Concrete structure, structural module, building, and method for manufacturing a concrete structure

Abstract

To provide a concrete structure or the like that can suppress vibration by being incorporated as part of a structure that constitutes an infrastructure facility or building without using any additional device. [Solution] A concrete structure has a frame, a mass, and beams connecting the frame and mass, all integrally formed from concrete. In this concrete structure, the mass supported by the beams responds with a time delay to external vibrations, thereby attenuating the external vibrations in the targeted vibration isolation zone.

Description

[Technical Field]

[0001] The present invention relates to a concrete structure, a structural module, a building, and a method for manufacturing a concrete structure. [Background technology]

[0002] Structures using concrete, which is primarily composed of cement, are often found in infrastructure facilities and buildings such as roads and bridges. Various methods have been proposed to suppress vibrations from external sources such as earthquakes and wind in such structures. For example, in buildings such as apartment buildings, a technique is known in which seismic dampers are installed between the foundation and the structure or between the beams and columns (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-199958 Summary of the Invention [Problem to be solved by the invention]

[0004] Countermeasures against vibrations using additional devices such as seismic dampers result in larger structures, more complicated maintenance, and increased costs.

[0005] The present invention has been made to solve these problems and provides a concrete structure that can be incorporated as part of the structure that makes up infrastructure facilities and buildings to suppress vibration without using additional devices. Here, "concrete" is broadly defined as a general term for paste, mortar made by mixing sand with paste, and concrete made by adding gravel to mortar. The binder for the paste may be not only a cement-based material, but also a geopolymer-based material. [Means for solving the problem]

[0006] In a first aspect of the present invention, a concrete structure has a frame, a mass, and beams connecting the frame and mass, all integrally formed from concrete. In a concrete structure configured in this manner, the mass supported by the beams responds to externally applied vibrations with a time delay, thereby attenuating the external vibrations in a targeted vibration isolation zone.

[0007] In addition, a structural module according to a second aspect of the present invention includes at least two of the above concrete structures arranged with their orientations reversed. By adopting a structural module combining multiple concrete structures in this way, it is possible to avoid a decrease in the damping effect against the direction of externally applied vibrations, compared to when a single concrete structure is used.

[0008] Furthermore, a building according to a third aspect of the present invention is a building incorporating the above-mentioned concrete structure, and such a building can protect the safety of residents, for example, by reducing shaking caused by earthquakes. Furthermore, by changing the size of the concrete structure, etc., and adjusting the target vibration isolation zone, it is possible to reduce noise from the external environment to the interior, or from the interior to the external environment.

[0009] A fourth aspect of the present invention is a method for manufacturing a concrete structure in which a frame, a mass, and beams connecting the frame and mass are integrally formed from concrete, and the method includes a form assembly process in which exterior wall materials surround a bottom surface material and slit molds for forming the beams sandwiched between the slits are inserted into insertion grooves provided in the bottom surface material to assemble the formwork, a pouring process in which concrete is poured into the formwork, and a demolding process in which, after the concrete has hardened, the bottom surface material is removed and the slit molds are pushed out in the direction the bottom surface material was removed, thereby dismantling the formwork and demolding it. By using this manufacturing method, even concrete structures with complex beam structures can be manufactured relatively efficiently. [Effects of the Invention]

[0010] The present invention makes it possible to provide a concrete structure or the like that can be incorporated as part of the structure that constitutes an infrastructure facility or building to suppress vibration without using any additional devices. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is an overall perspective view of a concrete structure. [Figure 2] FIG. 2 is an exploded view of elements for explaining the structure of a concrete structure. [Figure 3] FIG. 1 is a diagram illustrating the principle of vibration damping. [Figure 4] FIG. 10 is a diagram illustrating a specific example of a unit structure. [Figure 5] FIG. 1 is a diagram illustrating an experimental environment for a verification experiment. [Figure 6] FIG. 10 is a diagram showing the results of a verification experiment. [Figure 7] FIG. 2 is a diagram showing members constituting a formwork. [Figure 8] FIG. 1 shows the assembled formwork. [Figure 9] FIG. 1 illustrates an example of a structure module including multiple concrete structures. DETAILED DESCRIPTION OF THE INVENTION

[0012] Specific embodiments will be described through the following disclosure, but the claimed invention is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential as means for solving the problems. In each drawing, elements with the same reference numerals have the same or similar configurations. Furthermore, in each drawing, when multiple structures with the same or similar configurations exist, some may be referenced with the same reference numerals, and others may not be referenced with the same reference numerals, in order to avoid complication.

[0013] FIG. 1 is an overall perspective view of a concrete structure 100. The concrete structure 100 comprises three structural parts (a first structural part 110, a second structural part 120, and a third structural part 130) that have similar configurations, and a base part 140 for assembly to other structures. Each structural part is a unit structure of the concrete structure that exhibits vibration control performance by itself. As will be described in detail later, each structural part is plate-shaped and has a plurality of slits 200. Furthermore, in this embodiment, there are no clear boundaries between the structural parts, and the entire structure is formed integrally.

[0014] In this embodiment, three structural parts are arranged in a row, but the number of structural parts may be one, two, or four or more. Furthermore, when three or more structural parts are provided, they may be arranged in a row or two-dimensionally.

[0015] The base portion 140 has a protruding portion 141 that protrudes laterally from the structural portion, and the protruding portion 141 has a bolt hole 142. The concrete structure 100 is assembled to another structure by a bolt (not shown) that passes through the bolt hole 142. The structure of the base portion 140 is not limited to the example shown in the figure, and can be changed as appropriate depending on the use of the concrete structure 100 and the object to which it is assembled.

[0016] In this embodiment, as shown by the coordinate axes in the figure, the direction in which the three structural elements are arranged is defined as the x-axis direction, and the planar direction of each structural element, perpendicular to the x-axis, is defined as the y-axis direction. Furthermore, the direction perpendicular to the x-axis and y-axis and corresponding to the depth of each structural element is defined as the z-axis direction. In subsequent drawings, similar coordinate axes based on the state in which the concrete structure 100 is arranged as shown in FIG. 1 are also included to indicate the orientation of the structure depicted in each drawing. In particular, the x-axis direction may be referred to as height, the y-axis direction as width, and the z-axis direction as depth or thickness.

[0017] Fig. 2 is an exploded view of elements to explain the first structural part 110 as a unit structure of the concrete structure 100. As shown in the upper diagram of Fig. 2, the first structural part 110 has a plate-like structure integrally formed from concrete, and four slits 200 are provided on its surface, which is the xy plane, spirally, so as to penetrate the first structural part 110 in the z direction (depth direction).

[0018] The four slits 200, the specific shape and arrangement of which will be described later, are arranged so as to rotate by 90° in sequence, thereby dividing the first structural unit 110 into three parts. Specifically, as shown in the lower left diagram, there is a frame portion 210 located outside the four slits 200; as shown in the lower center diagram, there is a beam portion 220 that extends spirally and is sandwiched between two opposing slits 200; and as shown in the lower right diagram, there is a mass portion 230 that is located inside the four slits 200. Therefore, it can be said that the first structural unit 110 as a whole is supported in a suspended state by the mass portion 230 located at the center, connected to the frame portion 210 located on the periphery via the four elongated spiral beam portions 220.

[0019] FIG. 3 is a diagram illustrating the principle of the vibration damping effect exerted by the first structural member 110. Because the beam member 220 is formed in a long, thin spiral shape as described above, it is capable of some deformation even though it is made of concrete, and acts similar to a spring. Therefore, the suspended mass member 230 follows the vibration of the frame member 210 with a time delay due to the deformation of the beam member 220. In other words, a physical model of a mass-spring-damper system is established between the frame member 210 and the mass member 230, and as a result, the vibration of the frame member 210 itself, which is subjected to external vibrations, is also suppressed.

[0020] When mass portion 230 is supported by spiral beam portion 220 as in this embodiment, mass portion 230 can be displaced in any of the x-axis, y-axis, and z-axis directions as indicated by the dotted arrows in response to vibrations applied to frame portion 210. In particular, because beam portion 220 is formed point-symmetrically around the z-axis, similar damping characteristics can be expected in the x-axis and y-axis directions.

[0021] An actual concrete structure 100 was prototyped and a verification experiment was conducted. The specifications of the unit structure used in the verification experiment, the experimental method, and the results are described below. Figure 4 is a diagram explaining the specifications of the first structural part 110 as a specific example of a unit structure. The damping characteristics against externally applied vibrations are determined mainly by the size, thickness, slit shape, and material of the unit structure.

[0022] The first structural element 110 is a square with a length and width of a = 250 mm. The first structural element 110 is formed in a plate shape with a > h and a thickness h = 50 mm. The spiral shape of the slit 200 is expressed as follows, where r1 is the distance to the first end point closest to the center O and r2 is the distance to the second end point farthest from the center O. r (s) = r2- (r2- r1)×s φ (s) = 2πns + φ0

[0023] Here, the values ​​are 0 ≦ s ≦ 1, and φ0 is the initial phase, φ0 = 15°. Also, n represents the number of rotations of the spiral, and n = 0.75 (= 270° / 360°). Also, r1 = 76 mm, r2 = 108 mm, and the slit width w = 4 mm. The other three slits 200 are the first slit 200 rotated by 90° each.

[0024] Each slit 200 has a central angle of 270° with respect to the center O and is disposed at 90° rotational angles relative to each other, so that the beam portion 220 sandwiched between two opposing slits 200 has a central angle of 180° with respect to the center O. In other words, each beam portion 220 surrounds half of the entire circumference of the mass portion 230. A certain length is required for the beam portion 220 to produce a spring-like action, and for this purpose, it is preferable that each beam portion 220 be formed so as to surround at least half of the entire circumference of the mass portion 230.

[0025] The concrete used was a high-strength fiber-reinforced engineered cementitious composite (ECC), which is a mixture of high-strength organic fibers and ordinary concrete ingredients such as cement, water, and sand.

[0026] FIG. 5 is a diagram illustrating the experimental environment of the verification experiment. In this verification experiment, the concrete structure 100 was fixed upright on a vibration table 310 as shown in the figure. The vibration of the vibration table 310 was controlled by a control device, and in this verification experiment, the control device Z in =A in ×sin(ωt) The input vibration expressed as

[0027] A vibration sensor 320 is attached to the upper end of the concrete structure 100, and its output signal is sent to a processing device and converted into a mathematical formula. The output vibration in the z-axis direction detected by the vibration sensor 320 is expressed as Z out =A out ×sin(ω't) The vibration transmittance, which is the ratio of the amplitude of the output vibration detected at the upper end to the amplitude of the input vibration input to the lower end of the concrete structure 100, is expressed as A out / A in The vibration transmittance plotted for each vibration frequency can be used to evaluate the damping characteristics of the concrete structure 100.

[0028] Figure 6 shows the results of the verification experiment. The horizontal axis represents the excitation frequency ω [Hz], and the vertical axis represents the vibration transmittance. The solid line shows the verification results for the concrete structure 100. The dotted line also shows the verification results for a comparative structure 900, which was conducted as a comparison experiment and is made of the same material and has the same external shape as the concrete structure 100 but does not have the slits 200.

[0029] If the vibration transmittance is below 1, it can be evaluated that the applied vibration has been attenuated. As shown in the figure, the concrete structure 100 was able to attenuate vibration more than the comparative structure 900 in the excitation frequency band of approximately 23 Hz to approximately 48 Hz. This excitation frequency band can be defined as the vibration isolation band in which the concrete structure 100 can effectively attenuate vibration.

[0030] The vibration isolation band can be changed by changing the size, thickness, slit shape, material, etc. of the unit structure. For example, simulation results showed that narrowing the slit width shifts the vibration isolation band to the higher frequency side and widens the bandwidth, while widening the slit width shifts the vibration isolation band to the lower frequency side and narrows the bandwidth. In other words, by adjusting the specifications of the unit structure, the vibration isolation band can be matched to a desired band. Therefore, the vibration isolation band can be set depending on the intended use of the concrete structure 100. For example, if you want to suppress earthquake shaking, you can set the vibration isolation band to target common earthquake frequencies, and if you want to suppress noise, you can set the vibration isolation band to target audible sound frequencies.

[0031] In addition, the above verification experiment verified the vibration isolation band for input vibration in the z-axis direction, but due to differences in the amount of deformation of the beam portion 220 in response to the input vibration, the vibration isolation band for input vibration in the x-axis and y-axis directions may differ from the vibration isolation band in the z-axis direction. However, by adjusting the specifications of the unit structure, it is possible to make the vibration isolation bands in the x-axis and y-axis directions approximate the vibration isolation band in the z-axis direction.

[0032] Next, an example of a manufacturing method for the concrete structure 100 will be described. Fig. 7 is a diagram showing the members that make up the formwork of the concrete structure 100. The formwork is mainly composed of a bottom surface material 500, an exterior wall material 510, and a slit mold 520. The bottom surface material 500 is a plate material that has a convex shape overall, and is provided with a spiral insertion groove 501 into which the slit mold 520 is inserted and set upright. The exterior wall material 510 is a rectangular plate material prepared to correspond to each side that forms the outer periphery of the bottom surface material 500. The slit mold 520 is a rectangular flexible member that is inserted into the insertion groove 501 to form a spiral wall.

[0033] The slit mold 520 is composed of a slit film 521 and a slit part 522. The slit film 521 is formed in a bag shape and is used by covering the slit part 522. For example, when the slit width w is set to 4 mm, the thickness of the slit film 521 is set to 1 mm, and the thickness of the slit part 522 is set to 2 mm.

[0034] When a typical concrete structure is manufactured using a formwork, the formwork is generally made of wood or steel. However, the concrete structure 100 according to this embodiment requires the formation of multiple slits 200 with relatively complex shapes and narrow widths. Therefore, wood is not suitable for the slit mold 520 for forming the slits 200, nor for the bottom surface material 500 in which the insertion grooves 501 are provided. Therefore, in this embodiment, both are made of resin. Furthermore, since dimensional accuracy is required for their manufacture, a 3D printer is used. More specifically, the bottom surface material 500 and the slit parts 522 are molded using a resin 3D printer that employs a layering method, which is suitable for manufacturing relatively large, voluminous parts, and the slit film 521 is molded using a resin 3D printer that employs a stereolithography method, which has a small layer pitch and high modeling accuracy. The slit film 521 may also be formed by folding a sheet-like resin film.

[0035] In this way, the formwork is assembled through a component forming process in which the bottom material 500, slit film 521, and slit parts 522 are formed using a 3D printer, and a formwork assembly process in which the bottom material 500 is surrounded by the exterior wall material 510, and the slit mold 520, which has the slit film 521 covering the slit parts 522, is inserted into the insertion groove 501 provided in the bottom material 500 to assemble the formwork.

[0036] 8 is a diagram showing an assembled formwork. Concrete structure 100 is completed through a pouring process in which concrete is poured into the assembled formwork, and a demolding process in which, after the concrete has hardened, bottom surface material 500 and exterior wall material 510 are removed, and slit mold 520 is pushed out in the direction from which bottom surface material 500 was removed, thereby dismantling and demolding the formwork. In particular, the demolding process includes an extrusion process in which a portion of slit film 521 is torn and slit parts 522 are pushed out in the direction from which bottom surface material 500 was removed, followed by a removal process in which slit film 521 is removed. By going through these processes, slit mold 520 can be removed relatively smoothly without damaging the slits 200 that have been formed.

[0037] Next, we will explain modified examples and application examples of the concrete structure 100. Figure 9 is a diagram showing an example of a structure module 600 including a plurality of concrete structures. Specifically, the structure module 600 includes four first structural sections 110 as concrete structures, and is erected on a base section 150 facing in all directions.

[0038] In this way, by including at least two concrete structures arranged with their orientations reversed, it is possible to expect equivalent vibration isolation effects against vibrations from at least two directions. For example, as shown in the figure, if the first structural parts 110 are arranged perpendicular to each other, it is possible to obtain equivalent vibration isolation effects in the xy plane and the xz plane. Furthermore, it is also possible to combine first structural parts 110 parallel to the yz plane. With such a combination, it is possible to obtain equivalent vibration isolation effects in the yz plane as well.

[0039] Although several specific examples have been described above, the concrete structure can be modified in many other ways. For example, although the examples described above are all plate-shaped concrete structures, the concrete structure may be a block-shaped structure in which the depth is greater than either the length or width of the unit structure.

[0040] In addition, in the above embodiments, a spiral beam is used to facilitate a spring-like action, but the beam does not have to be spiral as long as it can have a relatively long and narrow shape that surrounds the mass. In that case, the space for forming the beam does not have to be a slit.

[0041] In the above embodiments, the frame 210, beam 220, and mass 230 have a uniform thickness to facilitate assembling the formwork and pouring concrete, but the thicknesses of each may be different. For example, the thickness of the beam may be smaller than the thickness of the frame and mass so that a spring-like action can be more easily achieved.

[0042] Furthermore, in the concrete structure 100, the three structural parts (first structural part 110, second structural part 120, and third structural part 130) have the same configuration, but when the concrete structure has multiple structural parts, the structural parts may have different configurations. For example, the widths of the slits 200 may be different from each other. Furthermore, various materials may be used for the concrete structure.

[0043] Furthermore, concrete structures and structural modules made up of concrete structures can be incorporated into a variety of objects. For example, incorporating them into buildings can reduce earthquake shaking and protect the safety of residents. Furthermore, by adjusting the targeted vibration isolation zone, they can be used to reduce noise from the external environment to the interior, or from the interior to the external environment. In addition to buildings, they can also be applied to social infrastructure such as bridges and embankments. [Explanation of symbols]

[0044] 100...concrete structure, 110...first structural part, 120...second structural part, 130...third structural part, 140, 150...base part, 141...extension part, 142...bolt hole, 200...slit, 210...frame part, 220...beam part, 230...mass part, 310...vibration table, 320...vibration sensor, 500...bottom material, 501...insertion groove, 510...exterior wall material, 520...slit type, 521...slit film, 522...slit part, 600...structural module, 900...comparison structure

Claims

1. A frame portion and parts by weight, and a beam portion connecting the frame portion and the mass portion; A concrete structure formed integrally from concrete.

2. The concrete structure according to claim 1 , wherein the beam portion is sandwiched in a slit provided between the frame portion and the mass portion.

3. 3. The concrete structure according to claim 2, wherein the slits are arranged in a spiral pattern.

4. The concrete structure according to claim 3 , wherein the beam portion surrounds at least half of the entire periphery of the mass portion.

5. 2. The concrete structure according to claim 1, wherein the entire structure is formed in a plate shape.

6. The concrete structure of claim 5 comprising a plurality of said masses.

7. A structural module comprising at least two concrete structures according to claim 1 arranged in a mutually oriented orientation.

8. A building incorporating the concrete structure according to claim 1.

9. A method for manufacturing a concrete structure in which a frame portion, a mass portion, and a beam portion connecting the frame portion and the mass portion are integrally formed of concrete, a form assembling process in which a bottom surface material is surrounded by an exterior wall material, and a slit mold for forming the beam portion sandwiched in the slit is inserted into an insertion groove provided in the bottom surface material to assemble a form; A pouring step of pouring concrete into the formwork; a demolding process in which the bottom surface material is removed after the concrete has hardened, and the slit mold is pushed out in the direction in which the bottom surface material was removed to dismantle the formwork and demold the concrete; A method for manufacturing a concrete structure comprising the steps of:

10. The slit mold includes a slit part and a slit film that covers the slit part, The method for manufacturing a concrete structure according to claim 9, wherein the demolding process includes an extrusion process in which a portion of the covering slit film is torn and the slit part is pushed out in the direction in which the bottom material was removed, and a removal process in which the slit film is then removed.

11. The method for manufacturing a concrete structure according to claim 10, further comprising a component forming step of forming the bottom material and the slit parts using a lamination type resin 3D printer and forming the slit film using a stereolithography type resin 3D printer.

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