JPH0637337B2 - ALC manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing ALC with few defects and improved quality, and more specifically, without forming cavities above and below a reinforcing bar, which is the direction of expansion of raw materials, Excellent adhesion between the reinforcing bars and ALC, and no appearance defects such as abnormal growth of cavities or bubbles appearing on the ALC plate surface due to turbulence of bubbles A
The present invention relates to an LC manufacturing method.

[Conventional technology]

In general, ALC products are mainly composed of crushed silica stone or siliceous raw material and calcareous raw materials such as lime and cement, to which aluminum powder as a foaming agent and water are added to form a slurry, and then reinforced reinforcing bars. After being poured into a mold which is arranged and foamed and semi-cured, it is cut into a required size by a piano wire or the like, and then transferred to an autoclave for high temperature and high pressure steam curing.

In this foaming process, aluminum powder as a foaming agent reacts with alkali as a calcareous raw material to generate gas, and the viscosity of the slurry gradually increases due to the hydration reaction of lime and cement. When the highly viscous slurry foams in the mold where the reinforcing bars are fixed, air bubbles are disturbed and cavities are formed above the reinforcing bars. Further, in foaming after hydration progresses and initial setting occurs, a force for lifting the reinforcing bar acts, so that a cavity is formed below the lowermost main bar where the relative displacement between the reinforcing bar and the cake in the initial setting state becomes large. These cavities around the reinforcing bar have a drawback that the adhesive force between the reinforcing bar and the ALC is reduced to impair the strength of the ALC product, or the appearance is damaged due to the disorder of bubbles.

[Problems to be Solved by the Invention]

The present invention is to provide a method of manufacturing an ALC that does not have the above-mentioned drawbacks and has improved quality.

[Means for Solving the Problems]

In order to achieve this object, the present invention is a method for manufacturing an ALC in which reinforcing bars are embedded. In the method, a raw material slurry containing a foaming agent is injected into a mold in which reinforcing bars are arranged and fixed by support rods, and foaming is almost completed. , Configured to perform high temperature and high pressure steam curing after applying vibration of 0.2 to 1.5 mm in amplitude and a frequency of 3000 to 10000 times / min to the supporting rod for 5 to 20 seconds before initial setting occurs Is.

Since the reinforcing bars hold the support rods vertically by the holes provided in the bridge spanning over the ALC manufacturing formwork, and are arranged in the formwork by engaging with the support rods, Practically, if vibration is applied to the bridge, the vibration will be transmitted to all the reinforcing bars.

The timing of giving vibration to the support rod must be before the end of the foaming and the initial condensation occurs, and it is less effective in the process of foaming being earlier than this and the initial condensation begins. After that, the full effect cannot be obtained. It is about 20 to 30 minutes after the slurry is injected in the usual raw material blending.

[Action]

According to the present invention, when the ALC raw material slurry is almost completely foamed by aluminum powder, the viscosity due to hydration is increased, and the reinforcing bar is vibrated immediately before the initial setting occurs, the slurry around the reinforcing bar or the cake in the initial setting state is generated. It was found that the fluidity of the reinforcing bar increases due to the increase in the fluidity around the reinforcing bar by applying vibration. By removing the lifting force, it is possible to prevent the occurrence of cracks or the like formed at the interface of the lowermost main muscles.

As a suitable vibration applied to the support bar, its direction is preferably in the direction perpendicular to the arranged reinforcing reinforcing steel mat surface, and the amplitude is 0.
If it is less than 2 mm, the range of increasing fluidity is too narrow to expect a sufficient effect even if the frequency is increased, and if the amplitude is greater than 1.5 mm, the bubbles are broken and aggregate to form large bubbles. There is a possibility that it may become dented or dented, and that the peeling of the coating may occur depending on the type of the rustproof coating of the reinforcing steel.

If the frequency is less than 3000 times / minute, the fluidity of the slurry does not improve so much, and if the vibration duration is 5 seconds or less, the effect is not sufficient. Even if the frequency is more than 10,000 times / minute, the vibration does not occur. Even if the duration of the above becomes 20 seconds or more, both have the same disadvantages as in the case where the amplitude is increased.

〔Example〕

 Examples will be described below.

Example 1 The raw material formulations used in this example are the following general ones.

Silica powder 50 parts by weight Quick lime powder 5 parts by weight Ordinary Portland cement 25 parts by weight ALC repeats 20 parts by weight Aluminum powder 0.07 parts by weight Water 70 parts by weight Among the above materials, the raw materials other than aluminum powder are mixed and stirred 46
Add aluminum powder to the slurry at ℃, stir for 30 seconds, and arrange the reinforcing bars. Size 6.0mL × 1.5mW × 0.6mH
Was poured into the mold. Bridge holding the support bar engaged with the reinforcing bar with a vibration of 0.5 mm amplitude and a frequency of 5000 times / min, when most of the foaming is almost complete 20 minutes after injection and the initial setting has not yet occurred. For 10 seconds. Then, it was semi-cured by a conventional method, cut with a piano wire, and aged in an autoclave to obtain an ALC panel having a thickness of 10 cm.

As a result of cutting the product and observing the area around the reinforcing bar, there was little turbulence of bubbles above the uppermost main bar, no cavities were observed, and almost no cavities below the lowermost bar were also observed. Further, when the adhesive force between the uppermost main bar and the lowermost main bar and ALC was measured, all showed satisfactory values. The results are shown in Table 1.

The adhesive force between the reinforcing bar and ALC was measured by the following method.

Adhesive force measurement method Cut a test piece measuring 5 cm in length and width and 15 cm in length so that the reinforcing bar is in the center of the length direction, place it on the Amsler tester so that the reinforcing bar is vertical, and press the center of the reinforcing bar. Apply the load to obtain the maximum rebar evacuation load and calculate the adhesive force per rebar surface area.

Comparative Example 1 The same raw material slurry as in Example 1 was poured into a mold, and the support rod was made into a product without any vibration.

Examples 2 to 8 The same raw material slurry as in Example 1 was used, and various vibration amplitudes, vibration frequencies, vibration durations, and vibration start times were tested.

Comparative Examples 2 to 5 The same raw material slurry as in Example 1 was used, and the test was conducted on the assumption that the vibration applied to the supporting rod included a portion other than the predetermined range.

The results of Examples 2-8 and Comparative Examples 1-5 are shown in Table 1. Write together.

〔effect〕

As described in detail above, according to the method of the present invention, the conventional foaming agent is added to foam the ALC raw material slurry in the mold to produce ALC. Poor appearance due to disorder, rebar and ALC
The problem such as insufficient adhesion to and can be solved by giving vibration to the reinforcing bar before the initial setting occurs, and the quality can be improved, so that there are great practical effects.

Claims (1)

[Claims] 1. A method for manufacturing an ALC in which reinforcing bars are embedded, in which a raw material slurry containing a foaming agent is injected into a mold in which reinforcing bars are arranged and fixed by a supporting rod, foaming is almost completed, and initial condensation occurs. Before the support rod had an amplitude of 0.2-1.
After applying a vibration of 5 mm and a vibration frequency of 3000 to 10000 times / minute for 5 to 20 seconds, high temperature and high pressure steam curing is performed.
LC manufacturing method.