Reinforcement Corrosion Monitoring Sensor For Reinforced Concrete Structures Research And Design

Reinforced concrete structure is the main structure of civil engineering field,is now widely used in housing construction,roads,bridges and other infrastructure.In the harsh environment of the reinforced concrete structure is susceptible to erosion of corrosive media,due to corrosion of steel bars caused by reinforced concrete building durability,premature destruction or even collapse of the phenomenon is not uncommon.Therefore,it is very important to develop a monitoring system which can reflect the corrosion status of reinforced concrete inside the reinforced concrete structure.At present,there are a wide variety of steel corrosion monitoring systems.Commonly there are anodic ladder system based on half-cell potential method,Bragg grating sensors for measuring the wavelength of strain gauges.In recent years,fiber grating strain gauges,piezoelectric ceramics,concrete materials and other new materials with its unique sensor and drive function more and more popular with the civil engineering sector.In this paper,the monitoring principle,design and preparation of several common tendon corrosion monitoring systems at home and abroad are analyzed.On the basis of the research of the majority of scholars,four kinds of steel corrosion monitoring sensors are proposed,and the preparation and principle of the sensor Was introduced.Through the special production,assembly process to produce a resistive steel corrosion monitoring sensor,for the parallel resistance of steel corrosion monitoring sensor to develop a pilot program to demonstrate.The ANSYS numerical simulation analysis of embedded steel corrosion ultrasonic monitoring sensor was carried out.Specific research work is as follows:(1)In the hollow,small tube surface paste respectively,FBG strain gauge,eliminate the influence of temperature on the monitoring results.Combined with the reinforced concrete structure corrosion model,theory of reinforced Prague grating wavelength and the volume of steel corrosion rate and the quality of corrosion rate,the relationship between the quality of steel corrosion rate and corrosion expansion force,change of fiber grating strain gauge wavelength can be corroded indirect reaction of steel.(2)Capacitive Reinforcement Uniform Corrosion Monitoring Sensor Capacitor chamber inside the four electrode plates consist of upper and lower capacitors.uniformcorrosion of steel on the plastic plate to produce downward pressure,the electrode plate composition of the capacitor can be a good distinction between uniform corrosion and non-uniform corrosion,uniform degree of corrosion can be reflected through the capacitor capacitor changes.(3)Theoretical analysis of the cross section and variable cross section resistance of steel bar corrosion monitoring sensor with the corrosion process,the wire resistance changes.In the factory custom two steel cross-sectional area are equal and three steel cross-section is not equal parallel resistance steel corrosion monitoring sensor,two iso-section sensors were placed in tap water and the concentration of 2%NaCl solution for single-sided soaking,three steel cross-section unequal sensor with2%,4%,6% NaCl solution single-sided soaking,resistive steel corrosion monitoring sensor The change is more sensitive,the resistance of the steel wire after the abrupt change,the test results and theoretical analysis are basically the same.(4)Embedded steel corrosion ultrasonic monitoring sensor at both ends of the reinforced section with piezoelectric ceramic,piezoelectric ceramic chip and signal transmitter and signal receiver are connected.Using ANSYS software to create different length of the rust-free situation,different corrosion depth,different corrosion length,different corrosion location of the steel bar model,and then the steel and piezoelectric ceramic pieces of the grid,the Hanning window modulated voltage signal loaded to The change of the signal amplitude at the receiving end is analyzed by using the piezoelectric ceramic for the segment.Using the analysis method of control variable,through simulation we found that with the increase of steel bar length,the amplitude of the received signal appeared later and the signal strength to be attenuation;with local corrosion depth increases,the amplitude of the received end signal attenuation,the receiver signal amplitude decreases with increasing the volume of the corrosion rate and length.In addition the position of the receiver signal corrosion effect,through the analysis of the signal receiving end can generally understand the internal corrosion information.