JP4046799B2 - Method for producing lightweight cellular concrete - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a lightweight lightweight concrete with an improved surface layer.
[0002]
[Prior art]
In general, lightweight cellular concrete is a mixture of siliceous raw material, calcareous raw material, water, foam concrete such as aluminum powder, or foam concrete made by adding surfactant, etc. Injected and cured into a mold to form a semi-cured mortar block, cut into a desired shape with a piano wire, etc., and then steam-cured under high-temperature and high-pressure conditions or manufactured under normal pressure It is.
The lightweight lightweight concrete produced in this way is excellent in fire resistance and strength characteristics, etc., and has a large amount of air bubbles inside, so it has excellent characteristics such as lightness, heat insulation, sound absorption, etc. Widely used as building exterior walls, partitioning materials, flooring, etc.
[0003]
However, since the air bubbles of the lightweight cellular concrete are uniformly dispersed in the inside thereof, the strength of the surface portion and the corner portion is not sufficiently high. For this reason, the surface may be crushed due to impact received during product transportation or construction, etc., and corners may be chipped, and the corners of the design part may be cut during cutting when the surface is designed by cutting or the like. There is a drawback that it is rounded and cannot be sharply designed.
In order to eliminate the above drawbacks, various methods for producing lightweight cellular concrete with a surface improvement layer have been proposed. For example, the cellular concrete slurry is injected into a formwork on which dummy partition plates are arranged, and when the mortar is condensed to some extent, the partition plates are removed to form a space, and high specific gravity cement slurry or the like is injected into this space. After injecting the high specific gravity cement slurry into the mold, the method of injecting the cellular concrete slurry thereon, or after injecting the cellular concrete slurry, injecting the high specific gravity cement slurry onto it There have been proposed a method in which a solid layer is formed on the surface portion to increase the strength by a method of integrating or a method of pressing semi-cured mortar with a roller, a press, or the like.
[0004]
[Problems to be solved by the invention]
However, in the above-described prior art, the method using the partition plate requires a mixer for mixing and injecting the high specific gravity cement slurry in addition to the partition plate, a cleaning facility for the partition plate, and the like, which increases the equipment burden. Also in the manufacturing process, there is a drawback that the product cost is increased because it is complicated compared to the manufacturing process of the usual lightweight cellular concrete, such as partition plate arrangement, removal, and high specific gravity cement slurry injection.
[0005]
In the method in which the lightweight cellular concrete slurry and the high specific gravity cement slurry are integrated, there is a disadvantage that the productivity is extremely low because the production method is inevitably limited to the production by the flat casting method. In addition, the product obtained by the above two technologies is a product made of a composite of different materials, so there is a strong risk of peeling and cracking at the interface between the foamed layer and the dense layer, and there is a problem with long-term durability. .
In the realization by pressing, there is little fear of the above-mentioned peeling, etc., and high productivity can be obtained if continuous pressing with a roller, but it is still sufficient because it is necessary to send semi-cured products one by one to the roller When handling an uncured cured product, defects such as chipping are likely to occur and the yield is low.
[0006]
Thus, the present condition is that the technique which manufactures the lightweight aerated concrete which does not produce a defect | deletion etc. in a surface part by simple equipment with high productivity at low cost has not yet been found.
Accordingly, the present invention has been made in order to eliminate the above-mentioned drawbacks of the prior art, and its purpose is to produce a lightweight cellular concrete having a high surface strength without occurrence of surface defects such as defects, that is, a dense surface layer. A low-cost lightweight cellular concrete having a solid surface layer is provided, and a lightweight cellular concrete having a dense surface layer can be easily produced with high productivity and at a low cost. It is an object to do.
[0007]
[Means for Solving the Problems]
The inventor is capable of liquefying the flow characteristics of the mortar, in particular, by applying a sudden shear force to the mortar in a semi-cured state, and returning to the semi-cured state again by releasing the application of the shear force, In other words, as a result of earnest research focusing on its thixotropic properties, it is possible to obtain lightweight cellular concrete whose surface portion is improved without impairing various features of lightweight cellular concrete, and to easily achieve the above object. I found what I could achieve.
[0008]
[Means for Solving the Problems]
The present invention has been made on the basis of the above knowledge, and the present invention relates to a rotating rod-like shape in which a rotating rod-like cross section is not a perfect circle and a foamed semi-cured mortar block is relatively moved. A method for producing lightweight cellular concrete, characterized in that a mortar block around a body is locally liquefied to liquefy it and cut the mortar block and form a solid layer in a surface layer portion.
[0009]
In the present invention, the shearing force that is locally applied to the semi-cured mortar block is provided to liquefy the portion of the mortar block that has received the shearing force, and the portion that has received the shearing force is locally liquid. There is no particular limitation on how to apply the shearing force.
As a method of giving a local shearing force, for example, a method using a rotating rod-shaped body as described later can be considered. In this case, if the cross section of the rod-shaped body is a perfect circle, it is not possible to give a shearing force locally to the semi-cured mortar, but if it has any other shape, the shearing force is locally applied to the semi-cured mortar. Can be given. In this case, a shearing force is applied to the semi-cured mortar along the rotation direction of the rod-like body, and the semi-cured mortar near the periphery of the rod-like body is locally liquefied by receiving a shearing force locally in the circumferential direction.
[0010]
Further, as another method, for example, it is conceivable to move a rod-shaped body having a neck as shown in the lower part of FIG. 4 in the axial direction of the rod-shaped body. In this case, since the semi-cured mortar foamed by the axial movement of the rod-shaped body is locally given a shearing force, the axial thickness of the rod-shaped body need not be constant. It may have a neck or protrusion. In this case, the cross section of the rod-shaped body may be a perfect circle. In this case, the foamed semi-cured mortar is subjected to a shearing force in the axial direction of the rod-like body, and locally shears and deforms in this direction to liquefy.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
An example of how to manufacture the lightweight cellular concrete according to the present invention will be described specifically with reference to the drawings. 1 and 2 are views schematically showing a cross section of the lightweight cellular concrete of the present invention. FIG. 3 is a schematic perspective view of an embodiment showing a method for producing lightweight aerated concrete according to the present invention. A surface layer improving apparatus 1 is a semi-cured mortar block 4 in which a motor 3 holding a rod-like body 2 is foamed. The frame 5 is fixed to the frame 5 that travels in the horizontal direction, and the foamed semi-cured mortar block 4 placed on the mounting table 6 and the frame 5 are relatively movable.
[0012]
The rotating rod-shaped body 2 and the foamed semi-cured mortar block 4 on the mounting table 6 are relatively moved to locally liquefy the mortar block around the rotating rod-shaped body by applying a shearing force. By cutting the semi-cured mortar block, an improved surface layer, ie, a solid layer, is formed. The principle is based on the use of the thixotropic properties of semi-cured mortar as shown below. First, when the rotating rod-shaped body 2 and the foamed semi-cured mortar block 4 come into contact, the mortar corresponding to the width corresponding to the rotation diameter is scraped off. At this time, the rotating rod-like body 2 gives a high shearing force to the semi-cured mortar and gives the semi-cured mortar abrupt shear deformation along the rotation direction of the rod-like body 2. Therefore, the semi-cured mortar Is liquefied locally. Next, the locally liquefied mortar is struck and adhered to the semi-cured mortar surface by the rotation of the rod-shaped body 2. Here, for example, when the rotation direction is right rotation, it is attached only to the left side with respect to the traveling direction. Next, when the rod-like body 2 moves away, the shearing force is removed from the liquefied mortar that has adhered, and the mortar is semi-cured again. Through this process, the semi-cured mortar becomes a solid mortar from which bubbles are almost removed, and is fixed to the surface of the semi-cured mortar. In this way, it is very easy to improve only the surface portion of the lightweight cellular concrete to a solid layer having a composition which is the same as the foamed layer but has almost no bubbles.
[0013]
The rod-like body 2 used in this case is longer than the thickness of the placed semi-cured mortar, and its cross-sectional shape can be locally liquefied by locally applying a shearing force to the semi-cured mortar. If it is a structure, there will be no restriction | limiting in particular.
For example, as shown in FIG. 4, not only a rod-like body having a quadrilateral or hexagonal cross section but also a rod-like body having a polygonal shape such as a triangle or an octagon may be used. Further, it is not a simple rod-shaped body, and the rod-shaped body may have a groove, or may have a constricted portion as shown in the lower part of FIG. Well, in this case, the constricted part and the protrusion part give different shearing force to the semi-cured mortar block from the other parts, so a streak pattern is obtained on the surface of the cut mortar. There is also an effect on the design that can be made.
The thickness of the rod-shaped body 2 used in this method is preferably about 5 to 30 mm, particularly preferably about 7 to 20 mm when the rod-shaped body is rotated.
[0014]
Further, as described above, for example, a rod-like body that moves in the axial direction can be used to locally apply a shearing force to the semi-cured mortar. In this case, when a hard rod-shaped body is used, it is preferable to reciprocate the rod-shaped body, but a method in which a flexible rod-shaped body is connected in a ring shape and continuously moved in one direction may be used.
The material of the rod-shaped body used in the present invention is not particularly limited as long as it is a material that is not easily deformed by running in a semi-cured mortar, for example, steel such as mild steel or hard steel, carbon, silicon nitride, etc. Any resin such as ceramic and polycarbonate may be used. Steel is preferable from the viewpoint of workability and cost.
The local shearing force applied to the semi-cured mortar is intended to locally liquefy the mortar, so the shearing force is within a range where the mortar can be liquefied locally. There is no particular limitation as long as it is present.
Optimum conditions differ depending on the state of the semi-cured mortar, and cannot be said unconditionally. For example, in the method using a rotating rod-shaped body, the rotational speed of the rod-shaped body may be about 100 to 5000 rpm, particularly preferably 500 to It is about 3000 rpm.
[0015]
The foamed semi-cured mortar block 4 is a mortar block for producing lightweight cellular concrete, and is formed by condensing lightweight cellular concrete slurry injected into a mold, but there are no particular restrictions on its composition and density. However, when the foamed semi-cured mortar block molded in various ways according to the application of the product is subjected to local shearing force for improving the surface layer, it can be self-supported without causing depression. Any hardness is acceptable. For example it is possible to improve the easy surface layer if a semi-cured state of the mortar for lightweight cellular concrete wide hardness range value Yamanaka hardness tester from 0.02 kg / cm ² of about 6 Kg / cm ^2.
[0016]
The relative speed between the frame 5 and the foamed semi-cured mortar block, that is, the relative movement speed between the rotating rod-shaped body 2 and the semi-cured mortar block 4 depends on the hardness of the foamed semi-cured mortar block. However, it is preferably about 0.05 to 10 m / min, particularly preferably about 0.1 to 5 m / min.
In addition, the surface layer is improved mainly in the longitudinal direction of the product, but in some cases, the surface layer of the short side edge can be improved by performing in the short side direction.
[0017]
Further, the improvement of the surface layer is not limited to one side of the lightweight cellular concrete as shown in FIG. 1, but for example, a part of the mortar attached to the surface of one side is attached to the opposite side, for example, the first mortar. A solid layer is formed on both sides of the lightweight cellular concrete as shown in FIG. 4 by running the second rod, which is slightly thinner than the rod, after the first rod while rotating in the opposite direction to the first. It is also possible.
Further, a lightweight cellular concrete having solid layers on both sides as shown in FIG. 2 can be obtained even by using a method of locally applying shearing force to a mortar using a rod-like body that moves in the axial direction instead of a rotating rod. it can.
In the present invention, the hardness of the mortar block, the shape of the rod-shaped body, the rotational speed of the rod-shaped body, the relative movement speed, etc. are appropriately selected according to the application of the product, thereby allowing the surface to have a dense shape having a rock texture or sandstone texture. Real layers can be formed, and high-design panels can be manufactured.
[0018]
【Example】
Next, the present invention will be described in detail with reference to examples.
[0019]
[Example 1]
Aerated concrete obtained by adding 0.07 parts of aluminum powder as a foaming agent to a slurry obtained by adding 70 parts of water to 28 parts of cement, 6 parts of quicklime, 2 parts of gypsum, 40 parts of silica, and 24 parts of recovered raw material. The slurry was poured into a mold and steam-cured under conditions of 60 ° C. and 95 RH. After reaching 2.5 kg / cm ² as the value of the Yamanaka hardness tester, it is placed on a mounting table and placed in a direction perpendicular to the mounting table. While rotating at 2500 rpm, it was run at a relative speed of 0.3 m / min in the longitudinal direction to cut the mortar block and obtain a molded body having a solid layer on the surface . As a result of autoclaving this at 180 ° C. for 4 hours, a lightweight cellular concrete having a solid layer without bubbles of about 7 mm on the surface was obtained. The surface of the resulting lightweight aerated concrete with a solid layer has high surface strength, and there is no crushing of the surface or chipping of corners under normal handling. It was possible to give a sharp design without causing chipping.
[0020]
[Example 2]
The mortar was injected and cured under the same conditions as in Example 1, and when the mortar hardness reached 0.02 Kg / cm ² , the mortar was placed on the mounting table and arranged in a direction perpendicular to the mounting table with a length of 70 cm and a side of 14 mm. While rotating a rod-shaped body having a regular square section made of mild steel at 1000 rpm, the rod was run at a relative speed of 3 m / min in the longitudinal direction to cut the mortar block and obtain a molded body having a solid layer on the surface . This was again steam-cured for 60 minutes under the conditions of 60 ° C. and 95 RH, and then autoclaved for 4 hours at 180 ° C. As a result, a lightweight aerated concrete having a solid layer without bubbles of about 10 mm in thickness was obtained. The obtained lightweight aerated concrete has a high surface strength as in Example 1, and does not cause crushing of the surface or chipping of corners under normal handling. It was possible to give a sharp design without causing any problems.
[0021]
[Example 3]
A lightweight cellular concrete was obtained by molding under the same conditions as in Example 1 except that a rod-shaped body having a regular hexagonal cross section made of mild steel having a diagonal length of 14 mm was used. The obtained lightweight cellular concrete has a solid layer without bubbles of about 7 mm in thickness on the surface, and the surface on the side having the solid layer has a high surface strength, as in Example 1, and has a normal surface. Handling did not cause crushing of the surface or chipping of corners, and a sharp design could be imparted without chipping of the corners of the design even if design processing or the like was performed.
[0022]
【The invention's effect】
Since the lightweight cellular concrete obtained using the production method of the present invention is solidified only on the surface portion, the obtained product does not impair various features of the lightweight cellular concrete, and has high surface strength, Under normal handling, crushing of the surface, chipping of corners, and the like are unlikely to occur, and a sharp design can be imparted even after design processing or the like. Moreover, since the solid layer on the surface is formed of the same mortar as the foamed layer, the adhesion at the interface is good, and even in a long-term exposure test, peeling and cracking are unlikely to occur. Moreover, since there are no air bubbles or graininess caused by cutting a piano wire on the surface like ordinary lightweight aerated concrete, the paintability can be improved, for example, the coating amount can be reduced.
[0023]
The production method of the present invention has high productivity because cutting and surface processing can be performed simultaneously.
In addition, the method using a rotating rod-shaped body is a simple facility such as a rod-shaped body and a motor, and the method is also very easy by simply moving the rod-shaped body relative to the mortar block, and the current production Since high productivity can be maintained without complicating the process, the product price can be reduced.
[Brief description of the drawings]
FIG. 1 is a view schematically showing a cross section of an example of a lightweight cellular concrete according to the present invention.
FIG. 2 is a view schematically showing a cross section of another example of the lightweight cellular concrete of the present invention.
FIG. 3 is a schematic perspective view showing an example of a method for producing a lightweight cellular concrete according to the present invention.
FIG. 4 is a perspective view showing an example of a rod-shaped body used for manufacturing the lightweight cellular concrete of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Surface improvement apparatus 2 Rod-shaped body 3 Motor 4 Semi-hardened mortar block 5 Frame 6 Mounting stand 7 Foam layer 8 Solid layer 9 Lightweight cellular concrete

Claims (1)

A rotating rod-like body whose rotating cross section is not a perfect circle and a foamed semi-cured mortar block are relatively moved to locally liquefy the mortar block around the rotating rod-like body by applying a shearing force. A method for producing lightweight aerated concrete, comprising cutting the mortar block and forming a solid layer in a surface layer portion.

Images