various mixed cements such as cement, pozzolan mixed cement, fly ash cement and the like can be mentioned. Of these, Portland cement, particularly ordinary Portland cement, is generally and preferably used.

The hardened cement according to the present invention is characterized in that the incineration ash (F) and the cement (C) are mixed at a mixing ratio of%.
(F / F + C) is in the range of 10% by mass or more. In particular,
It is preferably from 15% by mass to 50% by mass. It is desirable to mix the incinerated ash as much as possible in the hardened cement body. However, if the incinerated ash (F) is mixed in a range exceeding the mixing ratio of 50% by mass, the amount of cement is relatively reduced. Mechanical strength (for example, bending strength, etc.) is deteriorated. In addition, when the incinerated ash (F) of the hardened cement is less than 10% by mass, the effect of imparting sufficient mechanical strength to the hardened cement is not seen, no matter how much the fiber reinforcing material described below is added. .

The hardened cement according to the present invention contains a fiber reinforcing material. As the fiber reinforcing material, fly ash fiber, inorganic fiber such as glass fiber, carbon fiber,
Synthetic fibers and natural fibers of resins such as vinylon can be used. In particular, among the inorganic fibers, fly ash fibers obtained by melting and spinning coal ash or the like at a high temperature are preferable.
The fly ash fiber is excellent in dispersibility in the above-mentioned fly ash, and can sufficiently increase the mechanical strength of a cured cement body using the fiber.

The fiber reinforcing material is in the range of 2 to 10% by volume, especially 4 to 6% by volume, based on the mixture (F + C).
Is preferably included in the range. When the fiber reinforcing material is within the above range, the mechanical strength of the cured cement body itself can be increased. When the fiber reinforcing material is less than 2% by volume, the compressive strength of the hardened cement cannot be sufficiently increased,
Also, the bending strength cannot be increased. On the other hand, if the fiber reinforcing material exceeds the range of 10% by volume, the mechanical strength, particularly the bending strength, of the hardened cement body is rather lowered.

The hardened cement according to the present invention is formed from a kneaded mixture obtained by premixing the above mixture and mixing an appropriate amount of water. Water is added to the kneaded mixture so that the water powder (S) is in the range of 0 ≦ (S) − (S0) ≦ 5% with respect to the optimum water content (S0). Here, the water powder ratio (S) is
It is represented by (W) / (F + C), where (W) is the amount of water.
The optimum water content (S0) refers to the water content at which the maximum dry density is obtained by compacting the specimens of each water content while changing the water content and performing the compaction test of the soil by compaction according to JIS A 1210-1979. .

The above water powder ratio (S) -optimal water content ratio (S0)
When the value exceeds 5%, the fiber reinforcing material is liable to be lump, etc., and the hardened cement becomes large in breathing,
Cracks may occur during drying. In addition, moisture remains in the cured product and hair cracks frequently occur. If the water powder ratio (S) -optimal water content ratio (S0) is less than 0% (negative value), it takes a long time to compact the hardened cement at the time of production, and the workability is deteriorated, so that the casting is difficult. Becomes

In the hardened cement according to the present invention, in addition to the above-mentioned combustion ash, cement and fiber reinforcing material, fine aggregate such as mountain sand, gypsum, and additives such as inorganic admixture and chemical admixture are blended. Can be. As the inorganic salts of the admixture,
Alkali metal halides such as sodium chloride, sodium bromide, potassium chloride and potassium fluoride; alkaline earth metal halides such as calcium chloride, magnesium chloride and magnesium bromide; and mixtures of two or more thereof be able to. These inorganic salts can be used as an admixture in the form of a powder or an aqueous solution. The concentration of the admixture is not critical, but is usually used as an aqueous solution of about 1 to 20% by weight. When seawater is added instead of fresh water and kneaded, the concentration is adjusted appropriately according to the above range.

As the chemical admixture, AE agent, water reducing agent, A
E water reducing agents, high-performance AE water reducing agents, fluidizing agents, and the like can be mentioned, and these can improve the workability and durability of the cured cement. In particular, an admixture such as a high-performance water reducing agent can sufficiently exert the effect of the fiber reinforcing material. By adding the admixture as described above, the short-term and long-term compressive strength of the cured product is enhanced.

Next, the method for producing a hardened cement according to the present invention will be described in detail. In the method for producing a hardened cement according to the present invention, in the hardened cement, the fiber reinforcing material, incineration ash, and cement are premixed, then, after being mixed with water, fluidized by vibration and compacted. Is what you do.

In the method for producing a hardened cement body, at least the fiber reinforcing material, incinerated ash, and cement are premixed. The fiber reinforcing material is usually defibrated before being mixed. The defibration is performed by a machine or a manual operation to about several centimeters. As a usual method of the premix, there can be mentioned a method in which incineration ash, cement, and fiber reinforcing material are put into a mixer and kneaded at low speed and medium speed. In the open mixer, incineration ash and fiber reinforcing material may be scattered. Therefore, it is preferable to add a part of the total amount of added water to mix the mixture, and the amount of added water is about 0 to 2/3 (total added water). (The ratio to the amount of water), particularly preferably in the range of about 1/3 to 1/2.

As the premixing method in the method for producing a hardened cement according to the present invention, a backflow high-speed mixing method is particularly preferable, and the backflow high-speed mixing method comprises a mixing tank for rotating the mixture, a fixed wall scraper, and an agitator for reverse rotation. , Forcibly mixing at high speed. By employing such a backflow high-speed mixing method, the fiber reinforcing material, particularly fly ash fiber, etc., can be uniformly kneaded with cement or the like with almost no damage. In addition, in such a backflow high-speed mixing method,
It can be seen that there is less variation in the cement hardened material and a constant mixing can be achieved as compared with the ordinary method. In the above-mentioned reverse flow type high-speed mixing method, it is desirable that after cement and fly ash are charged and kneaded for a predetermined time, a fiber reinforcing material is charged and mixed again.

Next, the addition of water (fresh water or seawater) to the mixture is completed, and the mixture is kneaded at a low speed and a medium speed for a predetermined time using a mortar mixer or the like. The water to be added to the mixture is based on a predetermined water powder ratio with respect to an optimum water content determined in advance from each of the components as described above. If the amount of water added is larger than the relationship between the optimum water content ratio and the water powder ratio, a large amount of fiber reinforcement such as fly ash fiber is liable to be lumped, and it becomes difficult to mix a large amount of fiber reinforcement.

Next, the kneaded mixture is poured into a mold or the like,
Fluidization and compaction are performed while applying vibration. The vibration can be applied while applying pressure from above the kneaded mixture. For example, FIGS. 1 (a) and 1 (b)
As shown in the figure, the vibration may be imparted by placing the mold 3 and the like of the kneaded mixture 1 on a vibrating table 5 (table vibrator) or the like. Alternatively, the vibration may be provided by using a vertical or movable diaphragm 7. The above-described vibration may be applied only from the upper portion by the vibrating plate 7 or only from the lower portion by the vibrating table 5, or may be applied from both upper and lower directions. In the manufacturing method according to the present invention, it is particularly desirable to apply uniform vibration from both the upper and lower directions. Such application of vibration from above and below does not cause bubbles or irregularities in the upper and lower layers before and after fluidization of the kneaded mixture.

The vibrating table 5 or the vibrating plate 7 is provided with a load weight or a normal vibrating motor 9 or the like.
It is desirable that the vibration acceleration by the vibration motor 9 and the like be 3 G or more, particularly in the range of 5 to 10 G. When the vibration acceleration is 3 G or more, the kneaded mixture can be fluidized in a relatively short time. Further, a load weight 9 or the like is placed on the vibration plate 7 or the like, and the kneaded mixture can be pressurized from above. Such pressurization may be from 0.01 to 0.
It is desirable to be in the range of 1 kg / cm ² . Pressurization from above can promote fluidization of the kneaded mixture. Further, when fluidization is at the final stage, the pressure from above the kneaded mixture may be released.

The fluidized state of the kneaded mixture by the application of the vibration can be examined by measuring the electric resistance value and the like of the kneaded mixture. For example, an electrode is placed at a predetermined distance in a mold, and while measuring the electric resistance value obtained by energizing between the electrodes, the change value is measured without regard to the absolute value of the electric resistance value. You can find out. That is, by changing the electric resistance value of the kneaded mixture itself with time, by vibrating the mold until the electric resistance value decreases,
The fluidization can be examined.

In the above-described vibration compaction method configured as described above, by employing a premix, particularly a backflow high-speed mixing method, a fiber reinforcing material, particularly a fiber such as a fly ash fiber, does not break. For this reason, the fiber reinforcing material can be uniformly and sufficiently mixed into the hardened cement. In addition, since the amount of water is kept within a certain range of the relation ratio between the water powder ratio and the optimum water content, the fiber reinforcing material is combined with the compaction method by applying vibration, so that the fiber reinforcing material, especially fiber such as fly ash fiber, etc. Does not cause lumps or the like. For this reason, the limit mixing ratio of the fiber reinforcing material can be increased. Furthermore, by giving vertical vibration at the time of compaction,
The hardened cement body can be formed uniformly without causing unevenness or the like, and its mechanical strength such as bending strength can be made stable and constant.

[0033]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. The hardened cement body and the method for producing the same according to the present invention are not limited to the following embodiments.

(Materials used) Cement Ordinary polytland cement (manufactured by Taiheiyo Cement Co., Ltd .: specific gravity 3.16, water powder ratio of flow 140, 2)
5.0%, optimal moisture content 18.5%)-Incinerated ash Fly ash (Matsuura Thermal Power Development: Specific gravity 2.20, Residue on ignition 1.0%, Flow 140 ratio of water powder 30.0) %, Optimal water content 23.0%) ・ Fiber reinforced material Fly ash fiber (Mitsuoka: specific gravity 2.50) ・ Water reducer High performance AE water reducer (Pozzolith products: polycarboxylic acid type)

(Manufacturing Method of Hardened Cement Body) (1) Premixing Method 1). Normal Method Prior to blank kneading, the fiber reinforcing material is defibrated to a size of about several centimeters manually. Put cement and fly ash, and fly ash fiber into the mixer, at low speed for 60 seconds,
Mix at medium speed for 120 seconds (when using an open mixer, cement and the like are scattered, so about 1/2 of the amount of water is added to perform premixing). 2). Reverse-flow high-speed mixing method First, cement and fly ash are charged using an Erich mixer (capacity: 10 liters) for 30 seconds to 6 hours.
Mix for 0 seconds. Next, the fiber reinforcement is charged and mixed for 180 seconds.

(2) Kneading method After premixing, a volume of 5 liters is watered using a mortar mixer, and kneaded for 60 seconds at a low speed and 120 seconds at a medium speed for a total of 180 seconds.

(3) Vibration Compaction Method (Form Injection and Vibration Application) Using a mold having an inner diameter in the range of 100 to 400 mm, a large VC vibrating table having an outer diameter of 500 mm (vibration frequency 66.7 Hz;
The mold is fixed at an amplitude of 1 mm and a vibration time of 5 minutes), and a predetermined amount of the kneaded mixture is injected into the mold. Also, a pressurizing plate (pressing force of 250 kg / c by weight etc.)
m ² ). The following five types of pressurized vibration methods were used. 1) .Continuous pressurized vibration (presses all during the vibration period of the shaking table) 2) .Release pressurized vibration (remove the diaphragm 60 seconds after the start of vibration) 3) .Repeated pressurized vibration (from the start of vibration) After 60 seconds, the diaphragm is removed for 10 seconds, the diaphragm is mounted again, and such a state is repeated continuously. 4). Upper press vibration (amplitude 180 and 21 on the press plate)
A vibration motor of 0 Hz is mounted, and pressure vibration is applied between the pressure plate and the vibration table in the above-mentioned pressurized state. 5). Both vertical vibration (amplitude 180 and 21 on the pressure plate)
A vibration motor of 0 Hz is mounted, and pressure vibration is applied between the pressure plate and the vibration table in the above-mentioned pressurized state. )

Example 1 and Comparative Example 1 Example 1 (fiber mixing ratio 6% by volume, fly ash mixing ratio (F /
F + C) 30% by mass) and Comparative Example 1 (fiber mixing ratio 0% by volume, fly ash mixing ratio (F / F + C) 30)
% By mass) of each of the cement hardened materials under the production conditions shown in Table 1 by using a backflow high-speed mixing method as a premix method.
Block manufactured. In addition, the evaluation method of the bending strength in Table 1 is an average value measured for each two blocks. The material age was evaluated on samples 7 days and 28 days after production.

[0039]

[Table 1]

As can be seen from Table 1, all of the samples of Example 1 in which the fiber was mixed had better bending strength than that of Comparative Example 1. In addition, it is considered that the degree of compaction is improved because the cement hardened body by both the upper and lower vibration methods is promoted to be fluidized by the effect of pressurization, and is easily fluidized from the bottom surface to remove bubbles.

(Examples 2 to 11 and Comparative Examples 2 to 1)
0) Under the conditions shown in Table 2, hardened cement bodies of Examples and Comparative Examples were produced. The water powder ratio (S) -optimal water content (S0) in each of Examples and Comparative Examples is all 0 to 5%.
And the vibration application is vibration by a vibration table.

[0042]

[Table 2]

Table 3 shows the flexural strength values of the cement hardened bodies of the examples in Table 2 at the ages of 7 days and 28 days.

[0044]

[Table 3]

FIGS. 1 and 2 show the relationship between the flexural strength and the mixing ratio of fly ash fiber of the hardened cement bodies of Examples 2 to 10 and Comparative Example 10 at the ages of 7 days and 28 days, respectively. Was. From this result, it can be seen that the strength increases when the mixing ratio (volume%) of the fly ash fiber is in the range of 2 to 10%, particularly 4 to 6%. Further, it can be seen that a constant premix method by the backflow high-speed mixing method can be stably obtained as a whole, and the strength of the hardened cement is slightly higher than that of a normal premix method.

On the other hand, FIG. 4 and FIG. 5 show the relationship between the flexural strength and the mixing ratio of fly ash fiber of the cured cement bodies of Comparative Examples 2 to 9 at the ages of 7 days and 28 days in Table 2. Was. From this result, it can be seen that the strength of the hardened cement material decreases as the mixing ratio (volume%) of the fly ash fiber increases. This shows that the effect of the fiber reinforcing material was not sufficiently observed in the cement hardened body containing no fly ash. Therefore, mixing a certain fiber reinforcing material within a certain range into a hardened cement body composed of cement and fly ash leads to an increase in the strength of the hardened cement body.

Further, FIG. 3 shows a relationship diagram between the water powder ratio and the dry density in the cement hardened products containing the high performance water reducing agents of Examples 8, 10 and 11. From this result, it can be seen that the dry density increases as the high-performance water reducing agent is added, and as shown in Table 3, the flexural strength of the cured cement body of Example 11 is improved by the high-performance water reducing agent.

[0048]

According to the hardened cement body and the method of manufacturing the same according to the present invention, the incinerated ash (F) and the cement (C) are used.
And the mixing ratio (F / F + C) of the above incinerated ash is 10
% Of the fiber reinforced material in the range of 2 to 10% by volume with respect to the mixture (F + C) composed of the incinerated ash (F) and the cement (C), and the water powder ratio (S ) Is 0 ≦ (S) − (S0) with respect to the optimum water content (S0).
Since it was formed from a kneaded mixture obtained by adding water and kneading so as to be within a range of ≤5%, the hardened cement can mix a large amount of incinerated ash as a substitute material for cement and has excellent mechanical strength.

[Brief description of the drawings]

FIGS. 1 (a) and 1 (b) are schematic views of an apparatus for imparting vibration when producing a hardened cement body according to the present invention.

FIG. 2 is a graph showing the relationship between the flexural strength and the mixing ratio of fly ash fiber in the hardened cement at the age of 7 days of the hardened cement according to the present invention.

FIG. 3 is an illustration of a cement hardened material according to the present invention having a material age of 28;
FIG. 4 is a graph showing the relationship between the mixing ratio of fly ash fiber and the flexural strength of a hardened cement body on a day.

FIG. 4 is a relation diagram showing a dry density when a high-performance water reducing agent is added to the hardened cement according to the present invention.

FIG. 5 is a diagram showing the relationship between the mixing ratio of fly ash fiber in the cement hardened material and the flexural strength at the age of 7 days in the comparative example.

FIG. 6 is a graph showing the relationship between the mixing ratio of fly ash fiber in a hardened cement body and the flexural strength at a material age of 28 days in a comparative example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 kneaded mixture 3 formwork 5 shaking table 7 diaphragm

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C04B 18/02 C04B 28/02 // (C04B 28/02 18:02 18:02 14:38 C 14:38 14: 42Z 14:42 14:38 A 14:38 16:06 Z 16:06) B28B 1/08 B A (72) Inventor Tatsuo Suzuki 2-5-8 Kitaaoyama, Minato-ku, Tokyo F Terms (reference) 4G012 PA15 PA17 PA20 PA24 PA27 4G056 AA07 AA13 AA14 AA15 AA18 CC01

Claims (8)

[Claims] 1. A hardened cement molded by kneading and molding a cement (C) containing incinerated ash (F), wherein said incinerated ash is
The mixture ratio (F / F + C) of the incinerated ash in (F) and the cement (C) is in a range of 10% by mass or more, and a mixture (F + C) composed of the incinerated ash (F) and the cement (C) And the water powder ratio (S) is in the range of 0 ≦ (S) − (S0) ≦ 5% with respect to the optimum water content ratio (S0). A hardened cement body formed from a kneaded mixture obtained by adding water and mixing. 2. The hardened cement body according to claim 1, wherein said incinerated ash is fly ash or sludge incinerated ash generated by thermal power generation. 3. The fiber reinforced material is fly ash fiber, glass fiber, carbon fiber, or resin fiber.
Or the cured cement according to 2. 4. A hardened cement body according to claim 3, wherein said fiber reinforcing material is fly ash fiber spun by melting coal ash at a high temperature. 5. The method for producing a hardened cement according to claim 1, wherein at least the fiber reinforcing material, incinerated ash and cement are premixed, then mixed with water, and then fluidized by applying vibration. And producing a cured cement body. 6. The method for producing a hardened cement body according to claim 5, wherein vibration is applied from above and below said kneaded mixture. 7. The method for producing a hardened cement according to claim 5, wherein the premix is a backflow high-speed mixing method. 8. When fluidizing by applying the vibration,
The vibration acceleration is set to 3 G or more.
8. The method for producing a cured cement body according to any one of items 1 to 7.