JP4315464B1 - Nondestructive evaluation method of soundness of reinforced concrete body and apparatus therefor - Google Patents

Abstract

The present invention provides a method for effectively evaluating a non-destructive soundness of a concrete body damaged by cracking or weakening of the concrete body.
In the non-destructive evaluation of the soundness of a reinforced concrete body, the above object is to search for the reinforcing bar h in the reinforced concrete body g by the electromagnetic wave radar k at a predetermined search interval. By performing over the whole, it is solved by acquiring at least the depth position of the reinforcing bar h, and evaluating the exploration location range in which the acquired depth location is disturbed as an unhealthy location of concrete.
[Selection] Figure 11

Description

The present invention bridges slab of digits, piers, abutments, tunnel lining, retaining wall, revetment, Non-destructive method for evaluating the soundness of reinforced concrete body of a building or the like.

The soundness of reinforced concrete bodies decreases with the progress of damage due to rust of the reinforcing bars (including deterioration, the same applies hereinafter), damage due to cracks in concrete, and weakening of concrete. These damages proceed in the order of incubation period (neutralization, rust generation), progress period (rebar expansion), acceleration period (cracking / growth), and deterioration period (peeling and dropping). More specifically, the reinforced concrete body is made of a combination of cement concrete and reinforcing bars. At the time of construction, the cement concrete is alkaline and the reinforcing bars are protected, but over time, the soundness decreases due to the occurrence of cracks due to repeated loads and fatigue, neutralization, salt damage, frost damage, chemical erosion, alkaline silica reaction, etc. To go.
Up to now, the soundness of such reinforced concrete bodies has been evaluated by visual cracking and hammering. However, the tapping inspection by the proximity inspection can be found only after the rust of the reinforcing bars progresses and the concrete floats due to the expansion, and only the damage that is completely exposed on the surface can be found by the visual inspection method. In order to use the structure in a good condition for a long period of time, it is important to evaluate as early as possible and to perform preventive maintenance.
Electrochemical methods (natural potential method, polarization resistance method, electrical resistance method) are also known in response to such demands, but the current situation is that they are not widespread due to the time and effort required for preparations such as chisel. In addition, the inspection method using infrared rays and the ground penetrating radar method is greatly influenced by weather conditions and the results are not reliable. Further, all of these methods are two-dimensional methods, and the damage information extracted is only one-dimensional line information, and the spread range cannot be specified. In particular, it is difficult to evaluate the floor slab after that in the bridge where the bottom of the floor slab is reinforced, such as adhesion of steel plates.
On the other hand, the applicant irradiates electromagnetic waves toward the concrete structure, receives the reflected waves with a receiver, and analyzes the received signal of the analog waveform, thereby allocating the bar arrangement and the cavities in the concrete structure. A technique for grasping three-dimensionally and three-dimensionally is proposed (see Patent Document 1), but this method does not evaluate the soundness of a concrete body damaged by cracking or weakening.
JP-A-9-88351

Therefore, a main object of the present invention is to provide a method for effectively evaluate nondestructively soundness of reinforced concrete body more damaged Re Hibiwari.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
Reinforcing bars in which electromagnetic wave reflection strength is different from concrete and a plurality of electromagnetic wave reflecting surfaces extending in the direction intersecting with the depth direction of the concrete body in the evaluation target area are arranged in parallel at intervals in the depth direction A non-destructive method for evaluating the integrity of a concrete body,
The reflecting surface is a pair of reflective surfaces adjacent groups out of the reflecting surface of the reinforcing bars embedded in the surface and reinforced concrete body of the reinforced concrete body,
At a predetermined reflection wave data acquisition interval over the entire evaluation object area of the reinforced concrete body performs search by electromagnetic waves radar acquires reflected wave data of the electromagnetic wave at each position,
Based on the reflected wave intensity in the acquired reflected-wave data, at least, to get along with each depth position before Symbol reflective surface adjacent the pair in its extending direction,
Based on the acquired depth position, the depth portion corresponding to between the depth distance in a reflection data acquisition portion that is disturbed and the pair of the reflective surface between the pair of reflective surfaces adjacent the concrete And a depth portion corresponding to the distance between the pair of reflecting surfaces, where there is no disturbance in the distance in the depth direction between the pair of adjacent reflecting surfaces. Evaluate as a healthy place without
Soundness of the non-destructive evaluation method of the reinforced concrete body, characterized in that.

(Function and effect)
When the concrete body is probed by the electromagnetic wave radar, since the sound concrete body is homogeneous and the relative dielectric constant is uniform, the reflected wave from the reflecting surface returns regularly. In contrast, over time, cracks due to repeated loads and fatigue, neutralization, salt damage, frost damage, chemical erosion, damage due to alkali silica reaction, etc., and the material of concrete due to air layer and water intrusion, etc. When the variation occurs, the uniform relative dielectric constant also varies, and the embedded objects such as reinforcing bars and pipes embedded in the interior and the position of the back surface of the concrete body appear to vary. The present invention is based on this finding. That is, the present invention utilizes the above-described phenomenon, obtains at least the depth position of a known electromagnetic wave reflection surface by an internal exploration using an electromagnetic wave radar at a predetermined interval, and obtains an exploration location range in which the obtained depth position is disturbed. It is evaluated as a cracked part of concrete. In the evaluation method of the present invention, it is needless to say that evaluation can be performed with high accuracy and high efficiency because the survey using an electromagnetic wave radar is used. For example, the evaluation of a concrete slab that is performed in a bridge inspection or the like can be performed nondestructively from the upper surface of the floor slab.

When multiple reflective surfaces overlap in parallel in the depth direction, for example, when the front and back surfaces of a concrete body overlap in parallel, or embedded objects such as reinforcing bars are embedded in the concrete with a space in the depth direction. In such a case, if there is a crack portion at a certain portion between certain reflection surfaces, the separation distance between the reflection surfaces obtained based on the electromagnetic wave radar is disturbed only at the crack portion. Therefore, it becomes possible to evaluate even the depth part of the cracked part due to the disturbance of the separation distance between the reflecting surfaces.

<Invention of Claim 2>
For each reflective surface, the distance from other reflective surfaces is calculated for each reflected wave data acquisition location, and the case where the statistical variation in the distance between the reflective surfaces is equal to or greater than a predetermined level, The nondestructive evaluation method of the soundness of the concrete body according to claim 1, wherein cracks are evaluated.

(Function and effect)
By performing the evaluation by such a method, the worker can objectively and mechanically evaluate, or can be automatically evaluated by an information processing apparatus such as a computer. The above-described disturbance in the separation distance between the reflecting surfaces can be easily visually determined by an operator by visualizing acquired data two-dimensionally or three-dimensionally, that is, by outputting the data to a display device or a printing device. Needless to say, objective evaluation and automation are desirable.

<Invention of Claim 3>
Frequency of the electromagnetic wave is a 0.5～3GHz, the reflected wave data acquisition interval is set to 20cm or less, according to claim 1 or 2 soundness of non-destructive evaluation methods Reinforced Concrete body according.

(Function and effect)
When intended for reinforcing bar concrete body, it is desirable to employ such a frequency and the reflected wave data acquisition interval. If the frequency is too low or too high, or the reflected wave data acquisition interval is too wide, the situation detection rate in the concrete body is lowered, which is not preferable.

<Invention of Claim 4>
A plurality of electromagnetic wave reflecting surface electromagnetic wave reflection intensity extending in a direction intersecting the depth direction of the reinforced concrete member in a different and evaluation region concrete, arranged in parallel at intervals in the depth direction the soundness of the reinforced concrete body there is provided an apparatus for evaluation in a non-destructive,
The reflecting surface is a pair of reflective surfaces adjacent groups out of the reflecting surface of the reinforcing bars embedded in the surface and reinforced concrete body of the reinforced concrete body,
At a predetermined reflection wave data acquisition interval over the entire evaluation object area of the reinforced concrete body, and means for perform exploration by electromagnetic waves radar, to obtain the reflection wave data of the electromagnetic wave at each position,
Based on the reflected wave intensity in the acquired reflected-wave data, at least, each depth position before Symbol reflective surface adjacent pair and means for obtaining along the extending direction,
Based on the acquired depth position, a reflection data acquisition portion having a disorder in the distance in the depth direction between a pair of adjacent reflecting surfaces, and a depth portion corresponding to the gap between the pair of reflecting surfaces is determined . While evaluating as a crack location, and a reflection data acquisition location where there is no disturbance in the distance in the depth direction between a pair of adjacent reflection surfaces, the depth portion corresponding to the gap between the pair of reflection surfaces Means to evaluate as no healthy place ,
Nondestructive evaluation apparatus soundness of reinforced concrete body, comprising the.

(Function and effect)
The same effect as that of the first aspect of the invention can be achieved.

According to the present invention as described above, it becomes possible to effectively detect nondestructively damage from Re crack split the reinforced concrete body, advantages such is provided.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the present invention, the “surface” of the concrete body means the incident surface of the electromagnetic wave, the “back surface” means the surface on the opposite side, and the “depth position” means the direction from the front surface to the back surface ( It means the position in the depth direction.

<About electromagnetic wave radar system>
The present invention performs an internal exploration of a concrete body using an electromagnetic wave radar. As electromagnetic wave radars, various electromagnetic wave radar systems (for example, SIR3000) manufactured by GSSI (USA), RC radars (for example, Handy Search NJJ-95B) manufactured by Japan Radio Co., Ltd., and reinforcing bars for concrete structures manufactured by IREC Engineering Co., Ltd. A known device such as a device (for example, Light Esper) or a radar probe (for example, an iron seeker) manufactured by Komatsu Engineering can be used without any particular limitation, but a radar system in which a large number of transmission / reception sensors are arranged in parallel is highly efficient and highly accurate. Therefore, it is preferable. Hereinafter, specific examples will be described.

  FIG. 1 is a schematic diagram of an entire evaluation system using an electromagnetic wave radar. A symbol a is a sensor in which an electromagnetic wave transmission / reception antenna and a transmission / reception circuit are integrated in a case, a symbol c is an array antenna formed by connecting n sensors a in parallel, and a symbol b is an array antenna c. A control unit that switches functions for each sensor a by switching and individually performs transmission / reception and signal processing is shown. The array antenna c and the control unit b constitute a radar system k.

  From each sensor a controlled by the control unit b, electromagnetic waves are oscillated substantially vertically from the surface of the concrete body g toward the inside. And the reflected wave from the inside of the concrete body g is received by each sensor a. The reflected wave received by each sensor a is converted into data converted from an analog signal to a digital signal by an A / D converter (not shown) built in the computer d as a processing device via the control unit b. Is input.

Here, assuming that the arrangement direction of the sensors a is the sub-scanning direction, and the direction perpendicular to the sub-scanning direction and the electromagnetic wave transmission direction is the main scanning direction, the radar system k is supported by moving means such as wheels, for example. It is possible to move in the scanning direction, and at this time, a signal of travel distance is output from an encoder that detects the rotation of the travel distance measuring wheel, and this signal is also input to the computer d. .
Further, the radar system k can arrange the shape in the sub-scanning direction into a straight line or an arc shape depending on the shape of the inspection object.

  FIG. 2 shows a process for processing information obtained by moving the radar system k shown in FIG. 1 in the main scanning direction. As shown in FIG. 2A, the radar system k having the movement distance measuring wheel p is placed on the upper surface of the concrete body g to be inspected, and moves manually along the main scanning direction, for example. At that time, the control unit b sequentially drives, for example, n sensors a (1, 2,..., N), and each of the sensors in the sub-scanning direction with respect to the computer d as shown in FIG. The reflected wave data at the position is output momentarily in the main scanning direction. That is, the reflected wave data (intensity (amplitude) and depth (time)) is acquired at a predetermined reflected wave data acquisition interval in the main scanning direction and at a predetermined reflected wave data acquisition interval in the sub-scanning direction.

  The computer d can visualize the exploration result based on the input data. In other words, if necessary, removal of singular data (removal of clearly different data) and background processing (intensities of reflected waves in parts excluding embedded objects such as reinforcing bars and reflective surfaces such as front and back surfaces) At least one of a concrete body surface position specifying process, a noise removing process (removing noise existing in lower and higher frequency bands than the reflected wave), and a gain process (enhancement process of the reflected wave waveform). Then, if necessary, the input data of the reflected wave data acquisition interval portion is interpolated, and if necessary, the object is emphasized (in the embedded surface such as a reinforcing bar or on the reflective surface such as the front surface or the back surface). After increasing the intensity of the reflected wave, the reflection at each position is two-dimensionally as shown in FIGS. 2C and 2E or three-dimensionally as shown in FIG. Wave intensity (colored) But by combining the image representing good), it can be output to the display device f2 and a printing device f1. The operator can know the exploration result by visually confirming this output.

These images may be displayed in real time, or may be displayed by specifying a display area after data acquisition. At least one of the input data and the processing data can be stored in the data storage device e.
Of the input data, the raw data relating to the position is the movement distance in the main scanning direction and the sensor interval in the sub-scanning direction, but can be converted into two-dimensional plane coordinates as necessary, and the reflected wave data is waveform data. However, it can be converted into reflection intensity and depth (depth) as needed.

  FIG. 3 shows an embodiment in which a radar bridge k shown in FIG. 1 is used to search for a concrete bridge for roads or railways. FIG. 3 (a) is a cylindrical type arranged in the bridge. In order to diagnose whether or not there is an air gap under the frame t1, the radar system k is moved while being applied to the lower surface of the concrete slab. Since the conventional radar system is a large-sized device as described above, it is very difficult to move the radar system while being applied to the lower surface of the concrete slab, especially by manual work. However, the radar system k of the present embodiment having a configuration in which n ultra-compact and ultra-light sensors a are arranged in parallel is small in size and small in size, and is therefore applied to the lower surface of the concrete slab. It can be moved easily.

  FIG. 3B shows an example of exploring a bridge slab. Inside the concrete of the bridge, a plurality of stages (two stages in the drawing) are arranged so that the reinforcing bars h overlap vertically. Here, the radar system k is placed on the upper surface of the bridge and is moved by a manual push method.

  Here, as the sensor a used in the radar system, one using impulse transmission by a step waveform and having a center band of 0.5 to 3 GHz is preferable, particularly as described above. In the case where the reinforcing bars are arranged in two upper and lower stages, if the exploration is performed with a frequency of 1 GHz or more, the resolution is improved because the wavelength is short, and for example, the electromagnetic wave in the upper reinforcement h1 of the concrete body g shown in FIG. The influence is reduced, the investigation deeper than the upper muscle becomes possible, and the electromagnetic waves transmitted through the upper muscle h1 further captures the surroundings of the lower muscle h2 and deeper conditions as reflected signals, so that Further investigation is possible. On the other hand, as the frequency of the electromagnetic wave increases, the attenuation in the object becomes severe. However, if the search is performed at 2 GHz or less, a sufficient search can be performed to a certain depth (40 cm or more).

  FIG. 4A shows the single array state shown in FIG. 1 when the radar system k is shown in FIG. 1. When the interval of the sensors a in the sub-scanning direction is d, the resolution of this single array state is d. On the other hand, as shown in FIG. 4B, the array antenna c2 can obtain m times the resolution by arranging the array antenna c1 of the single array of n columns in a staggered pattern of m rows. This determines the horizontal resolution. The array antenna c2 arranged in m rows has a resolution of d / m with respect to the resolution d of the array antenna c1 in the single array.

  Further, as shown in FIG. 5, an array antenna c3 in which sensors a are arranged in m rows × n columns may be used. In this configuration, the search can be performed in a range of m rows × n columns at a time without moving the array antenna c3.

  When a cylindrical or cylindrical concrete body, for example, a concrete support g1 is to be evaluated, an array antenna structure as shown in FIG. 6 can be employed. The array antenna c4 has n sensors a arranged in a single array, and is curved in accordance with the outer shape of the concrete column g1 to be evaluated. The moving bodies w provided at both ends are arranged in the length direction of the concrete column g1. It can be moved along. And the signal of each sensor a is input into the measuring device v from the one end side of the array antenna c4, and a bar arrangement state etc. can be displayed now.

  As described above, when the array antenna c4 is curved and arranged in accordance with the outer shape of the concrete support g1, the air gap that is the distance between the n sensors a and the surface of the concrete support g1 can be made constant. Measurement is possible. The array antenna c4 may be arranged in a matrix as shown in FIG. 5 or in a staggered manner as shown in FIG. 4 in addition to a single arrangement.

  Further, as shown in FIGS. 7A and 7B, the radar system k is installed in the front part of the exploration vehicle s, and the exploration vehicle s is mounted in the vehicle while traveling on the road surface or the upper surface of the concrete body g2. The measuring device v can also be configured to search the situation under the road surface or in the concrete body.

  As concrete objects to be evaluated, in addition to those shown in the above-mentioned respective forms, as shown in FIG. 8A, a reinforced concrete floor slab 11 provided with an asphalt pavement 10 which is an upper structure of a bridge, FIG. As shown in FIG. 8B, a bridge pier, for example, a T-type pier frame 12, a bridge seat 13, a footing 14, a tunnel lining wall 15 covering the inner surface of the tunnel as shown in FIG. Can be illustrated.

  More specifically, the radar system k can be configured as shown in FIG. That is, FIG. 9 is a block diagram showing a specific configuration of the radar system k. The sensor a is composed of a transmission unit TX and a reception unit RX, and power supply to n sensors a is provided in, for example, the control unit b. The power supply battery 31 supplies power to each circuit in the control unit b.

  The transmission command to the transmission unit of the n sensors a is sequentially transmitted by the switch switching control circuit 34 sequentially switching the first changeover switch 34a, and the timing of this switching is the timing source oscillation circuit. This is performed by a clock pulse of several MHz generated at 32, and is sequentially switched, for example, every cycle of the timing clock pulse. After a few μs, it makes a round of n sensors a of the array antenna.

The electromagnetic wave transmitted from each sensor a repeats reflection and transmission with respect to the measurement object, and the internal state is received by the receiving unit RX of the sensor a as a reflection signal. The received reflected signal is sampled according to the synchronizing signal from the synchronizing signal generation circuit 33, converted into low frequency received signals 1 to n, and output from each sensor. The received signals output from the sensors are processed in the switch switching circuit 34 by the A / D conversion circuit 35 and the buffer 36, and are sequentially output to the data processing device by switching the second selector switch 34b. .
In addition, as a size of the sensor a, it can form in the magnitude | size of the grade on the palm, or the size below it.

<About evaluation of soundness>
The present invention utilizes the exploration of the concrete body g by electromagnetic waves radar as described above, is to evaluate the soundness of reinforced concrete. The concrete body g to be evaluated is different from the concrete in electromagnetic wave reflection strength and intersects with the depth direction of the concrete body g in the evaluation target region (an orthogonal direction is desirable, but an oblique direction may also be used). It includes a known electromagnetic wave reflecting surface extending along. Reflective surface, for example, rebar h, pipe, buried objects of mold or the like, there are front and back surfaces, etc. of the concrete body g, the reflecting surface of the reinforcing bars embedded in the surface and reinforced concrete body of at least reinforced concrete body in the present invention A plurality are selected from the above.

  The electromagnetic wave radar survey is performed at a predetermined reflected wave data acquisition interval over the entire evaluation target region of the concrete body g. The reflected wave data acquisition interval is preferably 20 cm or less. Specifically, in the above-described radar system, the reflected wave data acquisition interval in the main scanning direction is preferably 1 to 7 cm, and the reflected wave data acquisition interval in the sub-scanning direction is preferably 20 cm or less, particularly preferably 12 cm or less.

  And at least the depth position of a reflective surface is acquired by this search. Therefore, as long as the depth position of the reflecting surface can be acquired over the entire extending direction of the reflecting surface, data on other positions is not necessary, but in general, the position of the reflecting surface cannot be accurately identified from the outside. In order to acquire the depth position of the surface over the entire extending direction of the reflecting surface, it is desirable to acquire the data of the entire predetermined region including the portion other than the reflecting surface in three dimensions.

For example, now, using the above-described electromagnetic wave radar shown in FIGS. 1 and 2, the main scanning direction can be the extending direction of the reinforcing bar h (Of course, the sub-scanning direction can be the extending direction of the reinforcing bar h). ) Considering the case where the reflecting surface is the front and back surfaces of the reinforcing bar h and the concrete body g, the horizontal axis (X axis) indicates the main scanning direction on the computer d based on the input data such as the reflected wave intensity from the electromagnetic wave radar k. The XZ plane visualized image of the reflecting surface in the plane including the entire rebar h among the planes whose depth direction is the vertical axis (Z axis) is synthesized and output to the display device f2 and the printing device f1, and this output image The worker can visually check the crack and evaluate the cracked part of the concrete.

FIG. 10 shows a state in which visualized image examples on the XY, XZ, and YZ planes are collectively displayed, FIG. 11 shows an example of visualized image on the XZ plane, and the reinforcing bars h1 and h2 and the back surface g2 of the concrete body g are Since the reflection intensity of electromagnetic waves is high, the stripes are darkly displayed. (A) to (c) in FIG. 11 have different exploration locations, and in the exploration location in (a), there is no disturbance in the depth position in all of the reinforcing bars h1 and h2 and the back surface g2 of the concrete body g. Therefore, it can be evaluated that this exploration location is sound throughout the depth direction. On the other hand, although the depth position of some reflective surfaces (that is, the lower reinforcing bar h2 and the back surface g2) is disturbed at the exploration location of (b), it is at the depth position of the upper reinforcing bar h1 that is another reflective surface. There is no disturbance. In this case, in the plan view, there is a cracked part at the exploration part, but the cracked part extends only to a part in the depth direction. More specifically, since there is no disturbance in the upper part of the upper reinforcing bar h1, there is no cracked portion, and there is no disturbance in the separation distance between the lower reinforcing bar h2 and the back surface g2, so that there is no disturbance between the lower reinforcing bar h2 and the back surface g2. It can be evaluated that there are no cracks in the part. However, since the distance between the upper reinforcing bar h1 and the lower reinforcing bar h2 is disturbed, it can be evaluated that a cracked portion exists between the upper reinforcing bar h1 and the lower reinforcing bar h2. On the other hand, in the case of FIG. 11C, the depth positions of all the reflection surfaces h1, h2, and g2 are disturbed, and it is highly possible that such a search location is a crack location extending in the entire depth direction. . In fact, the exploration location in FIG. 11 (c) was a crack location as shown in FIG. In this way, it is possible to evaluate even the depth range of the cracked portion by searching for a plurality of parallel reflecting surfaces and observing the disorder in the separation distance between the adjacent reflecting surfaces.

On the other hand, as described above, the disturbance in the present invention can be easily visually determined by an operator by visualizing acquired data two-dimensionally or three-dimensionally, that is, outputting it to a display device or a printing device. However, it goes without saying that objective evaluation and automation are desirable. Therefore, we propose a method to make the evaluation objective and automated. That is, when a plurality of reflecting surfaces are provided in parallel so as to overlap in the depth direction, such as the above-described rebar h and the front and back surfaces of the concrete body g, based on the disorder of the separation distance between adjacent reflecting surfaces. When evaluating cracked locations, for each reflective surface, calculate the separation distance for other adjacent reflective surfaces for each exploration location, and when the statistical variation of the separation distance between the reflective surfaces is a predetermined level or more, The cracked part can be evaluated when there is a disturbance. Part or all of the processing in this evaluation may be performed manually, and even in that case, there is a merit that the objectivity of the evaluation is improved, but it is automatically performed by the computer d and the evaluation result is displayed on the visualized image. Or as an image different from the visualized image or numerical data, can be output to the display device f2 or the printing device f1.

  Since the evaluation method of the present invention is based on the premise that the reflecting surface is accurately detected, experiments for examining the relationship between the antenna frequency and the reflecting surface detection rate, and the search interval (reflected wave data acquisition interval) and the reflecting surface detection are performed. An experiment was conducted to examine the relationship with the rate. The test object was a reinforced concrete floor slab with asphalt pavement similar to that shown in FIG. The concrete floor slab thickness is 25cm, the asphalt pavement thickness is 8cm, the upper rebar position is about 11cm from the surface of the asphalt pavement, the lower rebar position is about 28cm from the surface of the asphalt pavement, the back side (plate lower surface position) Was about 33 cm from the surface of the asphalt pavement.

  Using an electromagnetic wave radar system similar to the structure shown in FIG. 1 described above, data was acquired by conducting an exploration from the surface side of the floor slab. Data was acquired by changing the antenna frequency and the search interval (sub-scanning direction). At each data acquisition position, the tester judges whether the reflection strength of the upper and lower reinforcing bars and the bottom of the plate is sufficiently high and can be detected separately from the surroundings, and the ratio of the number of detectable data to the total number of data Was calculated. All other test conditions were common.

  The experimental results are shown in FIGS. From this result, it was found that the antenna frequency is preferably 1 to 2 GHz, particularly 1.2 to 1.5 GHz, and the exploration interval (reflected wave data acquisition interval) is preferably 20 cm or less, particularly 12 cm or less.

  INDUSTRIAL APPLICABILITY The present invention can be used for nondestructive evaluation of concrete bodies such as bridge decks, girders, piers, girders, tunnel linings, retaining walls, revetments, and buildings.

It is a figure which shows schematic structure of the whole system. It is a figure which shows the order of information processing of a system. It is a figure which shows the operating method of a radar system. It is a figure which shows the arrangement | sequence state of an array antenna. It is a figure which shows the arrangement | sequence state of an array antenna. (A) of another antenna structure example is a cross-sectional view, (b) is a side view. It is the schematic of a vehicle mounting form. It is the schematic which shows the example of another target object. It is a block diagram of a control unit. It is a figure which shows the example of a visualization image of each plane of XY, XZ, YZ. It is a figure which shows the example of a visualization image of (a) healthy part, (b) a crack location , (c) a crack location . It is a photograph of a cracked part . It is a graph which shows the relationship between an antenna frequency and a reflective surface detection rate. It is a graph which shows the relationship between a search interval (reflected wave data acquisition interval) and a reflective surface detection rate.

  a ... sensor, b ... control unit, c ... array antenna, d ... computer, e ... data storage device, f1 ... printer, f2 ... display display device, g ... concrete structure, h ... rebar, k ... radar system, p ... wheel, q ... dielectric lens, s ... exploration vehicle, v ... measuring device.

Claims (4)

A plurality of electromagnetic wave reflecting surface electromagnetic wave reflection intensity extending in a direction intersecting the depth direction of the reinforced concrete member in a different and evaluation region concrete, arranged in parallel at intervals in the depth direction the soundness of the reinforced concrete body there is provided a method of evaluation in a non-destructive,
The reflecting surface is a pair of reflective surfaces adjacent groups out of the reflecting surface of the reinforcing bars embedded in the surface and reinforced concrete body of the reinforced concrete body,
At a predetermined reflection wave data acquisition interval over the entire evaluation object area of the reinforced concrete body performs search by electromagnetic waves radar acquires reflected wave data of the electromagnetic wave at each position,
Based on the reflected wave intensity in the acquired reflected-wave data, at least, to get along with each depth position before Symbol reflective surface adjacent the pair in its extending direction,
Based on the acquired depth position, the depth portion corresponding to between the depth distance in a reflection data acquisition portion that is disturbed and the pair of the reflective surface between the pair of reflective surfaces adjacent the concrete And a depth portion corresponding to the distance between the pair of reflecting surfaces, where there is no disturbance in the distance in the depth direction between the pair of adjacent reflecting surfaces. Evaluate as a healthy place without
Soundness of the non-destructive evaluation method of the reinforced concrete body, characterized in that. For each reflective surface, the distance from other reflective surfaces is calculated for each reflected wave data acquisition location, and the case where the statistical variation in the distance between the reflective surfaces is equal to or greater than a predetermined level, to evaluate the cracking point, health of the non-destructive evaluation methods Reinforced concrete body according to claim 1, wherein. Before Stories frequency of the electromagnetic wave and 0.5～3GHz, the reflected wave data acquisition interval is set to 20cm or less, soundness of nondestructive evaluation method according to claim 1 or 2 reinforced concrete body according. A plurality of electromagnetic wave reflecting surface electromagnetic wave reflection intensity extending in a direction intersecting the depth direction of the reinforced concrete member in a different and evaluation region concrete, arranged in parallel at intervals in the depth direction the soundness of the reinforced concrete body there is provided an apparatus for evaluation in a non-destructive,
The reflecting surface is a pair of reflective surfaces adjacent groups out of the reflecting surface of the reinforcing bars embedded in the surface and reinforced concrete body of the reinforced concrete body,
At a predetermined reflection wave data acquisition interval over the entire evaluation object area of the reinforced concrete body, and means for perform exploration by electromagnetic waves radar, to obtain the reflection wave data of the electromagnetic wave at each position,
Based on the reflected wave intensity in the acquired reflected-wave data, at least, each depth position before Symbol reflective surface adjacent pair and means for obtaining along the extending direction,
Based on the acquired depth position, a reflection data acquisition portion having a disorder in the distance in the depth direction between a pair of adjacent reflecting surfaces, and a depth portion corresponding to the gap between the pair of reflecting surfaces is determined . While evaluating as a crack location, and a reflection data acquisition location where there is no disturbance in the distance in the depth direction between a pair of adjacent reflection surfaces, the depth portion corresponding to the gap between the pair of reflection surfaces Means to evaluate as no healthy place ,
Nondestructive evaluation apparatus soundness of reinforced concrete body, comprising the.