阅读说明：本技术 一种预埋型钢筋锈蚀率监测传感器及方法 (Embedded type steel bar corrosion rate monitoring sensor and method ) 是由 肖德文 杨楠 宋宇 张萌 赵保才 于 2021-08-31 设计创作，主要内容包括：本发明属于工程监测技术领域,尤其涉及一种预埋型钢筋锈蚀率监测传感器及方法；包括温度传感器阵列、电阻率传感器、加热模块、环境温度检测器和监测主机；使用电阻率传感器和温度传感器共同作用,监测钢筋的导热特性和电阻率特性随温度的变化规律,当锈蚀率达到一定程度时,电阻率随温度的变化特性会发生变化,同时由于钢筋的成分变化,被氧化后钢筋的导热特性也会变化,由此监测钢筋的锈蚀率更加精准；由于系统的巧妙设计,仅仅需要在钢筋表面设置温度传感器即可,结构简单,稳定性好,比设置光纤传感器更能克服外界的干扰,适应性强,成本更低。(The invention belongs to the technical field of engineering monitoring, and particularly relates to a pre-embedded type steel bar corrosion rate monitoring sensor and a method; the system comprises a temperature sensor array, a resistivity sensor, a heating module, an environment temperature detector and a monitoring host; the heat conduction characteristic and the change rule of the resistivity characteristic along with the temperature of the steel bar are monitored by using the combined action of the resistivity sensor and the temperature sensor, when the corrosion rate reaches a certain degree, the change characteristic of the resistivity along with the temperature changes, and meanwhile, the heat conduction characteristic of the oxidized steel bar also changes due to the change of the components of the steel bar, so that the corrosion rate of the steel bar is monitored more accurately; due to the ingenious design of the system, only the temperature sensor needs to be arranged on the surface of the steel bar, the structure is simple, the stability is good, the external interference can be overcome compared with the arrangement of the optical fiber sensor, the adaptability is strong, and the cost is lower.)

1. A pre-buried type steel bar corrosion rate monitoring sensor system is characterized by comprising a temperature sensor array, a resistivity sensor (2), a heating module (3), an environment temperature detector and a monitoring host; wherein

The temperature sensor array is formed by a plurality of temperature sensors (1) arranged along the extending direction of the steel bars, the distances among the temperature sensors (1) on the same steel bar are the same and are marked as L, and the distances between the temperature sensors (1) and the temperature sensor (1) which is closest to the temperature sensor (1) on one steel bar are also the same and are marked as L;

the heating modules (3) are arranged at two ends of one steel bar with a temperature sensor array, and the resistivity sensors (2) are arranged at two ends of the other steel bar with the temperature sensor array;

the monitoring host is connected with the temperature sensor array, the resistivity sensor (2), the heating module (3) and the ambient temperature detector, so that the temperature sensor array, the resistivity sensor (2), the heating module (3) and the ambient temperature detector are controlled to work and collect data.

2. The embedded steel bar corrosion rate monitoring sensor system according to claim 1, wherein each temperature sensor (1) in the temperature sensor array is attached to the surface of a steel bar, and a heat conduction material is coated at a contact position of the temperature sensor (1) and the steel bar.

3. The embedded steel bar corrosion rate monitoring sensor system according to claim 1, wherein the resistivity sensor (2) comprises a voltmeter and an ammeter arranged at two ends of the same steel bar.

4. The embedded steel bar corrosion rate monitoring sensor system according to claim 1, wherein the heating module (3) is a constant temperature heater.

5. A method for monitoring the corrosion rate of a steel bar is characterized by comprising the following steps:

firstly, calibrating a system;

selecting two reinforcing steel bars, wherein temperature sensor arrays are arranged on the 1 st reinforcing steel bar and the 2 nd reinforcing steel bar, heating modules (3) are arranged at two ends of the 1 st reinforcing steel bar, and a resistivity sensor (2) is arranged at the end part of the 2 nd reinforcing steel bar;

the monitoring host collects the temperature value of the ambient temperature detector, and sets the heating temperature of the heating module (3) to be T + M according to the ambient temperature T; wherein M is the temperature difference between the environmental temperature and the heating temperature which are preset in the monitoring host;

monitoring host computer collects temperature initial value T of temperature sensor array at the same time_0ijAnd record, wherein T_0ijThe initial temperature value of a jth temperature sensor (1) on the ith reinforcing steel bar is represented;

the resistivity sensor (2) sends the detected voltage and current values to the monitoring host, and the monitoring host calculates the resistivity R according to the voltage and current values₀And R is₀As initial resistivity record;

step two, heating and measuring;

the heating module (3) on the 1 st steel bar starts to heat up, and the monitoring host collects the temperature value T detected by the temperature sensor array at the same time_nijWherein T is_nijIndicating the jth of the ith reinforcementTemperature value data of the temperature sensor (1) at the nth second;

in the heating process of the 1 st steel bar, the monitoring host calculates and records the resistivity R according to the voltage and current values transmitted by the resistivity sensor (2) on the 2 nd steel bar_nAnd recording its change with time while establishing a temperature-resistivity curve, wherein R_nThe resistivity data which is calculated and recorded by the nth second monitoring host is represented, and the unit is omega/m;

step three, analyzing the corrosion rate;

the monitoring host firstly carries out temperature value data T of the temperature sensor array_nijAnd temperature value initial data T_0ijBy difference, i.e. finding DeltaT_nij＝T_nij-T_0ij；

When T is_n1jWhen T + M is equal to_j＝(△T_n1j-△T_n2j)-(△T_n1j-△T_n1(j+1))＝△T_n1(j+1)-△T_n2jIs T_n1jWhen T + M is equal to T, the temperature changes of the jth temperature sensor (1) to the jth +1 temperature sensor (1) on the 1 st steel bar caused by the heat conduction of the steel bars; wherein T is_n1jIs the temperature value T of the jth temperature sensor (1) on the 1 st steel bar in the nth second_n2jThe temperature value of the jth temperature sensor (1) on the 2 nd steel bar in the nth second;

the monitoring host calculates the temperature change coefficient Q_j＝△T_jL; then calculating the temperature change coefficients of all the temperature sensors (1) on the 1 st steel bar, and calculating the average value Q of the temperature change coefficients as the temperature change coefficient of the 1 st steel bar;

the monitoring host calculates and records the average temperature of the 2 nd steel bar in each second, namely calculates and records the average temperature value measured by all temperature sensors (1) on the 2 nd steel bar in each second, and then calculates the resistivity of the 2 nd steel bar at the moment; then, drawing a temperature-resistivity curve of the 2 nd steel bar by taking the average temperature as an abscissa and the resistivity R of the 2 nd steel bar as an ordinate;

the monitoring host machine compares the temperature change coefficient Q of the 1 st reinforcing steel bar with a threshold value in the monitoring host machine, judges whether the temperature change coefficient Q exceeds the threshold value range, and alarms on the monitoring host machine if the temperature change coefficient Q exceeds the threshold value range; and the monitoring host machine compares the temperature-resistivity curve of the 2 nd reinforcing steel bar with a standard curve prestored in the monitoring host machine, calculates the variance or standard deviation between the temperature-resistivity curve and the data on the standard curve, and gives an alarm on the monitoring host machine if the value of the variance or standard deviation exceeds a threshold value.

Technical Field

The invention belongs to the technical field of engineering monitoring, and particularly relates to a pre-embedded type steel bar corrosion rate monitoring sensor and a method.

Background

The corrosion of the steel bars greatly affects the durability and safety of the concrete structure. Reinforced concrete is the most widely used building material in civil engineering, water conservancy and road engineering. The corrosion of the steel bars in the reinforced concrete structure often harms the safety of buildings, and the caused harm is difficult to repair and recover, which causes huge loss. The problem of durability of reinforced concrete structures caused by corrosion of reinforcing steel bars is receiving more and more attention and attention from the engineering field. Therefore, it is necessary to monitor the corrosion of the steel bars in the concrete structure, and to timely deal with the problems and reduce the occurrence of accidents.

The traditional steel bar corrosion generally uses a pressure point sensor or an optical fiber sensor, the cost of the sensor is high, the sensor is very easily influenced by the external environment, the temperature cannot be monitored by the sensor due to the fact that the property of the steel bar has a certain relation with the temperature of the steel bar, and the error is large.

Disclosure of Invention

Aiming at the content, in order to solve the problems, the invention provides a system and a method for monitoring the corrosion rate of an embedded steel bar, wherein a resistivity sensor and a temperature sensor are used for acting together to monitor the change rule of the heat conduction characteristic and the resistivity characteristic of the steel bar along with the temperature; due to the ingenious design of the system, only the temperature sensor needs to be arranged on the surface of the steel bar, the structure is simple, the stability is good, the external interference can be overcome compared with the arrangement of the optical fiber sensor, the adaptability is strong, and the cost is lower.

A pre-buried type steel bar corrosion rate monitoring sensor system comprises a temperature sensor array, a resistivity sensor 2, a heating module 3, an environment temperature detector and a monitoring host; wherein

The temperature sensor array isArranged along the direction of elongation of the barsMultiple temperaturesThe temperature sensors 1 are arranged on the same steel bar, the distance between the temperature sensors 1 on the same steel bar is the same and is marked as L, and the distance between the temperature sensor 1 and the temperature sensor 1 which is closest to the temperature sensor 1 on one steel bar is also the same and is marked as L;

heating module 3Is arranged at the position ofTemperature sensor arrayAt both ends of a steel bar of the steel bar,resistivity sensor 2Is arranged at The other hasTemperature sensor arrayTwo ends of the steel bar;

the monitoring host is connected with the temperature sensor array, the resistivity sensor 2, the heating module 3 and the ambient temperature detector, so that the temperature sensor array, the resistivity sensor 2, the heating module 3 and the ambient temperature detector are controlled to work and collect data.

Every temperature sensor 1 in the temperature sensor array all attaches on the surface of reinforcing bar, and has coated the heat conduction material in temperature sensor 1 and reinforcing bar contact position.

The resistivity sensor 2 comprises a voltmeter and an ammeter which are arranged at two ends of the same steel bar.

The heating module 3 is a constant temperature heater.

A method for monitoring the corrosion rate of the steel bar by using the monitoring sensor system comprises the following steps:

firstly, calibrating a system;

selecting two reinforcing steel bars, wherein temperature sensor arrays are arranged on the 1 st reinforcing steel bar and the 2 nd reinforcing steel bar, heating modules 3 are arranged at two ends of the 1 st reinforcing steel bar, and a resistivity sensor 2 is arranged at the end part of the 2 nd reinforcing steel bar;

the monitoring host collects the temperature value of the ambient temperature detector, and sets the heating temperature of the heating module 3 to be T + M according to the ambient temperature T; wherein M is the temperature difference between the environmental temperature and the heating temperature which are preset in the monitoring host;

monitoring host computer collects temperature initial value T of temperature sensor array at the same time_0ijAnd record, wherein T_0ijThe initial temperature value of the jth temperature sensor 1 on the ith steel bar is represented;

voltage to be detected by the resistivity sensor 2The sum current value is sent to a monitoring host, and the resistivity R is calculated by the monitoring host according to the voltage and current values₀And is combined withWill be provided withR₀ As initial resistivityRecording;

step two, heating and measuring;

the heating module 3 on the 1 st steel bar starts to heat up, and the monitoring host simultaneously collects the temperature value T detected by the temperature sensor array_nijWherein T is_nijData of temperature value of the nth second of the jth temperature sensor 1 on the ith reinforcing steel bar is represented;

in the heating process of the 1 st steel bar, the monitoring host calculates and records the resistivity R according to the voltage and current values transmitted by the resistivity sensor 2 on the 2 nd steel bar_nAnd recording its change with time whileA temperature-resistivity curve is established and,wherein R is_nThe resistivity data which is calculated and recorded by the nth second monitoring host is represented, and the unit is omega/m;

step three, analyzing the corrosion rate;

the monitoring host firstly carries out temperature value data T of the temperature sensor array_nijAnd temperature value initial data T_0ijBy difference, i.e. finding DeltaT_nij＝T_nij-T_0ij；

When T is_n1jWhen T + M is equal to_j＝(△T_n1j-△T_n2j)-(△T_n1j-△T_n1(j+1))＝△T_n1(j+1)-△T_n2jIs T_n1jWhen T + M is equal to T + M, the temperature changes caused by the heat conduction of the steel bar from the jth temperature sensor 1 to the jth +1 temperature sensor 1 on the 1 st steel bar; wherein T is _{n 1j}Is composed ofSecond nTemperature value, T, of jth temperature sensor 1 on 1 st steel bar_n2j Second nThe temperature value of the jth temperature sensor 1 on the 2 nd steel bar;

the monitoring host calculates the temperature change coefficient Q_j＝△T_jL; then, the temperature change coefficients of all the temperature sensors 1 on the 1 st steel bar are calculated, and the temperature change coefficients are obtainedGo out of itThe average value Q is used as the temperature change coefficient of the 1 st steel bar;

the monitoring host calculates and records the 2 nd steel bar per secondThe average temperature of the molten steel is measured,namely, it isTo pairPer second calculationThe average value of the temperature measured by all the temperature sensors 1 on the 2 nd reinforcing steel bar is calculated and recordedThen, thenComputingResistance of the 2 nd steel bar at the moment Rate of change(ii) a Then, drawing a temperature-resistivity curve of the 2 nd steel bar by taking the average temperature as an abscissa and the resistivity R of the 2 nd steel bar as an ordinate;

the monitoring host machine compares the temperature change coefficient Q of the 1 st reinforcing steel bar with a threshold value in the monitoring host machine, judges whether the temperature change coefficient Q exceeds the threshold value range, and alarms on the monitoring host machine if the temperature change coefficient Q exceeds the threshold value range; and the monitoring host machine compares the temperature-resistivity curve of the 2 nd reinforcing steel bar with a standard curve prestored in the monitoring host machine, calculates the variance or standard deviation between the temperature-resistivity curve and the data on the standard curve, and gives an alarm on the monitoring host machine if the value of the variance or standard deviation exceeds a threshold value.

The invention has the beneficial effects that:

according to the invention, the resistivity sensor 2 and the temperature sensor 1 are used for coaction, so that the heat conduction characteristic and the change rule of the resistivity characteristic along with the temperature of the steel bar are monitored, when the corrosion rate reaches a certain degree, the change characteristic of the resistivity along with the temperature changes, and meanwhile, due to the change of the components of the steel bar, the heat conduction characteristic of the oxidized steel bar also changes, so that the corrosion rate of the steel bar is monitored more accurately; due to the ingenious design of the system, only the temperature sensor 1 is required to be arranged on the surface of the steel bar, the structure is simple, the stability is good, the external interference can be overcome compared with the arrangement of an optical fiber sensor, the adaptability is strong, and the cost is lower.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.

FIG. 1 is a system architecture diagram of the present invention.

Fig. 2 is a monitoring schematic of the present invention.

Wherein: 1-a temperature sensor; 2-a resistivity sensor; 3-heating the module; 4-concrete.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used based on the orientations and positional relationships shown in the drawings only for convenience of description and simplification of operation, and do not indicate or imply that the referred device or element must have a specific orientation, be configured and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

As shown in fig. 1 and 2, a pre-buried steel bar corrosion rate monitoring sensor system comprises a temperature sensor array, a resistivity sensor 2, a heating module 3, an ambient temperature detector and a monitoring host; wherein

The steel bars are multiple steel bars in concrete in a concrete building, and the temperature sensor array is arranged onWhereinAt least two steel bars; the temperature sensor array isArranged along the direction of elongation of the barsThe temperature sensors 1 are arranged on the same steel bar, the distance between the temperature sensors 1 on the same steel bar is marked as L, and the distance between the temperature sensor 1 and the temperature sensor 1 which is closest to the temperature sensor 1 on one steel bar is also marked as L;

namely: the distance between the temperature sensors 1 on the same steel bar is L, and the distance L between one temperature sensor 1A and the temperature sensor 1B which is closest to the temperature sensor 1A on the same steel bar is equal to the distance between the temperature sensor 1A and the temperature sensor 1C which is closest to the temperature sensor 1A on the other steel bar;

heating module 3Is arranged at the position ofTemperature sensor arrayAt both ends of a steel bar of the steel bar,resistivity sensor 2Is arranged at The other hasTemperature sensor arrayTwo ends of the steel bar;so that one of the two reinforcing bars is used for monitoring the heat conduction characteristic,in additionOne for monitoring resistivity characteristics;

the monitoring host is connected with the temperature sensor array, the resistivity sensor 2, the heating module 3 and the ambient temperature detector, so that the temperature sensor array, the resistivity sensor 2, the heating module 3 and the ambient temperature detector are controlled to work and collect data.

And the monitoring host machine analyzes the corrosion rate of the steel bars according to the collected heat conduction characteristics and resistivity characteristics.

The temperature sensor array is pre-embedded on the surface of a steel bar during concrete manufacturing, is fixed by using a metal wire, and the contact position of the temperature sensor 1 and the steel bar is coated with a heat conduction material;

the resistivity sensor 2, the heating module 3, the ambient temperature detector and the monitoring host are externally connected monitoring modules and are powered by the outside; the data signal of the temperature sensor array is derived from the wiring harness.

Along the same direction, the temperature sensor 1 is respectively marked with S₁₁、S₁₂、S₁₃、…、S_ij(ii) a Wherein i and j represent the jth sensor on the ith reinforcing steel bar;

the heating modules 3 are arranged at two ends of the steel bar, and the heating modules 3 are constant-temperature heating modules 3; the resistivity sensor 2 includes a voltmeter and an ammeter provided at both ends of the reinforcing bar, and is used to measure the resistance of the entire reinforcing bar and calculate the resistivity R of the reinforcing bar per unit length, which is in Ω/m, according to the length of the reinforcing bar.

The ambient temperature detector is used to detect the temperature of the environment for providing a reference of the ambient temperature to the heating module 3.

Every temperature sensor 1 in the temperature sensor array all attaches on the surface of reinforcing bar, and has coated the heat conduction material in temperature sensor 1 and reinforcing bar contact position.

The resistivity sensor 2 comprises a voltmeter and an ammeter which are arranged at two ends of the same steel bar.

The heating module 3 is a constant temperature heater.

A method for monitoring the corrosion rate of the steel bar by using the monitoring sensor system comprises the following steps:

firstly, calibrating a system;

selecting two reinforcing steel bars, wherein a 1 st reinforcing steel bar and a 2 nd reinforcing steel bar are both provided with a temperature sensor array, two ends of the 1 st reinforcing steel bar are provided with heating modules 3, and the end part of the 2 nd reinforcing steel bar is provided with a resistivity sensor 2 (namely a voltmeter and an ammeter of the resistivity sensor 2 are respectively arranged at two end parts of the 2 nd reinforcing steel bar);

the monitoring host collects the temperature value of the ambient temperature detector, and sets the heating temperature of the heating module 3 to be T + M according to the ambient temperature T; wherein M is the temperature difference between the environmental temperature and the heating temperature which are preset in the monitoring host;

monitoring host computer collects temperature initial value T of temperature sensor array at the same time_0ijAnd record, wherein T_0ijThe initial temperature value of the jth temperature sensor 1 on the ith steel bar is represented;

the resistivity sensor 2 sends the detected voltage and current values to a monitoring host, and the monitoring host calculates the resistivity R according to the voltage and current values₀And is combined withWill be provided withR₀ As initial resistivityRecording;

step two, heating and measuring;

the heating module 3 on the 1 st steel bar starts to heat up, the temperature is controlled to be constant at T + M, and the monitoring host collects the temperature value T detected by the temperature sensor array at the same time_nijAnd recording the change of temperature value with time, and recording multiple groups of data, wherein T_nijData of temperature value of the nth second of the jth temperature sensor 1 on the ith reinforcing steel bar is represented; and will T_nijRecording in a monitoring host;

in the heating process of the 1 st steel bar, the monitoring host calculates and records the resistivity R according to the voltage and current values transmitted by the resistivity sensor 2 on the 2 nd steel bar_nAnd recording its change with time whileA temperature-resistivity curve is established and,wherein R is_nThe resistivity data which is calculated and recorded by the nth second monitoring host is represented, and the unit is omega/m;

step three, analyzing the corrosion rate;

the monitoring host firstly carries out temperature value data T of the temperature sensor array_nijAnd temperature value initial data T_0ijBy difference, i.e. finding DeltaT_nij＝T_nij-T_0ijTo exclude the influence of the initial temperature;

reference numerals of the temperature sensor 1 are denoted by S₁₁、S₁₂、S₁₃、…、S_ij(ii) a Wherein S_ijThe j-th temperature sensor 1 on the ith reinforcing steel bar is shown, and the distance between two adjacent temperature sensors 1 on the same reinforcing steel bar is set as L, so that the codes of the temperature sensors 1 are continuous, namely S_1jAnd S_1(j+1)The distance between is L, S_1jAnd S_2jThe distance between is also L; that is to say S_1jAnd S_1(j+1)The temperature difference of (A) reflects the combined effect of the transfer temperatures of the steel reinforcement and the concrete, and S_1jAnd S_2jThe temperature difference of (a) reflects the effect of the concrete temperature transfer temperature, so that:

when T is_n1jWhen T + M is equal to_j＝(△T_n1j-△T_n2j)-(△T_n1j-△T_n1(j+1))＝△T_n1(j+1)-△T_n2jIs T_n1jWhen T + M is equal to T + M, the temperature changes caused by the heat conduction of the steel bar from the jth temperature sensor 1 to the jth +1 temperature sensor 1 on the 1 st steel bar; wherein T is _{n 1j}Is composed ofSecond nTemperature value, T, of jth temperature sensor 1 on 1 st steel bar_n2j Second nThe temperature value of the jth temperature sensor 1 on the 2 nd steel bar;

the monitoring host calculates the temperature change coefficient Q_j＝△T_jL; then the temperature change coefficients of all the temperature sensors 1 on the 1 st steel bar are measuredI.e. each oneTemperature sensor 1 _jCorresponding QCalculate and findGo out of itThe average value Q is taken as the temperature change coefficient of the 1 st steel bar, and the temperature change coefficient reflects the heat conduction characteristic of the 1 st steel bar;

the monitoring host calculates and records the average temperature of the 2 nd reinforcing steel bar every second,namely, it isTo pairPer second calculationThe average value of the temperature measured by all the temperature sensors 1 on the 2 nd reinforcing steel bar is calculated and recordedThen, thenComputingResistance of the 2 nd steel bar at the moment Rate of change(ii) a Then, drawing a temperature-resistivity curve of the 2 nd steel bar by taking the average temperature as an abscissa and the resistivity R of the 2 nd steel bar as an ordinate;

the monitoring host machine compares the temperature change coefficient Q of the 1 st reinforcing steel bar with a threshold value in the monitoring host machine, judges whether the temperature change coefficient Q exceeds the threshold value range, and alarms on the monitoring host machine if the temperature change coefficient Q exceeds the threshold value range; and the monitoring host machine compares the temperature-resistivity curve of the 2 nd reinforcing steel bar with a standard curve prestored in the monitoring host machine, calculates the variance or standard deviation between the temperature-resistivity curve and the data on the standard curve, and gives an alarm on the monitoring host machine if the value of the variance or standard deviation exceeds a threshold value.

Example 1:

a pre-buried type reinforcing bar corrosion rate monitoring sensor system comprises a temperature sensor array, a resistivity sensor 2, a heating module 3, an environment temperature detector and a monitoring host.

The steel bars are a plurality of steel bars positioned in concrete in a concrete building, and the temperature sensor array is arranged on at least two steel bars; the temperature sensors 1 are attached to the surfaces of the steel bars, the temperature sensor array comprises a plurality of temperature sensors 1 which are arranged along the extending direction of the steel bars, the distance between the temperature sensors 1 on the same steel bar is L, and the distance L between one temperature sensor 1A and the temperature sensor 1B which is closest to the temperature sensor 1A on the same steel bar is equal to the distance L between the temperature sensor 1A and the temperature sensor 1C which is closest to the temperature sensor A on the other steel bar;

the heating module 3 is arranged at two ends of one steel bar with a temperature sensor array, and the resistivity sensor 2 is arranged at two ends of the other steel bar with the temperature sensor array; one of the two steel bars is used for monitoring the heat conduction characteristic, and the other steel bar is used for monitoring the resistivity characteristic;

the monitoring host is connected with the temperature sensor array, the resistivity sensor 2, the heating module 3 and the environment temperature detector, so that the temperature sensor array, the resistivity sensor 2, the heating module 3 and the environment temperature detector are controlled to work and collect data;

and the monitoring host machine analyzes the corrosion rate of the steel bars according to the collected heat conduction characteristics and resistivity characteristics.

The temperature sensor array is pre-embedded on the surface of a steel bar during concrete manufacturing, is fixed by using a metal wire, and the contact position of the temperature sensor 1 and the steel bar is coated with a heat conduction material;

the resistivity sensor 2, the heating module 3, the ambient temperature detector and the monitoring host are externally connected monitoring modules and are powered by the outside; the data signal of the temperature sensor array is derived from the wiring harness.

Along the same direction, the temperature sensor 1 is respectively marked with S₁₁、S₁₂、S₁₃、…、S_ij(ii) a Wherein i and j represent the jth sensor on the ith reinforcing steel bar;

the heating module 3 comprises heating modules 3 arranged at two ends of the steel bar, and the heating modules 3 are constant-temperature heating modules 3; the resistivity sensor 2 includes a voltmeter and an ammeter provided at both ends of the reinforcing bar, and is used to measure the resistance of the entire reinforcing bar and calculate the resistivity R of the reinforcing bar per unit length, which is in Ω/m, according to the length of the reinforcing bar.

The ambient temperature detector is used to detect the temperature of the environment for providing a reference of the ambient temperature to the heating module 3.

Example 2:

a method of monitoring the corrosion rate of steel reinforcement using the monitoring sensor system of embodiment 1, comprising the steps of:

firstly, calibrating a system;

temperature sensor arrays are arranged on the 1 st steel bar and the 2 nd steel bar, heating modules 3 are arranged at two ends of the 1 st steel bar, and resistivity sensors 2 are arranged at two ends of the 2 nd steel bar;

the monitoring host collects the temperature value of the ambient temperature detector, and sets the heating temperature of the heating module 3 to be T + M according to the ambient temperature T; wherein M is the temperature difference between the environmental temperature and the heating temperature which are preset in the monitoring host;

monitoring host computer collects temperature initial value T of temperature sensor array at the same time_0ijAnd record, wherein T_0ijThe initial temperature value of the jth temperature sensor 1 on the ith steel bar is represented;

the resistivity sensor 2 detects the resistivity R of the 2 nd reinforcing steel bar₀And sends it to the monitoring host computer, which sends R₀As initial resistivity record;

step two, heating and measuring;

heating module 3 on the 1 st reinforcing steel bar begins to heat up, controls the temperature to be constant at T + M, and the monitoring host collects temperature value T of the temperature sensor array at the same time_nijAnd recording the change of temperature value with time, and recording multiple groups of data, wherein T_nijRepresents the temperature of the jth temperature sensor 1 on the ith reinforcing steel bar in the nth secondValue data of the degree; and will T_nijRecording in a monitoring host;

recording the resistivity R detected by the resistivity sensor 2 on the 2 nd reinforcing steel bar in the heating process of the 1 st reinforcing steel bar_nAnd recording its change with time, wherein R_nThe resistivity data recorded in the nth second is expressed in the unit of omega/m;

step three, analyzing the corrosion rate;

the monitoring host firstly carries out temperature value data T of the temperature sensor array_nijAnd temperature value initial data T_0ijBy difference, i.e. finding DeltaT_nij＝T_nij-T_0ijTo exclude the influence of the initial temperature;

reference numerals of the temperature sensor 1 are denoted by S₁₁、S₁₂、S₁₃、…、S_ij(ii) a Wherein S_ijThe j-th temperature sensor 1 on the ith reinforcing steel bar is shown, and the distances between two adjacent temperature sensors 1 on the same reinforcing steel bar are set to be L, so that the codes of the temperature sensors 1 are continuous, namely S_1jAnd S_1(j+1)The distance between is L, S_1jAnd S_2jThe distance between is also L; that is to say S_1jAnd S_1(j+1)The temperature difference of (A) reflects the combined effect of the transfer temperatures of the steel reinforcement and the concrete, and S_1jAnd S_2jThe temperature difference of (a) reflects the effect of the concrete temperature transfer temperature, and thus can be obtained

When T is_n1jWhen T + M is equal to_j＝(△T_n1j-△T_n2j)-(△T_n1j-△T_n1(j+1))＝△T_n1(j+1)-△T_n2jIs T_n1jWhen T + M is equal to T + M, the temperature changes caused by the heat conduction of the steel bar from the jth temperature sensor 1 to the jth +1 temperature sensor 1 on the 1 st steel bar; wherein T is_n1jThe temperature value of the jth temperature sensor 1 on the 1 st steel bar in the nth second is obtained;

the monitoring host calculates the temperature change coefficient Q_j＝△T_jL; then, the temperature change coefficients of all the temperature sensors 1 on the 1 st steel bar, namely Q corresponding to each temperature sensor 1 are measured_jCalculate and find its averageThe mean value Q is taken as the temperature change coefficient of the 1 st steel bar, and the temperature change coefficient reflects the heat conduction characteristic of the 1 st steel bar;

the monitoring host records the average temperature of the 2 nd steel bar, namely the average value of the temperature sensor 1 on the second steel bar is calculated every second, namely the average value of the temperature measured by all the temperature sensors 1 on the 2 nd steel bar is calculated, and then the resistivity of the 2 nd steel bar at the moment is measured; then, drawing a temperature-resistivity curve of the 2 nd steel bar by taking the average temperature as an abscissa and the resistivity R of the 2 nd steel bar as an ordinate;

the monitoring host machine compares the temperature change coefficient Q of the 1 st reinforcing steel bar with a threshold value in the monitoring host machine, judges whether the temperature change coefficient Q exceeds the threshold value range, and alarms on the monitoring host machine if the temperature change coefficient Q exceeds the threshold value range; and the monitoring host machine compares the temperature-resistivity curve of the 2 nd reinforcing steel bar with a pre-stored standard curve in the monitoring host machine, calculates the variance or standard deviation between the temperature-resistivity curve and the data on the standard curve, and gives an alarm on the monitoring host machine if the value of the variance or standard deviation exceeds a threshold value.

Before monitoring, manufacturing a steel bar with the same material as the steel bar to be monitored in a laboratory, and carrying out gradient corrosion by using an electrochemical corrosion mode; obtaining a group of corroded steel bars, and dividing the corroded steel bars into effective steel bars and ineffective steel bars, wherein the ineffective steel bars are steel bars which can not ensure that the strength of concrete meets the national standard; manufacturing the steel bars with different corrosion rates into reinforced concrete, and embedding the temperature sensor array during manufacturing;

measuring the temperature change coefficient Q and the temperature-resistivity curve of the reinforced concrete with different corrosion rates in a laboratory by using the method; then taking the temperature-resistivity curve of the effective steel bar without corrosion as a standard curve, and taking the minimum variance value of the temperature-resistivity curve of the ineffective steel bar with the lowest corrosion rate and the standard curve as a comparison threshold value of the curves; and taking the range of the temperature change coefficient Q of the effective reinforcing steel bars as the threshold range for judging Q.

Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the scope of the present invention is not limited to the specific details of the above embodiments, and any person skilled in the art can substitute or change the technical solution of the present invention and its inventive concept within the technical scope of the present invention, and these simple modifications belong to the scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.