JPH0822544B2 - Method for manufacturing lightweight foam concrete - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing lightweight cellular concrete, and particularly to a method for producing lightweight cellular concrete reinforced with reinforcing bars.

[Conventional technology]

Conventionally, when manufacturing lightweight cellular concrete, for example, reinforcing bars having a so-called U-shaped structure in which reinforcing rods are used vertically and horizontally, and a mat in which the intersections are welded is used and a spacer or the like is attached between the two mats. Muscles are used.

Each of these reinforcing bars has a structure having two mat portions and a spacer at the center between the two mat portions. Then, by engaging the spacer of the reinforcing bar and the reinforcing bar support (9), the reinforcing bar was held at a predetermined position in the mold. According to this holding method, as shown in FIG. 4, according to this holding method, the reinforcing bar support (9) causes the reinforcing bar (2) to move to the form (3).
Hold vertically inside. In this way, when the composition for lightweight cellular concrete is injected into the mold (3) in which a large number of reinforcing bars (2) are held and cured, heat is generated due to a hydration reaction of the composition in the curing process. As a result, the thermal expansion of the large bubbles and the like causes the cured body to tear above the portion close to the adjacent reinforcing bar (2) as shown in FIG.
Shown by 5 in the figure. ) Is easy to occur. In Fig. 5, the reinforcing bar (1
The spacer between the mat parts (1) consisting of 1) is not shown. The lightweight cellular concrete block (12) hardened in the mold has the support rod (9) removed at an appropriate time of hardening, and then, as shown by 10 in FIG. 5, by a cutting material such as a piano wire, The peripheral part of the mold, the upper surface part, and the lower bottom part are cut and removed, and also cut into individual panels, and then autoclaved to obtain product panels. However, the part where the tearing phenomenon occurs remains on the product panel and is apt to become a defect of the product. This drawback is also found in lightweight cellular concrete that uses a foaming agent such as a surfactant, but especially in lightweight cellular concrete that uses metallic aluminum as a foaming agent,
This defect is likely to occur because the volume expansion due to the foaming of aluminum simultaneously occurs with the heat generation due to the curing of the lightweight cellular concrete composition.

[Problems to be solved by the invention]

The object of the present invention is to produce a tear phenomenon that occurs on the upper surface of the reinforcing bar without significantly changing the method of the above-mentioned conventional lightweight cellular concrete manufacturing method in which a large number of reinforcing bars are vertically held in a formwork. It is to provide a method that does not prevent it.

[Means for solving problems]

According to the present invention, a large number of reinforcing bars (2) composed of two mat portions (1) (1) are held vertically at predetermined positions in a mold (3) to form a mold (3). In a method for producing a lightweight cellular concrete in which a composition for a lightweight cellular concrete is poured and cured, the composition for a lightweight cellular concrete is poured into a mold (3), and then the lightweight cellular concrete is filled in the mold (3). Reinforcing bar (2) from the top of composition (7) for
In the method for producing lightweight cellular concrete, there is a treatment step of inserting the insert body (4) at a central position between the two mat portions (1) and (1) and pulling it out.

There are various specific examples of the reinforcing bar having two mat portions used in the present invention. For example, the reinforcing bar having the double reinforcing structure or the U-shaped reinforcing structure as described above is used. First
The figure schematically shows a cross section at a position where there are no commonly used spacers or reinforcing bar supports, but a large number of reinforcing bars (2) consisting of two mat parts (1) (1) It is held vertically in the frame (3). Reference numeral 8 in the figure indicates a cutting position when cutting into individual panels.

The composition for lightweight cellular concrete may be a composition used in the production of ordinary lightweight cellular concrete, and may be a composition containing a foaming agent for foam formation or a composition containing a foaming agent. The composition other than the bubble forming agent is composed of, for example, cement, lime, silica stone and water.
Among them, the composition for lightweight cellular concrete to which a foaming agent such as metallic aluminum is more likely to be cracked unless the present invention is applied is a preferable composition of the present invention.

In the present invention, after pouring these compositions into a mold, the insert (4) is pierced from the upper surface of the composition for lightweight cellular concrete (7) filled in the mold (3). May be a plate or a rod, but a rod is generally preferred. The rod-shaped body may be a prism or a round bar. The thickness of the plate or prism and the diameter of the round bar (hereinafter referred to as thickness) vary depending on the conditions of the composition for lightweight cellular concrete to be used, but generally 2 to 20 m / m, preferably 5 to It is of 15 m / m.

Generally, if a thin one is used, it is necessary to increase the number of uses, and if it is too thick, it causes deterioration of the product associated therewith, which tends to be not preferable. When the insertion depth is made shallow, the same effect as deep insertion can be obtained by inserting two or more inserts between the two mats. The insertion position of the insert body (4) is the central portion of the two mat portions (1) (1) of the reinforcing bar (2) in the form (3) as shown in FIG. The central part is a position at least 5 m / m away from the inside of the mat part (1), and a preferable position is 1/3 to 2/3 of the distance between the two mat parts (1) (1). And the most preferable is near the equidistant position between the mat portions. In addition, when there is a space between the adjacent reinforcing bars, it is preferable to pierce the insert body also during this, but in general, the distance between the adjacent reinforcing bars is
It is small compared to the distance between the mat parts in the reinforcing bar, and it is not necessary to poke the insert body between them.

The depth of insertion from the upper surface is usually 10 to 300 m / m, and the insertion is preferably performed at least up to the upper surface position of the reinforcing bar. Especially 10 to 100m below the position of the reinforcing bar at the top of the reinforcing bar
It is preferable to insert / m. If it is inserted deeper than this, there is a risk that defects will occur in the product.

Furthermore, the timing of the process of inserting and pulling out the insert is after the composition for lightweight cellular concrete injected into the form has reached the upper part of the reinforcing bar, and after too much curing, the product is defective. May occur. Generally, a few minutes to 1 after injection of the composition for lightweight cellular concrete
It is preferable to process in time, especially from 20 minutes to 40 minutes after injection.
It is preferably up to minutes. The insertion may be stopped while it is butt-inserted, may be moved laterally along the reinforcing bar, and the insertion and withdrawal may be repeated.

As shown in FIG. 2, this insert body (4) can be moved along the mold by assuming that a large number of insert bodies (4) are provided on one mounting rod in accordance with the position of the reinforcing bar. Good
As shown in FIG. 3, the frame-like body (6) may be vertically moved as a frame-like body (6) having a large number of mounting rods at a predetermined pitch, for example, 30 to 100 mm pitch.

Thus, at the central position between the two mat parts (1) (1) of each reinforcing bar (2) from the upper surface of the composition for lightweight cellular concrete (7) filled in the formwork (3). When the insert body (4) is subjected to a process of inserting and pulling it out, surprisingly, the phenomenon in which the cured body is torn off almost disappears, although its function and effect are unknown.

〔Example〕

 Next, the present invention will be described in more detail with reference to examples.

Example 1 A composition for lightweight cellular concrete comprises 100 parts by weight of a mixture comprising 30% by weight of cement, 8% by weight of quick lime, 35% by weight of silica, 2% by weight of gypsum, and 25% by weight of crushed debris of lightweight cellular concrete. 70 parts by weight of water and 0.06 parts by weight of metallic aluminum powder were added and kneaded, and the composition for lightweight cellular concrete immediately after the kneading was mixed as shown in FIG.
A large number of reinforcing bars having a distance between the mat parts of 150 m / m were poured into a mold (3) vertically held.

The insert (4) used has a diameter, as shown in FIG.
The mounting rod holding the 5m / m insert (4) at 100m / m intervals
A frame-like body (6) attached at 100 m / m intervals (distance 1 in the figure) was used. 20 minutes after starting the injection of the insert (4) into the composition for lightweight cellular concrete (at this time, the composition for lightweight cellular concrete reached the upper part of the reinforcing bar) to 40 minutes, With the insert in the center of the two mats, the depth from the top of the composition for lightweight cellular concrete to 50 m / m below the top end of the reinforcing bar (2) (the depth at this time is the top of the mortar). More than 200m / m depth)
40 minutes after the injection, it was pulled out.
As a result, there was no occurrence of the tearing phenomenon as shown in FIG.

When the treatment with the insert was not performed, the occurrence rate of this tear phenomenon (the ratio of the places where the tear phenomenon occurred between the adjacent reinforcing bars) was 50%.

[Example 2] 60 parts by weight of silica powder, 10 parts by weight of quicklime powder and 30 parts by weight of ordinary Portland cement were mixed, 70 parts by weight of water was added to 100 parts by weight of the mixture, and further aluminum metal powder was added.
0.07 parts by weight was added and mixed to obtain a lightweight cellular concrete composition. This was poured into the mold as in Example 1. The insert (4) used is that shown in FIG.
A rod-shaped composition object (4) having a diameter of 10 m / m is held at 100 m / m intervals, and after starting the injection of the composition for lightweight cellular concrete into the formwork, 30 minutes to 5 minutes, the reinforcement bar (2) At the intermediate position between the two mats, pierce the tip of this insert (4) from the uppermost position of the reinforcing bar (2) to a depth of 50 m / m, and repeat the process of pulling it out to reinforce it. Moved along the muscle.

Even in this result, the tearing phenomenon as shown in FIG. 5 did not occur. Further, even if the curing speed was increased by heating from the mold, the tearing phenomenon did not occur. By increasing the curing speed in this way, the rotation rate of the mold was increased and the productivity of lightweight cellular concrete could be improved.

〔The invention's effect〕

According to the present invention, it is possible to prevent the occurrence of defects (breakage phenomenon) seen in conventional products while maintaining the feature of the conventional technique of molding a large number of reinforcing bars while holding the mat portion vertically.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, FIGS. 2 and 3 are perspective views showing an entire assembly assembly apparatus used in an embodiment of the present invention, and FIG. It is sectional drawing which shows the support state of a reinforcement, FIG. 5 is sectional drawing of the product obtained by a prior art. 1 ....... mat part, 2 .... reinforcing bar 3 .... form, 4 ....... inserted body 5 .... defect (breaking phenomenon) 6 .... frame-like body 7 .... for lightweight cellular concrete Composition 8. …… Scheduled cutting position 9. …… Reinforcing bar support (supporting rod) 10. …… Cutting position, 11. …… Reinforcing bar 12. …… Lightweight cellular concrete block

Claims (1)

[Claims] 1. A large number of reinforcing bars (2) composed of two mat portions (1) (1) are held vertically at predetermined positions in a mold (3) to form a frame ( 3) In the method for producing a lightweight cellular concrete, which comprises injecting the composition for a lightweight cellular concrete into the interior and hardening the composition, the lightweight composition for a lightweight cellular concrete is injected into the mold (3), and then lightly filled in the template (3). A treatment step in which the insert body (4) is inserted from the upper surface of the composition for cellular concrete (7) at the central position between the two mat portions (1) and (1) of each reinforcing bar (2), and is pulled out. A method for producing lightweight cellular concrete, characterized in that