JP3258141B2 - How to cast foam concrete by spraying - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for casting foam concrete on a wall or the like by spraying a foaming slurry on a construction surface.

[0002]

2. Description of the Related Art Aerated concrete contains a large amount of air bubbles in concrete or mortar, and is characterized in that it is lightweight and has heat insulation and vibration absorption. In order to cast this aerated concrete, many require a certain amount of cement, aggregate,
A concrete material such as water, a foaming surfactant, a crack inhibitor, a thickener and other foam materials are put into an agitator drum of a concrete mixer truck and mixed to form a foamed slurry or a ladies' mix. There has been a method in which concrete (or mortar) and air bubbles are mixed by a concrete mixer truck to form a foamed slurry, which is poured into a mold or the like and hardened. This method is
Uses a concrete mixer truck (truck agitator) used for placing ordinary concrete to mix ready-mixed concrete and mortar with air bubbles. No special mixing equipment is required. There is an advantage that the concrete placing operation can be performed continuously. However, agitator drums
It "mixes fresh concrete and keeps it evenly, and discharges it completely". It is a kind of stirrer and has no kneading function. Therefore, in the agitator drum of the concrete mixer truck, the foam cannot be uniformly dispersed in the slurry, so that a foamed slurry having a high content of bubbles cannot be obtained. In addition, after the ladies' mix concrete is poured into the agitator drum, rotation must be continued until all the foamed slurry has been discharged, so that the bubbles once dispersed in the foamed slurry are gradually separated from the slurry inside the drum. And defoam. Thus, the foamed slurry in the agitator drum has a reduced bubble content over time,
The later the product foamed concrete is cast, the lower the porosity. As a result, the foamed product of the foam had uneven distribution of air bubbles, unevenness in specific gravity and shrinkage, and had cracks.

[0003]

Conventionally, as a measure for solving the above-mentioned problems of the aerated concrete casting method, a foaming device and a line mixer are provided at the casting site, and are carried into the casting site by a concrete mixer truck or the like. The mixed concrete, raw mortar, etc., and the air bubbles produced by this air bubble generator are supplied to a line mixer in a fixed amount, and the two are kneaded to form a foam slurry, which is continuously poured. Was done. This method has the advantage that a cell slurry with a constant cell content can be obtained, but since it is a method in which the cell slurry is poured into a mold or the like and hardened similarly to the above-mentioned method, its use range is to strengthen soft ground or They were limited to backfilling civil works and flooring materials for buildings. The present invention intends to provide a method of casting foamed concrete on a vertical surface or an inclined surface by spraying a foamed slurry onto the surface and curing the surface without using a formwork or the like. What we do is to make the work of placing aerated concrete on these construction surfaces simple and easy,
For example, by casting foam concrete of a predetermined thickness on the wall or ceiling surface of a steel structure, etc., this surface has fire resistance, heat insulation, sound insulation, etc., and at the same time, enhances the decorativeness of this surface. On the point.

[0004]

According to the present invention, about 20% by weight of cement, about 70% by weight of sand, and an appropriate amount of additives such as a dispersant and a thickener and about 10% by weight of water are mixed. Concrete material, about 200 liters of air bubbles, and appropriate amounts of dispersant, thickener, etc. are kneaded to form a foamed slurry,
The above-mentioned object is attained by means of forming a layer of cellular concrete by applying a wire mesh to the construction surface and spraying a desired amount of foaming slurry toward this surface.

[0005]

According to the present invention, the foaming slurry has a considerable thixotropic property by adding about 10 wt% of water to about 20 wt% of cement and about 70 wt% of sand, so that a spray gun for concrete can be used. It can be used for spraying. In addition, by laying a wire mesh on the construction surface, there is almost no possibility that the foamed slurry will flow down during construction, and this will function as a reinforcing material for cellular concrete after construction.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for casting cellular concrete by spraying according to the present invention will be specifically described below. In this example, the equipment used for the casting of cellular concrete is
It comprises a concrete material metering pump 1, a bubble generator 2, a line mixer 3, and a spray gun 4 for foam concrete. The constant-rate supply pump 1 quantitatively feeds the concrete material stirred and mixed by the agitator drum 5 of the concrete mixer truck to the line mixer 3, and the bubble generator 2 includes a foaming agent solution tank (not shown) and a pressure-resistant foaming agent. Buffer tank, pressure pump, compressor,
And a bubble generating nozzle, etc., and are connected to the line mixer 3 so that bubbles for cellular concrete are quantitatively fed into the line mixer 3. The line mixer 3 continuously kneads the concrete material fed by the metering pump 1 and the bubbles sent from the bubble generator 2 to form a bubble slurry, and sends this to the spray gun 4 by the squeeze pump 6. It is designed to blow out from the nozzle.

[0007] Welding wire mesh at a distance of about 10 mm from the surface of the pillar of the steel structure, 350kg of cement and 1,288kg of sand on the agitator drum 5 of the concrete mixer truck,
And an appropriate amount of a dispersant and a thickener, and further add water 1
75 kg was added and mixed with stirring to obtain a concrete material. Then, the concrete material was quantitatively fed into the line mixer 3 and bubbles were generated by the bubble generator 2, and the bubbles were quantitatively fed into the line mixer 3 at a ratio of about 11 liters per 100 kg of the concrete material. Then, both were kneaded by the line mixer 3 to form a foam slurry having considerable thixotropic properties. Therefore, when this foamed slurry was sprayed on the pillars of the steel structure to a thickness of about 30 to 40 mm on the place where the welded wire mesh was stretched, the foamed slurry adhered to the place and became layered, requiring several hours. And completely cured,
It became cellular concrete.

[0008]

As described above in detail, according to the present invention, a foam slurry having considerable thixotropic properties can be obtained by mixing an appropriate amount of cement, sand and water and kneading air bubbles. Can be Therefore, since the foamed slurry can be sprayed and cast on a construction surface, the casting operation is remarkably simple and easy as compared with the conventional construction method requiring a formwork, etc. Casting is also possible on places such as the walls and ceiling of objects where it was almost impossible to place it in the past, giving this surface fire resistance, heat insulation, sound insulation, etc. This has the effect that the decorativeness of the lever can be enhanced.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a state in which a method of casting cellular concrete by spraying according to the present invention is performed.

[Explanation of symbols]

 Reference Signs List 1 metering pump 2 bubble generator 3 line mixer 4 spray gun 5 agitator drum 6 squeeze pump

Claims (3)

(57) [Claims] Claims: 1. A cement containing 18 to 25 wt% and 60 to 8 wt%.
0 to 1% by weight of sand and an appropriate amount of dispersant, thickener, etc.
3 wt% of water is stirred and mixed by an agitator drum of a concrete mixer truck, and a concrete material produced and 150 to 250 liters of bubbles produced by a bubble generator are kneaded with a line mixer to form a foam slurry. A method of casting foamed concrete by spraying, wherein the foamed slurry is sprayed on a construction surface using a spray gun for concrete. 2. Concrete materials are prepared by adding an appropriate amount of a dispersant, a thickener, etc. to ready-mixed concrete produced by adding 18 to 25 wt% of cement and 60 to 80 wt% of sand to 8 to 13 wt% of water. 2. A method for casting foam concrete by spraying according to claim 1, wherein the concrete is stirred and mixed. 3. A concrete material is prepared by adding 8 to 13% by weight of water to a mixture of 18 to 25% by weight of cement, 60 to 80% by weight of sand, and an appropriate amount of a dispersant, a thickener, etc., and stirring and mixing. The method for casting foamed concrete by spraying according to claim 1, characterized in that the concrete is produced by spraying.