CN212904661U - Non-uniform corrosion nondestructive monitoring sensor for existing reinforced concrete structure steel bar - Google Patents
Non-uniform corrosion nondestructive monitoring sensor for existing reinforced concrete structure steel bar Download PDFInfo
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- CN212904661U CN212904661U CN202021785396.2U CN202021785396U CN212904661U CN 212904661 U CN212904661 U CN 212904661U CN 202021785396 U CN202021785396 U CN 202021785396U CN 212904661 U CN212904661 U CN 212904661U
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The non-uniform corrosion nondestructive monitoring sensor for the existing reinforced concrete structure steel bar comprises a magnetic induction intensity monitoring unit and a data processing unit, wherein the magnetic induction intensity monitoring unit comprises an external sensor and a veneer sensor, and the external sensor comprises an external sensor left magnetic core, an external sensor right magnetic core, an external sensor permanent magnet, a first Hall sensor, a second Hall sensor and an external sensor packaging shell; the surface-mounted sensor comprises a surface-mounted sensor permanent magnet, an inner magnetic core, an outer magnetic core and a surface-mounted sensor packaging shell. The utility model discloses a magnetic field carries out the effective survey of the inhomogeneous corrosion of reinforcing bar through the inhomogeneous corrosion region of reinforcing bar, and a veneer sensor corresponds many reinforcing bars, an external sensor and corresponds a plurality of reinforced concrete structures and carry out the corrosion monitoring, and the principle is clear, the method is simple and convenient, survey is fast, used repeatedly, engineering application nature is strong and stability is good.
Description
Technical Field
The utility model relates to a reinforcing bar corrosion monitoring technology among the building engineering, in particular to existing reinforced concrete structure reinforcing bar inhomogeneous corrosion nondestructive monitoring sensor based on magnetic field principle.
Background
Since 1824 the cement was invented, concrete became the most widely used building material in the world, and because of its abundant raw materials, simple manufacturing process, low cost, and high compressive strength, it has been widely used in civil and industrial buildings, bridges, tunnels and other civil engineering fields. In 1991, the corrosion of steel reinforcement caused by chloride corrosion was indicated to be the most serious and prevalent problem of durability of concrete structures at the second international academic conference on concrete durability.
Corrosion of the steel reinforcement not only reduces the load-bearing capacity of the reinforced concrete structure, but also reduces the effective cross-sectional area of the steel reinforcement and the adhesion between the reinforced concrete. Therefore, the method has important significance for reasonably formulating a maintenance scheme of the reinforced concrete structure and guaranteeing the safety of the concrete structure by quantitatively representing and monitoring the corrosion degree of the steel bars in the reinforced concrete structure.
At present, the monitoring method of the steel bar corrosion is divided into damage detection and nondestructive detection. The damage detection measurement result is more accurate, but need to carry out the broken type to reinforced concrete structure and take out the reinforcing bar, and the harm that causes the concrete structure is irreversible, and is not suitable for being adjusted the reinforced concrete structure in service period well. The nondestructive testing method is a hotspot of current research, and mainly comprises a half-cell potential method, an acoustic emission technology and a built-in monitoring technology. The half-cell potential method utilizes the potential change caused by the electrochemical reaction of the steel bar corrosion to determine the steel bar corrosion state, but the accuracy is lower, the probability of the steel bar corrosion can be only determined qualitatively, and no unified determination standard exists; the acoustic emission technology can only qualitatively judge the corrosion occurrence probability according to parameters such as accumulated impact number and the like, and can not quantitatively measure the corrosion rate of the steel bar; a steel bar corrosion monitoring method based on a magnetic field principle is disclosed in Chinese patent No. CN109374726A, wherein the publication date is 22 days in 2019 and 2 months, the name of the steel bar corrosion nondestructive dynamic monitoring sensor and system in concrete based on a magnetic field is 'Chinese patent No. CN208420791U, the publication date is 22 days in 2019 and 1 month, the name of the steel bar corrosion electromagnetic field variable response device', two patents provide a steel bar corrosion monitoring sensor built in concrete, and the sensor can accurately measure the uniform corrosion condition of steel bars, but the defects exist: the built-in monitoring sensor can limit corrosion expansion of the reinforcing steel bar due to clamping of the reinforcing steel bar, the natural corrosion rule of the reinforcing steel bar is influenced, the sensor can only accurately measure the uniform corrosion condition of the reinforcing steel bar, but the corrosion of the reinforcing steel bar under the natural environment is not uniform. In addition, the sensor is arranged in the concrete and can only be used once, so that the cost is higher; the Chinese patent publication No. CN108469514A, which is published as 2018, 8, 31 and is named as 'equipment and method for monitoring corrosion behavior of steel bars in concrete', the sensor related to the patent is an external sensor, the defects exist, the corrosion can be only determined aiming at small steel bar concrete samples in a laboratory, and the test results are greatly influenced by different steel bar positions. In actual engineering, the reinforced concrete columns, beams and plates often have complex steel bar arrangement, and the corrosion distribution of the angle steel bars and the middle steel bars presents different trends, so the above patents cannot carry out corrosion monitoring on the steel bars of the existing reinforced concrete structure.
In the actual construction engineering, a sensor and a test method for accurately measuring the corrosion rate of the existing structural steel bars still do not exist.
Therefore, the steel bar non-uniform corrosion monitoring sensor with the advantages of clear principle, simple and convenient method, high measuring speed, repeated use, strong engineering applicability, good stability and the like is found, and the improvement of the steel bar corrosion degree evaluation and prediction has important significance for continuous deepening.
Disclosure of Invention
In order to overcome the not enough of current building engineering reinforcing bar corrosion nondestructive monitoring technique, the utility model provides a stability is high, easy and simple to handle, can realize the non-uniform corrosion monitoring of existing structural steel bar, especially relates to the non-uniform corrosion nondestructive monitoring technique of existing reinforced concrete structure reinforcing bar based on the application magnetic field principle, and this monitoring technique comprises wainscot formula sensor and external sensor two parts: the veneering type sensor is externally attached to the surface of the reinforced concrete structure, namely the magnetic core is externally arranged outside the reinforced concrete structure, the magnetic circuit passes through the corrosion area of the non-uniform corrosion reinforcing steel bar, the non-uniform corrosion condition of the magnetic circuit passing through the length reinforcing steel bar can be monitored, and the corrosion condition of a single middle part of the reinforced concrete structure for detecting the reinforcing steel bar can be effectively judged through the Hall voltage obtained through testing; the external sensor is externally arranged outside the reinforced concrete structure; the bayonet of the magnetic core is designed into a trapezoidal bayonet, so that the reinforced concrete square column can be effectively clamped, and the corrosion condition of a single detection reinforcing steel bar at the corner of the reinforced concrete square column can be effectively detected; the magnetic circuit passes through the non-uniform corrosion steel bar corrosion area of the corner steel bar and is symmetrically arranged through the Hall sensors so as to accurately detect the position of the steel bar; the veneer sensor and the external sensor are used for measuring the corrosion rate of the steel bar, evaluating the corrosion degree of the steel bar and predicting the service life of the steel bar so as to solve the problem that no effective method for measuring the corrosion rate of the steel bar of the reinforced concrete structure exists at present.
In order to solve the technical problem, the utility model provides a following technical scheme:
the non-uniform corrosion nondestructive monitoring sensor for the existing reinforced concrete structure steel bar comprises a magnetic induction intensity monitoring unit and a data processing unit, wherein the magnetic induction intensity monitoring unit comprises an external sensor and a veneer sensor, and the external sensor comprises an external sensor left magnetic core, an external sensor right magnetic core, an external sensor permanent magnet, a first Hall sensor, a second Hall sensor and an external sensor packaging shell; the external sensor packaging outer shell comprises an external sensor inner shell and an external sensor packaging cover; the external sensor inner shell comprises an external sensor permanent magnet placing groove, a left magnetic core placing groove, a right magnetic core placing groove, a third fixing hole, a fourth fixing hole, a second cable bending space and a second cable hole; the surface-mounted sensor comprises a surface-mounted sensor permanent magnet, a surface-mounted sensor left magnetic core, a surface-mounted sensor right magnetic core, a surface-mounted sensor packaging shell, a third Hall sensor and a fourth Hall sensor; the surface-mounted sensor packaging outer shell comprises a surface-mounted sensor inner shell and a surface-mounted sensor packaging cover; the sensor inner shell comprises a first fixing hole, a second fixing hole, a veneering type sensor left magnetic core placing groove, a veneering type sensor right magnetic core placing groove, a veneering type sensor permanent magnet placing groove, a first cable bending space and a first wire hole; the sensor inner shell and the packaging cover both comprise a first fixing hole and a second fixing hole;
the data processing unit comprises a signal collector, a signal processor and a central controller, wherein the input end of the signal collector is electrically connected with the signal output end of the Hall sensor, and the signal output end of the signal processor is electrically connected with the port of the central controller.
Further, left magnetic core of veneer sensor and right magnetic core of veneer sensor be the rectangular cross section, left magnetic core of external sensor and right magnetic core of external sensor be trapezoidal bayonet socket.
The left magnetic core of the veneer type sensor, the right magnetic core of the veneer type sensor, the left magnetic core of the external sensor and the right magnetic core of the external sensor are of symmetrical structures.
The left magnetic core of the veneer type sensor, the right magnetic core of the veneer type sensor, the left magnetic core of the external sensor and the right magnetic core of the external sensor are made of silicon steel.
The external sensor permanent magnet and the veneering type sensor permanent magnet are made of neodymium-nickel-boron materials.
The veneer type sensor packaging shell and the external sensor packaging shell are made of plastic materials.
The veneer sensor and the external sensor are arranged outside the reinforced concrete structure.
The first fixing hole, the second fixing hole, the third fixing hole and the fourth fixing hole are threaded holes.
The veneering type sensor inner shell and the packaging cover comprise a first fixing hole and a second fixing hole, and corresponding screws and nuts are used for bolt connection during installation.
The external sensor inner shell and the external sensor packaging cover comprise a third fixing hole and a fourth fixing hole, and corresponding screws and nuts are used for bolt connection during installation.
The veneer sensor and the external sensor are connected with the signal collector through the first indicator lamp and the second indicator lamp, and the first indicator lamp and the second indicator lamp prompt whether the external sensor, the veneer sensor and the signal collector work normally or not.
The Hall sensor can be arranged with 1 or more sensors according to the precision requirement and the actual engineering requirement.
As an improvement, the veneering type sensor permanent magnet, the external sensor permanent magnet, the veneering type sensor left magnetic core, the veneering type sensor right magnetic core, the external sensor left magnetic core and the external sensor right magnetic core are required to be placed in a magnetic isolation environment after being detected, so that the influence of demagnetization on detection precision is avoided.
As an improvement, the veneer sensor can be used for monitoring the non-uniform corrosion of the steel bars on a plurality of steel bars, and can be used repeatedly and used for flow monitoring.
As an improvement, the external sensor corresponds to a plurality of reinforced concrete structure monitoring, and can be used repeatedly and used for flow monitoring.
As an improvement, the veneering type sensor packaging shell and the external sensor packaging shell contain bending spaces of circuit board connecting cables so as to ensure that the circuits can be effectively bent.
As an improvement, the data processing unit and the related control circuit can be realized by using the existing mature technology, and mainly comprises the steps of measuring the Hall voltage of the Hall sensor so as to calculate the corrosion rate. The Hall voltage measuring system and the data processing system finish data storage, post-processing and real-time display through the signal processor and the central controller.
The utility model discloses a theory of operation: hall voltage of the Hall voltage detection unit of the Hall sensor is sent to the signal processor; the signal processor collects the data of the signal collector according to the set frequency, calculates and analyzes the data, stores the collected data and the calculation result in the central controller in real time, and displays the analysis and calculation result in real time by the display.
The utility model has the advantages that: the utility model discloses based on nondestructive test method, utilize magnetic induction technique and adopt the veneer formula of unique innovation and external sensor test method to realize the inhomogeneous corrosion nondestructive monitoring of reinforcing bar, calculate the corrosion rate that obtains the reinforcing bar according to theoretical formula. The limit of the test stability, accuracy and using times of the traditional test method is broken through, and the test of the corrosion rate of the reinforced concrete structure steel bar is realized; the measured corrosion rate of the steel bars can be applied to the evaluation of the current service performance and the prediction of the durability of the reinforced concrete structure. The test object is applicable to the concrete column, roof beam and the board of not unidimensional and shape, the external part of veneer sensor can correspond a plurality of interior magnetic cores and detect, external sensor can correspond a plurality of people's reinforced concrete structure and detect, have that the principle is clear, the method is simple and convenient, the survey is fast, used repeatedly and stability advantage such as good, can compensate current method and equipment reinforcing bar corrosion rate survey not enough.
Drawings
Fig. 1 is the schematic diagram of the working structure of the sensor of the present invention.
Fig. 2 is a three-dimensional schematic diagram of the internal shell of the external sensor of the present invention.
Fig. 3 is a three-view diagram of the internal shell of the external sensor of the present invention.
Fig. 4 is a three-view diagram of the external sensor package cover of the present invention.
Fig. 5 is a three-view diagram of the present invention.
Fig. 6 is a three-dimensional schematic view of the present invention.
Fig. 7 is a three-dimensional schematic diagram of the inner shell of the veneer sensor of the present invention.
Fig. 8 is a three-view diagram of the left magnetic core of the veneer sensor of the present invention.
Fig. 9 is a three-view diagram of the right magnetic core of the veneer sensor of the present invention.
Fig. 10 shows the result of the XY-direction position shift of the external sensor according to the present invention.
Figure 11 bit the utility model discloses external sensor Z direction position shift result.
Reference numbers in the figures: 1. a reinforced concrete test piece; 2. a veneered sensor left magnetic core; 3-1, detecting the reinforcing steel bars at the left side corners; 3-2, detecting the steel bars at the right side corners; 4. detecting the steel bars in the middle; 5. a veneered sensor right magnetic core; 6-1, a first Hall sensor; 6-2, a second Hall sensor; 6-3, a third Hall sensor; 6-4, a fourth Hall sensor; 7. a veneered sensor permanent magnet; 8. a face-mounted sensor package housing; 8-1, a first fixing hole; 8-2, a second fixing hole; 8-3, placing a permanent magnet placing groove of the veneer sensor; 8-4, placing a magnetic core placing groove on the left side of the veneer sensor; 8-5, placing a magnetic core placing groove on the right side of the veneering type sensor; 8-6, a first cable bending space; 8-7, a first wire hole; 8-8, packaging cover; 9-1, a first circuit indicator light; 9-2, a second circuit indicator light; 10. a signal collector; 11. a signal processor; 12. a central controller; 13. an external sensor permanent magnet; 14. a left magnetic core of the external sensor; 15. the external sensor right magnetic core; 16. an external sensor packaging shell; 16-1, placing a permanent magnet placing groove of the external sensor; 16-2, placing a left magnetic core placing groove of the external sensor; 16-3; a right magnetic core placing groove of the external sensor; 16-4, a third fixing hole; 16-5, a fourth fixing hole; 16-6, a second wire hole; 16-7, a second cable bending space; 16-8 and an external sensor packaging cover.
Detailed Description
The present invention will be further described with reference to the accompanying drawings.
Referring to fig. 1 to 11, the non-uniform corrosion nondestructive monitoring sensor for the existing reinforced concrete structure steel bar comprises a magnetic induction intensity monitoring unit and a data processing unit, wherein the magnetic induction intensity monitoring unit comprises an external sensor and a veneer sensor, and the external sensor comprises an external sensor left magnetic core 14, an external sensor right magnetic core 15, an external sensor permanent magnet 13, a first hall sensor 6-1, a second hall sensor 6-2 and an external sensor packaging shell 16; the external sensor packaging outer shell comprises an external sensor inner shell and an external sensor packaging cover 16-8; the external sensor inner shell comprises an external sensor permanent magnet placing groove 16-1, a left magnetic core placing groove 16-2, a right magnetic core placing groove 16-3, a third fixing hole 16-4, a fourth fixing hole 16-5, a second cable bending space 16-7 and a second cable hole 16-8.
The veneer sensor comprises a veneer sensor permanent magnet 7, a veneer sensor left magnetic core 2, a veneer sensor right magnetic core 5, a veneer sensor packaging shell 8, a third Hall sensor 6-3 and a fourth Hall sensor 6-4; the surface-mounted sensor packaging outer shell comprises a surface-mounted sensor inner shell and a surface-mounted sensor packaging cover 8-8; the sensor inner shell comprises a first fixing hole 8-1, a second fixing hole 8-2, a veneer sensor left magnetic core placing groove 8-4, a veneer sensor right magnetic core placing groove 8-5, a veneer sensor permanent magnet placing groove 8-3, a first cable bending space 8-6 and a first wire hole 8-7; the sensor inner shell and the encapsulation cover both comprise a first fixing hole 8-1 and a second fixing hole 8-2.
The data processing unit comprises a signal collector 10, a signal processor 11 and a central controller 12, wherein the input end of the signal collector 10 is electrically connected with the signal output end of the Hall sensor, and the signal output end of the signal processor 11 is electrically connected with a port of the central controller 12.
Further, veneer sensor left side magnetic core 2 and veneer sensor right side magnetic core 5 be the rectangular cross section, external sensor left side magnetic core 14 and external sensor right side magnetic core 15 be trapezoidal bayonet socket.
The left magnetic core 2 of the veneer type sensor, the right magnetic core 5 of the veneer type sensor, the left magnetic core 14 of the external sensor and the right magnetic core 15 of the external sensor are of symmetrical structures.
The left magnetic core 2 of the veneer type sensor, the right magnetic core 5 of the veneer type sensor, the left magnetic core 14 of the external sensor and the right magnetic core 15 of the external sensor are made of silicon steel.
The external sensor permanent magnet 13 and the veneer sensor permanent magnet 7 are made of neodymium-nickel-boron materials.
The veneer type sensor packaging shell 8 and the external sensor packaging shell 16 are made of plastic materials.
The veneer sensor and the external sensor are arranged outside the reinforced concrete structure 1.
The first fixing hole 8-1, the second fixing hole 8-2, the third fixing hole 16-4 and the fourth fixing hole 16-5 are threaded holes.
The inner shell and the encapsulation cover 8-8 of the veneer sensor comprise a first fixing hole 8-1 and a second fixing hole 8-2, and corresponding screws and nuts are used for bolt connection during installation.
The external sensor inner shell and the external sensor packaging cover 16-8 comprise a third fixing hole 16-4 and a fourth fixing hole 16-5, and corresponding screws and nuts are used for bolt connection during installation.
A first indicator light 9-1 and a second indicator light 9-2 are arranged between the veneer sensor and the external sensor and the signal collector 10, and the first indicator light 9-1 and the second indicator light 9-2 prompt whether the external sensor, the veneer sensor and the signal collector 10 work normally or not.
The Hall sensor can be arranged with 1 or more sensors according to the precision requirement and the actual engineering requirement.
As an improvement, the surface-mounted sensor permanent magnet 7, the external sensor permanent magnet 13, the surface-mounted sensor left magnetic core 2, the surface-mounted sensor right magnetic core 5, the external sensor left magnetic core 14 and the external sensor right magnetic core 15 need to be placed in a magnetic isolation environment after detection, so that the influence of demagnetization on detection precision is avoided.
As an improvement, the veneer sensor can be used for monitoring the non-uniform corrosion of the steel bars on a plurality of steel bars, and can be used repeatedly and used for flow monitoring.
As an improvement, the external sensor corresponds to a plurality of reinforced concrete structure monitoring, and can be used repeatedly and used for flow monitoring.
As an improvement, the surface-mounted sensor package housing 8 and the external sensor package housing 16 contain a bending space for connecting a circuit board with a cable, so as to ensure that the circuit can be effectively bent.
As an improvement, the data processing unit and the related control circuit can be realized by using the existing mature technology, and mainly comprises the steps of measuring the Hall voltage of the Hall sensor so as to calculate the corrosion rate. The Hall voltage measuring system and the data processing system complete data storage, post-processing and real-time display through the signal processor 11 and the central controller 12.
The testing method of the non-uniform corrosion nondestructive monitoring sensor for the existing reinforced concrete structure steel bar based on the magnetic field principle takes the HPB300 smooth round steel bar with the diameter of 16mm as an example, and comprises the following steps:
firstly, preparing a reinforced concrete test piece 1 before being tested, wherein the process is as follows:
1.1 taking an optical round steel bar with the length of 400cm and the diameter of 16mm as a calibration steel bar, a middle steel bar to be measured 4, a left steel bar to be measured 3-1 and a right steel bar to be measured 3-2, and weighing the mass m of the steel bar to be measured1I，m2I，m3I，m4I，m5I，m6I，m7IAnd calibrating the steel bar mass m0And recording;
1.2 the calibration reinforcing steel bar and the reinforcing steel bar to be measured are coated with epoxy resin at the position of 20cm which is the half length of the two ends, the left side is measured, the distance between the reinforcing steel bar to be measured 3-1 and the right side reinforcing steel bar 3-2 and the calibration reinforcing steel bar and the middle reinforcing steel bar to be measured 4 is 25mm, and the concrete is prepared from the following raw materials: the cement is P.I 525 grade Portland cement, the sand adopts river sand with fineness modulus of 2.6, the coarse aggregate adopts continuous graded broken stone (the maximum grain diameter is 25mm), the water adopts tap water, the effective section size of a test piece poured in the mould is 150mm multiplied by 150mm, the length of the steel bar is 400mm, the protruding length of the steel bars at two sides is 50mm, and the length of the test piece is 300 mm;
second, preparation before measurement, as follows:
2.1 respectively placing a veneered sensor permanent magnet 7, a veneered sensor left magnetic core 2 and a veneered sensor right magnetic core 5 into a veneered sensor permanent magnet placing groove 8-3, a veneered sensor left magnetic core placing groove 8-4 and a veneered sensor right magnetic core placing groove 8-5, installing a circuit board, a third Hall sensor 6-3 and a fourth Hall sensor 6-4, bending the cable at a cable bending space 8-6, externally connecting an indicator lamp 9-1 and a signal collector 10 through a wire hole 8-7, and finally connecting a sensor inner shell and a sensor packaging cover 8-8 through a first fixing hole 8-1 and a second fixing hole 8-2 by bolts and nuts;
2.2, placing the left magnetic core 14 of the external sensor, the right magnetic core 15 of the external sensor and the permanent magnet 13 of the external sensor into a left magnetic core placing groove 16-2 of the external sensor, a right magnetic core placing groove 16-3 of the external sensor and a permanent magnet placing groove 16-1 of the external sensor respectively, installing a first Hall sensor 6-1, a second Hall sensor 6-2 and a circuit board, bending the cable at a bending space 16-7 of the second cable, externally connecting a second indicator lamp 9-2 and a signal collector 10 through a second wire hole 16-6, and finally connecting an inner shell of the external sensor and a packaging cover of the external sensor through a third fixing hole 16-4 and a fourth fixing hole 16-5 by using screws and nuts;
2.3 placing the steel bars into a mould for casting forming, maintaining for 28 days under standard conditions, and soaking a casting forming calibration reinforced concrete test piece 1 and a reinforced concrete test piece 1 to be detected in a standard salt concentration solution until the standard salt concentration solution is saturated, wherein the concentration of the standard sodium chloride solution is 0.1-2 mol/L;
2.4 the veneering type sensor is packaged by a veneering type sensor packaging shell 8 and then is arranged on a reinforced concrete test piece 1 and is communicated with a magnetic circuit of a middle monitoring reinforcing steel bar 4, the external sensor is clamped at the corner of a reinforced concrete structure by an external sensor packaging shell package 16 and is communicated with magnetic circuits of corner monitoring reinforcing steel bars 3-1 and 3-2, the collection frequency of a signal collector 10 is controlled by a central controller 12, the test sensor is electrified to ensure that the first Hall sensor 6-1, the second Hall sensor 6-2, the third Hall sensor 6-3 and the fourth Hall sensor 6-4 carry out normal collection work, and the initial positions of the veneering type sensor and the external sensor are marked by a marker pen;
thirdly, a calibration test is carried out, and the process is as follows:
3.1 recording mass m1I，m2I，m3I，m4I，m5I，m6I，m7ICorresponding steelHall voltage V for calibrating reinforcing steel bar before corrosion of reinforced concrete test piece1I，V2I，V3I，V4I，V5I，V6I， V7I；
3.2, marking the placement positions of the veneering type sensor and the external sensor on the surface of the concrete through a marking pen so as to ensure in-situ monitoring;
3.3 simulation experiment of reinforcing bar corrosion is realized with the mode of corrosion is accelerated to the electric current, and control current density is the same, and the quality is m1I，m2I，m3I，m4I，m5I，m6I，m7ICorresponding reinforced concrete test piece is electrified at equal intervals t1，t2，t3，t4，t5，t6，t7；
3.4 record the Hall voltage data V of the calibrated steel bar after the reinforced concrete test piece is corroded1II， V2II，V3II，V4II，V5II，V6II，V7IIAnd steel bar quality data m1II，m2II，m3II，m4II， m5II，m6II，m7II；
3.5 respectively calculating and calibrating the change rate Delta m of the steel bar quality1，△m2，△m3，△m4，△ m5，△m6，△m7The calculation formulas are respectively formulas (1) to (7);
3.6 separately calculating and calibrating Hall voltage delta V of reinforcing steel bar1，△V2，△V3，△V4，△V5，△V6，△V7The calculation formulas are respectively the formulas (8) to (14)
3.7, performing linear fitting on the relationship between the steel bar mass change rate and the Hall voltage to obtain a linear relationship coefficient alpha;
step four, measuring the test, the process is as follows:
4.1 recording Hall voltage V before corrosion of a piece to be tested0I；
4.2 placing the reinforced concrete test piece to be tested in an environment which is easy to cause the reinforcing steel bars to be corroded, such as a dry-wet cycle environment, so as to cause the reinforcing steel bars to be corroded;
4.3 the veneer sensor and the external sensor are put back to the original position, and the Hall voltage V after the steel bar is corroded is recorded0II；
4.4 Corrosion Rate P of Steel barsIIThe calculation formula is formula (15)
PII＝α(V0II-V0I)
(15)。
Example (c): use the actual reinforced concrete roof beam of engineering as the test case, the bottom of the beam reinforcing bar is 3 HRB400 ribbed steel bars of diameter 20mm, and the beam reinforcing bar interval of the left and right sides is 25mm, and the reinforcing bar is built up to upper portion and is 2 HPB300 smooth round steel bars that the diameter is 16mm, and the raw and other materials of concrete are: the cement is P.I 525 grade Portland cement, the sand adopts river sand with fineness modulus of 2.6, the coarse aggregate adopts continuous graded broken stone (the maximum grain diameter is 25mm), the water adopts tap water, the effective section size of a casting sample in a standard mould is 150mm multiplied by 150mm, the beam length is 1m, the standard maintenance is carried out in a maintenance room for 28d after the casting forming, and the concrete beam cast by taking the concrete beam as an example makes specific explanation on the actual engineering reinforced concrete beam corrosion prediction:
1. testing method steps according to actual size of engineering reinforced concrete beam
1.1-3.7, carrying out indoor test calibration, and carrying out linear fitting on the relationship between the steel bar mass change rate and the Hall voltage to obtain a linear relationship coefficient alpha.
2. Respectively placing a veneered sensor permanent magnet 7, a veneered sensor left magnetic core 2 and a veneered sensor right magnetic core 5 into a veneered sensor permanent magnet placing groove 8-3, a veneered sensor left magnetic core placing groove 8-4 and a veneered sensor right magnetic core placing groove 8-5, installing a circuit board, a third Hall sensor 6-3 and a fourth Hall sensor 6-4, bending the cable at a cable bending space 8-6, externally connecting an indicator lamp 9-1 and a signal collector 10 through a wire hole 8-7, and finally connecting a sensor inner shell and a sensor packaging cover 8-8 through a first fixing hole 8-1 and a second fixing hole 8-2 by bolts and nuts.
3. Respectively placing an external sensor left magnetic core 14, an external sensor right magnetic core 15 and an external sensor permanent magnet 13 into an external sensor left magnetic core placing groove 16-2, an external sensor right magnetic core placing groove 16-3 and an external sensor permanent magnet placing groove 16-1, installing a first Hall sensor 6-1, a second Hall sensor 6-2 and a circuit board, bending the cable at a second cable bending space 16-7, externally connecting a second indicator lamp 9-2 and a signal collector 10 through a second wire hole 16-6, and finally connecting an external sensor inner shell and an external sensor packaging cover through a third fixing hole 16-4 and a fourth fixing hole 16-5 by using screws and nuts
4. Placing a steel bar into a mold for casting molding, maintaining for 28 days under standard conditions, and soaking a casting molding calibration reinforced concrete test piece 1 and a reinforced concrete test piece 1 to be tested in a standard salt concentration solution until the samples are saturated with salt, wherein the concentration of the standard sodium chloride solution is 0.1-2 mol/L;
5. the veneering type sensor is packaged by a veneering type sensor packaging shell 8 and then is placed on a reinforced concrete test piece 1 and is communicated with a middle monitoring steel bar 4 magnetic circuit, the external sensor is clamped at the corner of a reinforced concrete structure after being packaged by an external sensor packaging shell 16 and is communicated with corner monitoring steel bars 3-1 and 3-2 magnetic circuits, the central controller 12 is used for controlling the acquisition frequency of the signal acquisition device 10, the test sensor is electrified to ensure that the first Hall sensor 6-1, the second Hall sensor 6-2, the third Hall sensor 6-3 and the fourth Hall sensor 6-4 carry out normal acquisition work, and a marker pen is used for marking the initial positions of the veneering type sensor and the external sensor;
6. after the actual reinforced concrete beam is corroded for a certain time under natural conditions, the veneering type sensor and the external sensor are put back to the original position, and the Hall voltage V after the reinforced concrete beam is corroded is recorded2II；
7. Corrosion rate P of rusted steel bar in reinforced concrete beamIIThe calculation formula is formula (16)
PII＝α(V2II-V2I) (16)。
Example 2: the diameter of the steel bar is 16mm, the length of the steel bar is 20cm, and the steel bar is HPB300 smooth round steel bar, and the concrete comprises the following raw materials: the cement is P.I 525 grade Portland cement, the sand adopts river sand with fineness modulus of 2.6, the coarse aggregate adopts continuous graded broken stone (the maximum grain diameter is 25mm), the water adopts tap water, the effective section dimension of a cast test piece in a standard die is 100mm multiplied by 100mm, the length of a steel bar is 200mm, the protruding length of the steel bars at two sides is 50mm, the length of the test piece is 100mm, the standard maintenance is carried out in a maintenance room for 28d after the cast molding, and the influence of the position change of the steel bar on the magnetic induction intensity of an external sensor is specifically explained by taking the cast reinforced concrete test piece as an example:
the x-axis is established in the front-back direction, the y-axis is established in the left-right direction, and the z-axis is established in the up-down direction. And (3) moving the reinforced concrete test piece 1 to the centers of the bayonets of the left magnetic core 14 and the right magnetic core 15 of the external sensor, and defining the three-dimensional relative coordinate value (x, y, z) of the bayonets of the magnetic cores at the moment as (0,0, 0).
The reinforced concrete test piece 1 is made to move along the z direction, the Hall voltage and the z coordinate value of the third Hall sensor 6-3 are recorded, the test data are shown in figure 11, the Hall voltage monitoring value can not be changed when the effective length of the steel bar in the bayonet area is not changed according to the test data, and the Hall voltage monitoring value can be remarkably reduced when the moving distance of the steel bar along the z direction is increased to the effective length of the steel bar in the bayonet area and is reduced.
The reinforced concrete test piece 1 is moved along the x direction and the y direction, the Hall voltage, the x coordinate value and the y coordinate value of the third Hall sensor 6-3 are recorded, the test data is shown in figure 10, and the test data shows that the influence on the magnetic induction intensity monitoring value is great when the steel bar moves along the x direction and the y direction, so the in-situ monitoring is required to be kept in the corrosion test process.
The embodiments of the present invention are merely provided to illustrate the embodiments of the present invention, and the protection scope of the present invention should not be construed as being limited to the specific forms set forth in the embodiments, but also includes equivalent technical means which can be conceived by those skilled in the art according to the present invention.
Claims (10)
1. The non-uniform corrosion nondestructive monitoring sensor for the existing reinforced concrete structure steel bar is characterized by comprising a magnetic induction intensity monitoring unit and a data processing unit, wherein the magnetic induction intensity monitoring unit comprises an external sensor and a veneer sensor, and the external sensor comprises an external sensor left magnetic core, an external sensor right magnetic core, an external sensor permanent magnet, a first Hall sensor, a second Hall sensor and an external sensor packaging shell; the external sensor packaging outer shell comprises an external sensor inner shell and an external sensor packaging cover; the external sensor inner shell comprises an external sensor permanent magnet placing groove, a left magnetic core placing groove, a right magnetic core placing groove, a third fixing hole, a fourth fixing hole, a second cable bending space and a second cable hole; the surface-mounted sensor comprises a surface-mounted sensor permanent magnet, a surface-mounted sensor left magnetic core, a surface-mounted sensor right magnetic core, a surface-mounted sensor packaging shell, a third Hall sensor and a fourth Hall sensor; the surface-mounted sensor packaging outer shell comprises a surface-mounted sensor inner shell and a surface-mounted sensor packaging cover; the sensor inner shell comprises a first fixing hole, a second fixing hole, a veneering type sensor left magnetic core placing groove, a veneering type sensor right magnetic core placing groove, a veneering type sensor permanent magnet placing groove, a first cable bending space and a first wire hole; the sensor inner shell and the packaging cover both comprise a first fixing hole and a second fixing hole;
the data processing unit comprises a signal collector, a signal processor and a central controller, wherein the input end of the signal collector is electrically connected with the signal output end of the Hall sensor, and the signal output end of the signal processor is electrically connected with the port of the central controller.
2. The non-uniform corrosion nondestructive monitoring sensor for the existing reinforced concrete structure steel bar as recited in claim 1, wherein said left magnetic core of the skin type sensor and said right magnetic core of the skin type sensor are rectangular in cross section, and said left magnetic core of the external type sensor and said right magnetic core of the external type sensor are trapezoidal bayonets; the left magnetic core of the veneer sensor, the right magnetic core of the veneer sensor, the left magnetic core of the external sensor and the right magnetic core of the external sensor are of symmetrical structures; the left magnetic core of the veneer type sensor, the right magnetic core of the veneer type sensor, the left magnetic core of the external sensor and the right magnetic core of the external sensor are made of silicon steel.
3. The non-uniform corrosion nondestructive monitoring sensor for the existing reinforced concrete structure steel bar as recited in claim 1 or 2, wherein the external sensor permanent magnet and the skin sensor permanent magnet are made of neodymium-nickel-boron material.
4. The non-uniform corrosion nondestructive monitoring sensor for existing reinforced concrete structure steel bar as claimed in claim 1 or 2 wherein said face sensor package and external sensor package are made of plastic.
5. The non-uniform corrosion nondestructive monitoring sensor for the existing reinforced concrete structure steel bar according to claim 1 or 2, wherein the veneer sensor and the external sensor are externally arranged outside the reinforced concrete structure.
6. The non-uniform corrosion nondestructive monitoring sensor for the existing reinforced concrete structure steel bar according to claim 1 or 2, wherein the first fixing hole, the second fixing hole, the third fixing hole and the fourth fixing hole are screw holes; the inner shell and the packaging cover of the veneer sensor comprise a first fixing hole and a second fixing hole, and are connected through a bolt by using a corresponding bolt and a corresponding nut during installation; the external sensor inner shell and the external sensor packaging cover comprise a third fixing hole and a fourth fixing hole, and corresponding screws and nuts are used for bolt connection during installation.
7. The non-uniform corrosion nondestructive monitoring sensor for the existing reinforced concrete structure steel bars as recited in claim 1 or 2, wherein a first indicator light and a second indicator light are installed between the surface-mounted sensor and the external sensor and the signal collector, and the first indicator light and the second indicator light prompt whether the external sensor, the surface-mounted sensor and the signal collector work normally or not.
8. The non-uniform corrosion nondestructive monitoring sensor for the steel reinforcement of the existing reinforced concrete structure as recited in claim 1 or 2, wherein said hall sensor is arranged with 1 or more sensors.
9. The non-uniform corrosion nondestructive monitoring sensor for the existing reinforced concrete structure steel bar as recited in claim 1 or 2, wherein said faced sensor permanent magnet, said external sensor permanent magnet, said faced sensor left magnetic core, said faced sensor right magnetic core, said external sensor left magnetic core and said external sensor right magnetic core are placed in a magnetic-insulated environment after being detected.
10. The non-uniform corrosion nondestructive monitoring sensor for the existing reinforced concrete structure steel bars as claimed in claim 1 or 2, wherein said one skin sensor can perform non-uniform corrosion monitoring, recycling and flow monitoring for the plurality of steel bars, said one external sensor corresponds to the plurality of reinforced concrete structure monitoring, recycling and flow monitoring;
the veneer type sensor packaging shell and the external sensor packaging shell contain bending spaces for connecting the circuit board with the cable so as to ensure that the circuit can be effectively bent;
in the data processing unit, the Hall voltage of the Hall sensor is measured, so that the corrosion rate is calculated, and the Hall voltage measuring system and the data processing system finish data storage, post-processing and real-time display through the signal processor and the central controller.
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