JPH06329483A - Method for curing mortal and concrete in magnetic field - Google Patents

Abstract

PURPOSE:To improve flexural strength of cement mortal and concrete itself without using asbestos, etc. CONSTITUTION:A kneaded material of mortal and concrete is put in a frame mold and the frame mold is placed in magnetic field and subjected to curing ranging from setting to hardening to orientate cement hydrate in the direction of magnetic field. By orientating the cement hydrate in the direction of magnetic field, flexural strength of the cured product is enhanced and mortal and concrete product having sufficient flexural strength can be produced without using a reinforcing material such as asbestos harmful to human body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curing method for mortar and concrete, and more particularly to a technique for improving the bending strength of mortar and concrete by curing them in a magnetic field.

[0002]

2. Description of the Related Art Cement mortar and concrete are
Since it has lower bending strength than compressive strength, it is commonly used as an actual structure by reinforcing it with reinforcing bars or fibers such as asbestos. In particular, for thin cement products such as slate boards, cement boards, and corrugated board materials, it is indispensable to use fibrous reinforcing materials such as asbestos. However, as is well known, asbestos is known to be harmful to the human body, and its use must be avoided. On the other hand, if the bending strength of cement mortar and concrete itself can be increased, the use of asbestos and the like, which is harmful to the human body, can be avoided, but an effective method therefor has not been provided.

[0003]

The present invention has been made in view of the above circumstances, and how to improve the bending strength of cement mortar and concrete itself without using asbestos or the like which is harmful to the human body. It is an issue.

[0004]

In order to solve the above problems, the present invention provides a mortar and concrete curing method in which a kneaded material of mortar and concrete is cast into a mold to coagulate and cure the material. It is characterized in that the kneaded material is cast into a mold and put in a magnetic field for curing from setting to hardening to orient the cement hydrate in the direction of the magnetic field.

[0005]

[Function] Cement hydrates such as ettringite produced by the hydration reaction can be obtained by placing a kneading material of mortar and concrete in a formwork and placing it in a magnetic field for curing from setting to hardening. Oriented in the direction of the magnetic field,
The oriented cement hydrate enhances the flexural strength of the cured cured product.

[0006]

The magnetic field curing method for mortar and concrete according to the present invention will be described in detail below with reference to the drawings. As the mortar and concrete materials used in the present invention, cement, water, aggregate, various admixtures, etc., which are materials for ordinary mortar and concrete production, are used, and as the cement material, the direction of the magnetic field is used. Any portland cement or alumina cement can be used as long as it can form a hydrate such as ettringite orientated in. Further, as this cement, in order to increase the amount of ettringite produced, it is more effective to use a mixture of ordinary Portland cement with 5 to 10% of ultra-rapid hardening cement, alumina cement and ferrite cement.

These cement materials and water, or the respective raw materials such as cement materials, water and aggregates, and admixtures added as necessary are kneaded in the same manner as in ordinary mortar and concrete production methods. The kneaded material is placed in a mold having a desired size and shape and cured in a magnetic field.

FIG. 1 is a diagram for explaining an example of the curing in the magnetic field. In this figure, reference numeral 1 is a mold, 2 is a kneading material, 3 is a permanent magnet, 4 is a magnetic field direction, and 5 is a magnetic field. The curing box is shown. The inside of the curing box 5 is maintained at a temperature and humidity suitable for curing the kneaded material 2 that has been cast. Then, the kneaded material 2 cast in the mold 1 is subjected to at least initial curing from solidification to hardening in a magnetic field generated by permanent magnets 3 attached to both sides of the mold 1. In this example, by arranging the permanent magnets 3 on both sides of the mold 1 so that one is facing the S pole and the other is facing the N pole, a magnetic force is applied along the longitudinal direction of the mold 1. There is.

FIG. 2 is a diagram for explaining the second method of the above-mentioned magnetic field curing. In this second method, an electric field is replaced by the permanent magnet 3 of the first method as a magnetic field generating means. Using the coil 6, the form 1 is placed in the electric coil 6,
The kneaded material 2 is cured in the magnetic field generated by the electric coil 6.

As described above, the kneading material 2 is cast into the mold 1, and the kneading material 2 is placed in a magnetic field and cured from setting to hardening, whereby hydration of ettringite and the like produced by the hydration reaction is generated. The object is oriented along the magnetic field, and the oriented cement hydrate enhances the flexural strength of the cured cured product. Hereinafter, the effects of the present invention will be clarified by experimental examples.

(Experimental Example 1) 10% of ultra-rapid hardening cement was mixed with ordinary Portland cement, and the water-cement ratio was 60.
%, A mortar with a sand-cement ratio of 2 was kneaded. This mortar was packed in a plastic mold, and permanent magnets were attached to both ends of the mold as shown in FIG.
After curing for a whole day and night in a curing box at a temperature of 90 ° C. and a relative humidity of 90% or more, the mold was removed and cured in a 20 ° C. constant temperature water tank to a specified age. After the prescribed material age, remove the mortar specimen from the curing water tank,
The flexural strength and compressive strength of the cured product were measured according to JIS R 5201 and compared with a specimen (normal curing) that was aged without a magnet. The results are shown in Table 1.

[0012]

[Table 1]

As is clear from the results shown in Table 1, permanent magnets are attached to both ends of the mold in which the kneading material is placed, and the mortar is cured in a magnetic field. It has been found that it is possible to increase it more than twice.

(Experimental Example 2) As in Experimental Example 1, ordinary Portland cement was mixed with 10% of ultra-rapid hardening cement, and water was added.
-Mortar with a cement ratio of 60% and sand-cement ratio of 2 was kneaded. This mortar was packed in a plastic mold, placed in a magnetic field of an electric coil as shown in FIG. 2, cured in a curing box at a temperature of 20 ° C. and a relative humidity of 90% or more for one day, and then demolded. It was aged in a constant temperature water bath at 20 ° C to a specified age. After the prescribed age, take out the mortar specimen from the curing water tank and check the bending strength and compressive strength of the cured product according to JIS.
It was measured according to R 5201 and compared with a specimen (normal curing) that was cured without being placed in an electric coil. The results are shown in Table 2.

[0015]

[Table 2]

As is clear from the results shown in Table 2, by placing a mold in which a kneaded material is placed in an electric coil and curing the mortar in a magnetic field, the bending strength of the mortar is about 10% higher than that of the ordinary curing mortar. It turned out that it is possible to increase it three times.

[0017]

As explained above, in the mortar and concrete curing method in the magnetic field according to the present invention, the kneading material of mortar and concrete is cast into a mold and put in a magnetic field to set from hardening to hardening. Cement hydrates such as ettringite produced by the hydration reaction are oriented in the direction of the magnetic field, and the bending strength of the cured product cured by the oriented cement hydrates can be significantly increased. . Therefore, according to the present invention, it is possible to produce a mortar and a concrete product having sufficient bending strength without using a reinforcing material such as asbestos that is harmful to the human body.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram for explaining an example of a magnetic field curing method of the present invention.

FIG. 2 is a schematic configuration diagram for explaining another example of the magnetic field curing method of the present invention.

[Explanation of symbols]

1 ... Formwork, 2 ... Kneading material, 3 ... Permanent magnet, 4 ...
… Direction of magnetic field, 5… Curing box, 6… Electric coil.

Claims (1)

[Claims] 1. A method of curing mortar and concrete in which a kneaded material of mortar and concrete is cast in a mold to cure and cure the material, and the kneaded material is cast in a mold, A method for curing mortar and concrete in a magnetic field, characterized in that the cement hydrate is oriented in the direction of the magnetic field by performing curing from setting to hardening in a magnetic field.