JP7610217B2 - Utility pole, utility pole deterioration time estimation device, and utility pole deterioration time estimation method - Google Patents

Description

The present invention relates to a utility pole, a utility pole deterioration time estimation device, and a utility pole deterioration time estimation method.

Utility poles are known that are installed to extend vertically and support overhead lines (e.g., electric wires, telephone lines, or communication cables) in the air. For example, the utility pole described in Patent Document 1 is shaped like a truncated cone with a central axis extending vertically. The utility pole comprises a hollow main body made of concrete that constitutes at least a portion of the utility pole other than both ends in the vertical direction. The utility pole comprises a plurality of reinforcing bars that extend axially between the inner peripheral surface of the main body and the outer peripheral surface of the main body.

JP 2002-345132 A

However, when moisture contained in wind, rain, snow, etc. adheres to the outer peripheral surface of the main body, the moisture penetrates from the outer peripheral surface into the inside of the main body. As a result, the reinforcing bars located inside the main body corrode and rust is generated. In particular, near the sea, wind, rain, snow, etc. contain a relatively large amount of salt. Therefore, salt also penetrates from the outer peripheral surface of the main body into the inside of the main body, which tends to accelerate corrosion of the reinforcing bars and the generation of rust.

The strength of the reinforcing bar decreases with corrosion. Furthermore, rust formed inside the main body generates stress within the main body. As a result, cracks may occur in the main body. In particular, if cracks occur on the outer peripheral surface of the main body, moisture and salt are more likely to penetrate from the outer peripheral surface of the main body into the inside of the main body. Therefore, in this case, corrosion and rust formation of the reinforcing bar are more likely to be accelerated.
Thus, the utility pole described in Patent Document 1 has the problem that it may deteriorate relatively quickly.

One of the objectives of this invention is to suppress deterioration of utility poles.

In one aspect, the pole is frusto-conical or cylindrical with a central axis extending vertically.
The utility pole includes a main body and a plurality of reinforcing bars. The main body constitutes at least a portion of the utility pole other than both vertical ends, is made of concrete, and is hollow. The reinforcing bars extend in the axial direction between an inner peripheral surface of the main body and an outer peripheral surface of the main body.

For each of the multiple reinforcing bars of the utility pole, the coating thickness ratio, which is the ratio of the inner coating thickness, which is the distance between the inner surface of the main body and the reinforcing bar, to the outer coating thickness, which is the distance between the outer surface of the main body and the reinforcing bar, is 1.2 or less.

In another aspect, a utility pole deterioration time estimation device estimates a deterioration time that represents the time required for a utility pole that is frustum-shaped or cylindrical and has a central axis extending in a vertical direction to deteriorate.
The utility pole includes a main body and a plurality of reinforcing bars. The main body constitutes at least a portion of the utility pole other than both vertical ends, is made of concrete, and is hollow. The reinforcing bars extend in the axial direction between an inner peripheral surface of the main body and an outer peripheral surface of the main body.

The utility pole deterioration time estimation device includes a coverage thickness ratio information acquisition unit and a deterioration time estimation unit.
The coating thickness ratio information acquisition unit acquires coating thickness ratio information representing a coating thickness ratio, which is the ratio of the inner coating thickness, which is the distance between the inner surface of the main body and the reinforcing bar, to the outer coating thickness, which is the distance between the outer surface of the main body and the reinforcing bar, for at least one of the multiple reinforcing bars.
The deterioration time estimation unit estimates the deterioration time of the utility pole based on the coverage thickness ratio represented by the acquired coverage thickness ratio information.

In another aspect, a utility pole deterioration time estimation method estimates a deterioration time that indicates the degree of deterioration of a utility pole that is shaped like a truncated cone or a cylinder and whose central axis extends in a vertical direction.
The utility pole includes a main body and a plurality of reinforcing bars. The main body constitutes at least a portion of the utility pole other than both vertical ends, is made of concrete, and is hollow. The reinforcing bars extend in the axial direction between an inner peripheral surface of the main body and an outer peripheral surface of the main body.

The method for estimating the deterioration time of utility poles is as follows:
Acquire, for at least one of the plurality of reinforcing bars, coating thickness ratio information that represents a coating thickness ratio that is a ratio of an inner coating thickness, which is the distance between an inner circumferential surface of the main body portion and the reinforcing bar, to an outer coating thickness, which is the distance between an outer circumferential surface of the main body portion and the reinforcing bar;
estimating a deterioration time of the utility pole based on the coverage thickness ratio represented by the obtained coverage thickness ratio information;
This includes:

It can prevent deterioration of utility poles.

FIG. 2 is an enlarged view of a portion of a horizontal cross section of a utility pole. FIG. 1 is an explanatory diagram showing the propagation of a crack that occurred near a reinforcing bar inside a utility pole. FIG. 2 is a diagram illustrating a horizontal cross section of the utility pole of the first embodiment. FIG. 4 is an enlarged view of a portion of FIG. 3 . FIG. 1 is an explanatory diagram showing a configuration of an accelerated deterioration test. 1 is a graph showing changes in strain over time in a utility pole according to an example of the first embodiment. 13 is a graph showing the change in strain over time in a utility pole of a comparative example. 1 is a graph showing the change in crack initiation time for a utility pole versus outer coating thickness. 1 is a graph showing the change in crack initiation time in a utility pole versus the thickness of the inner coating. 1 is a graph showing the change in time to crack occurrence in a utility pole versus the coating thickness ratio. FIG. 13 is a block diagram showing the configuration of a utility pole deterioration time estimation device according to a second embodiment. FIG. 11 is a block diagram showing functions of a utility pole deterioration time estimation device according to a second embodiment. 13 is a graph showing the relationship between crack occurrence time and coating thickness ratio used by the utility pole deterioration time estimation device of the second embodiment.

Hereinafter, the embodiments of the utility pole, utility pole deterioration time estimation device, and utility pole deterioration time estimation method of the present invention will be described with reference to Figs. 1 to 13.

Figure 1 is an enlarged view of a portion of a horizontal cross section of a utility pole. As indicated by the arrows marked with the symbol WS in Figure 1, moisture and salt adhering to the outer peripheral surface OS of the main body 91 of the utility pole penetrate from the outer peripheral surface OS of the main body 91 into the inside of the main body 91. Therefore, as shown in Figure 2 (A), the outer peripheral surface OS side of the reinforcing bar 92 located inside the main body 91 is more susceptible to corrosion and rust RU than the inner peripheral surface IS side of the main body 91, so it can be hypothesized that cracks CR are more likely to occur on the outer peripheral surface OS of the main body 91 before the inner peripheral surface IS of the main body 91 by extending cracks CR that occur near the reinforcing bar 92 to the outer peripheral surface OS of the main body 91.

On the other hand, the main body 91 is often a centrifugal reinforced concrete pipe formed by compacting concrete using centrifugal force. In this case, the water-cement ratio (in other words, W/C), which is the ratio of the weight of water to the weight of cement in the concrete, and the ratio of the volume of air contained in the concrete (in other words, the air ratio or air volume) tend to be lower than when the concrete is formed by compacting it using methods other than centrifugal force (e.g., vibration, etc.), so the concrete tends to be dense.

The portion of the main body 91 near the outer peripheral surface OS is formed by applying a greater centrifugal force than the portion near the inner peripheral surface IS. For this reason, the portion of the main body 91 near the outer peripheral surface OS is often denser than the portion near the inner peripheral surface IS. Therefore, as shown in FIG. 2B, it can be hypothesized that the inner peripheral surface IS of the main body 91 is more likely to develop cracks CR before the outer peripheral surface OS of the main body 91.

As such, there are many aspects of the relationship between the corrosion and rust formation of reinforcing bars and the occurrence of cracks in utility poles that remain unclear. As a result of extensive research into this relationship, the inventors of the present application came up with the invention of the present application.

First Embodiment
(overview)
The utility pole of the first embodiment has a truncated cone or cylinder shape with a central axis extending in the vertical direction. The utility pole includes a main body and a plurality of reinforcing bars. The main body constitutes at least a portion of the utility pole other than both ends in the vertical direction, is made of concrete, and is hollow. The plurality of reinforcing bars extend in the axial direction between an inner peripheral surface of the main body and an outer peripheral surface of the main body.
The utility pole has, for each of a plurality of reinforcing bars, a coating thickness ratio, which is the ratio of the inner coating thickness, which is the distance between the inner surface of the main body and the reinforcing bar, to the outer coating thickness, which is the distance between the outer surface of the main body and the reinforcing bar, of 1.2 or less.

After extensive investigation, the inventors of the present application have found that if a crack occurs on the inner circumferential surface of the main body before it occurs on the outer circumferential surface of the main body, cracks are less likely to occur on the outer circumferential surface of the main body, and that if the coating thickness ratio is 1.2 or less, cracks are more likely to occur on the inner circumferential surface of the main body before it occurs on the outer circumferential surface of the main body.

Therefore, according to the utility pole of the first embodiment, since cracks are likely to occur on the inner circumferential surface of the main body before they occur on the outer circumferential surface of the main body, it is possible to suppress the occurrence of cracks on the outer circumferential surface of the main body, thereby suppressing deterioration of the utility pole.
Next, the utility pole of the first embodiment will be described in more detail.

(composition)
As shown in Figures 3 and 4, the utility pole 1 has a truncated cone shape with a central axis extending in the vertical direction. The diameter of the utility pole 1 decreases in the vertically upward direction. In this example, the diameter of the utility pole 1 is a length of 150 mm to 450 mm. The utility pole 1 may also be cylindrical. Figure 3 shows a cross section of the utility pole 1 cut by a horizontal plane. Figure 4 is an enlarged view of an area IV surrounded by a dashed line in Figure 3.

The utility pole 1 comprises a main body 11, a number of axial reinforcing bars 12 (in this example, 12), circumferential reinforcing bars (not shown), a lid (not shown), and a bottom (not shown).

The main body 11 constitutes at least a part of the utility pole 1 other than the lid and the bottom that constitute both ends in the vertical direction. In this example, the main body 11 constitutes the portion of the utility pole 1 between the lid and the bottom that constitute both ends in the vertical direction.
The cover portion constitutes the vertically upper end of the utility pole 1. The bottom portion constitutes the vertically lower end of the utility pole 1.

The main body 11 is made of concrete and is hollow. In this example, the main body 11 is a centrifugal reinforced concrete pipe. A centrifugal reinforced concrete pipe is formed by compacting concrete using centrifugal force. A centrifugal reinforced concrete pipe may also be referred to as a Hume pipe. In this example, the distance between the inner circumferential surface IS of the main body 11 and the outer circumferential surface OS of the main body 11 (in other words, the thickness of the main body 11) is 30 mm to 80 mm.

Each axial reinforcing bar 12 extends in the axial direction of the main body 11 between the inner peripheral surface IS of the main body 11 and the outer peripheral surface OS of the main body 11. In this example, the multiple axial reinforcing bars 12 are positioned at approximately equal intervals in the circumferential direction of the main body 11. Each axial reinforcing bar 12 is a tension member or a non-tension member. For example, each axial reinforcing bar 12 is a PC (Prestressed Concrete) steel wire or a PC steel rod. In this example, the diameter of each axial reinforcing bar 12 is 7 mm to 10 mm in length.

Each axial reinforcing bar 12 has a coating thickness ratio of 1.2 or less. In this example, each axial reinforcing bar 12 has a coating thickness ratio of 0.4 to 1.2. Preferably, each axial reinforcing bar 12 has a coating thickness ratio of 0.4 to 0.8.
4, the coating thickness ratio is the ratio of an inner coating thickness T1, which is the distance between an inner circumferential surface IS of the main body 11 and the axial reinforcing bars 12 in the direction along the reference line RL, to an outer coating thickness T2, which is the distance between an outer circumferential surface OS of the main body 11 and the axial reinforcing bars 12 in the direction along the reference line RL. In this example, the reference line RL is a straight line passing through the central axis of the main body 11 and the central axis of the axial reinforcing bars 12 in a horizontal plane.

Each axial reinforcing bar 12 has an inner coating thickness T1 of 3 mm or more. In this example, each axial reinforcing bar 12 has an inner coating thickness T1 of 3 mm to 35 mm. Each axial reinforcing bar 12 has an inner coating thickness T1 of preferably 5 mm or more, more preferably 9 mm or more.

Each axial reinforcing bar 12 has an outer coating thickness T2 of 35 mm or less. In this example, each axial reinforcing bar 12 has an outer coating thickness T2 of 9 mm to 35 mm.

The circumferential rebar is wound around the multiple axial rebars 12 and fixed to the multiple axial rebars 12. For example, the circumferential rebar is fixed to the multiple axial rebars 12 by spot welding. In this example, the circumferential rebar is spiral and extends over the entire axial direction of the main body 11. The utility pole 1 may include multiple annular circumferential rebars. The utility pole 1 may not include a circumferential rebar.

The utility pole 1 is installed so as to extend in the vertical direction by having its vertically downward end buried in the ground.
In this example, an overhead line (not shown) is installed between utility pole 1 and another utility pole (not shown) other than utility pole 1. For example, the overhead line is an electric wire, a telephone line, a communication cable, etc. Utility pole 1 supports the overhead line at an end of utility pole 1 in the vertically upward direction.

As described above, the utility pole 1 of the first embodiment is a truncated cone or cylinder (in this example, a truncated cone) with a central axis extending in the vertical direction. The main body 11 includes the main body 11 and a plurality of reinforcing bars (in this example, axial reinforcing bars) 12. The main body 11 constitutes at least a portion of the utility pole 1 other than both ends in the vertical direction, is made of concrete, and is hollow. The plurality of reinforcing bars 12 extend in the axial direction between the inner peripheral surface IS of the main body 11 and the outer peripheral surface OS of the main body 11. For each of the plurality of axial reinforcing bars 12, the utility pole 1 has a coating thickness ratio of 1.2 or less, which is the ratio of the inner coating thickness, which is the distance between the inner peripheral surface IS of the main body 11 and the reinforcing bar 12, to the outer coating thickness, which is the distance between the outer peripheral surface OS of the main body 11 and the reinforcing bar 12.

According to this, since cracks are more likely to occur on the inner circumferential surface IS of the main body 11 before the outer circumferential surface OS of the main body 11, it is possible to suppress the occurrence of cracks on the outer circumferential surface OS of the main body 11. As a result, deterioration of the utility pole 1 can be suppressed.
Furthermore, it is preferable that the coating thickness ratio is 1.1 or less. In this case, it is possible to further suppress the occurrence of cracks on the outer peripheral surface OS of the main body 11. As a result, deterioration of the utility pole 1 can be suppressed.

Furthermore, the utility pole 1 of the first embodiment has a coating thickness ratio of 0.4 to 0.8 for each of the multiple axial reinforcing bars 12.

As a result of careful investigation, the inventors of the present application have found that when the coating thickness ratio has a value of 0.4 to 0.8, the time required for cracks to occur on the outer peripheral surface OS of the main body portion 11 tends to be long.
Therefore, according to the utility pole 1 of the first embodiment, it is possible to sufficiently extend the time required for cracks to occur in the outer peripheral surface OS of the main body 11. Therefore, deterioration of the utility pole 1 can be suppressed.

Furthermore, the utility pole 1 of the first embodiment has an inner coating thickness T1 of 9 mm to 35 mm for each of the multiple axial reinforcing bars 12.

However, if the thickness of the inner coating is less than 9 mm, there is a risk that the bending strength of the utility pole 1 will be too low. In contrast, the utility pole 1 of the first embodiment can sufficiently increase the bending strength of the utility pole 1.

<Example>
An experiment conducted to investigate the relationship between the corrosion and rust generation of the reinforcing bar 12 and the occurrence of cracks in the utility pole 1 of the example of the first embodiment will be described.
In this example, as shown in FIG. 5, an accelerated deterioration test was carried out in which the reinforcing bar 12 was corroded to cause cracks to occur.

The sample SM is a part of the main body 11. The sample SM is supported vertically above the water tank WP so that the axial direction of the main body 11 is horizontal. The positive terminal of the constant current power supply CC is connected to one of the reinforcing bars 12 of the sample SM.

The water tank WP stores salt water SW having a concentration of 3% by weight.
A wire mesh (in this example, a wire mesh made of stainless steel) WM is immersed in salt water SW. A negative terminal of a constant current power source CC is connected to the wire mesh WM.
A part of the sponge SP is immersed in salt water SW. The wire mesh WM is in contact with a portion of the outer circumferential surface OS of the sample SM that is vertically below the reinforcing bar 12 via the sponge SP.

A constant DC current is supplied from the constant current power supply CC, causing a DC current to flow through the reinforcing bar 12. In this way, corrosion and rust formation in the reinforcing bar 12 is promoted.

Two outer strain gauges SGO are attached to the outer peripheral surface OS of the sample SM so as to measure the strain in the circumferential direction of the sample SM. Two inner strain gauges SGI are attached to the inner peripheral surface IS of the sample SM so as to measure the strain in the circumferential direction of the sample SM. The inner strain gauges SGI and the outer strain gauges SGO face each other so as to sandwich the reinforcing bar 12.

In this accelerated deterioration test, the salt penetration that occurs in a natural environment near the sea for 3,000 to 8,000 hours is achieved in about one hour.

Table 1 shows the results of the accelerated aging test for each of the samples with sample numbers 1 to 20. The samples with sample numbers 1 to 12 are parts of the utility pole 1 of the example of the first embodiment. The samples with sample numbers 13 to 20 are parts of the utility pole of the comparative example.

In this example, the crack initiation time is the time required (or elapsed) for the strain measured by the outer strain gauge SGO to reach 500μ. In this example, the length of each of the outer strain gauge SGO and the inner strain gauge SGI is 30 mm. Therefore, a strain of 500μ corresponds to an elongation of the outer strain gauge SGO and the inner strain gauge SGI of 15 μm.

The inward-first type of crack indicates that a crack occurs on the inner surface of the sample before it occurs on the outer surface of the sample. On the other hand, the outward-first type of crack indicates that a crack occurs on the outer surface of the sample before it occurs on the inner surface of the sample. When a crack occurs, the strain increases rapidly. Therefore, in this example, the crack type is determined based on the relationship between the time when the strain measured by the outer strain gauge SGO increases rapidly and the time when the strain measured by the inner strain gauge SGI increases rapidly.

Figure 6 shows the change in strain over time measured for the comparative sample, sample number 14. In Figure 6, the curve labeled CO1 represents the strain measured by the outer strain gauge SGO. In Figure 6, the curve labeled CI1 represents the strain measured by the inner strain gauge SGI.

6, the strain measured by the outer strain gauge SGO increases sharply at about 15 hours elapsed time, while the strain measured by the inner strain gauge SGI increases sharply at about 20 hours elapsed time.
In this way, the comparative sample is an outward-first type in which cracks occur on the outer peripheral surface of the sample before they occur on the inner peripheral surface of the sample.

Figure 7 shows the change in strain over time measured for the example sample No. 1. In Figure 7, the curve labeled CO2 represents the strain measured by the outer strain gauge SGO. In Figure 7, the curve labeled CI2 represents the strain measured by the inner strain gauge SGI.

7, the strain measured by the inner strain gauge SGI increases sharply at about 15 hours elapsed time, while the strain measured by the outer strain gauge SGO increases sharply at about 55 hours elapsed time.
In this way, the sample of the embodiment is an inward-first type in which cracks occur on the inner peripheral surface of the sample before they occur on the outer peripheral surface of the sample.

As shown in Figures 6 and 7, if a crack occurs on the inner circumferential surface of the main body before it occurs on the outer circumferential surface of the main body, it becomes difficult for a crack to occur on the outer circumferential surface of the main body.

Figure 8 shows the change in crack initiation time versus outer coating thickness. Figure 9 shows the change in crack initiation time versus inner coating thickness. Figure 10 shows the change in crack initiation time versus coating thickness ratio.

As shown in FIG. 10, when the coating thickness ratio is 1.2 or less, cracks are more likely to occur on the inner circumferential surface of the main body before they occur on the outer circumferential surface of the main body. Furthermore, when the coating thickness ratio is 1.2 or less, the smaller the coating thickness ratio, the longer the time it takes for cracks to occur.

Furthermore, when the coating thickness ratio is 1.2 or less, the relationship between the coating thickness ratio x and the crack initiation time y is approximated by Equation 1, as represented by the straight line labeled AL in Fig. 10. In this example, the first parameter a is -39.2, and the second parameter b is 69.8.

In this way, according to the utility pole 1 of the first embodiment, cracks are more likely to occur on the inner circumferential surface IS of the main body 11 before they occur on the outer circumferential surface OS of the main body 11, so it is possible to prevent cracks from occurring on the outer circumferential surface OS of the main body 11. As a result, deterioration of the utility pole 1 can be suppressed.

Second Embodiment
(overview)
The utility pole deterioration time estimation device of the second embodiment estimates a deterioration time that represents the time required for a utility pole having a truncated cone shape or a cylindrical shape with a central axis extending in the vertical direction to deteriorate. The utility pole includes a main body and a plurality of reinforcing bars. The main body constitutes at least a part of the utility pole other than both ends in the vertical direction, is made of concrete, and is hollow. The plurality of reinforcing bars extend in the axial direction between an inner peripheral surface of the main body and an outer peripheral surface of the main body.

The utility pole deterioration time estimation device includes a coverage thickness ratio information acquisition unit and a deterioration time estimation unit.
The coating thickness ratio information acquisition unit acquires coating thickness ratio information representing a coating thickness ratio, which is the ratio of the inner coating thickness, which is the distance between the inner surface of the main body and the reinforcing bar, to the outer coating thickness, which is the distance between the outer surface of the main body and the reinforcing bar, for at least one of the multiple reinforcing bars.
The deterioration time estimation unit estimates a deterioration time based on the coating thickness ratio represented by the acquired coating thickness ratio information.

Incidentally, there is a strong correlation between the deterioration time of a utility pole and the insulation thickness ratio. Therefore, the utility pole deterioration time estimation device of the second embodiment can estimate the deterioration time of a utility pole with high accuracy.
Next, the utility pole deterioration time estimation device of the second embodiment will be described in more detail.

(composition)
As shown in Fig. 11, the utility pole deterioration time estimation device 20 includes a processing device 21, a storage device 22, an input device 23, and an output device 24, which are connected to each other via a bus BU1. For example, the utility pole deterioration time estimation device 20 is configured by a computer (in other words, an information processing device). The computer may be a server type computer, a desktop type computer, a laptop type computer, or a tablet type computer. The computer may also be at least a part of a smartphone or the like. The utility pole deterioration time estimation device 20 may also be configured by a plurality of devices connected to each other so as to be able to communicate with each other.

The processing device 21 executes a program stored in the storage device 22 to control the storage device 22, the input device 23, and the output device 24. In this way, the processing device 21 realizes the functions described below.

In this example, the processing device 21 is a CPU (Central Processing Unit). Note that the processing device 21 may include an MPU (Micro Processing Unit), a GPU (Graphics Processing Unit), or a DSP (Digital Signal Processor) instead of or in addition to the CPU.

In this example, the storage device 22 includes volatile memory and non-volatile memory. For example, the storage device 22 includes at least one of a RAM (Random Access Memory), a ROM (Read Only Memory), a semiconductor memory, an organic memory, a HDD (Hard Disk Drive), and an SSD (Solid State Drive).

The input device 23 inputs information from outside the utility pole deterioration time estimation device 20. In this example, the input device 23 includes a keyboard and a mouse. The input device 23 may also include a microphone.

The output device 24 outputs information to the outside of the utility pole deterioration time estimation device 20. In this example, the output device 24 includes a display. The output device 24 may also include a speaker.
In addition, the utility pole deterioration time estimation device 20 may be equipped with a touch panel type display that constitutes both the input device 23 and the output device 24.

(function)
As shown in FIG. 12 , the functions of the utility pole deterioration time estimation device 20 include an input information receiving unit 201 , a coverage thickness ratio information acquisition unit 202 , and a deterioration time estimation unit 203 .

The input information receiving unit 201 receives the coating thickness information and the salinity information input by the user of the utility pole deterioration time estimation device 20 via the input device 23 .
In this example, the utility pole to be estimated is the utility pole 1 of the first embodiment. Note that the utility pole to be estimated may be the utility pole of the comparative example.

In this example, the coating thickness information includes information representing the outer coating thickness, information representing the thickness of the main body 11, and information representing the diameter of the axial rebar 12. The coating thickness information may also include information representing the outer coating thickness and information representing the inner coating thickness. For example, the coating thickness information may be obtained using a non-destructive testing technique that uses ultrasonic waves or electromagnetic waves.

In this example, the salt information represents the amount of salt present in the natural environment in the area where the utility pole 1 is installed. For example, the salt information represents the level of the amount of salt (e.g., high or low). For example, the salt present in the natural environment includes salt contained in the wind (in other words, airborne salt). Note that the salt present in the natural environment may also include salt attached to the surface of the utility pole 1 (in other words, attached salt). Furthermore, the salt present in the natural environment may also include salt contained in rain, snow, etc.

For example, the amount of airborne salt may be measured using the dry gauze method defined by JIS (Japanese Industrial Standards) Z 2382, or the wet candle method defined by ISO (International Organization for Standardization) 9225. Also, for example, the amount of deposited salt may be measured using a method for measuring equivalent salt deposit density (ESDD) (e.g., brush washing method, etc.), or a handheld X-ray fluorescence analyzer, etc.

The coating thickness ratio information acquisition unit 202 acquires coating thickness ratio information based on the coating thickness information received by the input information reception unit 201. The coating thickness ratio information represents a coating thickness ratio. In this example, the coating thickness ratio information acquisition unit 202 calculates the coating thickness ratio by subtracting the sum of the outer coating thickness and the diameter of the axial reinforcing bar 12 from the thickness of the main body 11 (in other words, the inner coating thickness) and dividing the result by the outer coating thickness.

The deterioration time estimation unit 203 estimates the deterioration time of the utility pole 1 based on the covering thickness ratio represented by the covering thickness ratio information acquired by the covering thickness ratio information acquisition unit 202. In this example, the deterioration time represents the time required for cracks to occur on the outer peripheral surface OS of the main body 11.

In this example, when the covering thickness ratio is equal to or smaller than a predetermined threshold, the deterioration time estimation unit 203 estimates the deterioration time of the utility pole 1 so that the deterioration time has a value that increases as the covering thickness ratio decreases. In this example, the threshold is 1.2. The threshold may be a value between 0.8 and 1.2.
Furthermore, in this example, when the coverage thickness ratio is greater than the threshold value, the deterioration time estimation unit 203 estimates the deterioration time of the utility pole 1 so as to have a constant value.

In addition, in this example, the deterioration time estimation unit 203 estimates the deterioration time of the utility pole 1 based on the salt information accepted by the input information acceptance unit 201 so that the deterioration time has a value that becomes shorter as the amount of salt present in the natural environment in the area where the utility pole 1 is installed increases. For example, when the covering thickness ratio is equal to or less than a threshold value, the deterioration time estimation unit 203 estimates the deterioration time of the utility pole 1 based on Equation 2 that expresses the relationship between the covering thickness ratio x and the crack occurrence time y. The first parameter a and the second parameter b are set in advance. The third parameter c has a value that becomes smaller as the amount of salt present in the natural environment in the area where the utility pole 1 is installed increases.

For example, as shown in FIG. 13, when the amount of salt is relatively low, the deterioration time estimation unit 203 estimates the deterioration time of utility pole 1 according to the relationship represented by the curve marked with the symbol L1, and when the amount of salt is relatively high, the deterioration time of utility pole 1 according to the relationship represented by the curve marked with the symbol L2.

In addition, when the covering thickness ratio is equal to or less than a threshold value, the deterioration time estimation unit 203 may estimate the deterioration time of the utility pole 1 based on Equation 3 which expresses the relationship between the covering thickness ratio x and the crack occurrence time y.

The deterioration time estimation unit 203 may estimate the deterioration time of the utility pole 1 without being based on the salt present in the natural environment in the area where the utility pole 1 is installed.

(Operation)
Next, the operation of the utility pole deterioration time estimation device 20 of the second embodiment will be described.
First, the utility pole deterioration time estimation device 20 receives the coating thickness information and the salinity information input by the user of the utility pole deterioration time estimation device 20 via the input device 23.
Next, the utility pole deterioration time estimation device 20 acquires coverage thickness ratio information based on the received coverage thickness information.
Next, the utility pole deterioration time estimation device 20 estimates the deterioration time of the utility pole 1 based on the coverage thickness ratio represented by the acquired coverage thickness ratio information and the received salinity information.

As described above, the utility pole deterioration time estimation device 20 of the second embodiment estimates a deterioration time that represents the time required for a utility pole that is a truncated cone or cylinder with a central axis extending in the vertical direction to deteriorate. The utility pole includes a main body and multiple reinforcing bars. The main body constitutes at least a portion of the utility pole other than both ends in the vertical direction, is made of concrete, and is hollow. The multiple reinforcing bars extend in the axial direction between the inner peripheral surface of the main body and the outer peripheral surface of the main body.

The utility pole deterioration time estimation device 20 includes a coverage thickness ratio information acquisition unit 202 and a deterioration time estimation unit 203.
The coating thickness ratio information acquisition unit 202 acquires coating thickness ratio information representing a coating thickness ratio, which is the ratio of the inner coating thickness, which is the distance between the inner surface of the main body and the rebar, to the outer coating thickness, which is the distance between the outer surface of the main body and the rebar, for at least one of the multiple rebars.
The deterioration time estimation unit 203 estimates the deterioration time of the utility pole based on the coverage thickness ratio represented by the acquired coverage thickness ratio information.

The deterioration time of a utility pole and the insulation thickness ratio have a strong correlation. Therefore, the utility pole deterioration time estimation device 20 can estimate the deterioration time of a utility pole with high accuracy.

Furthermore, in the utility pole deterioration time estimation device 20 of the second embodiment, the deterioration time represents the time required for cracks to occur on the outer peripheral surface of the main body. When the covering thickness ratio is equal to or less than a predetermined threshold, the deterioration time estimation unit 203 estimates the deterioration time of the utility pole to have a value that increases as the covering thickness ratio decreases.

The time required for cracks to appear on the outer peripheral surface of the main body and the coating thickness ratio are strongly correlated. Furthermore, when the coating thickness ratio is equal to or less than a predetermined threshold, the time required for cracks to appear on the outer peripheral surface of the main body tends to be longer as the coating thickness ratio decreases. Therefore, the utility pole deterioration time estimation device 20 can estimate the deterioration time of the utility pole with high accuracy.

The utility pole deterioration time estimation device 20 may be equipped with a communication device that communicates with devices external to the utility pole deterioration time estimation device 20. The communication device communicates according to a specific communication standard. For example, the communication standard is a standard related to a wireless LAN (Local Area Network) (e.g., IEEE (Institute of Electrical and Electronics Engineers) 802.11) or a standard related to short-range wireless communication (e.g., Bluetooth (registered trademark)).

In this case, the input information receiving unit 201 may receive the coating thickness information transmitted by the device that acquires the coating thickness information via the communication device. Also, the input information receiving unit 201 may receive the salinity information transmitted by the device that acquires the salinity information via the communication device.

The present invention is not limited to the above-described embodiment. For example, various modifications that can be understood by a person skilled in the art may be made to the above-described embodiment without departing from the spirit of the present invention.

REFERENCE SIGNS LIST 1 Utility pole 11 Main body 12 Reinforcing bar 20 Utility pole deterioration time estimation device 21 Processing device 22 Storage device 23 Input device 24 Output device 201 Input information reception unit 202 Covering thickness ratio information acquisition unit 203 Deterioration time estimation unit 91 Main body 92 Reinforcing bar BU1 Bus CC Constant current power source IS Inner surface OS Outer surface SGI Inner strain gauge SGO Outer strain gauge SM Sample SP Sponge SW Salt water WM Wire mesh WP Water tank

Claims (6)

A utility pole having a truncated cone or cylinder shape with a central axis extending in a vertical direction,
A main body portion that constitutes at least a portion of the utility pole other than both ends in the vertical direction and is made of concrete and hollow;
A plurality of reinforcing bars extending in an axial direction between an inner circumferential surface of the main body and an outer circumferential surface of the main body,
A centrifugal reinforced concrete pipe is formed by compacting concrete by centrifugal force so that a portion near an outer circumferential surface of the body portion is denser than a portion near an inner circumferential surface of the body portion,
a coating thickness ratio, which is a ratio of an inner coating thickness, which is the distance between the inner circumferential surface and the reinforcing bar, to an outer coating thickness, which is the distance between the outer circumferential surface and the reinforcing bar, for each of the plurality of reinforcing bars, has a value of 0.4 to 1.2 . 2. The utility pole according to claim 1,
A utility pole, wherein the coating thickness ratio has a value of 0.4 to 0.8. The utility pole according to claim 1 or 2,
The inner coating thickness has a value between 9 mm and 35 mm. A utility pole deterioration time estimation device that estimates a deterioration time that represents a time required for a utility pole having a truncated cone shape or a cylindrical shape with a central axis extending in a vertical direction to deteriorate, comprising:
The utility pole is
A main body portion that constitutes at least a portion of the utility pole other than both ends in the vertical direction and is made of concrete and hollow;
A plurality of reinforcing bars extending in an axial direction between an inner circumferential surface of the main body and an outer circumferential surface of the main body,
The utility pole deterioration time estimation device comprises:
A coating thickness ratio information acquisition unit that acquires coating thickness ratio information representing a coating thickness ratio, which is a ratio of an inner coating thickness, which is the distance between the inner circumferential surface and the reinforcing bar, to an outer coating thickness, which is the distance between the outer circumferential surface and the reinforcing bar, for at least one of the plurality of reinforcing bars;
a deterioration time estimation unit that estimates the deterioration time based on a coating thickness ratio represented by the acquired coating thickness ratio information;
A utility pole deterioration time estimation device comprising: The utility pole deterioration time estimation device according to claim 4,
The deterioration time represents the time required for cracks to occur on the outer circumferential surface,
The deterioration time estimation unit estimates the deterioration time so that the deterioration time has a value that increases as the covering thickness ratio decreases when the covering thickness ratio is equal to or smaller than a predetermined threshold. A utility pole deterioration time estimation method for estimating a deterioration time representing a degree of deterioration of a utility pole having a truncated cone shape or a cylindrical shape with a central axis extending in a vertical direction, comprising:
The utility pole is
A main body portion that constitutes at least a portion of the utility pole other than both ends in the vertical direction and is made of concrete and hollow;
A plurality of reinforcing bars extending in an axial direction between an inner circumferential surface of the main body and an outer circumferential surface of the main body,
The utility pole deterioration time estimation method includes:
Acquire coating thickness ratio information representing a coating thickness ratio, which is a ratio of an inner coating thickness, which is the distance between the inner circumferential surface and the reinforcing bar, to an outer coating thickness, which is the distance between the outer circumferential surface and the reinforcing bar, for at least one of the plurality of reinforcing bars;
estimating the deterioration time based on the coating thickness ratio represented by the acquired coating thickness ratio information;
A method for estimating deterioration time of a utility pole, comprising:

Images