JPH02213599A - Frozen aggregate concrete spraying method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a frozen aggregate concrete spraying method that can be suitably used for spraying on ground surfaces where spring water exists.

``Conventional technology'' Conventional concrete spraying methods can be roughly divided into dry and wet methods.

In the dry method, cement and aggregate are mixed without adding water, that is, in a dry kneading state, and water is added to this mixed material immediately before it is discharged from a discharge nozzle, and the mixture is sprayed onto a wall surface or the like.

Although it has the advantage of being easy to transport because it can be transported in the form of powder within a hose, it has drawbacks such as a large amount of rebound, resulting in large material loss, and uneven material composition.

On the other hand, in the wet method, cement and aggregate are kneaded in advance with water added thereto, and the mixture is sprayed directly onto walls etc. without adding water when ejected from a nozzle. Although it has the advantage of stable quality because it can be blended accurately, it has the disadvantage that transportation by hose is troublesome and the equipment becomes large.

``Problems to be Solved by the Invention'' However, with the conventional concrete spraying method described above, whether it is a wet or dry method, it is difficult to spray if there is spring water on the spraying surface, and there is also material loss due to splashing. This has the disadvantage that it becomes larger.

By the way, if there is spring water on the spraying surface, it may be possible to freeze the spraying surface in advance by spraying liquefied gas such as liquid nitrogen, and then spraying concrete in this state, but in this case, it is possible to spray concrete in limited areas such as tunnels. In such a space, it may not be possible to carry out this method because the direct use of gas may cause oxygen deficiency or poisoning.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a frozen aggregate concrete IJ-toe spraying method that allows desired concrete spraying to be carried out safely even if there is spring water or the like on the spraying surface. It is.

"Means for Solving the Problems" In order to achieve the above object, the present invention creates a frozen blank sliver material by mixing cement with frozen aggregate obtained by injecting liquefied gas, and It is characterized by forming a concrete wall surface by spraying dry wire material while adding water.

1.According to the present invention, by adding water to a dry-mixed freezing material made of frozen aggregate, cement, etc. and spraying it onto a wall surface, the frozen aggregate concrete is instantly frozen and adhered to the sprayed surface containing spring water. be able to.

Therefore, the amount of rebound is reduced and material loss is reduced.

Thereafter, the frozen aggregate concrete on the spraying surface gradually melts due to the transfer of energy, but at the same time, the cement hardens and develops a predetermined strength.

"Example" Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In the method of the present invention, a frozen dry mix is first made.

That is, sand, small gravel, etc., which are aggregates, are received in hoppers H and H, and weighed down by a predetermined amount with weighing scales S, S, respectively, and then put into an aggregate cooling device (sand cooler) L.
Liquefied gas (for example, liquid nitrogen) is injected to simultaneously perform mixing and cooling to a predetermined temperature (for example, -100'C). The cooled aggregate and the cement received in the hopper H1 and weighed in a predetermined amount with a scale S3 are charged into a mixing device (mixer) 2 and stirred. As a result, a cooled air-kneaded material in a smooth state similar to dry sand is obtained.

Next, this cooled dry kneading material (frozen dry kneading material) is transferred to a refrigerated transport vehicle 3 and transported to a predetermined location.

In addition, when making frozen dry wire near the site, it may be transported using a hose or the like.

Furthermore, the above-mentioned frozen empty wire material is applied to the dry Funkrete spraying machine 4.
Then, using compressed air, it is sprayed toward the spraying surface H from a nozzle 6 attached to the tip of the transfer pipe 5. At this time, in front of the nozzle 6, the quick-setting agent S and water W pumped by the pump 7.7 are mixed into the frozen blank wire material.

Thus, even if the spray surface H is accompanied by spring water, 2. By forming frozen aggregate concrete with the quick-setting agent and the frozen blank wire material, these materials can be attached to the spray surface H. That is, by instantaneously forming solidified concrete using the extremely low temperature energy of the frozen blank wire material, efficient spraying becomes possible, and spraying with less rebound and less material loss becomes possible.

Thereafter, the frozen aggregate concrete gradually melts due to the transfer of energy, but the quick-setting agent and cement contained in the concrete material develop strength and prevent peeling, peeling, and water seepage.

The above-mentioned construction methods can be used in a wide range of ways, including NATM) tunnels, reinforcing methods for trenching in open-cut construction, slope spraying, and auxiliary construction methods for trenching underground tanks.

In the above example, in addition to water W, a quick-setting agent S is used to freeze the spring water on the spraying surface early and to harden the concrete quickly after thawing, but the amount of spring water is Under certain conditions, such as when the amount is small, it is also possible to carry out the process without using an accelerating agent.

"Effects of the Invention" As explained above, according to the present invention, by instantly forming a solidified concrete body using the cryogenic energy of the frozen dry wire material, the surface becomes wet with spring water, etc. Not only can spraying be performed efficiently even on the spraying surface in poor condition,
It is possible to perform concrete spraying with a small amount of rebound (less material loss) and to achieve the specified strength.In addition, it does not use liquefied gas directly (because it is used indirectly).
Problems such as oxygen deficiency or poisoning can be avoided.

[Brief explanation of the drawing]

The drawings are diagrams showing one embodiment of the construction method of the present invention. H,,H,,H,・・・Hopper S,,S,,S
,...Measuring instrument,■... Aggregate cooling device (
Sand cooler), 4...Dry concrete spraying machine, 5...Transfer pipe, 6...Nozzle, S
...Accelerating agent, W...Water, I (...
... Sprayed surface.

Claims (1)

[Claims] Frozen concrete is characterized in that frozen aggregate obtained by injecting liquefied gas is mixed with cement to create frozen air mix, and this frozen air mix is sprayed while adding water to form a concrete wall surface. Spraying method.