Method and apparatus for improving material fluidity

Abstract

To provide a method for efficiently improving the fluidity of materials and a fluidizing device.SOLUTION: A method for improving the fluidity of a material includes an irradiation step of applying ultrasonic waves through a medium to a material that is any one of fresh concrete, fresh mortar and fresh cement paste. A fluidizing device includes a storage part for storing the material, a medium part 12 for storing the medium so that the medium is in contact with the storage part, and an oscillation part 13 for propagating ultrasonic waves to the medium.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method or apparatus for improving the fluidity of a material that is any one of fresh concrete, fresh mortar, and fresh cement paste.

Background Art

[0002] As a conventional technique, a kneading apparatus for mortar or concrete using ultrasonic waves has been proposed (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When using the conventional technique, an ultrasonic generator is attached to a container for storing mortar or concrete, and ultrasonic waves are irradiated onto the mortar or concrete through the housing of the container. However, problems such as damage to the container and formation of holes in the container occur when ultrasonic waves are conducted, resulting in a state where kneading of the mortar or concrete itself cannot be performed.

[0005] In view of the above problems, an object of the present invention is to provide a method or apparatus for efficiently improving the fluidity of a material.

Means for Solving the Problems

[0006] To solve the above problems, the present invention provides, as one aspect, a method for improving the fluidity of a material, including an irradiation step of irradiating ultrasonic waves to a material that is any one of fresh concrete, fresh mortar, and fresh cement paste through a medium.

Effects of the Invention

[0007] According to the present invention, a method or apparatus for efficiently improving the fluidity of a material can be provided.

Brief Description of Drawings

[0008]

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Embodiments for Carrying Out the Invention

[0009] A method for improving the fluidity of a material which is any one of fresh concrete, fresh mortar, and fresh cement paste according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 13. Note that "fresh" means the state before the material hardens.

[0010] <Device Outline> In this embodiment, the device 10 shown in FIGS. 1 and 2 is used, and ultrasonic waves are irradiated onto a material such as fresh concrete through water. The device 10 includes a container 11 for storing the material, a rectangular medium section 12 for storing water, an oscillation section 13 for generating ultrasonic waves (sound waves of 20 kHz or higher), a support member 14 for supporting the container 11, and a controller 15 for controlling the oscillation section 13.

[0011] The container 11 is a hollow container with an open upper part, and can store a material such as fresh concrete inside. Various shapes such as rectangular and kettle-shaped can be adopted for the shape of the container 11.

[0012] The container 11 is supported at the upper end of the medium section 12 via the support member 14. The container 11 is arranged at the central part of the medium section 12 in a top view so as not to contact the medium section 12 and so that the bottom surface is horizontal. The lower surface and side surfaces of the container 11 are in contact with the water stored in the medium section 12.

[0013] The media section 12 is a hollow container formed such that its upper part is open, and is formed in a rectangular parallelepiped shape by rectangular side plates and a bottom plate. The media section 12 stores water (corresponding to the media of the present invention) inside. The media section 12 has dimensions that are larger than those of the container 11 in both the horizontal and vertical directions and does not come into direct contact with the container 11. The amount of water in the media section 12 is adjusted such that the water level is higher than the upper surface of the material stored in the container 11.

[0014] The oscillation section 13 is installed on the upper surface of the bottom of the media section 12. The oscillation section 13 has a rectangular parallelepiped shape and can oscillate ultrasonic vibrations from its upper surface. The generated ultrasonic waves propagate through the water and are transmitted to the material stored inside the container 11.

[0015] The controller 15 has a function of controlling the output of the oscillation section 13 and the frequency of the ultrasonic waves. The user controls the operation of the oscillation section 13 via the controller 15.

[0016] <Test> In addition, in order to examine the influence of ultrasonic irradiation on the fluidity of the material, and to confirm how much the fluidity of materials such as fresh concrete changes depending on differences in conditions such as frequency and the shape of the container, Tests 1 to 5 were conducted using the apparatus 10 as follows.

[0017] In each of the following tests, any of fresh concrete, fresh mortar, and fresh cement paste can be used as a sample. However, in order to eliminate the influence of variations in the material, shape, and size of the aggregate, a cement paste without aggregate was selected as the sample. In any of the following tests, ordinary Portland cement (density 3.16 g / cm 3 , manufactured by Taiheiyo Cement Corporation) cement paste was used, and the water-cement ratio was 0.45.

[0018] In any of the tests, the test was carried out by storing the cement paste, in which the mixing of water and cement was completed, that is, the manufacturing process was finished, in the container 11 and oscillating ultrasonic waves from the oscillation section 13.

[0019] In each test, as a means of measuring the fluidity of the sample and its changes, the slump flow of the sample before the test (base sample) and after the test was measured (Figure 3). The measurement method conformed to JIS (Japanese Industrial Standards) R5210.

[0020] 〔Test 1: Examination of the influence of frequency〕 In Test 1, the frequency of the ultrasonic wave was changed and the ultrasonic wave was irradiated to confirm the change in the fluidity of the cement paste due to the difference in frequency. In Test 1, as shown in Figure 4, eight types of test cases were set, and different ultrasonic waves were irradiated in the range of 28 kHz (kilohertz) to 170 kHz. The output of the oscillation unit 13 was 500 watts in any test case, as shown in Figure 4(a). The irradiation time (also called the vibration time) was 3 minutes.

[0021] The shape of the container 11 used in Test 1 is shown in Figure 3B(a). The container 11 used in Test 1 is a metal (steel) bat-shaped container with a rectangular parallelepiped shape with a wide bottom surface. The dimensions of the container 11 are as shown in Figure 3B(c).

[0022] The results of Test 1 are shown in Figure 4(b) and Figure 5. It can be seen that the lower the frequency, the greater the change in flow before and after irradiation, and the fluidization of the sample is promoted.

[0023] 〔Test 2: Examination of the influence of output〕 In Test 2, test cases with different ultrasonic outputs were set to investigate the influence of the difference in output on the fluidization of the cement paste.

[0024] In Test 2, as shown in Figure 6(a), at two frequencies of 28 kHz and 40 kHz, ultrasonic irradiation was performed for 3 minutes with outputs of 100, 300, and 600 watts.

[0025] The container 11 used in Test 2 is a metal (steel) pot-shaped container with a curved bottom and a shape that tapers downward (Fig. 3B(b)). The dimensions of the container 11 are as shown in Fig. 3B(c).

[0026] As shown in Fig. 6(b) and Fig. 7, it was found that the fluidity of the cement paste increases as the output increases at any frequency.

[0027] 〔Test 3: Examination of the influence of irradiation time〕 In Test 3, the influence of the ultrasonic irradiation time (also referred to as the vibration time) on the fluidity of the cement paste was examined. As shown in Fig. 8, ultrasonic irradiation was performed at an output of 600 W at two frequencies of 28 kHz and 40 kHz. The ultrasonic irradiation time for the samples was set to 1 minute (min), 3 minutes, and 5 minutes.

[0028] The container 11 used in Test 3 is the same as the pot-shaped container used in Test 2 (Fig. 3B(b), (c)).

[0029] As shown in Fig. 9, at any frequency, the longer the irradiation time, the larger the flow after irradiation, and it can be read that the change amount of the flow also tends to increase. Also, when the irradiation time exceeds 3 minutes, the increment of the change amount of the flow levels off.

[0030] 〔Test 4: Time-dependent change of cement paste〕 As Test 4, the time-dependent change of the flow of the cement paste was measured. In Test 4, as shown in Fig. 10, ultrasonic waves of 26 kHz were irradiated to the sample at 500 W for 3 minutes, and the relationship between the elapsed time after irradiation and the paste flow was measured. Also, these test results were compared with a sample (base) without ultrasonic irradiation.

[0031] The container 11 used in Test 4 is the same as the pot-shaped container used in Tests 2 and 3 (Fig. 3B(b), (c)).

[0032] The test results are shown in Fig. 11. The base elapsed time in the test results is defined as the elapsed time after the completion of kneading. For the samples irradiated with ultrasonic waves, the time after the completion of irradiation is defined as the elapsed time.

[0033] As shown in the graph, a significant loss of flow was confirmed after 10 minutes for the sample without ultrasonic irradiation (base). On the other hand, it was found that the flow properties were maintained from about 30 minutes to 40 minutes for the samples irradiated with ultrasonic waves.

[0034] 〔Test 5: Examination of the influence of container shape〕 In Test 5, the relationship between the shape of container 11 and the fluidity of the cement paste was investigated. As container 11 used in Test 5, two types of containers, the vat-shaped container used in Test 1 and the kettle-shaped container used in Tests 2 to 4, were prepared (Fig. 3B). As shown in Fig. 12(a), in any test case, the output of the oscillation unit 13 was set to 500 W, and ultrasonic irradiation was performed at two frequencies of 28 kHz and 40 kHz.

[0035] The test results are shown in Fig. 12(b) and Fig. 13. As a result, it was obtained that the amount of change in flow was large when the shape of container 11 was vat-shaped at any frequency.

[0036] 〔Summary〕 Summarizing the above, in any of Tests 1 to 5, regardless of the test conditions, it was obtained that the fluidization of the cement paste was promoted by performing ultrasonic irradiation through water as the medium.

[0037] In addition, when measuring the compressive strength of the cement paste before and after ultrasonic irradiation, no change was observed. Also, in any test, no damage occurred in container 11.

[0038] <Effect> In the above-described embodiment, a method for improving the fluidity of a material, which is any one of fresh concrete, fresh mortar, and fresh cement paste, by an irradiation step of irradiating ultrasonic waves through a medium is disclosed.

[0039] With the above configuration, the fluidity of the material is efficiently improved. In particular, when ultrasonic waves are irradiated on the storage container of the material, there is a risk of problems such as damage to the container and formation of holes. On the other hand, in this configuration, since ultrasonic waves are irradiated through a medium, container damage does not occur, and thus it is possible to efficiently promote and improve the fluidization of the material.

[0040] In the above embodiment, water is used as the medium for propagating ultrasonic waves. Since water, which can be prepared inexpensively and in large quantities, is used as the medium and the above-described fluidity promoting effect is obtained, the working efficiency of fluidizing the material is high and the cost is good.

[0041] In the above configuration, after the manufacturing process of manufacturing the material using cement and water, an ultrasonic irradiation treatment is performed, and as a result, it is confirmed that an improvement effect of fluidization is obtained. Since it is not necessary to perform ultrasonic treatment simultaneously with the manufacture of the material, complicated work is prevented.

[0042] A container 11 for storing the material (corresponding to the storage unit of the present invention), a medium unit 12 for storing the medium such that the medium is in contact with the container 11, and an oscillation unit 13 for irradiating ultrasonic waves on the medium are provided, and ultrasonic waves are irradiated on the material through the medium. By performing ultrasonic irradiation on the material using such a device 10, work can be efficiently executed.

[0043] The container 11 is preferably made of metal. Also, according to the results of Test 5, the container 11 is preferably in a rectangular parallelepiped shape or a rectangular shape. By making the container 11 made of metal or in a rectangular parallelepiped shape, the fluidity of the material can be efficiently improved.

[0044] <Modification Example> In the above embodiment, water is used as the medium through which ultrasonic waves propagate, but the present invention is not limited to this embodiment. For example, liquids other than water or gel-like substances may be used.

[0045] In the above embodiment, the material of the container is not limited to steel, and other metal materials may be used.

[0046] Moreover, the present invention does not limit the shape of the medium portion 12 and the arrangement position of the oscillation portion 13 to the embodiment. It is also possible to change the shape according to the application, change the arrangement position by installing the oscillation portion 13 on the side wall of the medium portion 12, or increase the number of oscillation portions 13.

Explanation of Reference Numerals

[0047] Device 10 Container 11 Medium portion 12 Oscillation portion 13 Support material 14

Claims

A method for improving the fluidity of a material, comprising an irradiation step of irradiating ultrasonic waves to a material stored in a metal storage unit, the material being any one of fresh concrete, fresh mortar, and fresh cement paste, through a medium selected from a liquid and a gel-like substance. A method for improving the fluidity of a material. Claim 2 The method according to claim 1, wherein the medium is water. Claim 3 The method according to claim 1 or 2, further comprising a manufacturing step of manufacturing the material using cement and water, and executing the irradiation step after the manufacturing step. Claim 4 The storage unit, a medium unit for storing the medium such that the medium is in contact with the storage unit, and an oscillation unit for propagating ultrasonic waves to the medium, and a fluidization device for executing the method according to any one of claims 1 to 3. Claim 5 The fluidization device according to claim 4, wherein the storage unit has a rectangular parallelepiped shape. Claim 6 A rectangular parallelepiped storage unit for storing a material that is any one of fresh concrete, fresh mortar, and fresh cement paste, a medium unit for storing the medium such that the medium selected from a liquid and a gel-like substance is in contact with the storage unit, and an oscillation unit for propagating ultrasonic waves to the medium, and executing an irradiation step of irradiating ultrasonic waves to the material through the medium. A fluidization device.

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