CN110865088A - Grouting sleeve plumpness detection method based on electromagnetic wave method - Google Patents
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Abstract
The invention relates to a grouting sleeve plumpness detection method based on an electromagnetic wave method. The propagation condition of electromagnetic waves in the steel bar sleeves with different plumpness under different frequencies is measured and analyzed through two large surfaces of a time domain and a frequency domain, and the internal condition of the steel bar sleeve to be measured is obtained through analysis according to the obtained measurement result. The method is simple and practical, convenient and fast to operate, accurate in result and suitable for being applied to actual engineering.
Description
Technical Field
The invention relates to the technical field of assembly type buildings and electromagnetic waves, in particular to a grouting sleeve plumpness detection method based on an electromagnetic wave method.
Background
The prefabricated building means that part or all of components and parts of the building are produced in a prefabrication factory, and the components are assembled by adopting a reliable connection mode and an installation machine when the components and the parts are transported to a construction site to form the building with the designed use function. Compared with the construction of a cast-in-place structure, the prefabricated structure has the advantages of convenience in construction, high engineering progress, small influence on the surrounding environment, easiness in ensuring the quality of building components and the like. The assembly type structure is applied to industrial buildings in China more frequently, and is popularized and applied to civil buildings, particularly residential buildings, in recent ten years.
The steel bar connection is realized through the special grouting sleeve and the high-strength non-shrinkage slurry, and the steel bar connection structure has the advantages of being fast in construction, simple in stress, small in additional stress, wide in application range, easy to absorb construction errors and the like. Because the number of joints on the same interface of the component is 100% in the connection mode, and important stress parts of the component are generally arranged, the connection quality is critical, and if grouting inside the grouting sleeve is not full, the connection of the steel bars cannot reach the designed expected performance, serious potential safety hazards of the structure can be brought.
In the construction process, the conditions of slurry leakage, less grouting and blockage in the grouting sleeve occur occasionally, the engineering problem that the connection quality of the grouting sleeve does not meet the requirement is also reported, and the problem of grouting fullness is particularly concerned when the engineering is accepted. The grout sleeve mainly adopts steel material, and the reinforcing bar inserts grout sleeve back and then grout in the sleeve, so detect the research difficulty of technical field when detecting grout sleeve inside defect.
At present, many colleges and research institutes in China carry out related research on grouting sleeve fullness detection, but most of the research institutes stay in the research stage, and the detection method and means cannot be popularized and applied on a large scale. At present, the main detection methods of the fullness of the grouting sleeve in China comprise a core drilling sampling method, an ultrasonic wave method, a ground penetrating radar method, an impact elastic wave method, a ray radiation method, an infrared thermal imaging method and the like. The above methods all have their own disadvantages and drawbacks. For example, the core drilling sampling method has the disadvantages of complex operation, low accuracy, high cost, poor operability, low efficiency, difficulty in practicability, unclear detection result of the ray method, susceptibility to electromagnetic interference of the ground penetrating radar method and the like. The quality of the fullness of the grouting sleeve directly influences the durability and safety of the building, so that the strengthening research and development of the detection technology of the fullness of the grouting sleeve have extremely important and profound significance.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a grouting sleeve fullness detection method based on an electromagnetic wave method.
The purpose of the invention can be realized by the following technical scheme:
a grouting sleeve plumpness detection method based on an electromagnetic wave method comprises the following steps:
step 1: inserting ribbed steel bars into a sleeve, and simultaneously injecting grouting raw materials into the sleeve so as to fixedly connect the sleeve and the ribbed steel bars;
step 2: waiting for the grouting raw material to be solidified and hardened;
and step 3: and taking the sleeve as a waveguide model, and detecting the plumpness of the waveguide model by adopting a frequency domain S parameter detection method or a time domain detection method to obtain a detection result.
Further, when the frequency domain S parameter detection method is adopted in step 3, the method includes the following sub-steps:
step 01: regarding the sleeve as a waveguide model, regarding a grouting port and a grout outlet on the sleeve as two ports, inputting a detection signal into one port, and receiving a signal at the other port;
step 02: based on the step 2, further utilizing a network analyzer to test a plurality of known sleeves with different grouting fullness degrees to obtain a test result, and establishing related S parameter models under different fullness degrees according to the test result;
step 03: based on the step 2, detecting the actual steel bar sleeve to be detected by the network analyzer again to obtain a corresponding S parameter model;
step 04: and comparing the S parameter model corresponding to the actual steel bar sleeve to be detected with the established related S parameter models under different plumpness to obtain the established S parameter model which is most matched with the S parameter model corresponding to the actual steel bar sleeve to be detected and the corresponding plumpness serving as a final detection result.
Further, the frequency domain S parameter detection by the network analyzer is performed using a dot frequency or a wide frequency.
Further, when the time domain detection method is adopted in the step 3, the method comprises the following sub-steps:
step 001: regarding the sleeve as a waveguide model, regarding a grouting port and a grout outlet on the sleeve as two ports, and performing corresponding electromagnetic wave transmitting and receiving operations on the two ports according to different conditions;
step 002: and comparing the received waveform of the electromagnetic wave with the transmitted waveform of the electromagnetic wave, and judging the fullness condition inside the steel bar sleeve as a final detection result according to the difference of amplitude, phase or time delay.
Further, when the positional relationship of the transmission and reception signals is a single transmission order in the step 001, the electromagnetic wave emitting device and the electromagnetic wave receiving device are respectively disposed at two port positions correspondingly.
Further, when the different situation in step 001 is that the position relationship of the transmission and reception signals is the same, the electromagnetic wave transmitting device and the electromagnetic wave receiving device are both disposed at any one of the two ports.
Further, when the different situation in step 001 is that the position relationship of the transmitting and receiving signals is the same as the transmitting and receiving, a device for forming an open circuit or a short circuit state is further disposed at the other port of the two ports.
Further, the detection method is also suitable for detecting the dryness and the humidity of the slurry in the steel bar sleeve and whether blockage exists.
Compared with the prior art, the invention has the following advantages:
(1) the method provided by the invention provides a grouting sleeve plumpness detection method, the detection technology makes up the blank of the existing grouting sleeve plumpness detection technology, and improves the grouting sleeve quality and the steel bar connection reliability, so that the seismic performance of an assembled structure is ensured, the technical level of the assembled structure is improved, and the development of the modern industry of the building industry is promoted.
(2) The frequency domain S parameter detection method adopted in the method comprises the steps of respectively changing the fullness and the emission frequency of the steel bar sleeve, carrying out S parameter simulation analysis on the steel bar sleeves with different saturations under different emission frequencies, establishing corresponding parameter models, finding out the most relevant parameter model through comparing the actual measurement result with the simulation parameter models in the actual detection process, obtaining the internal fullness result of the steel bar sleeve, conveniently, quickly and accurately detecting the grouting fullness of the steel bar sleeve in the fabricated concrete, and judging whether the grouting fullness is qualified or not after the grouting material is filled or solidified in the construction process.
(2) The time domain detection method adopted in the method can artificially set a switch or a block in the actual detection process due to the excessively high transmission speed of the electromagnetic wave, delays the transmission of the electromagnetic wave and facilitates the detection.
Drawings
FIG. 1 is a schematic diagram of a slurry jacket according to the method of the present invention;
FIG. 2 is a schematic diagram of a single-shot single-receive detection operation when time domain detection is employed in the method of the present invention;
FIG. 3 is a schematic diagram of the detection operation of the transmit-receive co-location when the time domain detection is employed in the method of the present invention;
fig. 4 is a schematic diagram of variation of the S parameter under different dielectric constants of the grouting material in the embodiment of the present invention, in which fig. 4(a) is a schematic diagram of variation of the S11 parameter under different dielectric constants of the grouting material, fig. 4(b) is a schematic diagram of variation of the S12 parameter under different dielectric constants of the grouting material, fig. 4(c) is a schematic diagram of variation of the S21 parameter under different dielectric constants of the grouting material, and fig. 4(d) is a schematic diagram of variation of the S22 parameter under different dielectric constants of the grouting material;
fig. 5 is a schematic diagram of variation of the S parameter under different plumpness in the embodiment of the present invention, where fig. 5(a) is a schematic diagram of variation of the S11 parameter under different plumpness, fig. 5(b) is a schematic diagram of variation of the S12 parameter under different plumpness, fig. 5(c) is a schematic diagram of variation of the S21 parameter under different plumpness, and fig. 5(d) is a schematic diagram of variation of the S22 parameter under different plumpness;
in the figure, 1 is a ribbed steel bar, 2 is a sleeve, 3 is a grout outlet, 4 is high-strength grout and 5 is a grouting opening.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.
The technical scheme of the invention is as follows:
the grouting sleeve is regarded as a waveguide model, and different filled grouts can be regarded as media with different dielectric constants. The fullness can be detected in the time domain and the frequency domain, respectively.
The following steps of the frequency domain and time domain detection method are introduced respectively:
1. frequency domain S parameter detection method, as shown in FIG. 1
Through changing the plumpness and the emission frequency of steel sleeve respectively, carry out S parameter simulation analysis under different emission frequencies to the steel sleeve of different plumpness, establish corresponding parameter model, in actual testing process, accessible contrast actual measurement result and simulation parameter model find out the parameter model that is relevant with it most, reachs the inside plumpness result of steel sleeve.
The sleeve of rebar is considered a two-port network. The grouting port and the grout outlet are regarded as two ports of the network, and the rest part of the sleeve is regarded as a waveguide model. During detection, a detection signal is input at one port, a signal is received at the other port, and then a related S parameter model is calculated. Obviously, factors influencing the S parameter mainly include the dielectric constant of the grouting slurry and the fullness degree of slurry filling, so in actual detection, after the dielectric constant of the slurry used is determined, the S parameter can be detected for the sleeve which is qualified in grouting (i.e., the fullness degree reaches 100%), S11, S12, S21 and S22 are obtained, (as shown in fig. 4(a) to 4(d) and fig. 5(a) to 5(d) in fig. 5), then the sleeve to be detected is detected by taking the S parameter as a standard, and the fullness degree of the slurry in the sleeve can be detected by comparing results of the S parameter.
The detection of the frequency domain S parameters can be carried out by detecting results by using a single S parameter, namely any one of S11, S12, S21 and S22, and can also be carried out by unifying the S parameters to carry out comparative analysis so as to carry out the fullness detection in the steel bar sleeve. In addition, the frequency domain S parameter can be detected using a dot frequency or a wide frequency.
2. Time domain
The time domain detection method detects the time delay generated in the transmission medium by the transmitted electromagnetic wave, namely the time difference of the transmitted and received signals.
In the time domain, due to different plumpness of the grout in the grouting sleeve and different grouting materials, the equivalent dielectric constants are different, so that the electromagnetic waves are lost and delayed when being transmitted in the steel bar sleeve. Therefore, the internal fullness of the steel bar sleeve can be detected according to the amplitude phase or the receiving and transmitting delay of the received electromagnetic wave signals.
The time domain detection method detects the energy loss of the transmitted electromagnetic wave in the transmission medium, and is embodied in the difference of the waveform, the amplitude and the phase of the transmitted and received signal.
(1) Single-transmitting and single-receiving, i.e. the means for transmitting electromagnetic waves and the means for receiving electromagnetic waves are in different locations, as shown in fig. 2
The sleeve of rebar is considered a two-port network. The grouting port and the grout outlet are regarded as two ports of a network, one port transmits an electromagnetic wave signal, and the other port receives the electromagnetic wave signal. And analyzing the amplitude, the phase and the time delay of the obtained electromagnetic wave signal to obtain a saturation result inside the steel bar sleeve.
(2) Transceiving being co-located, i.e. the means for transmitting electromagnetic waves and the means for receiving electromagnetic waves being in the same location, as shown in figure 3
The transceiver is arranged at the same port, and the other port can carry out open circuit or short circuit operation on the transceiver. And analyzing the amplitude, the phase and the time delay of the obtained electromagnetic wave signal to obtain a fullness result inside the steel bar sleeve.
The method is not only limited to detecting the fullness of the grouting sleeve, but also can be used for detecting the dryness and humidity of the slurry in the steel bar sleeve, whether the slurry is blocked or not, and the like.
Second, concrete practical embodiment
The method comprises the following concrete implementation steps:
1. frequency domain S parameter detection method
(1) The ribbed steel bar 1 is inserted into the sleeve 2, and high-strength slurry 4, namely grouting raw materials, is injected inwards, so that the materials can fill a gap generated between the ribbed steel bar 1 and the sleeve 2, the ribbed steel bar 1 and the sleeve 2 can be completely matched, and the ribbed steel bar and the sleeve are connected.
(2) And waiting for the slurry to set and harden.
(3) The inlet 5 and the outlet 3 are considered as two ports, one of which inputs a detection signal and the other of which receives a signal.
(4) And (3) testing by using a professional network analyzer, firstly detecting the known sleeves with different grouting fullness to obtain a test result, and establishing related S parameter models under different fullness conditions.
(5) And then, detecting the steel bar sleeve to be detected by using the network analyzer to obtain an actual S parameter model of the steel bar sleeve to be detected.
(6) And (5) comparing the S parameter models obtained in the step (4) and the step (5), and finding the S parameter model which is most matched with the result obtained in the step (5) from the parameter models established in the step (4), so that the fullness of the steel bar sleeve to be measured can be obtained.
2. Time domain detection method
The first two steps are identical to the frequency domain.
(3) Consider the grout outlet 5 and the grout outlet 3 as two ports:
i. if the single-transmitting and single-receiving condition is adopted, one port transmits electromagnetic waves, and the other port receives the electromagnetic waves.
ii. If the condition of simultaneous transmission and receiving is adopted, the transmission and the reception are on the same port. The other port is open or short circuited.
(4) And comparing the received electromagnetic wave waveform with the transmitted electromagnetic wave waveform to obtain the difference of amplitude, phase or time delay, thereby judging the fullness condition in the steel bar sleeve.
While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (8)
1. A grouting sleeve plumpness detection method based on an electromagnetic wave method is characterized by comprising the following steps:
step 1: inserting ribbed steel bars into a sleeve, and simultaneously injecting grouting raw materials into the sleeve so as to fixedly connect the sleeve and the ribbed steel bars;
step 2: waiting for the grouting raw material to be solidified and hardened;
and step 3: and taking the sleeve as a waveguide model, and detecting the plumpness of the waveguide model by adopting a frequency domain S parameter detection method or a time domain detection method to obtain a detection result.
2. The method for detecting the fullness of a grouting sleeve based on an electromagnetic wave method as claimed in claim 1, wherein when a frequency domain S parameter detection method is adopted in the step 3, the method comprises the following sub-steps:
step 01: regarding the sleeve as a waveguide model, regarding a grouting port and a grout outlet on the sleeve as two ports, inputting a detection signal into one port, and receiving a signal at the other port;
step 02: based on the step 2, further utilizing a network analyzer to test a plurality of known sleeves with different grouting fullness degrees to obtain a test result, and establishing related S parameter models under different fullness degrees according to the test result;
step 03: based on the step 2, detecting the actual steel bar sleeve to be detected by the network analyzer again to obtain a corresponding S parameter model;
step 04: and comparing the S parameter model corresponding to the actual steel bar sleeve to be detected with the established related S parameter models under different plumpness to obtain the established S parameter model which is most matched with the S parameter model corresponding to the actual steel bar sleeve to be detected and the corresponding plumpness serving as a final detection result.
3. The method as claimed in claim 2, wherein the frequency domain S parameter is detected by the network analyzer using a dot frequency or a broadband.
4. The grouting sleeve fullness detection method based on the electromagnetic wave method as claimed in claim 1, wherein when the time domain detection method is adopted in step 3, the method comprises the following sub-steps:
step 001: regarding the sleeve as a waveguide model, regarding a grouting port and a grout outlet on the sleeve as two ports, and performing corresponding electromagnetic wave transmitting and receiving operations on the two ports according to different conditions;
step 002: and comparing the received waveform of the electromagnetic wave with the transmitted waveform of the electromagnetic wave, and judging the fullness condition inside the steel bar sleeve as a final detection result according to the difference of amplitude, phase or time delay.
5. The method as claimed in claim 4, wherein when the positional relationship between the transmitter and receiver is a single transmitter, the electromagnetic wave emitting device and the electromagnetic wave receiving device are respectively disposed at two port positions.
6. The method as claimed in claim 4, wherein when the transmitting/receiving position of step 001 is the same, the electromagnetic wave emitting device and the electromagnetic wave receiving device are both disposed at either of the two ports.
7. The method as claimed in claim 6, wherein when the transmitting/receiving position relationship in step 001 is the same as the transmitting/receiving position, the other of the two ports is further provided with a device for forming an open-circuit or short-circuit state.
8. The method for detecting the fullness of the grouting sleeve based on the electromagnetic wave method as claimed in any one of claims 1 to 7, wherein the method is also suitable for detecting the dryness and humidity of the slurry in the steel sleeve and the existence of blockage.
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| CN113484346A (en) * | 2021-06-23 | 2021-10-08 | 苏州信安检测技术有限公司 | Method and system for detecting grouting defects inside metal grouting sleeve |
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