JPH0710631A - Production of hydraulic inorganic material - Google Patents

Abstract

PURPOSE:To provide production of a hydraulic inorganic material capable of reducing the amount of a hardening accelerator and readily controlling hardening reaction. CONSTITUTION:In obtaining a hydraulic inorganic material consisting essentially of Portland cement powder, Portland cement is mixed with gamma-alumina powder having particle diameters smaller than those of Portland cement powder to give a blend. 0.5-20kw/kg mechanical energy is applied to the blend to attach the gamma-alumina particles to the surface of the Portland cement powder.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a hydraulic inorganic material.

[0002]

2. Description of the Related Art As a hydraulic inorganic material (hydraulic cement composition) having a rapid hardening property, which is mainly composed of Portland cement powder and which is capable of producing a high-strength molded article with good size and efficiency and at low cost. JP-A-63-285
There is one disclosed in Japanese Patent Publication No. 144-144.

The hydraulic inorganic material disclosed in Japanese Unexamined Patent Publication No. 63-285144 is a composition composed of Portland cement, alumina cement, slaked lime, gypsum, reinforcing fibers and a setting retarder, which is a continuous cement-based molding. As suitable for production, Portland cement is mixed with alumina cement and slaked lime to provide rapid hardening, and a setting retarder is used to adjust the setting time.

Among the substances that give rapid hardening to Portland cement, those containing aluminum include aluminum sulfate in addition to the calcium aluminate solid solution represented by alumina cement disclosed in the prior document in this publication. Calcined alum and aluminum hydroxide are known.

[0005]

By the way, Japanese Patent Laid-Open No. Sho 63-63
When using alumina cement and slaked lime as a rapid hardening agent like the hydraulic inorganic material of -285144, rapid hardening is seen unless alumina cement is added 10 parts by weight or more to 100 parts by weight of Portland cement. Absent. In addition, since it will rapidly set when water is added as it is, it is necessary to mix a setting retarder like the hydraulic inorganic material.

That is, in this hydraulic inorganic material, the setting-hardening characteristics are determined by the combination of alumina cement, slaked lime, and set retarder in this way, but in the hydraulic inorganic material provided with such a combination, it is used. It is difficult to prepare when the temperature changes. In view of such circumstances, it is an object of the present invention to provide a method for producing a hydraulic inorganic material that can reduce the amount of a rapid hardening agent and facilitate the adjustment of a hardening reaction.

[0007]

In order to achieve such an object, the method for producing a hydraulic inorganic material according to the present invention is intended to obtain a hydraulic inorganic material containing Portland cement powder as a main component. 0.5 to 20 to a mixture of a powdered powder and a γ-alumina powder having an average particle size smaller than Portland cement powder.
Mechanical energy of kw / kg was applied to adhere the γ-alumina particles to the surface of the Portland cement powder.

In the above structure, applying mechanical energy means applying compressive force, shearing force, impact force, etc. to the powder. For example, the device 1 shown in FIGS. 1 and 2 is used. And mechanical energy can be applied to the powder. That is, as shown in FIG. 1, this apparatus 1 rotates a container 2 containing a mixture of Portland cement and γ-alumina powder, and forms a powder layer 3 along an inner peripheral surface 21 of the container by centrifugal force. Then, as shown in FIG. 2, the powder layer 3 is passed between the pressing member 4 and the inner peripheral surface 21 of the container to apply a compressive force or a shearing force to the powder. In FIG. 1, 41 is a scraping blade.

Since Portland cement and γ-alumina particles are both hard, this device 1
When mechanical energy is applied by using, the inner peripheral surface 21 of the container 2 is preferably rotated at a speed of 16 m / s or more. That is, if the speed is lower than this, the γ-alumina particles are less likely to adhere, so that the required γ-
The amount of alumina particles tends to increase. Further, since the load on the device 1 becomes large, it is preferable that the upper limit of the speed is generally 40 m / s or less.

Incidentally, in addition to the device 1, there is a Japanese Patent Laid-Open No. 62-
It is also possible to use a device with an impact-type striking means as shown in Japanese Patent No. 83029. Mechanical energy applied to powder is 0.5 kW / kg or more, 20 kW / k
It is limited to g or less. That is, if it is less than 0.5 kW / kg, the γ-alumina particles are less likely to adhere, and the amount of γ-alumina particles required increases.

On the other hand, if it exceeds 20 kW / kg, the load on the apparatus increases. The time for applying mechanical energy is usually 2 to 60 minutes. The mechanical energy shown above is calculated by subtracting the input power when the device is operated without powder from the power supplied to the device when the device is operated with powder. did.

As the Portland cement, ordinary Portland cement, early strength Portland cement, super early strength Portland cement, moderate heat Portland cement,
Examples thereof include sulfate resistant Portland cement and the like, and from the viewpoint of use in a molded body, ordinary Portland cement and early-strength Portland cement are preferable. The average particle size of the Portland cement powder is preferably 5 to 100 μm.

The γ-alumina particles are low crystalline powder obtained by firing aluminum hydroxide at about 400 to 1000 ° C and 1200 ° C.
It is preferable to use one that has higher reactivity than α-alumina that is fired as described above, and that has an average particle diameter of 0.1 to 10 μm and is smaller than the average particle diameter of Portland cement powder. γ−
If the particle size of the alumina particles is larger than that of the Portland cement powder, it is difficult to adhere to the Portland cement powder, and if the average particle size is less than 0.1 μm, it is easy to aggregate and thus it is difficult to handle.

The amount of γ-alumina particles is preferably 1 to 5 parts by weight with respect to 100 parts by weight of Portland cement powder. When the amount is less than 1 part by weight, the curing reaction is hardly promoted, and when the amount is more than 5 parts by weight, the curing tends to be too fast to be suitable for molding. Further, the hydraulic inorganic material obtained by the method for producing a hydraulic inorganic material according to the present invention,
It is preferable to further add gypsum, which is usually added to Portland cement.

That is, when gypsum is added, needle-like crystals of ettringite are formed and it becomes difficult to quickly set. The addition amount of gypsum is preferably 1 to 25 parts by weight with respect to 100 parts by weight of Portland cement powder, and if less than 1 part by weight, γ-
If the amount of alumina is large, it tends to be rapidly consolidated, and if it is more than 25 parts by weight, the physical properties of the molded body tend to be deteriorated.

Further, the hydraulic inorganic material of the present invention includes
As in the case of producing ordinary Portland cement compacts, aggregates for cement mortar such as silica sand and river sand, fly ash, silica flower, silica fume, bentonite, cement mixture such as blast furnace slag, sepiolite, wollastonite, Fillers such as natural minerals such as calcium carbonate and mica, synthetic fibers such as vinylon, polyamide, polyester and polypropylene, and reinforcing fibers such as natural fibers such as glass fiber and pulp can be further mixed.

Generally, the amount of the filler added is preferably 200 parts by weight or less with respect to 100 parts by weight of Portland cement powder to which γ-alumina particles are attached. Generally, the amount of the reinforcing fiber added is preferably 20 parts by weight or less with respect to 100 parts by weight of the Portland cement powder to which γ-alumina particles are attached. In addition, when gypsum, a filler, and a reinforcing fiber are added, it is preferable to apply mechanical energy to adhere the γ-alumina particles to the surface of the Portland cement powder and then perform the addition.

[0018]

According to the above construction, by adhering the γ-alumina particles to the Portland cement powder, the Portland cement itself exhibits rapid hardness, and the curing reaction can be adjusted by the amount of the γ-alumina particles attached.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings showing the embodiments thereof. (Examples 1 to 6 and Comparative Examples 1 to 3) Under the conditions shown in Table 1, ordinary Portland cement or early-strength Portland cement (manufactured by Onoda Cement Co., Ltd., average particle size 20)
μm, about 15 μm) and γ-alumina particles are mixed, and a gap between the pressing member 4 and the inner peripheral surface 21 of the container is 5 mm by a mechanofusion device AM-20FS manufactured by Hosokawa Micron Co., Ltd. as shown in FIGS. 1 and 2. The powder inner layer 21 is rotated at a rotational speed of 21 m / s for 10 minutes to press the powder layer 3 with the pressing member 4, and the γ-alumina particles (manufactured by Sumitomo Chemical Co., Ltd.) on the surface of the Portland cement powder. KC-
501 (average particle size 1 μm) or BK-103 (average particle size 3 μm)) was attached.

The dihydrate gypsum shown in Table 1 was further added to this mixture and mixed in a mortar, and water was added so that water / cement = 0.35 to obtain a pasty hydraulic inorganic material.
As shown in FIG. 3, the hydraulic inorganic material 51 obtained above is put in a paper cup 5, the paper cup 5 is put in a Dewar bottle 6, and then cured by a thermocouple 7 connected to a recording device 8. The temperature change with the reaction was measured.

As a comparative example, as shown in Table 1,
Normal Portland cement only, normal Portland cement mixed with γ-alumina by a rocking mixer were prepared, and the temperature change was similarly measured with water / cement = 0.35. The results are shown in FIGS. 4 and 5, and the time when the largest peak was reached and the temperature at that time are shown in Table 2.

[0022]

[Table 1]

[0023]

[Table 2] As shown in Table 2, it can be seen that the curing reaction is accelerated by this method.

[0024]

EFFECT OF THE INVENTION Since the method for producing a hydraulic inorganic material according to the present invention is configured as described above, rapid hardness is exhibited by attaching γ-alumina particles to Portland cement powder, and γ- The curing reaction can be adjusted by the amount of alumina.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of an apparatus used for adhering γ-alumina particles to a Portland cement powder while applying mechanical energy in a method for producing a hydraulic inorganic material according to the present invention.

FIG. 2 is an explanatory diagram illustrating a state in which the powder layer of the apparatus of FIG. 1 is pressed by a pressing member.

FIG. 3 is an explanatory diagram illustrating a method of measuring a temperature change associated with a curing reaction of a hydraulic inorganic material.

FIG. 4 is a graph showing the results of measuring the hydraulic inorganic material obtained in each example or comparative example using the measuring method of FIG.

5 is a graph showing the results of measuring the hydraulic inorganic material obtained in each example or comparative example by using the measuring method of FIG.

[Explanation of sign]

 51 Hydraulic inorganic material

Claims (1)

[Claims] 1. A mixture of Portland cement powder and γ-alumina powder having an average particle size smaller than that of Portland cement powder in obtaining a hydraulic inorganic material containing Portland cement powder as a main component. 0.
A method for producing a hydraulic inorganic material, which comprises applying γ-alumina particles to the surface of Portland cement powder by applying mechanical energy of 5 to 20 kw / kg.