JPH01317143A - Production of concrete and production of concrete molded product therefrom - Google Patents

Abstract

PURPOSE:To obtain a high-strength concrete in good workability in cold districts, the polar regions, etc., by kneading cement, aggregate and finely granulated ice smaller in size than cement. CONSTITUTION:When concrete is to be produced in cold districts, the polar regions, etc., a mixer is first charged with cement, fine aggregate, coarse aggregate and finely granulated ice smaller in size than cement and, if needed, an admixture followed by agitation and kneading to make concrete. Thence, a closed hollow mold 1 formed in conformity with the shape of the molded product to be made is charged with the resultant concrete followed by pressurization by inserting a relevant device 3 as well as application of vibration on both the mold 1 and concrete with a vibrator 4. Furthermore, pressurized air is introduced through an air feed pipe 2 into the mold to apply pressure on the concrete along with heating by a heating means 5 to melt the granular ice followed by curing said concrete, thus obtaining the objective concrete molded product.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for producing concrete and a method for producing concrete molded products in cold regions, polar regions, and even outside the earth's sphere.

"Conventional technology and its challenges" Due to the expansion of the range of human activities and the demand for shorter construction times, construction of concrete structures in harsh environments such as cold regions and polar regions, which have not been attempted in the past, has become possible. It has been considered in recent years.

The main points to consider when manufacturing concrete or casting concrete to manufacture concrete structures or concrete molded products such as concrete blocks in cold or polar regions are listed below. be.

■ Because the hydration reaction between cement and water is affected by the surrounding temperature, it takes a long time to develop the required strength, resulting in a long curing time.

■ If the temperature is low (approximately 4°C or less) during concrete placement or in the early stage of curing, the concrete temperature will drop and the water in the concrete will freeze, resulting in excess water and having negative effects.

On the other hand, due to recent advances in space technology, the possibility of human survival outside the Earth's sphere, such as on the moon, is no longer a dream, but is entering the stage of realistic consideration. In this case, concrete is a suitable material for the space structure because it has advantages such as large heat capacity and high ability to block heat and radiation. At this time, we will produce concrete that has properties equivalent to those on Earth even under conditions such as low gravity, vacuum, and ultra-low temperatures.
The development of the technology to build it is eagerly awaited.

This invention was made in view of the above circumstances.
The purpose of the present invention is to provide a method for producing concrete and a method for producing concrete molded products that can produce high-quality concrete or concrete molded products in polar regions or outside the Earth's sphere.

"Means for Solving the Problems" In order to solve the above-mentioned problems, the present invention is characterized by employing the following means.

That is, the concrete manufacturing method according to the first aspect is characterized in that concrete is manufactured by mixing cement, aggregate, and micronized ice grains having a particle size smaller than that of the cement.

Further, the method for producing a concrete molded product according to the second claim includes placing a mixture of cement, aggregate, and micronized ice grains smaller in particle size than the cement in a closed molding container, and then pouring the mixture into a closed molding container. The method is characterized in that a concrete molded product is manufactured by applying vibration to the mixture while pressurizing it, and then heating the mixture while pressurizing it with a compressed air means in a closed state.

Furthermore, a method for manufacturing a concrete molded product according to a third aspect of the present invention is characterized in that, in the manufacturing method according to the second aspect, the mixture is heated by irradiating the mixture with electromagnetic waves.

"Example" Hereinafter, an example of the method for manufacturing a concrete molded product of the present invention will be described with reference to the drawings.

(i) Concrete production Cement, fine aggregate, coarse aggregate, micronized ice particles, and necessary admixtures are put into a mixer, and all of these are stirred and kneaded by the mixer to produce concrete.

Among these concrete constituent materials, cement, fine aggregate, coarse aggregate, and admixtures may be those used in general concrete, and are not required to have any special properties. Also, when producing concrete on the moon,
There is no need to transport them from Earth, except for admixtures. In other words, fine aggregate and coarse aggregate can be produced by appropriately crushing lunar rocks. On the other hand, since lunar rocks contain a large amount of cement components, it is necessary to separate and extract this cement component. Cement can be manufactured by doing this.

The particle size of the micronized Iζ ice is smaller than the particle size of cement particles (for example, about 0.1 μm to 5.0 μm). Such ice can be obtained, for example, by spraying water into a closed container under 1 atm using a nozzle in a cold atmosphere below zero degrees. Of course, if the temperature during concrete production is below zero, ice particles can be obtained simply by spraying water into a closed container under 1 atmosphere. Furthermore, the means for obtaining micronized ice particles may be appropriately selected from well-known means and is not limited in any way.

The following methods can be used to obtain water, which is the raw material for ice on the moon. In other words, oxygen can be obtained by decomposing oxides, since most of the rocks on the moon are oxides. Regarding hydrogen, the existence of hydrogen and hydrogen compounds on the lunar surface has not been confirmed at this time, so it is sufficient to transport it from Earth to the lunar surface. Water can then be obtained by reacting these oxygen and hydrogen.

In addition, if this were to be turned into ice grains, the temperature at a shaded spot on the moon would reach approximately -160°C, and the moon would be in a vacuum.
Because of the low gravity, ice particles with an average particle size compared to those on Earth can be easily obtained by spraying into a closed container under 1 atm as described above.

The mixer for mixing the aforementioned concrete constituent materials such as cement, fine aggregate, coarse aggregate, and micronized ice particles may be any well-known mixer for mixing concrete, and no special functions are required. Not done. However, when mixing concrete on the lunar surface, it is desirable to use a closed mixer because there is a concern that the constituent materials may scatter under low gravity. Also, during the day on the lunar surface, approximately +1
Since the temperature can reach up to 20°C, each process, including concrete pouring, which will be described later, must be carried out in the shade at a low temperature. Other than this, there are no other factors that adversely affect concrete crosstalk on the lunar surface; rather, under low gravity, there is an advantage that material separation due to density differences between constituent materials becomes smaller.

(ij) Concrete pouring As shown in the drawing, the concrete manufactured by the above-mentioned process is poured into a sealed formwork.

In the drawings, reference numeral 1 indicates a closed hollow formwork formed to match the shape of the concrete molded product to be manufactured (for example, pillars, gates, precast concrete plates, concrete blocks). , a concrete inlet (not shown) is provided at the upper part thereof, and an air supply pipe 2 is provided in communication therewith. The tip of the air supply pipe 2 is connected to a pneumatic means (not shown) for delivering gas such as compressed air. The formwork 1 also has a safety valve (
(not shown) and a pie break 4 that vibrates the entire formwork 1. Concrete C manufactured by the above-described process is poured into the formwork 1 and placed through an inlet.

With the concrete C poured into the formwork 1 and poured, pressurize it by inserting the pressurizing device 3 from the inlet to pressurize it (for example, 2 kgf).
/ cm2). At the same time, the pie break 4
is activated to give vibration to the formwork 1 and the concrete C, and together with the above-mentioned pressurization of the concrete C, the concrete C is compacted downward. Furthermore, the concrete C is pressurized to a predetermined pressure (for example, 2 atmospheres) by introducing gas such as compressed air into the formwork 1 using the above-mentioned pressurized air means and the air pipe 2. By heating the concrete C with the heating means 5, the ice particles mentioned above are melted, and the temperature of the concrete C is adjusted to a temperature at which the water-cement hydration reaction becomes easy (
(usually about 2000℃).

The heating means 5 is not limited in type or method as long as it is a well-known heating means, but in this embodiment, a microwave electron tube is used to irradiate microwaves toward the concrete C to heat it. A wave heating means 5 is used.

After heating the concrete C in this way, the pressurization of the concrete C by the air pressure means and the heating of the concrete C by the heating means 5 are stopped, and the concrete C is cured until it hardens and reaches a predetermined strength. Then, by removing the formwork 1 after the concrete C has hardened, a concrete molded product having a predetermined shape can be obtained.

Therefore, in this example, micronized ice particles having a particle size smaller than cement particles are used instead of mixing water for concrete C, so that the work of melting the ice particles after mixing concrete C is simplified. be done. At the same time, the surfaces of the cement particles are covered with micronized ice particles, and most of the ice particles introduced into the mixer are used for the hydration reaction with the cement, so there is little risk of excess water being generated.

Therefore, this ice can be used as a concrete constituent material in cold regions and polar regions where ice is relatively easily available.

On the other hand, water evaporates on the lunar surface because of the vacuum, but ice in the shade on the lunar surface (approximately -160'c) does not evaporate (sublimate), so if you mix it in an icy state, you can make concrete. can be manufactured. In this case as well, by pulverizing the ice, there is less risk of excess water being generated in the manufactured concrete C, which is very preferable.

In addition, during pouring of concrete C, the concrete c is pressurized by the pressurizing device 3 and vibrated by the pie break 4, so that the gas in the spaces between the concrete constituent materials can be easily and reliably removed. It is possible to cast and form dense concrete c by expelling the concrete. In addition, since the heating means 5 melts the ice grains in the concrete C and heats it to the required temperature while applying pressure with the compressed air means in a closed state to the applied vibration diameter, the ice grains are melted in the concrete C at the initial stage of curing. In addition to being able to reliably eliminate it, the water-cement hydration reaction is promoted, and high-strength concrete C can be cast and formed. In particular, such effects are necessary and essential, as the lunar surface has low gravity and extremely low temperatures, and if concrete is poured while left unused, the concrete may lack strength with many voids.

Therefore, as described above, according to this embodiment, high quality concrete or concrete molded products can be manufactured in cold regions, polar regions, or outside the earth's sphere such as on the moon.

In addition, in this example, since micronized ice grains with a smaller particle size than cement particles are used as described above, ice grains can easily form in the gaps between particles of concrete constituent materials other than ice grains during crosstalk in the mixer. I'm getting into it. Therefore, ice grains (
In other words, water) is evenly distributed throughout the concrete,
Concrete mixing work is greatly simplified. Conversely, it is possible to reduce the amount of excess water conventionally required to facilitate mixing, making it easier to obtain higher quality concrete.

In addition, the concrete manufacturing method and concrete of this invention
1. The details of the method for manufacturing a molded product are not limited to the above embodiments, and various modifications are possible.

"Effects of the Invention" As explained in detail above, in this invention, micronized ice particles having a particle size smaller than cement are used instead of mixing water for concrete, so the ice particles are dissolved after concrete is mixed. This simplifies the work, and the surface of the cement particles is covered with micronized ice particles.
Most of the ice particles put into the mixer are used for the water utilization reaction with cement, so there is little risk of surplus water being produced.

In addition, during concrete pouring and shaping, the concrete is pressurized and vibrated, so gas in the gaps between each concrete mortar material is easily and reliably expelled, resulting in dense concrete pouring. It can be set and molded. In addition, since heating is carried out under pressure using air pressure means in a sealed state, ice grains can be reliably extinguished in the early stage of curing, and the water-cement irrigation reaction can be promoted, allowing high-strength concrete to be cast. Can be molded.

Therefore, according to the present invention, high-quality concrete or concrete molded products can be manufactured in cold regions, polar regions, or outside the earth's sphere, such as on the moon.

[Brief explanation of the drawing]

The drawing is a diagram showing the structure of a formwork used in a method for manufacturing a concrete molded product, which is an embodiment of the present invention. 1... Formwork (molding container), 2... Air pipe, 3... Pie break, 4... Heating means.

Claims (3)

[Claims] (1) A method for producing concrete, which comprises producing concrete by mixing cement, aggregate, and micronized ice particles having a particle size smaller than that of the cement. (2) A mixture of cement, aggregate, and micronized ice particles having a particle size smaller than that of the cement is placed in a sealed molded container, and the mixture is vibrated while being pressurized. A method for manufacturing a concrete molded product, characterized in that the concrete molded product is manufactured by heating while pressurizing the concrete molded product in a closed state using air pressure means. (3) The method for manufacturing a concrete molded product according to claim 2, characterized in that the mixture is heated by irradiating the mixture with electromagnetic waves.