CN107064228B - Reinforcing steel bar corrosion monitoring method - Google Patents
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- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/041—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body
Abstract
The invention belongs to the technical field of steel bar corrosion monitoring, and relates to a steel bar corrosion monitoring method, which utilizes the resistance value change of a built-in steel wire to reflect the corrosion condition of a steel bar, is mainly used for corrosion monitoring and durability assessment of steel bar components in a reinforced concrete structure, and is realized in a parallel resistance type steel bar corrosion monitoring device, the technical process comprises two steps of installing the parallel resistance type steel bar corrosion monitoring device and monitoring the corrosion condition of the steel bar, the steel wire is buried at different depths from the surface of the concrete in a parallel manner, only a group of wires with equal cross section or variable cross section are led out, the sensitivity of the resistance change of a metal conductor caused by steel bar corrosion is ensured, the gradient of the parallel resistance type steel bar corrosion monitoring device can be adjusted, and the monitoring of the corrosion condition of the steel bar in different concrete protection layer thicknesses is facilitated; the principle is scientific and reliable, the monitoring is simple and convenient, the monitoring result is accurate and reliable, the resistance signal is simple, the change sensitivity is high, the analysis and the monitoring are easy, and the application range is wide.
Description
Technical field:
the invention belongs to the technical field of steel bar corrosion monitoring, and particularly relates to a steel bar corrosion monitoring method, which utilizes the resistance value change of a built-in steel wire of a parallel resistance type steel bar corrosion monitoring device to reflect the steel bar corrosion condition and is mainly used for corrosion monitoring and durability evaluation of steel bar components in a reinforced concrete structure.
The background technology is as follows:
in a reinforced concrete structure, rust of a steel bar is one of important factors affecting safety and durability of a construction engineering structure; when the steel bar is corroded, the volume is expanded, the binding force between the steel bar and the concrete is reduced, the concrete protective layer is peeled off, the strength of the building structure is reduced, the steel bar corrosion is difficult to be perceived by naked eyes, when the slightly damaged building caused by the steel bar corrosion is repaired, the problems of large workload, high manufacturing cost and poor benefit exist, and when the damage of the building is serious, immeasurable loss is brought to the life and property safety of people; therefore, it is necessary to monitor the rust state of the reinforcing steel bars in the concrete and grasp the internal condition of the building structure so as to perform early warning before the damage of the building occurs, thereby minimizing the loss. The invention discloses a trapezoid anode concrete structure embedded nondestructive detection sensor system which is widely applied to reinforcement corrosion monitoring, but has the problems of high manufacturing cost, complex structure and special measuring instrument requirement, and is invented by the civil engineering research institute of the university of the America industry in Germany at the end of the 80 th century; at present, the monitoring of steel bar corrosion is realized by measuring certain electrochemical parameters of steel bars in a concrete structure through a sensor: the steel bar corrosion time prediction device disclosed in China patent 201120123530.7 comprises steel wires, PVC rods, wires, a bracket provided with side grooves, screws and fixing rods, wherein the steel wires are wound on the PVC rods and are led into the side grooves of the bracket, the two ends of the steel wires are connected with the wires, epoxy resin filling layers are arranged in the side grooves of the bracket, the effect of the epoxy resin filling layers is to fix the wires and the PVC rods, the screws are arranged at one end of the bracket, and pass through the stainless steel fixing rods, the effect of the epoxy resin filling layers is to adjust the distance between the fixing rods and the bracket, each group of steel wires is provided with a group of external wires, the number of the external wires is numerous, and the junction box structure is complex; the device comprises a fiber bragg grating strain sensor, a signal processing unit, a stainless steel inclined plane bracket, at least three fiber bragg grating strain sensors and a wire, wherein the fiber bragg grating strain sensors are sequentially arranged on the inclined plane of the inclined plane bracket, signals acquired by the fiber bragg grating strain sensors are sent to the signal processing unit through the wire, the fiber bragg grating strain sensors are used for measuring tensile strain and time of strain generation caused by the rust expansion force generated by a steel bar corrosion product at different concrete protective layer thicknesses, and the steel bar corrosion rate and the steel bar corrosion initial corrosion time in the reinforced concrete structure are deduced for indirectly monitoring the steel bar corrosion condition. Therefore, the research and design of the steel bar corrosion monitoring method easy to operate monitors and evaluates the corrosion condition of the steel bars in the concrete structure in real time, and has good social and economic benefits and wide application prospect.
The invention comprises the following steps:
the invention aims to overcome the defects in the prior art, and develops a steel bar corrosion monitoring method which can accurately monitor and evaluate the corrosion condition of steel bars in a concrete structure in real time.
In order to achieve the above purpose, the method for monitoring the corrosion of the steel bar is realized in a parallel resistance type steel bar corrosion monitoring device, and the technical process comprises two steps of installing the parallel resistance type steel bar corrosion monitoring device and monitoring the corrosion condition of the steel bar:
(1) And (3) installing a parallel resistance type steel bar corrosion monitoring device: according to the thickness of the concrete protective layer, the inclination of the parallel resistance type steel bar corrosion monitoring device is adjusted by changing the length of the bolt member penetrating into the fixing rod, the fixing rod and the steel bar to be tested are bound together, a terminal box connected with the external resistance measuring instrument is fixed on the outer side of the template, and concrete is poured;
(2) Monitoring the corrosion condition of the steel bars: starting a resistance measuring instrument, wherein in the monitoring process, corrosive substances permeate to the surface of a metal conductor which is the same as the steel bar material at different depths from the surface of the concrete, the metal conductor at the outer layer is corroded and firstly rusted, so that the resistance of the metal conductor at the outer layer is changed, and monitoring and predicting the corrosion condition of the steel bar in the reinforced concrete structure are realized by monitoring and judging the penetration depth of the corrosive substances; since r=ρ·l/S, where R is the resistance of the metal conductor, R is in ohms (Ω), ρ is the metal conductorIn ohm meters (Ω.m), L is the length of the metal conductor, L is in meters (m), S is the cross-sectional area, and S is in square meters (m) 2 ) The method comprises the steps of carrying out a first treatment on the surface of the When the metal conductor is externally connected with a power supply and forms a closed loop, electrons in the metal conductor directionally move under the action of potential, and n metal conductor resistors are in parallel connection in the circuit, the total resistance R of the circuit Total (S) And the respective metal conductor resistances satisfy the relationship:
then->
Wherein R is 1 、R 2 ……R n Resistance of the first and second … … nth metal conductors;
when the lengths, materials and sectional areas of all the metal conductors are the same, R is present 1 ＝R 2 ＝……＝R n Wherein R is 1 、R 2 ……R n The resistance of the metal conductor from outside to inside
The metal conductors are sequentially rusted off from the outside to the inside under the action of corrosive substances, when the mth metal conductor is rusted off,
at this time, the rate of change of resistance is:
the method comprises the steps of carrying out a first treatment on the surface of the R when the innermost metal conductor is rusted off Total n Is infinite; the more the metal conductors are connected in parallel, the more the resistance number is, namely, the larger n is, the smaller the change rate of the resistance is, and the sensitivity of the sensor formed by the metal conductors connected in parallel is lower; when n is fixed, the smaller m is, the smaller the change rate of the resistance is, which indicates that the change rate of the resistance is lower at the initial stage of corrosion, and the metal is developed with timeThe resistance change rate caused by the rust breakage of the conductor is increased, and the resistance change rate of the sensor formed by parallel connection of the metal conductors with the same cross section is lower;
when the length and the material of the metal conductor are the same, the sectional area of the metal conductor is reduced by K (K > 1) times from outside to inside, and the resistance R of the metal conductor at the outermost layer 1 R is the resistance value of R 1 、R 2 ……R n The method meets the following conditions:
at this time:
when the metal conductor is subjected to the action of corrosive substances, the metal conductor is sequentially rusted from outside to inside, when the mth metal conductor is rusted,
when the nth metal conductor is rusted, R Total n Is infinite; along with the rust of the metal conductor, the ratio of the parallel circuit resistance when the mth metal conductor is rusted to the parallel circuit resistance when the mth-1 metal conductor is rusted is as follows:
the resistance change rate of the metal conductor caused by rust breakage of the steel bar is related to the area ratio K of the cross sections of the adjacent metal conductors, when the K value is larger than 1, the resistance change rate of the metal conductor is more obvious relative to the change of the equal cross section, and the sensor formed by parallel connection of the metal conductors is more sensitive to monitoring data; when the metal conductor is rusted, the resistance value signal of the parallel metal conductor is obviously changed, the moment when the resistance value of the metal conductor is suddenly changed is the time point of rusting of the steel bar, the rusting condition of the steel bar at a certain position is assessed according to the resistance value of the measured metal conductor, the rusting time of the steel bar to be measured is predicted by analyzing the rusting time of the steel bar at different concrete depths, and the guarantee can be provided for scientific decision of rusting protection or repairing rusting measures of the steel bar.
The invention relates to a main structure of a parallel resistance type steel bar corrosion monitoring device, which comprises a bracket, a bolt piece, a fixed rod, a sleeve, an arc-shaped groove, an insulating rod, a steel wire, a wire and a terminal box, wherein the bracket is arranged on the bracket; one end of each of the two parallel brackets is connected with a fixing rod of a cylindrical structure through a bolt piece to form a triangular structure, the opposite surfaces of the two brackets of an inner hollow structure are respectively and uniformly nested with five sleeves of a circular structure at intervals, the inner walls of the sleeves are provided with arc grooves, the two opposite sleeves are connected with each other through an insulating rod of the cylindrical structure, steel wires are wound on the insulating rods, two ends of each steel wire are respectively connected with a wire in the arc grooves, the wires extend out of the sleeves to be converged in the brackets and extend out of the brackets to be connected with a terminal box, and the parts of the wires extending out of the brackets are coated with insulating sheaths; the gaps between the bracket and the sleeve are smeared with adhesive glue for fixing, sealing and insulating, the gaps between the arc-shaped grooves and the steel wire and the gaps between the bracket and the wire are filled with epoxy resin, the resistivity of the wire is extremely small, and the resistance of the wire is negligible relative to the resistance of the steel wire; each component is matched to form a parallel resistance type steel bar corrosion monitoring device for monitoring the corrosion condition of steel bars in a concrete structure.
The bracket is made of stainless steel; the bolt piece and the fixed rod form a triangle structure with adjustable angle; the sleeve is used for tightly connecting the bracket with the insulating rod and fixing the lead; the arc-shaped groove is used for penetrating the steel wire and the lead; the insulating rod is used for bearing the steel wire; the steel wire is the same as the steel bar to be measured; the conducting wires are made of copper wires with negligible resistivity, and the cross sections of the conducting wires are the same or multiplied; the terminal box is used for connecting an external resistance measuring instrument.
Compared with the prior art, the parallel resistance type steel bar corrosion monitoring device has the advantages that steel wires are buried at different depths from the surface of the concrete in a parallel connection mode, only a group of wires with equal cross sections or variable cross sections are led out, the sensitivity of resistance change of a metal conductor caused by steel bar corrosion is guaranteed, the gradient of the parallel resistance type steel bar corrosion monitoring device can be adjusted, the monitoring of steel bar corrosion conditions in different concrete protection layer thicknesses is facilitated, the parallel resistance type steel bar corrosion monitoring device is simple in structure, the lead-out quantity of the wires is small, the whole rigidity is high, the binding is easy, the disturbance of concrete pouring is avoided, the materials are convenient, the cost is low, the resistance change of the metal conductor is increased when the variable cross section wire is used, and the sensitivity of the parallel resistance type steel bar corrosion monitoring device is improved; the principle is scientific and reliable, the monitoring is simple and convenient, the monitoring result is accurate and reliable, the resistance signal is simple, the change sensitivity is high, the analysis and the monitoring are easy, and the application range is wide.
Description of the drawings:
fig. 1 is a flow chart of the present invention for monitoring the rust condition of the steel bar.
Fig. 2 is a schematic diagram of the main structure of the parallel resistance type steel bar corrosion monitoring device according to the present invention.
Fig. 3 is a schematic diagram of a side view structure of a parallel resistance type steel bar corrosion monitoring device according to the present invention.
Fig. 4 is a schematic structural view of a sleeve according to the present invention.
Fig. 5 is a schematic view showing a state in which the parallel resistance type steel bar corrosion monitoring device according to the present invention is located in a concrete structure.
The specific embodiment is as follows:
the invention will now be described in further detail by way of examples with reference to the accompanying drawings.
Example 1:
the method for monitoring corrosion of the steel bars is realized in a parallel resistance type steel bar corrosion monitoring device, and the monitoring process comprises two steps of installing the parallel resistance type steel bar corrosion monitoring device and monitoring the corrosion condition of the steel bars:
(1) And (3) installing a parallel resistance type steel bar corrosion monitoring device: according to the thickness of the concrete protection layer, the inclination of the parallel resistance type reinforcement corrosion monitoring device is adjusted by changing the length of the bolt 2 penetrating into the fixing rod 3, the fixing rod 3 and the reinforcement to be tested are bound together, a terminal box connected with an external resistance measuring instrument is fixed at the outer side of the template, and concrete is poured;
(2) Monitoring the corrosion condition of the steel bars: starting the resistance measuring instrument, wherein in the monitoring process, corrosive substances of chloride ions or sulfate ions penetrate into the concrete from the outside to the inside, the steel wire 7 close to the fixing rod is nearest to the surface of the concrete, so that corrosion can occur at first, five steel wires 7 with the same length and material and different sectional areas are connected in parallel, wherein the resistance of the steel wires 7 is inversely related to the sectional area of the steel wires 7, R 1 、R 2 、R 3 、R 4 And R is 5 The resistances of the five wires 7 from the outside to the inside are respectively that the resistance value of the outermost layer of the wires 7 is R 1 ＝R 2 /2＝R 3 /4＝R 4 /8＝R 5 The total resistance of the parallel wires 7 is/16=r:
when the outermost layer steel wire 7 is rusted and broken, the resistance of the outermost layer steel wire 7 becomes infinite, and the total resistance is:
the total resistance when the second steel wire 7 is broken by rust is:
the total resistance when the third steel wire 7 is broken by rust is:
the total resistance when the fourth steel wire 7 is broken by rust is:
when the fifth steel wire 7 is broken by rust,R total 5 When the steel wire 7 is rusted, the resistance value of the parallel steel wire 7 is suddenly changed, the resistance of the parallel steel wire 7 is measured by a resistance measuring instrument, when the resistance value of the steel wire 7 is suddenly changed for the first time, the outermost steel wire 7 is rusted, and the like; and evaluating the rust condition of the steel bar at a certain position according to the resistance of the measured steel wire 7, and monitoring the rust time of the steel bar to be measured by analyzing the rust breaking time of the steel wire 7 at different concrete depths.
The main structure of the parallel resistance type steel bar corrosion monitoring device related to the embodiment comprises a bracket 1, a bolt piece 2, a fixed rod 3, a sleeve 4, an arc groove 5, an insulating rod 6, a steel wire 7, a lead 8 and a terminal box 9; one end of each of the two parallel brackets 1 is connected with a fixing rod 3 of a cylindrical structure through a bolt piece 2 to form a triangular structure, five sleeves 4 of circular structures are respectively and uniformly nested at intervals on the opposite surfaces of the two brackets 1 of the hollow structure, an arc-shaped groove 5 is formed in the inner wall of each sleeve 4, the two opposite sleeves 4 are connected with each other through an insulating rod 6 of the cylindrical structure, steel wires 7 are wound on the insulating rods 6, two ends of each steel wire 7 are respectively connected with a wire 8 in the arc-shaped groove 5, the wires 8 extend out of the sleeves 4 to be converged in the brackets 1 and extend out of the brackets 1 to be connected with a terminal box 9, and the part of each wire 8 extending out of the brackets 1 is coated with an insulating sheath; the gaps between the bracket 1 and the sleeve 4 are smeared with adhesive glue for fixing, sealing and insulating, the gaps between the arc-shaped groove 5 and the steel wire 7 and the wire 8 and the gaps between the bracket 1 and the wire 8 are filled with epoxy resin, the resistivity of the wire 8 is extremely small, and the resistance of the wire 8 is negligible relative to the resistance of the steel wire; each component is matched to form a parallel resistance type steel bar corrosion monitoring device for monitoring the corrosion condition of steel bars in a concrete structure.
The material of the bracket 1 according to the embodiment is stainless steel; the bolt 2 and the fixed rod 3 form a triangle structure with adjustable angles, the inclination of the parallel resistance type steel bar corrosion monitoring device is adjusted by changing the length of the bolt 2 penetrating into the fixed rod 3 according to the thickness of the concrete protection layer, so that the parallel resistance type steel bar corrosion monitoring device is convenient to monitor the corrosion condition of steel bars in concrete structures with different thicknesses; the sleeve 4 is used for tightly connecting and fixing the bracket 1 and the insulating rod 6A wire 5; the arc-shaped groove 5 is used for penetrating the steel wire 7 and the lead wire 8; the insulating rod 6 is used for bearing the steel wire 7; the sectional area of the steel wire 7 is multiplied by 0.01mm, and the sectional areas of the steel wires 7 are respectively increased 2 、0.02mm 2 、0.04mm 2 、0.08mm 2 And 0.16mm 2 The method comprises the steps of carrying out a first treatment on the surface of the The conducting wire 8 is made of copper wires with negligible resistivity; the terminal box 9 is used for connecting an external resistance measuring instrument.
Example 2:
the method for monitoring corrosion of the steel bars is realized in a parallel resistance type steel bar corrosion monitoring device, and the monitoring process comprises two steps of installing the parallel resistance type steel bar corrosion monitoring device and monitoring the corrosion condition of the steel bars:
(1) And (3) installing a parallel resistance type steel bar corrosion monitoring device: according to the thickness of the concrete protection layer, the inclination of the parallel resistance type reinforcement corrosion monitoring device is adjusted by changing the length of the bolt 2 penetrating into the fixing rod 3, the fixing rod 3 and the reinforcement to be tested are bound together, a terminal box connected with an external resistance measuring instrument is fixed at the outer side of the template, and concrete is poured;
(2) Monitoring the corrosion condition of the steel bars: in the monitoring process, five steel wires 7 with the same diameter, length and material are connected in parallel, and the total resistance is as follows:
wherein R is 1 、R 2 、R 3 、R 4 And R is 5 The resistances of the five steel wires 7 from the inside to the outside are R, when the first steel wire 7 at the outermost layer is rusted and broken, the resistance of the first steel wire 7 is infinite, and the total resistance is as follows:
when the third steel wire 7 is broken, the total resistance is:
when the fourth steel wire 7 is broken, the total resistance is:
when the fifth steel wire 7 is rusted, the total resistance is infinite; when the steel wire 7 is broken by rust, the resistance value of the parallel steel wire 7 is suddenly changed, the resistance of the parallel steel wire 7 is measured by a resistance measuring instrument, when the resistance value of the steel wire 7 is suddenly changed for the first time, the outermost steel wire 7 is broken by rust, and the like; evaluating the rust condition of the steel bar at a certain position according to the resistance of the measured steel wire 7, and monitoring the rust time of the steel bar to be measured by analyzing the rust breaking time of the steel wire 7 at different concrete depths; the rate of change of the electrical resistance of the constant-section steel wire 7 is smaller than that of the variable-section steel wire 7, and particularly, when the steel wire 7 is broken in the early stage, the rate of change of the electrical resistance is small, and the sensitivity is insufficient.
The main structure of the parallel resistance type steel bar corrosion monitoring device according to this embodiment is the same as that of embodiment 1, and the cross-sectional areas of the steel wires 7 are the same.
Claims (3)
1. The method is characterized by being implemented in a parallel resistance type steel bar corrosion monitoring device, and the technical process comprises two steps of installing the parallel resistance type steel bar corrosion monitoring device and monitoring the steel bar corrosion condition:
(1) And (3) installing a parallel resistance type steel bar corrosion monitoring device: according to the thickness of the concrete protective layer, the inclination of the parallel resistance type steel bar corrosion monitoring device is adjusted by changing the length of the bolt member penetrating into the fixing rod, the fixing rod and the steel bar to be tested are bound together, a terminal box connected with the external resistance measuring instrument is fixed on the outer side of the template, and concrete is poured;
(2) Monitoring the corrosion condition of the steel bars: starting a resistance measuring instrument, wherein in the monitoring process, corrosive substances permeate to the surface of a metal conductor which is the same as the steel bar material at different depths from the surface of the concrete, the metal conductor at the outer layer is corroded and firstly rusted, so that the resistance of the metal conductor at the outer layer is changed, and monitoring and predicting the corrosion condition of the steel bar in the reinforced concrete structure are realized by monitoring and judging the penetration depth of the corrosive substances; since r=ρ·l/S, where R is the resistance of the metal conductor, R is in ohms, ρ is the resistivity of the metal conductor, ρ is in ohm meters, L is the length of the metal conductor, L is in meters, S is the cross-sectional area, and S is in square meters; when the metal conductor is externally connected with a power supply and forms a closed loop, electrons in the metal conductor directionally move under the action of potential, and n metal conductor resistors are in parallel connection in the circuit, the total resistance R of the circuit Total (S) And the respective metal conductor resistances satisfy the relationship:
then->
Wherein R is 1 、R 2 ……R n Resistance of the first and second … … nth metal conductors;
when the lengths, materials and sectional areas of all the metal conductors are the same, R is present 1 ＝R 2 ＝……＝R n Wherein R is 1 、R 2 ……R n The resistance of the metal conductor from outside to inside
The metal conductors are sequentially rusted off from the outside to the inside under the action of corrosive substances, when the mth metal conductor is rusted off,
at this time, the rate of change of resistance is:
r when the innermost metal conductor is rusted off Total n Is infinite; the more the metal conductors are connected in parallel, the more the resistance number is, namely, the larger n is, the smaller the change rate of the resistance is, and the sensitivity of the sensor formed by the metal conductors connected in parallel is lower; when n is fixed, the smaller m is, the smaller the change rate of the resistance is, which shows that in the initial stage of corrosion, the change rate of the resistance is lower, the change rate of the resistance is increased along with the development of time caused by the rust breakage of the metal conductor, and the change rate of the resistance of the sensor formed by parallel connection of the metal conductors with equal sections is lower;
when the length and the material of the metal conductor are the same, the sectional area of the metal conductor is reduced from outside to inside in turn by K times, wherein K is more than 1, and the resistance R of the metal conductor at the outermost layer 1 R is the resistance value of R 1 、R 2…… R n The method meets the following conditions:
at this time:
when the metal conductor is subjected to the action of corrosive substances, the metal conductor is sequentially rusted from outside to inside, and when the mth metal conductor is rusted, the metal conductor is rusted>
When the nth metal conductor is rusted, R Total n Is infinite; along with the rust of the metal conductor, the ratio of the parallel circuit resistance when the mth metal conductor is rusted to the parallel circuit resistance when the mth-1 metal conductor is rusted is as follows:
the resistance change rate of the metal conductor caused by rust breakage of the steel bar is related to the area ratio K of the cross sections of the adjacent metal conductors, when the K value is larger than 1, the resistance change rate of the metal conductor is more obvious relative to the change of the equal cross section, and the sensor formed by parallel connection of the metal conductors is more sensitive to monitoring data; when the metal conductor is rusted, the resistance value signal of the parallel metal conductor is obviously changed, the moment when the resistance value of the metal conductor is suddenly changed is the time point of rusting of the steel bar, the rusting condition of the steel bar at a certain position is assessed according to the resistance value of the measured metal conductor, the rusting time of the steel bar to be measured is predicted by analyzing the rusting time of the steel bar at different concrete depths, and the guarantee can be provided for scientific decision of rusting protection or repairing rusting measures of the steel bar.
2. The steel bar corrosion monitoring method as claimed in claim 1, wherein the main structure of the parallel resistance type steel bar corrosion monitoring device comprises a bracket, a bolt member, a fixing rod, a sleeve, an arc-shaped groove, an insulating rod, a steel wire, a wire and a terminal box; one end of each of the two parallel brackets is connected with a fixing rod of a cylindrical structure through a bolt piece to form a triangular structure, the opposite surfaces of the two brackets of an inner hollow structure are respectively and uniformly nested with five sleeves of a circular structure at intervals, the inner walls of the sleeves are provided with arc grooves, the two opposite sleeves are connected with each other through an insulating rod of the cylindrical structure, steel wires are wound on the insulating rods, two ends of each steel wire are respectively connected with a wire in the arc grooves, the wires extend out of the sleeves to be converged in the brackets and extend out of the brackets to be connected with a terminal box, and the parts of the wires extending out of the brackets are coated with insulating sheaths; the gaps between the bracket and the sleeve are smeared with adhesive glue for fixing, sealing and insulating, the gaps between the arc-shaped grooves and the steel wire and the gaps between the bracket and the wire are filled with epoxy resin, the resistivity of the wire is extremely small, and the resistance of the wire is negligible relative to the resistance of the steel wire; each component is matched to form a parallel resistance type steel bar corrosion monitoring device for monitoring the corrosion condition of steel bars in a concrete structure.
3. The method for monitoring corrosion of steel bars according to claim 2, wherein the bracket is made of stainless steel; the bolt piece and the fixed rod form a triangle structure with adjustable angle; the sleeve is used for tightly connecting the bracket with the insulating rod and fixing the lead; the arc-shaped groove is used for penetrating the steel wire and the lead; the insulating rod is used for bearing the steel wire; the steel wire is the same as the steel bar to be measured; the conducting wires are made of copper wires with negligible resistivity, and the cross sections of the conducting wires are the same or multiplied; the terminal box is used for connecting an external resistance measuring instrument.
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