Method for installing RFID module

Abstract

To provide a method for installing an RFID module that can accurately fix the RFID module while preventing communication of the RFID module from being obstructed.SOLUTION: A method for installing an RFID module on a rebar before pouring concrete includes the steps of: fixing a first end portion 31 in a first direction D1 of a protective case 3 that houses an RFID module 4 to a first rebar 1; and fixing a second end portion 32 of the protective case 3 opposite to the first end portion 31 in the first direction D1 to a second rebar 2 that intersects with the first rebar 1. When viewed from a line of sight parallel to a vertical direction Z, the first direction D1 of the protective case 3 is inclined in both axial direction X of the first rebar 1 and axial direction Y of the second rebar 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method for installing an RFID module in reinforced concrete. [Background technology]

[0002] In general concrete construction, installation, or product manufacturing, formwork is assembled, concrete is poured into the formwork, and after a period of curing, the concrete is removed from the formwork once it is estimated to have reached a predetermined strength that allows it to be removed.

[0003] For example, Patent Document 1 describes a method for estimating the strength of concrete by embedding an RFID module equipped with a temperature sensor in poured concrete, continuously measuring and storing temperature changes with the temperature sensor in the RFID module, and reading temperature history data from the RFID module with a reader. The temperature history data is used to calculate important information during the concrete construction.

[0004] RFID (Radio Frequency Identification), a type of short-range wireless communication, enables an RFID module (also called a tag) with a tiny wireless chip to communicate with a reader using radio or electromagnetic waves and transmit data from the RFID module to the reader. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4633416 [Patent Document 2] Patent No. 2006-348538 [Patent Document 3] Patent No. 4651115 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when using RFID technology in reinforced concrete, there is a problem that the rebars in the reinforced concrete can interfere with communication between the RFID module and the reader, and the RFID module must be firmly fixed without changing its position when the concrete is poured (see, for example, Patent Documents 2 and 3).

[0007] The present disclosure provides a method for installing an RFID module that allows accurate fixation while suppressing interference with RFID module communication. [Means for solving the problem]

[0008] The method of installing an RFID module on a reinforcing bar before pouring concrete of the present disclosure includes the steps of fixing a first end of a protective case that houses the RFID module in a first direction to a first reinforcing bar, and fixing a second end of the protective case opposite the first end in the first direction to a second reinforcing bar that intersects the first reinforcing bar, and when viewed from a line of sight parallel to the vertical direction, the first direction of the protective case is inclined in both the axial direction of the first reinforcing bar and the axial direction of the second reinforcing bar. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to accurately fix an RFID module while suppressing interference with communication of the RFID module. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 10 is a perspective view showing a state in which a protective case accommodating an RFID module is fixed to a reinforcing bar. [Figure 2] FIG. 2 is a plan view corresponding to FIG. [Figure 3] 3A and 3B are front and right side views of the protective case. [Figure 4]Figure 4A is a rear view of the protective case, Figure 4B is a plan view of the protective case, and Figure 4C is a bottom view of the protective case. [Figure 5] 10 is a side view showing a schematic diagram of the relationship between the protective case, the concrete surface, and the reinforcing bars after concrete has been poured. FIG. [Figure 6] 10 is a side view showing a schematic diagram of the relationship between the protective case, the concrete surface, and the reinforcing bars after concrete has been poured. FIG. [Figure 7] FIG. 10 is a rear view showing a protective case 3 according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] [First embodiment] Hereinafter, a first embodiment of the present disclosure will be described with reference to the drawings.

[0012] Fig. 1 is a perspective view showing a state in which a protective case 3 accommodating an RFID module 4 is fixed to a reinforcing bar. Fig. 2 is a plan view corresponding to Fig. 1.

[0013] A method for constructing reinforced concrete includes the steps of constructing a formwork, placing reinforcing bars in a grid pattern within the formwork, and pouring concrete into the formwork. The method for installing the RFID module 4 of the present disclosure includes fixing the RFID module 4 to the placed reinforcing bars before pouring the concrete.

[0014] In a reinforced concrete structure, multiple reinforcing bars are arranged in a lattice pattern. Each reinforcing bar is held perpendicular to the other. Figures 1 and 2 show a first reinforcing bar 1 and a second reinforcing bar 2 that is perpendicular to the first reinforcing bar 1 among the multiple reinforcing bars. In the example shown in the figure, each reinforcing bar (1, 2) extends horizontally, but this is not limited thereto; each reinforcing bar (1, 2) may extend horizontally. The horizontal direction means an angle of 30 degrees or less with respect to the horizontal direction. For ease of explanation in this specification, the axial direction of the first reinforcing bar 1 will be expressed as X, the axial direction of the second reinforcing bar 2 as Y, and the vertical direction as Z.

[0015] 1 and 2, a first end 31 of the protective case 3 in the first direction D1 is fixed to the first reinforcing bar 1, and a second end 32 of the protective case 3 opposite to the first end 31 in the first direction D1 is fixed to the second reinforcing bar 2. In this case, as shown in FIG. 2, when viewed from a line of sight parallel to the vertical direction Z, the first direction D1 of the protective case 3 is inclined in both the axial direction X of the first reinforcing bar 1 and the axial direction Y of the second reinforcing bar 2.

[0016] FIG. 3A is a front view showing the protective case 3. FIG. 3B is a right side view showing the protective case 3. The left side view of the protective case 3 is the same as the right side view, so it is omitted. FIG. 4A is a rear view showing the protective case 3. FIG. 4B is a plan view showing the protective case 3. FIG. 4C is a bottom view showing the protective case 3.

[0017] As shown in FIGS. 1 and 3A, the protective case 3 can accommodate the RFID module 4 and protects the RFID module 4 from external forces during concrete pouring. The protective case 3 may be made of any non-metallic material, such as resin or wood. The protective case 3 can be made using a mold, cutting, or a resin 3D printer. In the first embodiment, as shown in FIGS. 3A-B and 4A-C, the protective case 3 is formed in a plate shape. The surface direction of the protective case 3 is parallel to a first direction D1 and a second direction D2 perpendicular to the first direction D1. The second direction D2 is perpendicular to both the thickness direction D3 and the first direction D1. As shown in FIGS. 1, 3A, and 4A, the protective case 3 has a shape formed by combining a rectangular plate portion and a triangular plate portion. When fixed to a reinforcing bar, the tapered tip of the triangular plate portion faces downward. As a result, the tapered shape of the triangular plate-like portion serves the function of indicating the orientation of the up-down direction Z when the protective case 3 is fixed.

[0018] A slit 30 for inserting the sheet-shaped RFID module 4 is formed on one side of the protective case 3 in the second direction D2 (the side that faces upward when fixed). The slit 30 serves as an opening of a housing space 33 for housing the RFID module 4 inside the protective case 3. After the RFID module 4 is inserted, the opening of the slit 30 may be sealed with a sealing material such as an adhesive.

[0019] The RFID module 4 of this embodiment has a sheet-like base, an IC chip (not shown) attached to the base, a communication antenna 40, a battery (not shown), and a sensor 41 such as a temperature sensor. The sensor 41 continuously measures the temperature of the concrete, and the IC chip records the temperature history. This RFID module 4 is an example and is not limited to this.

[0020] In the housing space 33 of the protective case 3, the communication antenna 40 is offset to one side in the second direction D2 (the side that faces upward when fixed), and the communication antenna 40 is disposed in a position close to the upper end of the protective case 3. This allows the communication antenna 40 to be located as close as possible to the concrete surface 60 after pouring.

[0021] Furthermore, when the protective case 3 is fixed to the reinforcing bars, it is preferable that the surface direction of the protective case 3 is along the vertical direction Z. This allows the communication antenna 40 inside the protective case 3 to be closer to the concrete surface 60 above, making communication easier. "The surface direction is along the vertical direction Z" means that the surface direction is within 30 degrees of the vertical direction Z when viewed from the side. Since communication is performed from above, this is suitable for pavement or concrete floors with few horizontal surfaces. Furthermore, compared to when the surface direction of the protective case 3 is horizontal, pouring concrete is easier and concrete pouring is less likely to be obstructed. Furthermore, by orienting the surface direction of the protective case 3 along the vertical direction Z, movement of the protective case 3 can be suppressed, and even when an RFID module that performs directional communication is used, obstruction of the directional communication due to a shift in the position or orientation of the RFID module can be reduced. Furthermore, if the surface direction of the protective case 3 is horizontal, there is a risk that the concrete above the protective case 3 will become a weak spot and become prone to peeling, but by orienting the surface direction of the protective case 3 along the vertical direction Z, the occurrence of weak spots in the concrete can be suppressed, making the protective case 3 suitable for pavement and floor concrete.

[0022] As shown in FIG. 3A, a window 34 is formed on the front of the protective case 3, exposing the sensor 41 of the RFID module 4 to the outside of the protective case 3. As a result, when concrete is poured, the concrete comes into contact with the sensor 41 through the window 34, allowing the sensor 41 to directly measure the physical properties of the concrete (e.g., temperature, capacitance, potential difference, corrosion, strain, etc.). Because the sensor 41 can measure the physical properties by coming into contact with the concrete 11, the accuracy of the measurement can be improved. The window 34 is rectangular, but the shape can be changed as appropriate.

[0023] As shown in FIGS. 1 and 2, 3A and 3B, and 4A and 4C, a first mounting portion 51 for fastening to a rebar is provided at a first end 31 of the protective case 3 in the first direction D1. A second mounting portion 52 for fastening to a rebar is provided at a second end 32 of the protective case 3 opposite the first end 31 in the first direction D1. In the first embodiment, the first mounting portion 51 and the second mounting portion 52 are at least one hole formed in the protective case 3. The protective case 3 can be fastened to the rebar by a wire 50 such as a wire passed through at least one hole. In the first embodiment, the protective case 3 is fastened to the rebar by a wire 50 passed through two adjacent holes. The first mounting portion 51 and the second mounting portion 52 are not limited to at least one hole. For example, the first mounting portion 51 and the second mounting portion 52 may be a wire fixed to the protective case 3, or a band or clip fixed to the protective case 3. Furthermore, the first mounting portion 51 and the second mounting portion 52 may be fastened to the rebar using a screw or an anchor.

[0024] After the protective case 3 is fixed to the reinforcing bar, concrete is poured. This embeds the reinforcing bar and the protective case 3 within the concrete. FIGS. 5 and 6 are side views schematically illustrating the relationship between the protective case 3, the concrete surface 60, and the reinforcing bar after the concrete has been poured. As shown in FIGS. 5 and 6, the cover depth (L1, L2) from the concrete surface 60 after pouring to the reinforcing bar (e.g., the second reinforcing bar 2) to which the protective case 3 is fixed may vary depending on the construction site. Even when the cover depth varies, there is a demand for the distance L3 from the concrete surface 60 to the communication antenna 40 to be as constant or as small as possible. Therefore, the first mounting portion 51 and the second mounting portion 52 are configured so that their mounting positions relative to the reinforcing bar can be changed in the vertical direction Z (second direction D2). In the first embodiment, the first mounting portion 51 and the second mounting portion 52 each have three or more holes. The height at which the protective case 3 is fixed to the rebar can be changed by selecting two adjacent holes from the three or more holes and passing wires 50 through the selected two holes to fix the protective case 3 to the rebar. In the first embodiment, the first mounting portion 51 and the second mounting portion 52 each have four holes, allowing three mounting positions to be selected. The number of mounting positions is not limited to three and can be changed as appropriate. The distance L3 is preferably 12 mm or more and 20 mm or less. The distance L4 between the protective case 3 and the concrete surface 60 is preferably 10 mm or more to avoid creating a weak point in the concrete.

[0025] As shown in FIGS. 2, 4B, and 4C, the first end 31 and the second end 32 have inclined surfaces 31a and 32a, respectively. Each of the inclined surfaces 31a and 32a is a chamfered portion that is inclined with respect to the first direction D1 when viewed from a line of sight parallel to the second direction D2. In the first embodiment, the inclined surfaces 31a and 32a are flat surfaces. The inclined surface 31a of the first end 31 preferably extends along the axial direction X of the first reinforcing bar 1. The inclined surface 32a of the second end 32 preferably extends along the axial direction Y of the second reinforcing bar 2. When the first end 31 and the second end 32 have the inclined surfaces 31a and 32a, respectively, the protective case 3 can make surface contact with the reinforcing bar, making the protective case 3 less likely to shift position relative to the reinforcing bar, compared to when the first end 31 and the second end 32 do not have the inclined surfaces 31a and 32a.

[0026] FIG. 2 shows an enlarged view of a portion of the first end 31, illustrating the cross-sectional shape of the hole through which the wire 50 passes. The inclined surfaces 31a and 32a reduce the thickness of the tips of the first end 31 and the second end 32. Therefore, the holes serving as attachment portions are inclined with respect to the thickness direction D3 of the protective case 3. This ensures a sufficient thickness for the components at the tips of the first end 31 and the second end 32, thereby increasing the component strength, compared to when the holes serving as attachment portions are parallel to the thickness direction D3. It is preferable that the depth of the holes serving as attachment portions be visible through the holes when viewed parallel to the normal to the inclined surfaces 31a and 32a. More preferably, the holes serving as attachment portions are perpendicular to the inclined surfaces 31a and 32a.

[0027] 2, in the first embodiment, the first angle α of the inclined surface 31a of the first end portion 31 relative to the axial direction X of the first reinforcing bar 1 is 45 degrees, and the second angle β of the inclined surface 32a of the second end portion 32 relative to the axial direction Y of the second reinforcing bar 2 is 45 degrees, but this is not limited to this. For example, β = 90 - α, and α is preferably 30 degrees or more and 60 degrees or less. If α is outside the range of 30 degrees or more and 60 degrees or less, the protective case 3 may easily get too close to either the first reinforcing bar 1 or the second reinforcing bar 2, which may deteriorate the communication environment.

[0028] As described above, by fixing the RFID module 4 to the first rebar 1 and the second rebar 2, the center of the RFID module 4 in the first direction D1 is spaced apart from the first rebar 1 and the second rebar 2, making it possible to suppress or prevent communication problems caused by the communication antenna 40 coming too close to the rebars. At the same time, since the protective case 3 is fixed to the rebars at two locations, the first end 31 and the second end 32, a firm fixation is possible. It is preferable that the distance between the center of the RFID module 4 in the first direction D1 and the intersection of the first rebar 1 and the second rebar 2 be 30 mm or more.

[0029] After the protective case 3 is fixed to the rebar, concrete is poured. The sensor 41 of the RFID module 4 measures the temperature periodically and continuously, measuring the temperature of the concrete. The temperature history of the concrete is recorded. The temperature history is then read by readers placed above the protective case 3 and the concrete via wireless communication using RFID technology, and is used to determine whether the concrete has reached a predetermined strength that allows it to be demolded.

[0030] [Another embodiment] (A) In the above embodiment, the protective case 3 has a shape in which a rectangular plate portion and a triangular plate portion are combined, but this is not limited to this. For example, as shown in Fig. 7, the protective case 3 may be formed in a rectangular plate shape. Also, the protective case 3 may be rod-shaped instead of plate-shaped.

[0031] (B) In the above embodiment, the first reinforcing bar 1 and the second reinforcing bar 2 to which the protective case 3 is fixed are perpendicular to each other, but this is not limited to this. For example, the protective case 3 may be attached to a location where the angle between the first reinforcing bar 1 and the second reinforcing bar 2 is an obtuse angle, or the protective case 3 may be attached to a location where the angle between the first reinforcing bar 1 and the second reinforcing bar 2 is an acute angle. The first reinforcing bar 1 and the second reinforcing bar may be on the same reinforcing bar with a corner formed thereon, with the first reinforcing bar 1 on one side of the corner and the second reinforcing bar on the other side of the corner.

[0032] (C) A mark or other indication may be provided on the protective case 3 to indicate the orientation of the protective case 3 in the up-down direction Z when the protective case 3 is fixed.

[0033] (D) A plurality of (five) recesses 7 are formed on the rear surface of the protective case 3, but this is not limitative. As shown in FIG. 7, the protective case 3 does not necessarily have to have recesses 7.

[0034] (E) In the above embodiment, the first end 31 and the second end 32 are provided with inclined surfaces 31a, 32a, but the inclined surfaces 31a, 32a do not have to be provided. Also, the inclined surfaces 31a, 32a are flat surfaces, but are not limited to flat surfaces. For example, they may be curved.

[0035] (F) In the above embodiment, the RFID module 4 has the sensor 41, but the RFID module 4 does not have to have the sensor 41. In that case, the protective case 3 does not have to have the window 34.

[0036] [1] As described above, the method of installing the RFID module 4 on the reinforcing bar before pouring concrete includes the steps of fixing the first end 31 in the first direction D1 of the protective case 3 that houses the RFID module 4 to the first reinforcing bar 1, and fixing the second end 32 of the protective case 3 opposite the first end 31 in the first direction D1 to the second reinforcing bar 2 that intersects the first reinforcing bar 1, and when viewed from a line of sight parallel to the vertical direction Z, the first direction D1 of the protective case 3 may be inclined in both the axial direction X of the first reinforcing bar 1 and the axial direction Y of the second reinforcing bar 2. By fixing the RFID module 4 to the first reinforcing bar 1 and the second reinforcing bar 2 in this way, the center of the RFID module 4 in the first direction D1 is separated from the first reinforcing bar 1 and the second reinforcing bar 2, which makes it possible to suppress or prevent communication failures caused by the communication antenna 40 coming too close to the reinforcing bars. At the same time, since the protective case 3 is fixed to the reinforcing bars at two locations, the first end 31 and the second end 32, a firm fixation is possible.

[0037] [2] In the method for installing the RFID module 4 described in [1] above, the protective case 3 may be formed in a plate shape, and the surface direction of the protective case 3 may be along the vertical direction Z. This makes it easier to pour concrete and less likely to interfere with pouring the concrete than if the surface direction of the protective case 3 were horizontal. Also, if the surface direction of the protective case 3 were horizontal, there would be a risk that the concrete above the protective case 3 would become a weak spot and become prone to peeling, but by aligning the surface direction of the protective case 3 along the up-down direction Z, it is possible to prevent weak spots from occurring in the concrete, making it suitable for pavement and floor concrete.

[0038] [3] The method for installing the RFID module 4 described in [2] above may be such that the RFID module 4 has a communication antenna 40, and when housed in the protective case 3, the communication antenna 40 is positioned at the top of the protective case 3. This allows the communication antenna 40 inside the protective case 3 to be closer to the concrete surface 60 above, making communication easier.

[0039] [4] In the method for installing the RFID module 4 according to any one of the above [1] to [3], the first end 31 and the second end 32 may have inclined surfaces 31a and 32a. This increases the area where the first end 31 and the second end 32 come into contact with the reinforcing bar, making it possible to prevent the protective case 3 from shifting out of position.

[0040] [5] In the method for installing the RFID module 4 described in any one of [1] to [4] above, the first end 31 and the second end 32 may each have three or more holes, and the wire 50 may be passed through two adjacent holes of the three or more holes to be fixed to the reinforcing bar. This makes it possible to fix the protective case 3 at multiple height positions with a simple configuration. In particular, the height position of the protective case 3 can be adjusted to match the concrete surface 60 after pouring. Also, the communication antenna 40 inside the protective case 3 can be brought closer to the concrete surface 60 above, making communication easier.

[0041] [6] In the method for installing the RFID module 4 described in any one of [1] to [5] above, the RFID module 4 may have a sensor 41, and the protective case 3 may have a window 34 for exposing the sensor 41 to the outside of the protective case 3. This allows the sensor 41 to directly measure physical properties such as the temperature of the concrete outside the protective case 3.

[0042] [7] The method for installing the RFID module 4 described in any one of [1] to [6] above may include a step in which the RFID module 4 has a sensor 41, and after the protective case 3 is fixed to a reinforcing bar, concrete is poured and the temperature history measured by the sensor 41 is recorded. This makes it possible to know the temperature history of the concrete and estimate physical properties such as the strength of the concrete.

[0043] [8] The method for installing the RFID module 4 described in [7] above may include a step of reading the temperature history measured by the sensor 41 with a reader placed above the protective case 3 and the concrete. This makes it possible to easily obtain the temperature history of the concrete.

[0044] Although the embodiments of the present disclosure have been described above with reference to the drawings, the specific configurations should not be considered to be limited to these embodiments. The scope of the present disclosure is defined not only by the description of the above embodiments but also by the claims, and further includes all modifications within the meaning and scope of the claims.

[0045] The structures employed in the above-described embodiments can be employed in any other embodiment. The specific configurations of the components are not limited to the above-described embodiments, and various modifications are possible within the scope of the present disclosure. [Explanation of symbols]

[0046] 1: First rebar 2: Second rebar 3: Protective case 4: RFID module 31:First end 31a, 32a: Inclined surface 32:Second end 34: Window 40: Communication antenna 41: Sensor 50: Wire rod D1: 1st direction X: Axial direction Y: Axial direction Z: Vertical direction

Claims

1. A method for installing an RFID module on a reinforcing bar before pouring concrete, comprising: Fixing a first end portion of a protective case accommodating an RFID module to a first rebar; and fixing a second end of the protective case opposite to the first end in the first direction to a second reinforcing bar that intersects with the first reinforcing bar, A method for installing an RFID module, wherein, when viewed from a line of sight parallel to the vertical direction, the first direction of the protective case is inclined both in the axial direction of the first reinforcing bar and in the axial direction of the second reinforcing bar.

2. The protective case is formed in a plate shape, The RFID module installation method according to claim 1 , wherein the surface direction of the protective case is along the vertical direction.

3. the RFID module has a communication antenna; 3. The RFID module installation method according to claim 2, wherein the communication antenna is disposed at an upper portion of the protective case when the RFID module is housed in the protective case.

4. 4. The RFID module installation method according to claim 1, wherein the first end and the second end have inclined surfaces.

5. the first end and the second end each have three or more holes; The RFID module installation method according to claim 4 , further comprising passing a wire through two adjacent holes of the three or more holes to fix the RFID module to the reinforcing bar.

6. the RFID module has a sensor; The RFID module installation method according to claim 1 , wherein the protective case has a window for exposing the sensor to the outside of the protective case.

7. the RFID module has a sensor; The RFID module installation method according to claim 1 , further comprising the step of pouring concrete after fixing the protective case to a reinforcing bar, and recording the temperature history measured by the sensor.

8. 8. The RFID module installation method according to claim 7, further comprising the step of reading the temperature history measured by the sensor with a reader disposed above the protective case.

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