JP2009137026A - Concrete producing apparatus using fine closed cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a concrete producing apparatus which is realistic and high in practicality and uses fine closed cells such as microbubbles effectively. <P>SOLUTION: The apparatus is equipped with admixture charging piping 12 for charging an admixture metered by an admixture metering tank 11 into a water metering tank 10 and water charging piping 13 for charging kneading water metered by a water metering tank 10 into a mixer 1. A microbubble generator 15 is made to intervene in the water charging piping 13. The fine closed cells such as the microbubbles are produced in the kneading water by making the kneading water incorporated with the admixture pass through the microbubble generator 15. The kneading water containing the detailed open cells and various residual concrete materials are kneaded by a mixer 1 to produce the concrete, so that the compression strength of the concrete can be increased, and the fine closed cells such as the microbubbles can effectively be used realistically and practically. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a concrete production apparatus for producing concrete by kneading various concrete materials such as coarse aggregate, fine aggregate, cement, kneaded water, and admixture.

  In recent years, it is known that microbubbles having a diameter of about 50 μm or less, called microbubbles, exhibit usefulness in various technical fields such as promoting the biological activity of organisms and having a bactericidal effect against bacteria and viruses. As a result, it has been featured in many media. By the way, although the mechanism of such fine bubbles has not yet been fully elucidated and is still in the research stage, as one of methods and apparatuses using these fine bubbles, for example, the fine bubbles can be converted into cement-based materials, Several proposals have been made for mixing or generating in kneaded water.

Patent Document 1 describes a method and an apparatus in which microbubbles are mixed in place of an admixture such as an AE agent, a foaming agent, and a foaming agent in producing cement milk, mortar, or concrete. Without using an admixture such as an AE agent, a large number of fine independent bubbles are uniformly distributed in the material to improve workability and frost resistance. Further, in Patent Document 2, air is injected in the middle of a flowing water pipe, and then pressurized with a pump, and then bubbles of 50 μm or less are generated by a mixer that breaks into ultrafine bubbles to produce fine bubble water. A method for producing kneaded water for hydraulic cement is described, and according to this, the use of this kneaded water accelerates hardening of the cement, saves cement, improves fluidity, durability and operation. It is said that it can improve the performance.
JP 2007-191358 A JP 2007-261242 A

  However, in any of the above-mentioned prior inventions, no demonstration data or the like is attached, and there are not a few unclear points, so it is difficult to say that it has been sufficiently established as a practical technique, and is still in the search stage. It is believed that there is.

  In view of the above points, an object of the present invention is to provide a practical and practical practical apparatus for producing concrete that effectively uses fine bubbles such as microbubbles.

  The present inventors pay attention to various usefulness possessed by microbubbles such as microbubbles, as in the above-described prior invention, etc., and if the one in which fine bubbles are generated in the kneaded water is used when producing concrete. The inventors have thought that the properties of the produced concrete, such as workability and frost resistance, may be improved. Under this assumption, after actually generating fine bubbles in the kneaded water, the admixture is mixed into the kneaded water, and the remaining concrete material such as coarse aggregate, fine aggregate, cement and the like are kneaded. The concrete test was made using this concrete, and a concrete test was attempted. However, due to the characteristics of the fine bubbles, the fine bubbles generated in the kneaded water disappeared only after a few minutes. Therefore, no matter how fast the work was done, fine bubbles could not be left until kneading. For this reason, there was almost no change in the properties of the concrete produced. .

  Therefore, the present inventors repeated trial and error, and as a result of intensive research, first, after mixing a predetermined amount of admixture into the kneaded water, fine bubbles were generated in the kneaded water containing the admixture, and this If concrete is produced by kneading the kneaded water containing fine bubbles and the remaining concrete materials such as coarse aggregate, fine aggregate, cement, etc., the life of the fine bubbles will be greatly increased by the effect of the admixture. It was found that it can be used in a state in which fine bubbles remain sufficiently in the kneaded water even when kneading (a state in which white turbidity has hardly disappeared). Then, when a concrete test was attempted on a specimen made of concrete manufactured in this way, although a clear reason is not clear, normal kneading water is used due to the influence of fine bubbles in the kneading water. It is confirmed that the compressive strength is greatly enhanced compared with concrete manufactured in this way, and this is sufficiently realistic and practical as a concrete manufacturing device that effectively uses fine bubbles. I thought.

  That is, in order to solve the above problems, in the concrete production apparatus using fine bubbles according to claim 1 according to the present invention, various concrete materials such as coarse aggregate, fine aggregate, cement, kneaded water, admixture, etc. Is a concrete manufacturing equipment that manufactures concrete by mixing these measured concrete materials with a mixer and mixing the measured concrete materials into a water measuring tank. It is provided with an admixture charging pipe and a water charging pipe for charging the kneaded water weighed in the water measuring tank into the mixer, and a fine bubble generating means is interposed in the middle of the water charging pipe. It is characterized in that fine bubbles are generated in the kneaded water by passing the kneaded water mixed with the admixture.

  Moreover, in the concrete manufacturing apparatus using the fine bubbles according to claim 2, the fine bubble generating means is a microbubble generating device.

  According to the concrete manufacturing apparatus using the fine bubbles according to claims 1 and 2 of the present invention, the admixture metering pipe for feeding the admixture measured in the admixture metering tank to the water metering tank is provided, and the water metering is performed. It is equipped with a water injection pipe for introducing the kneaded water weighed in the tank into the mixer, and a microbubble generator such as a microbubble generator is interposed in the middle of the water input pipe, and an admixture is mixed in the microbubble generator. By forming the fine water bubbles in the kneaded water by allowing the kneaded water to pass through, it is possible to increase the compressive strength of the manufactured concrete, which is suitable for improving the properties of the concrete and is suitable for microbubbles. Such fine bubbles can be effectively used practically and practically.

  In the concrete manufacturing apparatus using fine bubbles according to the present invention, an admixture introduction pipe for introducing an admixture such as an AE agent or an AE water reducing agent measured in an admixture measurement tank into the water measurement tank, and a water measurement Each is equipped with a water injection pipe for supplying the kneaded water weighed in the tank to the mixer, and a microbubble generation device, for example, a microbubble generation device is interposed in the middle of the water injection pipe. Then, after mixing the admixture that has been weighed into the kneading water in the water metering tank via the admixture charging pipe, the kneading water mixed with this admixture is discharged from the water charging pipe and the microbubble generating device in the middle By passing the water, fine bubbles such as microbubbles are generated in the kneaded water. At this time, the fine bubbles generated in the kneaded water do not disappear in a short time due to the effect of the admixture, and many fine bubbles remain for a relatively long time. In this way, kneading water containing a lot of fine bubbles is kneaded for a predetermined time with a mixer together with the remaining concrete materials such as coarse aggregate, fine aggregate, cement and the like to produce concrete.

  And the concrete manufactured in this way expresses high compressive strength compared with the concrete manufactured using normal kneading water due to some influence of fine bubbles such as microbubbles in kneading water, and is very remarkable. Therefore, it is possible to effectively use fine bubbles such as microbubbles in a concrete manufacturing apparatus in a practical and practical manner.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic view of a main part of a concrete production apparatus adopting the present invention. In FIG. 1, reference numeral 1 denotes a biaxial mixer for kneading various concrete materials. FIG. 2 is a detailed plan view (a) and a side sectional view (b) of the biaxial mixer 1, in which two parallel kneading shafts 3 are passed through the kneading tank 2 and can be rotated in opposite directions. In addition, a large number of arms 4 project around the kneading shaft 3 so as to be spiral along the axis, and kneading blades 5 are attached to the tip of each arm 4. Each kneading shaft 3 is rotated in the opposite direction in accordance with the drive of the drive motor 6, and various concrete materials in the mixing tank 2 can be kneaded by the mixing blades 5 that rotate accordingly.

  Above the biaxial mixer 1, a coarse aggregate measuring tank 7 for measuring coarse aggregate such as gravel, which is a concrete material, a fine aggregate measuring tank 8 for measuring fine aggregate such as sand, and cement A cement metering tank 9 for metering water and a water metering tank 10 for metering kneaded water are arranged, and admixtures such as AE agent and AE water reducing agent are metered above the water metering tank 10. An admixture metering tank 11 is provided.

  The admixture metering tank 11 is connected to the lower end portion of the admixture metering tank 11 with an admixture introduction pipe 12 for discharging the measured admixture and introducing it into the lower water metering tank 10. Is connected to a water input pipe 13 for discharging the measured kneaded water and supplying it to the lower mixer 1, and the admixture discharged from the admixture measuring tank 11 is mixed into the kneaded water measured in the water measuring tank 10. After that, it is configured so as to be put into the mixer 1 together with the kneaded water.

  A line pump 14 for pressurizing the kneaded water discharged from the water metering tank 10 and feeding it to the mixer 1 in a short time is interposed in the middle of the water supply pipe 13, and downstream of the line pump 14. Is provided with a microbubble generating device 15 which is a fine bubble generating means.

  The micro-bubble generating device 15 is mainly composed of an air pump and a bubble generating unit. When air is sent into the bubble generating unit as the air pump is driven, the air is fined by the inner wall of the staggered structure formed in the bubble generating unit. The structure is such that fine bubbles such as microbubbles of 50 μm or less are generated in the course of time, and the kneaded water discharged from the water metering tank 10 via the water input pipe 13 to the mixer 1 as required. Thus, microbubbles such as microbubbles can be generated as appropriate.

  The microbubble generator 15 does not necessarily have to have the above-described structure. For example, after a large amount of air is dissolved under high pressure, the microbubbles are re-bubbled by reducing pressure to generate fine bubbles. It is possible to adopt various structures such as what is called a pressure reduction method or a method in which fine bubbles are generated by passing water and air through a venturi tube together. What is necessary is just to be able to produce | generate fine bubbles, such as a microbubble, stably in water.

  When fine bubbles such as microbubbles are generated in pure kneaded water such as tap water, microbubbles such as microbubbles disappear in only a few minutes. When microbubbles such as microbubbles are generated in kneaded water in which a predetermined amount of an admixture such as an AE agent or AE water reducing agent is mixed in advance, the microbubbles such as microbubbles are the surface activity in the admixture. It does not disappear in a short time due to the action of the agent, and can remain for a relatively long time after the mixer 1 is charged.

  Reference numeral 16 denotes an air pump connected to the water supply pipe 13. When air bubbles are mixed and remain in the water supply pipe 13 due to the influence of fine bubbles generated by the microbubble generator 15, the air pump 16, compressed air is appropriately fed into the water input pipe 13 to be ejected into the mixer 1.

  And when manufacturing concrete with the concrete manufacturing apparatus of the said structure, first, a coarse aggregate is measured in the coarse aggregate measuring tank 7, a fine aggregate is measured in the fine aggregate measuring tank 8, and the cement measuring tank 9 is used. Each of the cements is weighed, while the admixture is weighed in the admixture metering tank 11, and this admixture is introduced into the lower water metering tank 10 through the admixture inlet pipe 12. Mix in the kneaded water to be weighed. Then, these various concrete materials that have been weighed out are dispensed at a predetermined timing and introduced into the lower mixer 1, but the kneaded water dispensed from the water metering tank 10 through the water introduction pipe 13 is in the middle. By passing through the microbubble generating device 15 interposed in the kneaded water, an appropriate amount of microbubbles such as microbubbles are generated in the kneaded water, and the microbubbles are introduced into the mixer 1.

  At this time, the fine bubbles such as microbubbles generated in the kneaded water do not disappear in a short time due to the effect of the admixture such as the AE agent and the AE water reducing agent previously mixed in the kneaded water. Many microbubbles such as microbubbles remain for a relatively long time. In this way, kneading water containing a lot of fine bubbles such as microbubbles is kneaded with the remaining concrete materials such as coarse aggregate, fine aggregate, cement and the like for a predetermined time to produce the desired concrete. Discharge from mixer 1.

  Next, a verification test (concrete test) was performed as follows on the properties of the concrete manufactured by the concrete manufacturing apparatus having the above configuration.

  First, the concrete materials to be used are shown in Table 1, and the composition is shown in Table 2.

  Then, according to the blending table of Table 2, the various concrete materials shown in Table 1 are put into a forced biaxial mixer having a kneading capacity of 60 liters as shown in FIG. 2 and the mixer is started. Thereafter, concrete was produced by kneading for 120 seconds. After completion of the kneading, the concrete was discharged from the mixer, and immediately after measuring and confirming the slump and the amount of air, a specimen (100 mm diameter × 200 mm standard cylinder) was produced.

  At this time, what used tap water as it is as kneaded water (N), after generating microbubbles in tap water (microbubbles almost disappeared at the time of kneading), used as kneaded water (MB), Microbubbles were generated in tap water mixed with an admixture in advance (microbubbles remained sufficiently even at the time of kneading) and used as kneaded water (Ad-MB).

  In addition, in generating microbubbles in tap water, a microbubble generating device (manufactured by Asp Co., Ltd., model AS-K2) which is a fine bubble generating means was used. As described above, this microbubble generating device is mainly composed of a pump and a bubble generating unit. When air is pumped into the bubble generating unit as the pump is driven, the microbubble generating device is formed by an inner wall of a staggered structure formed in the bubble generating unit. The air is finely sheared, and eventually, fine bubbles such as microbubbles of 50 μm or less are generated.

And the compressive strength test (JIS A 1108) of each said test body was done to the material age 91 days. The results are shown in FIG. 3, and when the microbubbles are not present in the kneaded water (N) or almost absent (MB), the compressive strength at the age of 7 days is both about 24 N / mm ^2. On the other hand, when there are many microbubbles in the kneaded water (Ad-MB), it is about 26 N / mm ² , and the effect of increasing strength by about 6% was confirmed by the presence of microbubbles. Further, in the compressive strength at the age of 28 days, (N) and (MB) are both about 31 N / mm ² , while (Ad-MB) is about 34 N / mm ² and about 9%. The compressive strength at the age of 91 days is (N) and (MB) both about 36 N / mm ² , while (Ad-MB) is 39 N / mm ^2. The strength enhancement effect of about 7% was confirmed.

  In addition, since the mass reduction rate due to drying of each specimen was also measured together with the compressive strength, the result is shown in FIG. 4, and almost no microbubbles are present in the kneaded water (N) or almost absent (MB). In contrast to the same value, in the case where many microbubbles exist in the kneaded water (Ad-MB), the value was always lower than (N) and (MB).

  From the above test results, in the concrete production process, kneaded water mixed with admixtures such as AE agent and AE water reducing agent in advance is passed through a microbubble generator, for example, a microbubble generator to generate microbubbles. By doing so, it was confirmed that the fine bubbles present in the kneaded water had some influence and greatly increased the compressive strength of the produced concrete.

  Thus, according to the concrete manufacturing apparatus using fine bubbles of the present invention, the admixture weighed in the admixture metering tank is introduced into the kneaded water of the water metering tank and mixed, and this admixture is mixed in advance. The micro-bubbles generated in the kneaded water by the action of the surfactant in the admixture by passing the kneaded water passed through the fine bubble generating means such as a micro-bubble generating device interposed in the water input pipe The fine bubbles can remain for a relatively long time, and the kneaded water containing a lot of fine bubbles is kneaded with the remaining concrete materials such as coarse aggregate, fine aggregate, cement, etc. in the mixer to produce concrete. It is suitable for manufacturing because it can greatly increase the compressive strength of concrete and can bring a significant advantage. It is possible to practically effective use.

  In this example, a microbubble generating device is employed as the fine bubble generating means, and microbubbles are generated by passing the kneaded water through the microbubble generating device. It has been reported that the generation of microbubbles called micro-nanobubbles and nanobubbles, which are considered to be much smaller in diameter than microbubbles and exhibit more remarkable utility, is becoming possible. It is also possible to employ these micro-nano bubbles and nano-bubble generation devices as generation means.

It is principal part schematic explanatory drawing which shows one Example of the concrete manufacturing apparatus using the fine bubble of this invention. It is the top view (a) and side sectional view (b) of the mixer of FIG. It is the graph which compared the compressive strength test result of the test body created with the concrete manufactured with this apparatus. It is a graph which shows the mass decreasing rate by drying of the test body created with the concrete manufactured with this apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Mixer 7 ... Coarse aggregate measuring tank 8 ... Fine aggregate measuring tank 9 ... Cement measuring tank 10 ... Water measuring tank 11 ... Admixture measuring tank 12 ... Admixture input pipe 13 ... Water input pipe 14 ... Line pump 15 ... Microbubble generator (fine bubble generator)

Claims (2)

  A concrete production equipment that measures concrete materials such as coarse aggregate, fine aggregate, cement, kneaded water, admixture, etc. in a measuring tank and kneads these measured concrete materials in a mixer to produce concrete. An admixture metering pipe for feeding the admixture weighed in the admixture metering tank into the water metering tank, and a water feed pipe for feeding the kneaded water weighed in the water metering tank into the mixer. A micro-bubble generating means is interposed in the middle of the input pipe, and the micro-bubbles are generated in the kneaded water by passing the kneaded water mixed with the admixture into the micro-bubble generating means. Concrete production equipment using bubbles.   2. The concrete production apparatus using micro bubbles according to claim 1, wherein the micro-bubble generating means is a micro-bubble generating device.

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