TW201445110A - Size detection method of double reinforced steel - Google Patents

Abstract

The purpose of the present invention provides a non-destructive size detection method of double reinforced steel. The method uses a scanning member (2) of ground penetrating radar (1) to obtain the sectional map (4) of the member (2) , and convert it to a power reflection coefficient map (5). The characteristics of reflective signal at the top edge of reinforced steel is captured from the power reflection coefficient map (5), which is used to deduct the entire steel reflection signal to get a power reflection coefficient map (6) after deduction. Compare power reflection coefficient map (5) with the power reflection coefficient map (6) after deduction to get data, such as reflective energy (E) coverage and the range of influence of electromagnetic waves incurring the steel (L), so that the size of double reinforced steel can be calculated.

Description

Double layer steel bar size detection method

The invention relates to a non-destructive steel bar detecting method, in particular to a method for detecting the size of a double layer steel bar using a ground penetrating radar.

Taiwan is located at the junction of the Eurasia plate and the Philippine sea plate. It is part of the Pacific Rim seismic zone. The seismic activity is very frequent. Therefore, the strength and safety of building components has always been a topic of great concern to the people. Even so, after the 921 earthquake Most people have a very deep understanding of the earthquake. Among them, the government is to strengthen the law on the safety of buildings. It does not want the same thing to happen again. In addition to the norms of legal prevention, it must be implemented. The strength and safety of buildings are tested to avoid the construction of old buildings and insufficient safety strength of components, which is harmful to society.

However, some old buildings and monuments, hope to obtain the strength information or damage degree of their structures without causing damage, must use non-destructive testing methods, and there are many non-destructive testing methods. In the current engineering world, the detection methods commonly used are: ground penetrating radar method, photoelastic method, tapping echo method, rebound sag detection, infrared image method, etc. Different detection methods have their fields and advantages. Disadvantages, among them, the ground penetrating radar method has the advantages of fast measurement and high resolution, so it is particularly valued.

The method of interpreting the size of the steel bars in the structure, although the use of magnetic induction in the industry to detect the position of the steel bar and the size of the steel bar, but failed to accurately determine the size of the steel bar; and as shown in Figure 1, generally using the ground penetrating radar When measuring the size of a single-layer steel bar, it may be considered that the part measured by the penetrating radar is the diameter of the steel bar, but it can be understood from the concept of wave propagation of electromagnetic waves, the range covered by electromagnetic wave energy and the reflection coefficient. The part measured by the ground radar should be the lower edge of the left side of the steel bar (10) to the lower edge of the right side of the steel bar (10). This length is similar to the circumference of the steel bar (10). Therefore, the ground penetrating radar is shown in Figure 1. 1) The amount of steel affected by the range, the actual The upper part is the energy broadband at this depth, plus the circumference of the steel bar. The relationship can be known as: S=LE, where S is the circumference of the steel bar and L is the long scan path of the penetrating radar (the range of the electromagnetic wave affecting the steel bar) E is the range of reflected energy, and E can be calculated from the first Fresnal zone's energy formula, so the value of E is related to the thickness of the protective layer of the steel bar (30); even if the penetrating radar can Through the above relationship, the size of the single-layer steel bar is measured. However, in the double-layer steel bar member, the size analysis of the steel bar is more difficult due to signal interference and shadowing effect between the upper and lower steel bars, and thus has not yet been There are accurate interpretation methods.

In view of this, how to accurately interpret the detection method of the double-layer steel bar size is the object of the present invention to be improved.

The object of the present invention is to provide a fast and accurate double-layer steel bar size detecting method.

In order to solve the above problems and achieve the object of the present invention, the technical means of the present invention is achieved by a double-layer steel bar size detecting method, which comprises the following steps: Step one (I): preparing a ground penetrating radar (1) ) and the component to be tested (2); step 2 (II): setting various parameters to the ground penetrating radar (1); step 3 (III): using the penetrating radar (1) to the surface of the component (2) In the range, electromagnetic wave scanning is performed; step 4 (IV): extracting the reflection signal of the electromagnetic wave, and obtaining the transflective cross-sectional view (4) and the power reflection coefficient diagram (5) of the present measurement; step 5 (V): From the power reflection coefficient diagram (5), the signal characteristic (51) reflected from the upper edge of the double-layer steel bar is extracted, and used to deduct the reflection signal of the overall steel bar, and the power reflection coefficient map after deducting the steel bar can be obtained ( 6); Step 6 (VI): Compare the power reflection coefficient diagram (5) with the power reflection coefficient diagram (6) after deducting the reinforcement, and find the values of L ₁ and L ₂ and protect by the upper reinforcement a layer thickness (301) to find E _1, a protective layer thickness of the lower reinforcement (302) to find E _2, wherein, L ₁ is the power reflection coefficient Drawing, the upper reinforcement electromagnetic wave range, E ₁ is reflected energy coverage of the upper reinforcement, L ₂ is a view of the power reflection coefficient deducting steel, the electromagnetic wave scope double reinforcement, E ₂ is the reflected energy lower steel Coverage; and Step 7 (VII): Determine the value of the radius R ₂ of the steel bar by the following formula: S ₁ = L ₁ - E ₁ ; S ₂ = L ₂ - E ₂ ; Where S ₁ is the perimeter of the upper rebar, S ₂ is the perimeter of the lower rebar, and R ₂ is the radius of the second rebar.

More preferably, the member (2) is a reinforced concrete member containing double-layered steel bars.

More preferably, the parameter (3) includes an Antenna Frequency, a Sampling Frequency, a Time Window, a Number of Samples, and a Number of Stacks. And the sampling interval (Interval).

More preferably, in the step (III), when the ground penetrating radar (1) is used to perform electromagnetic wave scanning on a surface of the member (2) within a certain range, wherein the scanning range is according to the component (2) ) depending on the size.

Compared with the prior art, the effects of the present invention are as follows:

First point: In the reinforced concrete members with double-layer steel bars, the present invention can more effectively measure the size of the lower layer of steel bars.

Second point: The method of the invention is a non-destructive test method capable of measuring old building components without damaging the structure.

Third point: The present invention mainly deals with the measurement data, and therefore does not change the measurement method of the ground penetrating radar. In other words, as long as it is a surveyer who is familiar with the operation of the ground penetrating radar, the measurement data can be simply completed. Collection.

1‧‧‧deep radar

10‧‧‧Rebar

11‧‧‧Upper reinforcement

12‧‧‧Under steel

2‧‧‧ components

21‧‧‧Reinforced concrete members with double-layer steel bars

30‧‧‧Rebar thickness

301‧‧‧ Upper layer of protective layer thickness

302‧‧‧ Lower layer of protective layer thickness

4‧‧‧Transparent radar profile

5‧‧‧Power reflection coefficient map

51‧‧‧Signal characteristics of the upper edge of the double-layer steel bar

6‧‧‧Power reflection coefficient after deduction of steel bars

E‧‧‧reflective energy coverage

L‧‧‧Electromagnetic waves affect the range of steel bars

S‧‧‧Reinforcement perimeter

R‧‧‧ Rebar radius

Figure 1: Schematic diagram of the effect of electromagnetic waves on steel bars.

Figure 2: Flow chart of the invention.

Figure 3: Schematic diagram of the present invention before application.

Fig. 4 is a schematic view showing the influence of electromagnetic waves on steel bars in the process of the present invention.

Figure 5: Schematic diagram of the transflectoscope profile converted to power reflection coefficient.

Figure 6: Schematic diagram of the power reflection coefficient of the upper and lower reinforcement bars.

Figure 7: Schematic diagram of the power reflection coefficient of double-layer steel bars after deducting steel bars.

Figure 8: Schematic diagram of the power reflection coefficient of double-layer steel bars before deducting steel bars and after deducting steel bars.

Figure 9: Thickness of the protective layer thickness 5.6cm / double layer #6 steel bar size calculation results

The following is a detailed description of the following embodiments according to the drawings: as shown in FIG. 2, the flow of the steps of the present invention is simply illustrated as follows: (I) preparation equipment, (II) setting parameters, (III) range scanning, (IV) Obtain the data, (V) organize the data, (VI) find the required value, and finally (VII) calculate the steel bar size.

A double-layer steel bar size detecting method, comprising the following steps: Step one (I): As shown in FIG. 3, first prepare a penetrating radar (1) and a reinforced concrete member (2) containing double-layer steel bars. Step 2 (II): Set various parameters for the ground penetrating radar (1), and the following are the parameters of each detection, antenna frequency (Antenna Frequency), sampling frequency (Sampling Frequency), time window (Time Window), sampling Number of Samples, Number of Stacks, Interval; Step 3 (III): As shown in Figure 4, the through-ground radar (1) is used to reinforce the steel with double-layer reinforcement. The electromagnetic wave scanning is performed within a certain range of the surface of the concrete member (21). When the electromagnetic wave scanning range of the ground penetrating radar (1) is scanned to the reinforcing bar (10), the electromagnetic wave reflecting signal received by the ground penetrating radar (1) is The range of a~e will receive the reflection signal of the lower reinforcement (12), where the range of b~d will be mixed with the reflection signal of the upper reinforcement (11); Step 4 (IV): as shown in Figure 5, use Ground radar (1) captures the reflected signal of electromagnetic waves and obtains the ground penetration of this test a cross-sectional view (4) and a power reflection coefficient diagram (5), wherein the through-the-earth radar profile (4) is converted into a digital image coding pattern through an encoding matrix, and finally the power reflection coefficient map (5) is obtained; V (V): As shown in Figure 6, if the power reflection coefficient maps of the upper and lower layers are taken separately, it should be a simple hill type. However, because the upper and lower layers of steel bars will interfere with each other. The graph of the power reflection coefficient map (5) is presented; therefore, as shown in Fig. 6 and Fig. 7, we extract the signal characteristic (51) reflected by the upper edge of the double layer steel bar, which is used to deduct the overall steel bar. The reflected signal, you can get the power reflection coefficient after the steel bar (6), as shown in Figure 8, after the steel bar after the power reflection coefficient map (6), can clearly distinguish four hills, and used Measure the values of L ₁ and L ₂ ; Step 6 (VI): compare the power reflection coefficient map (5) with the power reflection coefficient map (6) after deducting the steel bars, and find the values of L ₁ and L ₂ , reinforced by the upper protective layer thickness (301) to find E _1, a protective layer thickness of the lower reinforcement (302) to find E _2, wherein, L ₁ are Of the reflection coefficient of the drawing, the upper reinforcement electromagnetic wave range, E ₁ is reflected energy coverage of the upper reinforcement, L ₂ is a view of the power reflection coefficient deducting steel, the electromagnetic wave scope double reinforcement, E ₂ is lower steel The reflected energy coverage range; and step 7 (VII): the value of the steel bar radius R ₂ is obtained by the following formula: S ₁ = L ₁ - E ₁ ; S ₂ = L ₂ - E ₂ ; Where S ₁ is the perimeter of the upper rebar, S ₂ is the perimeter of the lower rebar, and R ₂ is the radius of the second rebar.

Figure 9 is a table (calculation unit) for calculating the steel bar size of the protective layer thickness 5.6 cm / double layer #6 steel bar, and Figure 9 shows the method of the present invention when the net spacing of the upper and lower steel bars is 8 cm - 15 cm The calculated results are within acceptable limits.

In the above, in the third step (III), when the electromagnetic wave scanning is performed on the surface of the member (2) using the ground penetrating radar (1), the scanning range is determined by the member (2). Size depends on size.

The structure, features and effects of the present invention are described in detail above based on the embodiments shown in the drawings. Since the novelty and the progressive requirements are met, the invention patent application is filed according to the law; however, the above description is only the preferred embodiment of the present invention. However, the present invention is not limited by the scope of the invention, and modifications that are in accordance with the meaning of the present invention are intended to be within the scope of the invention as long as they are within the scope of the invention.

Claims (4)

A double-layer steel bar size detecting method, comprising the following steps: Step one (I): preparing a ground penetrating radar (1) and a component to be tested (2); and step 2 (II): facing a ground penetrating radar (1) ) setting various parameters; step 3 (III): using the penetrating radar (1) to perform electromagnetic wave scanning within a certain range of the surface of the member (2); step 4 (IV): extracting the reflected signal of the electromagnetic wave, and obtaining The ground penetrating radar profile (4) and the power reflection coefficient diagram (5) of this test; Step 5 (V): From the power reflection coefficient diagram (5), the signal characteristics of the upper edge of the steel bar are extracted. It can be used to deduct the reflection signal of the whole steel bar, and the power reflection coefficient after deduction of the steel bar can be obtained (6); Step 6 (VI): the power reflection coefficient (5) and the power reflection after the steel bar is deducted FIG coefficient (6), and find the value of L ₁ and L _2, reinforced by the upper protective layer thickness (301) to find E _1, a protective layer thickness of the lower reinforcement (302) to find E _2, wherein, L ₁ is a power reflection coefficient of the drawings, the upper range of reinforcement of an electromagnetic wave, E ₁ is reflected energy coverage of the upper reinforcement, L ₂ is a deduction Reected view of the reinforcement, the electromagnetic wave of the scope tier reinforced ,, E ₂ is lower steel coverage reflected energy; and a step of seven (VII): a value obtained from the formula reinforced radius of R _2: S ₁ = L ₁ - E ₁ ; S ₂ = L ₂ - E ₂ ; Where S ₁ is the perimeter of the upper rebar, S ₂ is the perimeter of the lower rebar, and R ₂ is the radius of the second rebar. The double-layer steel bar size detecting method according to claim 1, characterized in that the component (2) is a reinforced concrete member containing double-layer steel bars. The double-layer steel bar size detecting method according to claim 1, wherein the parameter includes an antenna frequency (Antenna Frequency), a sampling frequency (Sampling Frequency), a time window (Time Window), and a number of samples (Number of Samples), number of overlays (Number Of Stacks) and the sampling interval (Interval). The double-layer steel bar size detecting method according to claim 1, wherein in the step (III), when the ground penetrating radar (1) is used to perform electromagnetic wave scanning on a surface of the member (2) within a certain range, The range of the scan depends on the size of the member (2).