JPH0717463B2 - Manufacturing method of lightweight cellular concrete sheet - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a lightweight cellular concrete (hereinafter referred to as ALC) having a thickness of 20 to 50 mm and an AL.
The present invention relates to a method for manufacturing a C thin plate, and more particularly, to a method for manufacturing a reinforcing wire net in the ALC thin plate that improves the positional accuracy.

[0002]

2. Description of the Related Art Generally, ALC panels are mainly composed of crushed siliceous raw materials such as silica stone or sand, and calcareous raw materials such as lime and cement, to which aluminum powder as a foaming material and water are added. After making it into a slurry, it was poured into the formwork with reinforcing bars, and after foaming and hardening, the supporting tools of the reinforcing bars were pulled out, cut to a predetermined thickness with a piano wire, etc., and then transferred to an autoclave. Manufactured by high temperature and high pressure steam curing.

In the above foaming step, most of the reaction is usually completed 20 to 40 minutes after the slurry is poured into the mold, but the reaction of the residual aluminum powder and the reaction heat of the cement and lime are continued thereafter. The expansion of the slurry continues for a while due to the rise in internal temperature due to. The expansion of the slurry subsides 60 to 70 minutes after being poured into the mold. On the other hand, the slurry injected into the mold is condensed as the hydration reaction of cement or the like progresses, gradually losing the initial fluidity and increasing the viscosity of the slurry. Therefore, when the expansion of the slurry and the convection accompanying it occur as described above, the reinforcing wire mesh moves, and this movement causes deformation and displacement of the reinforcing wire mesh.

Conventionally, many wire mesh fixing devices have been devised and used in order to prevent the movement of the reinforcing wire mesh due to the convection of the slurry, but normally, it is not necessary to remove this fixing device and fill the extraction holes naturally with the slurry. The limit is about 60 minutes after the slurry is injected. However, if the fixing device is removed before 60 minutes from the slurry injection to eliminate the removal hole of the fixing device, the reinforcing wire mesh moves vertically and horizontally due to the slurry convection, and the positional accuracy of the reinforcing wire mesh in the product is improved. It was difficult to maintain, and the wire mesh was exposed on the surface of the ALC thin plate, and the panel bending proof strength was lowered due to the eccentricity of the wire mesh, and cracks were likely to occur when the ALC thin plate was lifted.

Many proposals have been made to solve this problem. In Japanese Utility Model Publication No. Sho 49-28188, reinforcing wire mesh is sandwiched by guide rods having cracks or gaps and arranged and fixed in a mold. With this fixing method, bending and position of the wire mesh are caused by convection of slurry that occurs during the foaming process. In order to prevent the slippage, it is necessary to thicken the guide rod to increase the rigidity against bending, and the traces of support rod removal left on the panel after curing the autoclave cause a significant decrease in the panel proof strength, especially when the panel thickness is 40 mm or less. It is not practical for thin plates.

[0006] In Japanese Utility Model Publication No. 51-46444 and Japanese Patent Publication No. 48-17532, a round bar having a thickness substantially equal to the panel is used as a support, a reinforcing wire mesh is arranged between the round bars, and a raw material slurry is poured and then cured. In this state, the round bar is pulled out, the hole is immediately filled with the same slurry to eliminate traces of the round bar's removal.However, in this method, the round bar obstructs the flow when injecting the slurry and uniform foaming does not occur. Also, it takes a lot of time and labor to fill the traces of the round bars that have been extracted, and the hardening state of the slurry that fills the holes is different from the hardening of the previously injected slurry. However, there is a disadvantage that the strength of the interface with the round hole is weakened.

Further, Japanese Patent Laid-Open Nos. 59-24616 and 5
The method of 9-41217 is to pull out the supporting rod which has been set in the mold in advance at the time when the foaming of the slurry is completed and the fluidity is maintained, or the reinforcing wire net tensioned by the supporting tool is put in the slurry. It is to remove the support tool only by burying it in the base material and then to fill the extraction mark of the support tool due to the self-disintegrating property of the slurry, which has a still high fluidity. It is necessary to pull out the supporting tool at a time when the fluidity is such that it does not move under its own weight, and due to the blending amount of the raw materials, the influence of the ambient temperature, the quality variation of the raw materials, etc. Also, because there are variations in temperature within the same mold and variations in setting time due to evaporation of water, it is important to control the time taken to remove the support so that no trace of removal remains. It is very difficult in Neai.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to produce an ALC thin plate which does not have the above-mentioned drawbacks, improves the positional accuracy of the reinforcing wire mesh in the product, and has no trace of the withdrawal of the support rod.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a raw material slurry is poured into a mold in which reinforcing wire nets supported by support rods are arrayed and fixed, and the support rods are withdrawn after semi-curing or curing to remove the desired thickness In the method for producing an ALC, which is cut into pieces and cured by autoclave, a first raw material obtained by prehydrating a mixture of cement, a siliceous raw material and a process repeating slurry, and a second raw material obtained by prehydrating a mixture of quicklime and gypsum. Is characterized by injecting a raw material slurry which is mixed so that the temperature becomes 50 ° C. or lower into a mold.

[0010]

The present invention is the first to carry out a relatively gentle hydration reaction.
By pre-hydrating the raw material and the second raw material, which undergoes a rapid hydration reaction, separately in advance and then mixing them, the viscosity of the slurry rises as shown in FIG. Since the reaction is completed, the viscosity of the slurry in the foaming process is small, and therefore the expansion of the slurry is stopped while the resistance of the slurry that acts on the wire mesh due to the expansion of the slurry is small, so that the deformation and displacement of the wire mesh can be suppressed. I found that I could do it.

In the present invention, the foaming reaction is accelerated because the cement particles form a stable hydration film on the surface by pre-hydrating cement and quick lime separately, and therefore foaming after mixing. It is considered that since the hydration reaction of the cement is suppressed and the increase in the viscosity of the slurry is delayed while the reaction is completed, the foaming reaction proceeds while the resistance of the slurry suppressing the foaming reaction is small.

On the other hand, in the conventional method in which the pre-hydration is not carried out, the hydration reaction is activated by the coexisting quick lime before the cement particles form a stable hydration film, and the viscosity of the slurry sharply increases during the foaming process. Therefore, it is considered that the resistance of the slurry to the foaming reaction becomes large, and therefore the time of the foaming reaction becomes long, and the deformation and displacement of the wire mesh become large.

Further, in the present invention, as shown in FIG. 2, since the temperature inside the slurry rises more gently than in the conventional method, the force of the slurry acting on the wire mesh due to the expansion of the slurry is reduced, and the wire mesh is deformed or displaced. Becomes smaller. The increase in the internal temperature is small because activation of the hydration reaction by the cement and lime can be suppressed by pre-hydrating the cement and quick lime separately as described above. Further, quick lime is mixed after the reaction heat is generated by prehydration, so that the temperature rise of the raw material slurry can be suppressed.

In the present invention, when the slurry temperature during prehydration of the mixture of cement, the siliceous raw material and the process repeated slurry is high, the hydration reaction of the cement rapidly progresses and it is injected into the mold. Since the viscosity of the slurry sharply increases, it is preferably 50 ° C or lower. In addition, when prehydrating a mixture of quick lime and gypsum, if the temperature of water is high, the hydration reaction of quick lime rapidly progresses, the viscosity of the slurry rises sharply like cement, or the slurry boils, so 50 ° C. The following are preferred. If the water temperature is low, quick lime digestion is slowed down, a hydration reaction may occur in the foaming step, and the expansion of the slurry may be increased.

In the present invention, the first raw material and the second raw material are mixed so as to have a temperature of 50 ° C. or lower. When the temperature exceeds 50 ° C., the hydration reaction rapidly progresses and the viscosity of the slurry increases rapidly. Therefore, the deformation and positional displacement of the wire mesh increase as the slurry expands. Further, when the temperature at the time of mixing is low, the foaming reaction becomes slow and the time required for the slurry to harden becomes long, so 40 ° C. or higher is preferable.

Examples 1 to 4 Examples 1 to 4 will be described below. The device shown in FIG. 3 was used as a device for fixing the reinforcing wire mesh in the mold. After the reinforcing wire netting 1 was arranged between the support rods 2, it was suspended on a movable member 4 provided on the bridge 3, and the movable member 4 was slid in the directions of arrows A and B to be stationary. The support rod used had a diameter of 5 mm or 9 mm. As the reinforcing wire mesh, a lath wire mesh having a longest diagonal of the opening of 32 mm and a wire diameter of 1 mm was used and arranged at 37 mm intervals. As the first raw material, 100 parts by weight of silica stone and 120 parts by weight of repeated slurry (of which 60 parts by weight of solid content) were used, and these were mixed with water 15 parts.
7 parts by weight was preliminarily prepared, 63 parts by weight of cement was added, and the mixture was stirred at a temperature of 48 ° C. for 5 minutes. In this way, the first raw material was pre-hydrated. As the second raw material, 14 parts by weight of gypsum was previously slurried with 23 parts by weight of water at 30 ° C., and then 15 parts by weight of quick lime was added. And this is 5
The second raw material was pre-hydrated by stirring for a minute.
Then, the 48 ° C. raw material slurry in which the first raw material and the second raw material were mixed was stirred for 4 minutes and poured into the mold. 60 minutes or 20 minutes after the injection, the supporting rod was taken out, and then the demolded ALC was cut by a piano wire having a wire diameter of 1 mm to manufacture an ALC thin plate having a thickness of 37 mm. The dimensions and the degree of eccentricity of the lath wire mesh were examined. The results are shown in Table 1.

The degree of eccentricity of the reinforcing wire mesh indicates the deviation of the center position in the thickness direction of the reinforcing wire mesh. The degree of eccentricity when the reinforcing wire mesh is at the center in the thickness direction of the ALC thin plate is normal. Is set to 0, and the deviation from that position is measured. Therefore, the thickness of the ALC thin plate is 37 mm,
Since the thickness of the lath wire mesh is 2 mm, the maximum eccentricity is 17.
The thickness is 5 mm, and in this case, the reinforcing wire mesh is exposed on the surface of the ALC thin plate. Further, the allowable range of the eccentricity of the reinforcing wire mesh is preferably ± 2.5 mm.

[0018]

[Table 1]

Further, after the raw material slurry was injected, the transition of the foaming height on the surface of the slurry was measured at intervals of 10 minutes for 90 minutes. The result is shown in FIG.

After the raw material slurry was injected, the transition of the internal temperature of the slurry was measured at 30 minute intervals for 3 hours. The result is shown in FIG.

Comparative Examples 1 to 4 As in Examples 1 to 4, instead of the method of Examples 1 to 4 in which the first raw material and the second raw material were separately prehydrated and then mixed to prepare the raw material slurry. After mixing the blended ingredients at once,
A 37 mm A was prepared in the same manner as in Examples 1 to 4 except that the raw material slurry at 48 ° C. was stirred for 3 minutes and poured into the mold.
An LC thin plate was manufactured, and the dimensions of the traces of withdrawal of the support rod and the degree of eccentricity of the lath wire mesh were examined in the same manner as in Examples 1 to 4.
The results are shown in Table 1.

Further, as in Examples 1 to 4, changes in foam height and changes in slurry internal temperature were measured. The results are shown in FIGS.

From Table 1, it can be seen that in Examples 1 to 4, the displacement of the reinforcing wire mesh is small, and the trace of extraction is small even when the support rod is extracted after the foaming of the slurry is completed. Further, it can be seen from FIGS. 1 and 2 that in Examples 1 to 4, the foaming reaction of the slurry was faster and the increase in the internal temperature of the slurry was milder than in the conventional method.

[0024]

As described in detail above, according to the present invention, since the resistance force acting on the reinforcing wire mesh due to the expansion of the slurry can be reduced, the supporting rod may be thin and before the hardening of the slurry. It is also possible to remove the support rod, and it is possible to manufacture a high-quality ALC thin plate with high positional accuracy of the reinforcing wire mesh and no trace of removal of the support rod.

[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the elapsed time after pouring a raw material slurry into a mold and the foam height.

FIG. 2 is a diagram showing a relationship between an elapsed time after pouring a raw material slurry into a mold and an internal temperature.

FIG. 3 is a perspective view of a reinforced wire mesh support device used in an embodiment of the present invention.

[Explanation of symbols]

 1 Reinforcing wire mesh 2 Support rod 3 Bridge 4 Movable material

Claims (1)

[Claims] 1. An autoclave in which a raw material slurry is poured into a mold in which reinforcing wire nets supported by support rods are arrayed and fixed, and the support rods are taken out after semi-curing or curing, demolded, and cut into a desired thickness. In the method for producing a lightweight cellular concrete for curing, a first raw material obtained by prehydrating a mixture of cement, a siliceous raw material and a process repeating slurry, and a second raw material obtained by prehydrating a mixture of quicklime and gypsum, A method for manufacturing a lightweight cellular concrete thin plate, which comprises injecting raw material slurry mixed so as to be 50 ° C. or lower into a mold