JPH01320280A - Foamed concrete structural body and production thereof - Google Patents

Abstract

PURPOSE:To obtain a foamed structural body which is excellent in heat retaining properties, heat insulating properties and noise insulating properties and low in water permeability by forming independent foams due to centrifugal force while kneading cement, water, a foaming agent and a vitreous air encapsulating body, curing and solidifying concrete in a concrete form. CONSTITUTION:When the vitreous air encapsulating bodies 4 are mixed with a foaming agent as an aggregate in a mixer 2B and both paste-like cement 3 and the air encapsulating bodies 4 are uniformly kneaded by high-speed rotation of the opposite impellers 5, 5, the gas generated from the foaming agent is uniformly formed into the complete and independent foams 13 without causing deformation and being squashed in cement 3 by centrifugal force and also the independent foams 4a are formed by the air encapsulating bodies 4. Then this kneaded material is allowed to flow into a concrete form 11 with a beating machine 10 and thereafter cured and solidified. Furthermore after concrete is cured and solidified, mold release work from the concrete form 11 is performed.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a foamed concrete structure suitable for use mainly in panels for architectural exterior walls, partitions, ceilings, floors, etc., and a method for producing the same. .

[Conventional technology]

Conventionally, panels molded from foamed concrete have been used as interior wall materials for architectural exterior walls, partitions, ceilings, floors, and the like.

This is because the foamed concrete itself is lighter than PC concrete panels containing PC reinforcing bars, and because of its light weight, it has excellent workability. It also has insulation and heat retention properties, making it especially suitable for use in cold regions. It has excellent sound insulation properties.

Moreover, instead of PC reinforcing bars, concrete plates containing reinforcing fibers are becoming popular, using inorganic fibers such as glass fibers and carbon fibers, or organic fibers as aggregates to reduce weight.

[Problem to be solved by the invention]

Conventional foamed concrete structures are made by mixing cement, sand, water, etc., then pouring it into the formwork while applying vibration to the formwork, and then mixing a foaming agent into the formwork. Foamed concrete structures with open cells were manufactured by foaming concrete with gas generated from a foaming agent within a frame and forcibly removing residual air by squeezing.

For this reason, the weight of the foamed concrete structure tends to increase, and the pressure caused by the vibrations may cause the foam to collapse or become incompletely shaped to form completely closed cells after the concrete has cured. In addition, the state of foaming inside the concrete is uneven, causing unevenness, poor heat retention and insulation properties, high sound transmission rate, and lack of sound insulation.

In order to compensate for this, conventionally a stabilizer was added to ensure that the bubbles were completely formed.

In addition, conventional foamed concrete has many open cells, which increases water permeability into the concrete, which leads to problems such as accelerated cracking and chipping and a decrease in strength.

Moreover, the above-mentioned conventional methods for manufacturing foamed concrete structures were aimed at manufacturing large-sized structures.

For example, in order to manufacture a piece of foamed concrete that is thinner than an exterior wall panel, a large foamed concrete structure is formed in a formwork, and then a diamond cutter, saw cutter, etc. are used to cut this large foamed concrete structure. Concrete structures must be cut to the required length, width, and thickness, which increases the number of steps and production time, increases costs, and requires pie-breaking, etc., which causes major damage to equipment. Equipment costs were also high. Yields were poor when manufacturing products that tended to suffer.

Also, PC with PC reinforcing bars has tensile strength and bending strength.
In the case of temporary concrete, the concrete must be molded to a predetermined thickness so that it is sufficiently buried in the concrete, so there is a structural constraint that it cannot be molded to a constant thickness.

This inevitably resulted in an increase in weight.

Therefore, this invention makes it possible to uniformly form closed cells inside concrete, which has excellent heat retention, heat insulation, and sound insulation properties.
Foam concrete structures with low water permeability, high strength and long life without cracking or chipping, and easy to form into thin panels, simplifying the process, lowering costs, and increasing yields. The purpose is to provide a method for producing the same.

[Means to solve the problem]

In order to achieve the above object, the invention set forth in claim 1 includes:
A method was adopted in which a vitreous air inclusion was mixed into cement as an aggregate and a closed cell molding substance, and the cement was molded to have individual closed cells formed by the air inclusion and a foaming agent.

The invention according to claim 2 also provides a step of mixing a foaming agent and a vitreous air-enclosed body as an aggregate into a kneaded mixture of cement and water, and foaming closed cells by centrifugal force while kneading the mixture; We adopted a method that consists of a process of pouring the material into a mold, curing it, and solidifying it.

[For production]

The invention as set forth in claim 1 is characterized in that cement is kneaded with vitreous air-enclosed bodies as aggregates together with water, and the cement is molded without being subjected to pie-break vibration or squeezing by simply flowing into the formwork. As a result, perfectly shaped closed cells can be uniformly formed inside the concrete by the vitreous air encapsulant and the foaming agent. As a result, it has excellent heat retention, heat insulation, and sound insulation properties, is lightweight, and can be easily and freely adjusted.

In addition, since the air enclosing body of some of the closed cells is formed of glass, the water permeability into the concrete is lower than that of conventional foamed concrete having closed cells. Moreover, there are no cracks or chips caused by water permeation, and high strength can be maintained.

According to the second aspect of the invention, the thickness is reduced by a simplified process of mixing cement and a foaming agent with water as aggregates and vitreous air inclusions, and pouring the mixture into a mold. A foamed concrete structure having complete and uniform closed cells can be manufactured using simple equipment without the foams collapsing.

〔Example〕

Hereinafter, one embodiment of the invention as claimed in claim 1 and the invention as claimed in claim 2 will be described with reference to the drawings.

1 is a casting chamber, and 2A is a mixer for kneading cement 3 and water into a paste. 2B is mixer 2
In the mixer located after A, the vitreous air inclusions 4 as aggregates and closed cell molding material together with the blowing agent are added.
and the air inclusion body 3 having a different specific gravity from the cement 3.
The purpose is to knead the paste with the cement using stirring blades 5°5 that rotate opposite each other at high speed so as to uniformly mix the powder, promote foaming, and form closed cells.

6 is a storage tank for the cement 3, 7 is a tank for accommodating the foaming agent, 8 is a tank for accommodating the air inclusion body 4, and 9 is a water storage tank.

As the foaming agent, for example, aluminum powder is used.

In addition, from the viewpoint of easy procurement of raw materials and cost, the air enclosing body 4 may be made of ore containing a large amount of glass component.
For example, it is obtained by finely crushing stone, rosinite, basalt, rhyolite, nacre, etc., and heating the crushed stone powder in an external heating kiln, with air sealed inside a glassy spherical body. is used. In this case, if zirconium (Zr) or a mixture thereof is mixed into the glass component of the air enclosure 4,
The alkali and acid resistance from cement is improved.

The size of the foamed concrete structure is selected from those with a diameter of 1 mm to 6 mm depending on the purpose of the foamed concrete structure to be manufactured.

10 is a pouring machine equipped with a pressure chamber pump P for pressure feeding, etc.;
The tip of the vibrator 10a has a spiral structure (not shown) inside to spray out the cement 3 evenly and to prevent the bubbles generated by the foaming agent from being crushed.
A nozzle 10a1 formed in is attached. Reference numeral 11 denotes a formwork, and the size and dimensions of the formwork 11 vary depending on the foamed concrete structure to be formed, but for example, when forming a partition panel as an inner wall material that is thinner than the outer wall material, The reduced internal volume is approximately 180CI
! 1. A device with a horizontal dimension of about 180 cm and an interior partitioned by a separator 12 with a width of about 1 cm is used.

This formwork 11 is transported from the pouring site using a conveyor or other transport means or a transport vehicle as necessary for concrete curing and subsequent demolding, and is assembled on a production line. , the product may be manufactured efficiently.

Hereinafter, the operation of the invention set forth in claim 1 will be explained for each manufacturing process together with an embodiment of the invention set forth in claim 2.

First, as the first step, add water to cement 3 and mixer 2.
Knead in A to make a paste. In this case, an epoxy resin may be mixed if necessary.

After that, in the second step, the vitreous air inclusions 4 are mixed together with a foaming agent as aggregate into the mixer 2B, and the paste-like cement 3 and the air inclusions 4 are evenly mixed by opposing high-speed rotation of the stirring blades 5.5. When kneaded uniformly, the gas generated from the blowing agent will not cause the cement 3 to lose its shape or be crushed due to centrifugal force, and will uniformly form complete closed cells 13, while the air inclusions 4 will form closed cells. 4a is formed.

The composition ratio of the cement 3, the foaming agent, and the air encapsulant 4 as an aggregate varies depending on the use of the foamed concrete structure 14, but in this example, it is 1:3 to 4:1.
A mixture of about 6% by weight is used.

The air enclosing body 4 used as aggregate has a diameter of approximately 1 mm. The kneading time is about 3 to 10 minutes, and the closed cells 13 are sufficiently foamed in the paste-like cement mixture, and the cement mixture is sufficiently expanded without hardening.

As a third step, the above-mentioned kneaded material is applied to the formwork 11 by the pouring machine 10.
Pour it inside, then let it cure and solidify.

In this embodiment, the time required for curing the concrete is about 4 to 24 hours, and at this time, in the above step, paste cement 3, a foaming agent, and an air enclosing body 4 are added as shown in FIG. The concrete structure 14 is thoroughly kneaded while applying centrifugal force by the opposing stirring blades 5°5 of the mixer 2A that rotate at high speed, so that the crab foam agent is sufficiently foamed and the cement itself is sufficiently expanded. Inside the concrete, perfectly shaped closed cells 13 are uniformly formed by the gas generated from the foaming agent, and the air enclosing body 4 itself is evenly mixed into the concrete, resulting in a perfectly spherical shape. Closed cells 4a are formed.

Moreover, since vibrations such as pie-breaking are not applied during pouring into the formwork 11, the bubbles generated from the foaming agent are not crushed and incompletely shaped closed cells are not formed. Further, the air inclusion body 4 as an aggregate is uniformly mixed into the concrete structure 14 in the formwork 11 and solidified with the cement slurry. At this time, if epoxy resin is mixed into the cement 3 and kneaded as necessary in the first step, an adhesive film layer of the epoxy resin is formed on the outer periphery of the air enclosing body 4, so that the air enclosing material can be used as an aggregate. The body 4 and the cement 3 are strongly bonded together, and the air inclusion bodies 4 are bonded to each other through point contact, which increases the specific gravity and increases the resistance. The inside of the cement 3 does not sink downward, and closed cells 4a and 13 can be formed on average in the cement 3 by the air inclusion body 4 and the foaming agent. Furthermore, after molding, the adhesive film layer made of epoxy resin hardens to firmly protect the air enclosing body 4 and to increase the strength of the foamed concrete structure 14 itself.

Thereafter, after the concrete has cured and solidified, stripping work is performed from the formwork 11.

In the stripping operation, since the cement 3 had already been sufficiently expanded before being poured into the mold 11, there was little expansion or contraction during curing within the mold 11, and the mold was easily stripped.

In this way, the vertical dimension is about tsocm, the horizontal dimension is 180ca
A partition panel made of foamed concrete with completely closed cells 4a, 13 having a thickness of 1 cffI is produced.

The thickness of board materials such as partition panels is 31m to 1Qm.
It is also possible to form extremely thin panels with a thickness of m.

The concrete structure 14 manufactured in this way is
As shown in FIG. 2, closed cells 13 formed by the gas generated by the blowing agent and closed cells 4a formed from the glassy air-enclosed body 4 as an aggregate form the cement 3.
It has a perfect shape without being crushed inside and is uniformly formed without any deviation. Therefore, it has low thermal conductivity, excellent heat retention and insulation properties, and can be molded lightweight.

Furthermore, in the concrete structure 14 of this embodiment, the closed cells 13 are formed from the foaming agent, and complete closed cells 4a are also formed from the air layer enclosed in the glassy air enclosure 4. It has extremely low water permeability and does not penetrate into the concrete. Therefore, due to chemical changes caused by moisture such as rain permeating into the concrete,
It can prevent cracks and chips. In addition, the air inclusion body 4 itself,
Since it is made of glass, it will not be altered or destroyed by chemical changes caused by water permeation.

Moreover, since cement slurry is formed around the air inclusions 4 as aggregates, the cement 3 and the air inclusions 4 are strongly bonded, and the strength of the foamed concrete 14 is increased, making it resistant to drying and shrinkage. Durability and impact resistance properties are strong.

At this time, the specified invention of the present application is based on the large number of air inclusion bodies 4 mixed in the cement 3.
During this time, closed cells 13 are formed due to the blowing agent, so when the type of blowing agent, the amount added, the kneading time, the stirring speed by the stirring blades 5, the stirring time, etc. are kept constant, By simply adjusting the amount of air inclusions 4 of a constant diameter mixed into the cement 3, the air inclusions 4 formed in the cement 3 can be changed from the state shown in FIG. 2 to the state shown in FIG. 3, for example.
The amount of closed cells 13 formed between them per unit volume can be adjusted. Therefore, physical properties such as thermal conductivity, heat retention, heat insulation, weight, strength, and water permeability can be easily and arbitrarily adjusted by mixing the air enclosing body 4. Moreover, at this time,
If epoxy resin is mixed into the cement 3 and kneaded as necessary, an adhesive film layer of epoxy resin is formed around the outer periphery of the air enclosing body 4, so that the air enclosing body 4 as an aggregate and the cement 3 are firmly bonded. and the air inclusion body 4
Since they are bonded together through point contact, the external volume becomes larger and the resistance increases, so the air inclusion body 4 does not sink downward in the cement 3 during curing and assimilation, and the Closed cells 4a formed by air inclusion body 4 and foaming agent.

13 can be formed. Furthermore, after molding, the adhesive film layer made of epoxy resin hardens to firmly protect the air enclosing body 4 and to increase the strength of the foamed concrete structure 14 itself.

Furthermore, as shown in FIG. 4, instead of using particles of a uniform particle size as shown in FIGS. 2 and 3, particles of different sizes are used for the air inclusion body 4. If this is used, the mutual arrangement of the air inclusions 4 as aggregate and closed-cell molded material will change, and the space occupied by the cement 3 will also change. The amount of bubbles 13 formed can also be adjusted.

In this way, physical properties such as thermal conductivity, heat retention, insulation, weight, strength, water permeability, etc. can be adjusted as well.

The foamed concrete structure of this example and the conventional foamed concrete structure using alumina as a foaming agent (simply referred to as A
Table 3 summarizes the physical properties of the LC (referred to as LC) based on experimental results.

Table I In the above explanation, the case of manufacturing a partition panel was explained as an example, but it is not limited to this (such as ceiling materials, ceiling materials, etc.).
It is also possible to manufacture other building materials such as flooring and other internal and external wall materials, and it is also easy to process curved surfaces.

In addition, as for the glassy air-enclosed body 4, in the above embodiment, a material obtained by heating and foaming the helium was used as a preferred embodiment, but it is possible to use a material made of ores such as rosinite, basalt, rhyolite, pearlite, etc. In addition, any material may be used as long as it contains a glass component in its composition and has foaming properties that enclose air, such as silica stone and verminiculite.

〔Effect of the invention〕

Since each invention of the present application is as described above, it has the following effects.

According to the invention set forth in claim 1, perfect-shaped closed cells can be uniformly formed inside the concrete by the vitreous air enclosing body and the foaming agent, so that heat retention, heat insulation,
Sound insulation will be excellent.

In addition, since the air enclosing body of some closed cell cells is molded with glass, the water permeability into the concrete is extremely low compared to conventional concrete structures, and cracks and chips may occur due to the influence of water permeation. It has high strength.

Further, according to the invention described in claim 2, the gas generated from the blowing agent is uniformly stirred into the cement paste by centrifugal force, and the mixture of cement, water, and vitreous air inclusions is mixed. By simply pouring the foam into a formwork, a foamed concrete structure with perfectly shaped closed cells that are uniformly formed without being crushed within the cement can be obtained. Therefore, the cutting process and reinforcing action are no longer necessary, simplifying the process, resulting in low cost, good heat retention, insulation properties, and water permeability, as well as thin thickness, excellent workability, and even special Equipment costs are low because no special equipment or formwork is required.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an example of the device used to carry out the second invention of the present application, Fig. 2 is a cross-sectional view showing an example of a foamed concrete structure as the specified invention of the present application, which was also manufactured; Fig. 3 Figure 4 is a sectional view showing another foamed concrete structure in which the amount of air inclusions added is increased, and Figure 4 is a sectional view showing another foamed concrete structure in which air inclusions of different sizes are inserted. It is. 2A, 2B...Mixer, 3...Cement, 4...
- Air inclusion body, 5... Stirring blade, 13... Closed cell, 14... Concrete structure. Patent applicant Kobayashi Co., Ltd. Figure 1

Claims (2)

[Claims] (1) A foamed concrete structure in which vitreous air inclusions are mixed into cement as aggregate and a closed-cell molding substance, and the foamed concrete structure is molded to have closed cells due to the air inclusions and a foaming agent. (2) A step of mixing a foaming agent and a vitreous air inclusion as aggregate into a mixture of cement and water, foaming closed cells by centrifugal force while kneading, and pouring the mixture into a mold. A method for manufacturing a foamed concrete structure comprising curing and solidifying steps.