JP4981475B2 - Method for producing lightweight cellular concrete panel - Google Patents

Description

  The present invention relates to a method for producing a lightweight cellular concrete panel (hereinafter referred to as ALC panel) by foaming a raw material slurry in a formwork provided with reinforcing bars.

In general, when manufacturing an ALC panel, reinforcing reinforcing bars in which reinforcing bars are assembled in a lattice shape are arranged in a mold, and aluminum powder, an aqueous surfactant solution, or the like is added to a mixture of calcareous raw materials and siliceous raw materials. The raw material slurry is placed in the mold, the aluminum powder is foamed to form bubbles, and the raw material slurry is hardened while volumetrically expanding. Then, the semi-cured body after foaming is removed from the mold, sliced to a predetermined thickness, and then autoclaved , and the surface layer portion of the main cured panel is cut out to complete the ALC panel having the required dimensions.

By the way, in the foaming process of the raw material slurry, when the upper surface of the slurry passes through the uppermost reinforcing bar of the reinforcing reinforcing bars, the reinforcing bars are crushed by bubbles, and the gas emitted from the bubbles gathers on the upper side of the uppermost reinforcing bars. To form a foamed nest (coarse cavity). As shown in FIG. 7A, the foamed nest 4 grows to a height of about 70 mm to 80 mm from the upper surface of the uppermost reinforcing bar 3 and adversely affects the strength of the cut surface 51 a of the ALC panel 51 . When the ALC panel 51 is cut in the extending direction of the reinforcing bar 3, as shown in FIG. 7 (b), the foaming nest 4 is exposed to the fore edge surface 51b, the appearance of the ALC panel 51 is lowered, and the commercial value is lowered.

Conventionally, the following methods have been proposed to suppress the generation of this type of foamed nest.
Patent Document 1: A method in which a rod-shaped vibrating body is inserted into a raw material slurry near the uppermost reinforcing bar and rotated or horizontally moved to reduce the viscosity of the slurry and allow excess gas to escape upward.
Patent Document 2: A method of injecting water or an aqueous solution into a raw material slurry near the uppermost rebar, delaying the viscosity increase of the slurry, and allowing excess gas to escape upward.
Patent Document 3: A method in which air is blown onto the surface of a raw material slurry, and the surface layer portion of the slurry is waved and stirred to uniformly expand the slurry.

Patent Document 4: A method in which raw material slurry immediately after placement is vibrated with a rod-like vibrator, and coarse bubbles entrained during slurry kneading are defoamed from the upper surface of the slurry.
Patent Document 5: A method in which the reinforcing bars are vibrated and the air bubbles mixed when the slurry is placed are discharged before the foaming agent in the raw material slurry starts foaming.
Patent Document 6: A method of vibrating a bottom plate of a mold in the initial stage of foaming in which a small amount of foaming agent is partially foamed to defoam air bubbles entrained during slurry placement.

JP-A-8-72035 Japanese Unexamined Patent Publication No. 7-277854 Japanese Patent Laid-Open No. 9-110548 JP-A-58-20767 JP-A-2001-232622 JP-A-60-141683

However, the conventional method has the following problems.
Patent Document 1: Since a rod-shaped vibrating body is inserted into a slurry, bubbles specific to ALC are crushed by vibration, and the crushed bubbles form new coarse bubbles above the uppermost reinforcing bars.
Patent Document 2: Since the water injection tube is inserted into the slurry, normal bubbles are crushed by the tube, and coarse bubbles are generated around the tube.
Patent Document 3: Since the stirring action by air is limited to the slurry surface layer portion, the growth of the foaming nest cannot be suppressed above the uppermost reinforcing bar at a deeper position.

Patent Document 4: Coarse bubbles entrained during slurry kneading can be defoamed by vibration immediately after the slurry is placed, but coarse bubbles generated by the slurry itself can be removed even if the slurry at a stage where the viscosity is increased is vibrated. Difficult to foam.
Patent Document 5: Similarly, it is difficult to discharge coarse bubbles even if vibration is applied to the slurry at a stage where condensation has progressed and the viscosity has increased via a reinforcing bar.
Patent Document 6: Since vibration applied to the bottom plate of the formwork is greatly damped in the vicinity of the uppermost reinforcing bar, the growth of the foaming nest generated after the upper surface of the slurry exceeds the uppermost reinforcing bar cannot be suppressed.

  An object of the present invention is to provide a method for manufacturing an ALC panel that solves the above-described problems and can effectively suppress the formation of a foaming nest above the uppermost reinforcing bar without hindering the growth of bubbles unique to ALC. .

In order to solve the above-mentioned problems, an ALC panel manufacturing method of the present invention includes silica particles, cement and quicklime particles and aluminum powder in a formwork provided with reinforcing reinforcing bars , and includes aluminum powder and alkaline substance. The raw material slurry that generates ALC-specific air bubbles is foamed in response to the reaction with the material, and the formwork is shaken during a rocking period including at least a part of time after the upper surface of the raw material slurry exceeds the uppermost reinforcing bar of the reinforcing steel bar. swings in dynamic acceleration ^{0.01m / s 2 ~0.1m / s 2} , delaying coagulation of the raw material slurry by the swing, which comprises suppressing the formation of foam nest in the upper top rebar . By swinging the formwork in this way, the raw slurry can be liquefied and the condensation thereof can be delayed, so that bubbles can be distributed in the liquefied slurry and can be made difficult to contact with the uppermost reinforcing bar. Generation of a foaming nest on the upper side of the uppermost reinforcing bar can be suppressed.

[1] Oscillation distance of mold frame Here, the oscillation distance of the mold frame is not particularly limited, but is preferably 0.3% to 10% of the length of the mold frame in the oscillation direction. The size of the mold is not particularly limited. For example, a standard mold used in an actual manufacturing facility has a length of about 6000 mm and a width of about 1500 mm. The distance when the mold is swung in the length direction is about 18 mm at 0.3% and about 600 mm at 10%. The distance when swinging in the width direction is about 4.5 mm at 0.3% and about 150 mm at 10%.

  When the rocking distance of the mold is 0.3% to 10% of the length in the rocking direction, the whole raw material slurry shakes greatly in the mold, the slurry condensing is delayed, and bubbles are uniformly distributed in the slurry. It becomes easy to do. When the rocking distance is less than 0.3%, the moving distance of the slurry is insufficient, the condensation progresses, the flowability of the bubbles is lowered, and the foamed nest tends to be generated. When the rocking distance exceeds 10%, the effect of delaying the setting does not change, but the rocking equipment becomes large-scale. The rocking distance of the mold is more preferably 1% to 5% in that the setting can be effectively delayed with a small rocking equipment.

[2] Swing direction of mold frame The swing direction of the mold frame is not limited to a specific direction, and it is sufficient that the raw slurry moves within the mold frame. The length direction, the width direction, the diagonal direction, and the vertical direction of the mold frame Any of the directions may be used, and the rotation may be performed in a horizontal plane.

[3] formwork rocking acceleration of the swinging acceleration formwork are preferably ^{0.001m / s 2 ~0.2m / s 2} . In general, the raw material slurry placed in the mold is in a state in which mixing is resisted by the frictional force between particles such as silica, cement, and quicklime. In this state, swinging the formwork and shaking the slurry breaks the contact between the particles, and water is evenly distributed in the slurry. Therefore, the slurry is liquefied and the setting speed of the slurry is that of natural foaming. Than can be delayed. However, if the swing acceleration of the mold is less than 0.001 m / s ² , the slurry follows the swing of the mold, the particles keep in contact with each other, and condensation progresses, so that the viscosity of the slurry is less likely to decrease. Tend to be.

On the other hand, the raw material slurry generates ALC-specific bubbles with the reaction between the aluminum powder and the alkaline substance. Since these bubbles are very fragile to shocks and vibrations, we want to keep the impact on the slurry as low as possible during the bubble growth process. When the rocking acceleration of the mold exceeds 0.2 m / s ² , normal bubbles are easily destroyed by impact. In that it can reliably prevent and foam breaking to lower the slurry viscosity, the rocking acceleration of the mold is because more preferably in the range of ^{0.01m / s 2 ~0.1m / s 2} , the range in the present invention Adopted .

[4] Mold swinging period The mold swinging period may be only a partial period after the upper surface of the raw material slurry exceeds the uppermost reinforcing bar of the reinforcing reinforcing bars, or in addition to this partial period and before that. A predetermined period before or after may be included.
This partial period is a period from when the upper surface of the raw material slurry exceeds 20 mm from the uppermost reinforcing bar to the position where it is 10 mm lower than the foaming end height (in this specification, suppression of the foaming nest due to oscillation during the same period) It is preferably a period in the range of at least 30 mm selected from the “optimum period” since the effect is best exhibited. This optimum period corresponds to the period during which the foamed nest grows when the raw material slurry spontaneously foams, and is defined because it is most effective to swing during this period. Next, it will be described in detail for the beginning and the end.

[4-1] About the beginning of the optimum period The generation time of the foaming nest varies depending on the composition of the raw material slurry and the height of the foaming end. Usually, as shown in FIG. After exceeding the reinforcing bar 3, the air bubbles collided with the reinforcing bar 3 and start to form a foamed nest 4 immediately above the reinforcing bar 3. However, in the foaming process before the upper surface of the slurry 2 exceeds the uppermost reinforcing bar 3 by 20 mm, the viscosity of the slurry 2 is low, and the internal bubbles rising together with the slurry 2 do not break even when contacting with the reinforcing bar 3. Therefore, the foaming nest 4 is difficult to occur. Therefore, at this stage, even if the mold is swung, the meaning of foaming nest suppression is weak. Therefore, the start of the optimum period is when the upper surface of the slurry 2 exceeds the uppermost reinforcing bar 3 by 20 mm.

[4-2] End of Optimal Period Foaming nests grow as the raw material slurry congeals, that is, as the slurry viscosity increases. As shown in FIG. 1 (b), when the upper surface of the slurry 2 further rises, the slurry viscosity around the uppermost reinforcing bar 3 rises, bubble breakage progresses, and the foam nest 4 continues to grow. As shown in FIG. 1C, when the upper surface of the slurry 2 approaches the foaming end height (H), the viscosity of the slurry around the uppermost reinforcing bar 3 becomes considerably high, so that foam breaks up, 4 is formed as a large gap 4 a on the uppermost reinforcing bar 3. Thereafter, the slurry 2 slightly rises over a relatively long time and finishes foaming. Even if the mold is swung just before the end of foaming, the viscosity of the slurry around the uppermost reinforcing bar 3 is unlikely to decrease, so it is less meaningful to suppress the foaming nest. Therefore, the end of the optimum period is when the upper surface of the slurry 2 reaches a position 10 mm lower than the foaming end height (H).

[4-3] Range of a partial period selected from the optimal period If the formwork is swung in a partial period appropriately selected from the above optimal periods, a foaming nest suppression effect can be obtained. The range of the period (range as viewed from the progress of the upper surface of the slurry) is preferably 30 mm or more, and more preferably 50 mm or more. When the mold is swung only during a period of less than 30 mm, not only the portion that can suppress the foaming nest but also the portion that cannot be suppressed tends to be generated. On the other hand, the upper limit of the same range is limited by how much the foam end height of the slurry is higher than the uppermost reinforcing bar. For example, when the upper limit is 140 mm, the same range can be set up to 110 mm. In this case, the same range is up to 40 mm.

[5] Continuous rocking and intermittent rocking During the partial period, the mold may be rocked continuously without resting, or may be rocked intermittently by setting a pause time. However, in the case of intermittent rocking, it is desirable that the total time of the rocking is 50% or more of a part of the period, and that the pause time of the rocking is 2 minutes or less. When the total rocking time is less than 50%, compared with the case of rocking continuously, the aggregation of the slurry proceeds and liquefaction tends not to proceed. Further, if the swinging of the formwork is stopped for more than 2 minutes, the condensation of the slurry proceeds, and it becomes difficult to suppress the increase in viscosity.

  According to the ALC panel manufacturing method of the present invention, the mold is swung during a rocking period including at least a partial period after the upper surface of the raw material slurry exceeds the uppermost reinforcing bar. Liquefaction is delayed and the fluidity of bubbles is increased. For this reason, air bubbles are uniformly distributed in the slurry and are less likely to come into contact with the uppermost reinforcing bar. Therefore, it is possible to suppress the generation of the foaming nest in a timely manner without crushing the air bubbles peculiar to ALC, and it is possible to manufacture an ALC panel having high appearance and strength and having a high commercial value.

  As shown in FIG. 2, the manufacturing method of the ALC panel according to the embodiment of the present invention foams the raw slurry 2 in the mold 10 in which the reinforcing reinforcing bars 11 are arranged, and the upper surface of the raw slurry 2 is the reinforcing reinforcing bars 11. The mold 10 is swung during a rocking period including at least a partial period in a range of 30 mm or more selected from an optimal period from exceeding the uppermost reinforcing bar 3 by 20 mm to reaching a position 10 mm lower than the foaming end height, The settling of the raw material slurry 2 is delayed by swinging, and the formation of the foaming nest on the upper side of the uppermost reinforcing bar 3 is suppressed.

  Next, the said manufacturing method is demonstrated in detail based on an Example. In this example, three ALC panels 1 were manufactured using an experimental mold 10 as shown in FIGS. The mold 10 has a length of 1000 mm, a width of 350 mm, and a height of 700 mm. The ALC panel 1 has a length of 840 mm, a width of 600 mm, and a thickness of 100 mm. The ALC panel 1 is manufactured with the length direction being horizontal and the width direction being vertical.

  In manufacturing this panel 1, first, three sets of reinforcing bars 11 were set inside the mold 10. Each reinforcing bar 11 was assembled in a lattice pattern with a main bar 12 extending horizontally in the length direction of the mold 10 and a secondary bar 13 extending vertically in the height direction of the mold 10 (the width direction of the panel 1). Two reinforcing bars are connected to each other by a connecting bar 14 extending in the width direction of the mold 10 (the thickness direction of the panel 1) to form a cage shape. The main muscle 12, the secondary muscle 13, and the connecting muscle 14 are 5 mm in diameter.

  Then, three sets of reinforcing bars 11 were suspended from the mold frame 10 via the plate 16 by the rod pins 15 at equal intervals. At this time, the foaming end height of the raw slurry 2 is set to 660 mm, and the foaming end height is 140 mm higher than the uppermost reinforcing bar 3 of the main reinforcing bars 12, that is, the uppermost reinforcing bar 3 is in the formwork. The height of the rod pin 15 was adjusted with the adjusting tool 17 on the plate 16 so as to be 520 mm higher than the bottom surface of 10, and the reinforcing steel bars 11 were set.

  Next, the raw material slurry 2 was placed inside the mold 10. In Examples 1 to 4 and Comparative Examples 1 to 5 below, as raw material slurry 2, 40 parts by mass of silica powder, 15 parts by mass of cement, 10 parts by mass of quicklime powder, 5 parts by mass of gypsum, 20 parts by mass of crust, crushing of ALC A mortar slurry in which 70 parts by mass of water and 0.06 parts by mass of aluminum powder (foaming agent) were added to the solid content of 10 parts by mass of the powder and kneaded sufficiently with a mixer was used.

  Subsequently, the raw material slurry 2 was foamed in the mold 10 provided with the reinforcing reinforcing bars 11. In this foaming step, the methods of Examples 1 to 4 that swing the mold 10 and the methods of Comparative Examples 1 to 5 that do not swing the mold 10 were applied. Then, after the foaming and volume expansion of the slurry 2 are completed, an ALC semi-cured body 2 having a height of 660 mm is obtained. Thus, three ALC panels 1 were completed.

<Comparative Example 1>
In Comparative Example 1, a method was adopted in which the mold 10 was kept stationary over the entire foaming period and the raw slurry 2 was naturally foamed. And as shown in FIG. 5, the foaming height and the toughness (viscosity) of the raw material slurry 2 were measured during the foaming period. In measuring the strength, an aluminum scale 21 having a diameter of 4 mm and a length of 400 mm as shown in FIG. 6 is used. When this is gently submerged in the raw slurry 2 and stopped naturally, The length protruding from the upper surface was measured to obtain the penetration value (mm).

  Further, as shown in FIG. 7A, the completed ALC panel 51 is cut in the vertical direction at an arbitrary position in the width direction, and the upper end of the panel 51 is turned in the horizontal direction as shown in FIG. 7B. The foamed nest 4 was observed in the longitudinal section 51a and the transverse section 51b. As a result, as shown in FIG. 7A, the foamed nest 4 stood up to a height of about 70 mm from the uppermost reinforcing bar 3 in the longitudinal section 51a.

  Regarding the cross section 51b, as shown in FIG. 7B, the three ALC panels 51 were cut so that the cover height T from the uppermost reinforcing bar 3 was 20 mm, 30 mm, and 70 mm. And the score X was evaluated based on the following reference | standard regarding the length X of the foaming nest 4 longest in the extending | stretching direction of the uppermost reinforcing bar 3 among the foaming nests 4 which appeared on the cut surface. The evaluation results are shown in Table 1.

Evaluation criteria X> 20 mm 4 points 20 mm ≧ X> 10 mm 3 points 10 mm ≧ X> 5 mm 2 points 5 mm ≧ X> 2 mm 1 point No foaming nest 0 points

<Example 1>
In Example 1, as shown in FIG. 4, the mold 10 is placed on the carriage 18, and after the upper surface of the raw material slurry 2 exceeds the uppermost reinforcing bar 3, the mold 10 together with the carriage 18 is placed on the floor surface by the tester. Rocked up. The rocking conditions are as follows. In an actual manufacturing facility, the above-mentioned large formwork can be placed on a moving body such as a roller conveyor and can be driven by a swing device using a motor or a fluid pressure cylinder.

Oscillating condition Oscillating period: A period from when the upper surface of the raw material slurry 2 exceeds the uppermost reinforcing bar 3 by 20 mm until it reaches a position 20 mm lower than the foaming end height (see FIG. 2)
Oscillation time: 100% of oscillation period (continuous oscillation without rest for about 20 minutes)
Oscillating direction: horizontal direction perpendicular to the extending direction of the uppermost reinforcing bar 3 (width direction of the mold 10)
Oscillating distance: About 5% (about 17.5 mm) of the width of the mold 10
Swing acceleration: 0.07 m / s ²
Swing cycle: 120 cycles per minute

  Similarly to Comparative Example 1, the foaming height and toughness of the slurry 2 were measured during the foaming period of the raw slurry 2. The measurement results are shown in FIG. Further, as shown in FIG. 9, the completed ALC panel 1 was cut in both the vertical and horizontal directions, the formation state of the foamed nest 4 in the vertical cross section 1 a and the horizontal cross section 1 b was observed, and evaluated in the same manner as in Comparative Example 1. The evaluation results are shown in Table 2.

  In the ALC panel 1 of Example 1, the three foamed nests 4 of the longitudinal section 1a were within a length of 25 mm or less from the uppermost reinforcing bar 3 (see FIG. 9a). As shown in Table 2, in the cross section 1b, the foam nests 4 having a length of 2-3 mm were scattered in the cover height of 20 mm, but the foam nests 4 did not appear above the panel 1, and the panel 2, As for 3, no foamed nest 4 appeared at any height (see FIG. 9b). When Table 1 is compared with Table 2, it can be seen that the formation of the foamed nest 4 is effectively suppressed by the swing of the mold 10.

  Next, the qualitative change given to the raw material slurry 2 by the swing of the mold 10 is confirmed based on FIGS. FIG. 10 shows the change over time in the foaming height of the raw slurry 2 in Comparative Example 1 and Example 1, and FIG. 11 shows the change over time in the strength. 10 and 11, the measurement data of Comparative Example 1 shown in FIG. 5 and the measurement data of Example 1 shown in FIG. 8 are cited.

  As shown in FIG. 10, the foaming height of the raw material slurry 2 changes in substantially the same manner between Comparative Example 1 and Example 1, and no significant difference is observed. Moreover, the temperature change of the raw material slurry was almost the same in Comparative Example 1 and Example 1. From this, it can be seen that the swing of the mold 10 does not affect the hydration reaction of the raw slurry 2. On the other hand, as shown in FIG. 11, the strength of the raw material slurry 2 shows a significant difference between Example 1 and Comparative Example 1 in terms of penetration value.

  The penetration value of Example 1 rises more slowly than the comparative example 1 from the beginning of the mold swing period, and a large difference is generated between the penetration value of the comparative example 1 at the end of the mold swing period. Further, the penetration value of Example 1 accelerates the rise immediately after the swing of the mold 10 is finished, and shows a value similar to that of Comparative Example 1 near the end of foaming of the raw slurry 2. From these facts, the rocking of the mold 10 does not affect the foaming period of the raw slurry 2 and the hardness of the ALC semi-cured product, and temporarily delays the setting of the slurry 2, thereby effectively producing the foamed nest 4. It can be seen that it can be suppressed.

<Example 2>
In Example 2, the same mold 10 as in Example 1 was used, and after the upper surface of the raw material slurry 2 exceeded the uppermost reinforcing bar 3, as shown in FIG. The three ALC panels were completed by rocking with distance, acceleration and period. And the completed ALC panel was cut | disconnected in the vertical and horizontal direction similarly to Example 1, and the production | generation state of the foaming nest in a vertical cross section and a cross section was observed and evaluated. The rocking conditions are shown below, and the evaluation results are shown in Table 3.

Oscillating condition Oscillating period: A period from when the upper surface of the raw material slurry 2 exceeds the uppermost reinforcing bar 3 by 20 mm until it reaches a position 20 mm lower than the foaming end height (see FIG. 2)
Oscillation time: 100% of oscillation period (continuous oscillation without rest for about 20 minutes)
Oscillating direction: direction that coincides with the extending direction of the uppermost reinforcing bar 3 (length direction of the mold 10)
Swing distance: about 3% of the length of the mold 10 (about 30 mm)
Swing acceleration: 0.03 m / s ²
Swing cycle: 60 cycles per minute

  In the ALC panel 1 of Example 2, almost the same as in Example 1, the three foamed nests in the longitudinal section of the panel were within a length of 25 mm or less from the uppermost reinforcing bar (see FIG. 9a). As shown in Table 3, in the cross section of the panel, the foamed nests 4 having a length of 2-3 mm were scattered in the cover height of 20 mm of the two panels (panels 1, 3), but the cover heights of 30 mm and 70 mm Then, no foaming nest appeared in any panel (see FIG. 9b). From the comparison between Table 2 and Table 3, it can be seen that the difference in the swinging direction of the mold 10 does not significantly affect the foaming nest suppression effect.

<Example 3>
In Example 3, the mold 10 was swung by two methods of the swing conditions of Example 1 that differed only in swing time.
In the first method, the mold 10 is intermittently rocked by setting a rocking pause time of less than 2 minutes at a time so that the total rocking time is 50% (about 10 minutes) of the rocking period. It moved.
In the second method, after ensuring a total rocking time of 50% or more, the mold 10 was rocked intermittently by setting a rocking pause time of 2 minutes or more at a time. FIG. 13 shows the effect of the change in the oscillation time on the strength of the raw slurry 2.

  As is clear from FIG. 13, both the first and second methods of Example 3 have the effect of slowing the penetration rate increase rate, that is, the progress of condensation, as compared with Comparative Example 1. However, in the case of the first method of the third embodiment, the penetration speed increases slightly compared with the first embodiment that is continuously swung. In the case of the second method according to the third embodiment, the penetration speed of the penetration value is further accelerated, particularly during the mold swing period. Therefore, in order to more effectively suppress the foaming nest, the total swing time of the mold 10 is 50% or more of the swing period, and the swing of the mold 10 is 2 minutes or more throughout the swing period. It can be seen that it is desirable not to pause continuously.

<Example 4>
In Example 4, the foaming end height of the raw slurry was set 140 mm higher than the uppermost reinforcing bar 3 as in Example 1, but among the swing conditions of Example 1, only three swing periods are different. The mold 10 was swung by this method.

  In the first method, the mold 10 is in a period in which the upper surface of the slurry is located 0 mm to 30 mm above the uppermost reinforcing bar 3 (a period from immediately after exceeding the uppermost reinforcing bar 3 until reaching a position 110 mm lower than the foaming end height). Rocked. In this case, as shown in FIG. 14 (a), in the panel vertical section 1a of the finished product, bubbles specific to ALC were uniformly distributed, but a foam nest 4 having a length of 55 mm was generated.

  In the second method, in a period in which the upper surface of the raw material slurry 2 is located 60 mm to 90 mm above the uppermost reinforcing bar 3 (a period from reaching the position where the uppermost reinforcing bar 3 exceeds 60 mm and 50 mm lower than the foaming end height). The mold 10 was swung. In this case, as shown in FIG. 14B, the state of the bubbles was good, and the foam nest 4 was shortened to a length of 40 mm.

  In the third method, in a period in which the upper surface of the raw material slurry 2 is located 60 mm to 120 mm above the uppermost reinforcing bar 3 (period from reaching the position 20 mm lower than the foaming end height after exceeding the uppermost reinforcing bar 3 by 60 mm). The mold 10 was swung. As a result, as shown in FIG. 14C, the state of the bubbles was good, and the foaming nest 4 was shortened to a length of 25 mm.

  Thus, in the present Example 4 in which the foaming end height is 140 mm higher than the reinforcing bar 3, the optimum period from when the slurry exceeds the uppermost reinforcing bar 3 to 20 mm until reaching the position 10 mm lower than the foaming end height. The ALC panel 1 excellent in both appearance and strength can be obtained by swinging the mold 10 during a partial period in the range of 30 mm or more (second or third method) selected from It was confirmed that the wider one is more preferable.

  In Comparative Examples 2 to 5 below, the influence of the conventional method for suppressing the foaming nest on the growth of the bubbles specific to ALC will be verified, thereby confirming the superiority of the method according to the present invention.

<Comparative example 2>
In Comparative Example 2, as shown in FIG. 15A, the upper part of the slurry 2 was agitated using a rake 23 during a period in which the upper surface of the raw material slurry 2 was positioned 90 mm to 115 mm above the uppermost reinforcing bar 3. . As a result, as shown in FIG. 15 (b), the foaming nest 4 was shortened to a length of about 10 mm, but a large number of large bubbles 6 that can be called foaming nests are wide on the upper side of the uppermost reinforcing bar 3. Had spread to the range. This is a result of crushing the air bubbles peculiar to ALC, which significantly reduces the commercial value.

<Comparative Example 3>
In Comparative Example 3, as shown in FIG. 16A, when the upper surface of the raw material slurry 2 reached about 30 mm above the uppermost reinforcing bar 3, water was sprayed with a watering device 24. As a result, as shown in FIG. 16B, the state of the bubbles appearing in the panel vertical section 1a was good, but the foaming nest 4 grew to the same length of about 70 mm as in Comparative Example 1, and was suppressed. The effect could not be confirmed.

<Comparative example 4>
In Comparative Example 4, as shown in FIG. 17 (a), the water 24 and the rake 23 are used together and water is sprinkled on the slurry 2 during the period in which the upper surface of the raw material slurry 2 is located 30 mm to 70 mm above the uppermost reinforcing bar 3. Stir while stirring. As a result, as shown in FIG. 17 (b), the length of the foaming nest 4 was shortened to about 50 mm, but a bubble-free portion 7 having a height of about 30 mm was generated on the upper side of the foaming nest 4 and further to the upper side. Coarse bubbles 6 were scattered. This is a result of the bubbles being crushed over a wide range by the synergistic action of watering and stirring, which worsens the appearance of the bubbles.

<Comparative Example 5>
In Comparative Example 5, as shown in FIG. 18 (a), during the period in which the upper surface of the raw material slurry 2 is positioned 90 mm to 120 mm above the uppermost reinforcing bar 3, the vibrator 25 attached on the plate 16 and the vibration plate 26 A vibration of about 200 Hz was applied to the reinforcing steel bar 11 through the rod pin 15. As a result, as shown in FIG. 18B, the state of the bubbles was almost good, but the foaming nest 4 was as long as 65 mm, and the suppression effect could not be confirmed. The upper end portion of the foamed nest 4 is not a coarse bubble generated as the slurry viscosity increases, but the bubble in the slurry that has passed through the uppermost reinforcing bar 3 is crushed by vibration during the vibration period by the vibrator 25. It is a coarse bubble.

  Unlike the comparative examples 2-5, the method by the rocking | fluctuation of the said Examples 1-4 does not use the means to contact the raw material slurry 2 of a foaming process directly. In addition, the swing method is not a method of physically destroying the foamed nest 4 that has been generated, but a method of suppressing the generation of the foam nest 3 by shaking the raw slurry 2. Therefore, the ALC panel 1 having an excellent appearance can be manufactured by uniformly distributing the liquefied slurry without crushing the bubbles unique to the ALC.

  The period during which the mold 10 is swung is not limited to the period of Examples 1 to 4, and the foaming end height is reached after the upper surface of the slurry exceeds the uppermost reinforcing bar 3 corresponding to the blending of the raw slurry 2. It can be set to any period until it reaches. Also, various swinging devices can be used, such as swinging the mold on a revolving rotary table. In addition, the swing condition of the mold 10 can be changed as appropriate without departing from the spirit of the present invention.

It is a schematic diagram explaining the production | generation mechanism of the foaming nest in an ALC panel. It is sectional drawing of the formwork which shows the outline | summary of the panel manufacturing method by this invention. It is a perspective view of a formwork and an ALC panel showing an example of the present invention. It is a longitudinal cross-sectional view of the formwork which shows the method of Example 1. FIG. 6 is a graph showing foaming height and strength of a raw material slurry in Comparative Example 1. It is a longitudinal cross-sectional view of a formwork which shows the method of measuring the tension of a slurry. It is a perspective view of the ALC panel which evaluates the method of the comparative example 1. 2 is a graph showing the foaming height and strength of a raw material slurry in Example 1. 1 is a perspective view of an ALC panel for evaluating the method of Example 1. FIG. It is a graph which shows the foaming height change of the slurry which evaluates the method of Example 1. FIG. 4 is a graph showing changes in the strength of a slurry for evaluating the method of Example 1; It is a front view of a formwork which shows the method of Example 2. FIG. 10 is a graph for evaluating the method of Example 3. 6 is a longitudinal sectional view of a panel showing a method of Example 4. FIG. It is a longitudinal cross-sectional view of the formwork and panel which show the method of the comparative example 2. It is a longitudinal cross-sectional view of the formwork and panel which show the method of the comparative example 3. It is a longitudinal cross-sectional view of the formwork and panel which show the method of the comparative example 4. It is a longitudinal cross-sectional view of the formwork and panel which show the method of the comparative example 5.

Explanation of symbols

1 ALC Panel 2 Raw Material Slurry 3 Top Rebar 4 Foam Foam 10 Formwork

Claims (6)

In the formwork in which the reinforcing steel bars are disposed, the raw material slurry containing silica, cement and quicklime particles and aluminum powder, and generating ALC-specific bubbles in response to the reaction between the aluminum powder and the alkaline substance, is foamed. at least including swinging period some time after providing the upper surface of the raw material slurry exceeds the top reinforcing steel reinforcement rebar, and swing the mold in the rocking acceleration 0.01m ^{/ s 2} ~0.1m ^/ s 2 A method for producing a lightweight cellular concrete panel, characterized in that the rocking of the raw material slurry is delayed by the swinging to suppress the formation of a foaming nest on the upper side of the uppermost reinforcing bar.   The method for producing a lightweight cellular concrete panel according to claim 1, wherein the rocking distance of the mold is 0.3% to 10% of the length of the mold in the rocking direction. The method for producing a lightweight cellular concrete panel according to claim 1 or 2 , wherein the swinging direction of the mold is the length direction or the width direction of the mold .   The partial period is a period in a range of 30 mm or more selected from an optimal period from when the upper surface of the raw material slurry exceeds 20 mm from the uppermost reinforcing bar to reach a position 10 mm lower than the foaming end height. A method for producing a lightweight cellular concrete panel according to claim 1.   The manufacturing method of the lightweight cellular concrete panel as described in any one of Claims 1-4 which rocks a formwork continuously in the said partial period.   The formwork is rocked intermittently during the partial period, wherein the total time of the rocking is 50% or more of the partial period, and the pause time of the rocking is 2 minutes or less. The manufacturing method of the lightweight cellular concrete panel as described in any one of 1-4.

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