JPH0353083B2 - - Google Patents

Description

[Detailed description of the invention]

BACKGROUND ART Conventionally, a method for manufacturing lightweight cellular concrete using metallic aluminum as a foaming agent has been known, for example, as seen in "Revised New Edition Concrete Engineering Handbook" published by Asakura Shoten. The foaming agent forms bubbles by reacting with an alkali such as cement and generating hydrogen gas. However, conventional lightweight cellular concrete produces large cavities on the surface and inside of the product, resulting in problems such as poor appearance. This is thought to be caused by air being entrained during injection of the raw material slurry into the mold or during the injection route. In order to avoid the formation of such coarse cavities, conventionally, after all the raw material slurry has been injected into the formwork, a rod-shaped vibrator is inserted into the formwork to vibrate the lightweight foam mortar inside the formwork. It is known that applying acceleration improves the appearance of the resulting product. However, according to this method, it is difficult to apply vibration uniformly over the entire area of the formwork, and bubbles are locally defoamed in the vicinity of the vibration, and even bubbles caused by the foaming agent are defoamed. Localized heavy mortar was unavoidable. In particular, if the vibration acceleration is applied for a long time, even the bubbles caused by the foaming agent are defoamed, resulting in partial heavyization, whereas if the vibration time is short, the generation of coarse cavities is unavoidable. Furthermore, even if a moderate amount of vibration is applied, the way the vibrations are transmitted differs between locations near and far from the vibration source, so the defoaming phenomenon of the mortar is partially different, so even in the resulting product, the bubble state is uniform. It wasn't something. The purpose of the present invention is to uniformly cause the defoaming phenomenon of mortar, that is, the phenomenon in which coarse bubbles are removed or become small bubbles and disappear, so that lightweight cellular concrete has the bubbles inherent in lightweight cellular concrete, and the bubbles are uniform. is to get the product. In the present invention, when a lightweight aerated concrete mortar slurry is continuously injected into a formwork from a mixer, an injection device with an open part at the top is provided separately from the mortar slurry injection pipe, and the mortar slurry is poured from the mixer through the mortar slurry injection pipe. This method of pouring mortar into lightweight cellular concrete is characterized by vibrating the pouring device itself which is continuously pouring into the formwork, and continuously pouring slurry while applying vibrational acceleration to the slurry due to the vibration. As described above, the first feature of the present invention is that lightweight aerated concrete is continuously injected from the mixer into the formwork while vibrating the inlet device itself, which is continuously injecting into the formwork from the mixer. This is an invention. The lightweight cellular concrete mortar slurry used in the present invention may be one that is used for the production of ordinary lightweight cellular concrete, such as crushed silica stone 60
10 parts of quicklime, 30 parts of ordinary Portland cement, 65 to 80 parts of water, and 0.055 to 0.075 parts of a foaming agent based on the solid matter. It is particularly preferable that the mortar viscosity at the time of pouring is about 500 to 750 g-cm as measured by a torque detection type Yamazaki rotational viscometer. Next, the present invention will be explained using the drawings. As shown in FIG. 1, the lightweight cellular concrete mortar slurry exemplified above is continuously injected into the formwork 5 from near the bottom of the formwork through the injection pipe 2 connected to the mixer 1. At this time, there is a valve in the middle of the injection pipe 2 for opening and closing, and by opening this valve, injection from the mixer 1 into the formwork 5 is started, and a predetermined amount of slurry is injected into the formwork 5. Close this valve. The injection port 3 that provides vibration, which is a feature of the present invention, is
It is provided between the injection pipe 2 and the mold 5. Inlet 3
has an open part at the top and comes with a vibrator 7. The vibrator 7 allows the lightweight aerated concrete mortar slurry, which is being continuously injected into the formwork 5 from the mixer 1, to defoam coarse air bubbles while passing through and staying in the injection port 3, and exit from the upper part of the injection port. Make it. Furthermore, by placing a wire mesh or the like in the injection port 7, it is possible to easily prevent foreign matter from entering the product. Regarding the shape of the lower tip of the inlet 7, it may have an inlet tip 6 (which can also be expressed as a multi-port type) as shown in FIGS. As shown in FIG. 4, it may be a long and narrow rectangular slit 9. In short, it is particularly preferable to have a structure that is located as close to the bottom plate of the formwork as possible, and that allows the flow of mortar to be horizontal to the bottom plate. Furthermore, since the inlet 3 including the inlet tip 6 is forced to vibrate by the vibrator 7, it is necessary to avoid a structure in which resonance becomes large or the inlet tip 6 is damaged due to this vibration. Furthermore, as shown in the drawings, it is particularly preferable to have a structure in which the injection port 3 is moved up and down by a lifting device 4. A spring, anti-vibration rubber, etc. are installed in the communication part of this lifting device to prevent vibrations from being transmitted to other parts. The reason why it is preferable to use the lifting device in this way is as follows. If the time from the start of mortar injection to the completion of injection is less than 1 minute, even if vibrations are transmitted to the mortar in the formwork from the tip of the injection port, the mortar near the injection port will hardly become heavier. However, if the time required for injection is long, it is possible to avoid the mortar near the injection port becoming heavier by gradually lifting the injection port upward as the level of mortar in the poured formwork increases. . The vibrator 7 applies a vibration acceleration of 1G or more, preferably 5G or more to the mortar in the injection port 3 during mortar injection, and a vibration frequency of 6000VPM or more.
More preferably, any material may be used as long as it can be applied with a frequency of 10,000 VPM or more. Generally, it is more preferable to make the vibrator variable speed in consideration of injecting mortar slurries having different viscosities. After the slurry injected according to the injection method of the present invention is cured and cured, the block is cut horizontally at a point 200 mm lower than the top of the block to measure the bubble diameter over the entire width and length. was measured, and the bubble entrainment coefficient was calculated. This bubble inclusion coefficient is
The bubble diameter is 3 mm or more and less than 5 mm, 5 mm or more and less than 7 mm,
Classify into 7 mm or more and less than 10 mm, 10 mm or more, count,
The values are calculated by multiplying by 16, 36, 64, and 100, respectively, and indicating the degree of bubble inclusion, and the larger the amount of large-diameter bubbles, the higher the value. As a comparative example, Table 1 shows the results of counting air bubbles when the conventional method etc. were followed and when the present invention was followed. In this table, the section 1m from the injection port is A, 1m
The section from 2m to 2m was classified as B, and the section longer than 2m was classified as C.

[Table] However, the first digit of the air bubble count was rounded off.
Further, the term "difference in absolute dry specific gravity" in Table 1 indicates whether each part becomes heavy due to vibration, and indicates a relative value when the absolute dry specific gravity of area C is set to 100.
110 means 10% higher specific gravity. According to this table, according to the present invention, there is little localized heaviness and a state in which bubbles are uniformly mixed over a wide area is achieved. Examples are given below. Example 1 In the injection apparatus shown in FIGS. 1 and 2, a mold 5 with an inner dimension of 4 m in length, a width of 1.8 m, and a height of 0.2 m was used, and the weight of each slurry was 70 parts of water is added to 100 parts of a mixture of 45 parts of crushed silica stone, 6 parts of quicklime, 27 parts of ordinary Portland cement, 20 parts of recovered waste from lightweight aerated concrete, and 2 parts of gypsum, and a foaming agent is added to the solid mixture. For,
0.007 part was added. Two vibrators 7 were used, and each vibrator 7 had a frequency of 1000 vibrations per minute, a vibration width of 100 μ, and a vibration acceleration of 5 G (actually measured values) at the injection port 3. The slurry stirred in the mixer 1 was poured into the mold 5 over a period of about 2 minutes. Vibration was continued by the vibrator 7 during this injection. After the injection was completed, the injection port 3 was moved upward by a hanger so as not to adversely affect the foaming and curing process. After curing the product obtained in this way, it was cut horizontally at a height of 150 mm from the bottom plate surface of the form, and the air bubble inclusion coefficient was measured at the center of the plate ^.
A good result of 16 hits was obtained. In this way, even in this example, a product with uniform air bubbles can be obtained without damaging the air bubbles inherent in lightweight cellular concrete. Example 2 Using the injection device shown in FIGS. 3 and 4, the mold 10 had an inner dimension of 4 m in length, 15 m in width, and 0.7 m in width.
As a slurry, water was added to 100 parts of a mixture of 45 parts of crushed silica stone, 6 parts of quicklime, 27 parts of ordinary Portland cement, 20 parts of recovered lightweight aerated concrete waste, and 2 parts of gypsum. 70
1 part and a blowing agent of 0.007 part based on the solid content was used. Two vibrators 7 were used, each with a frequency of 12,000 times/min and a vibration width when pouring mortar.
100μ, vibration acceleration 5G (actual measurement). The slurry stirred by the mixer 1 is poured into the mold 10 over a period of approximately 2.5 minutes. During the injection into the mold 10, the vibrator 7 continues to vibrate.
The tip 9 of the injection port 8 is a rectangular slit, and the inside of the rectangular slit has a slit structure divided at 5 cm pitches, so as to increase the contact area between the injection port 8 and the mortar. There is. Also, while pouring mortar, close the injection port 8 to 30
The tip of the injection port 8 is always positioned inside the mortar near the surface of the mortar in the formwork by lifting it every second to perform injection and vibration. When the mortar injection is finished, the injection port 8 device is moved upward so as not to affect the foaming and curing process of the mortar. After the product thus obtained is cured, it is removed from the bottom plate of the formwork.
Cut horizontally at a height of 450 mm and measure the air bubble entrainment coefficient. The product obtained in this example is not heavy and has the air bubbles inherent in lightweight cellular concrete, and the air bubble inclusion coefficient ^per square meter is 48 in all areas, making it a lightweight cellular concrete product with uniform air bubbles. Become. As shown in the above examples, according to the present invention, the lightweight cellular concrete product has no coarse air bubbles, does not become heavy, has the air bubbles inherent in lightweight cellular concrete, and has a uniform air bubble state. is obtained. That is, the (partial) heavy mortar found in the conventional mortar vibration method can be minimized to the extent that there is no practical problem. Further, since the vibration is applied during pouring into the mold, no additional time is required for applying the vibration. Furthermore, compared to the conventional method of vibrating the mortar after pouring it into the mold, the method of the present invention of vibrating the injection port can be implemented with simpler equipment.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of an apparatus applied to carry out the method of the present invention, and FIG. 2 is a plan view thereof. Third
The figure is a schematic side view showing another example of the apparatus used for implementing the present invention, and FIG. 4 is a plan view thereof. In the figure, 1 is a mixer, 2 is an injection pipe, 3
and 8 are the inlet device, 4 is the inlet lifting device, 5 and 1
0 is a mold, 6 and 9 are injection inlet tips, and 7 is a vibrator.

Claims (1)

[Claims] 1. When continuously injecting lightweight aerated concrete mortar slurry into the formwork from a mixer, an injection port device with an open part at the top is provided separately from the mortar slurry injection pipe, and the mortar slurry is poured from the mixer through the mortar slurry injection pipe into the formwork. A method for pouring mortar into lightweight aerated concrete, which is characterized by vibrating the pouring device itself, which is continuously pouring into the slurry, and continuously pouring the slurry while applying vibrational acceleration to the slurry.