Research On The Infrared Imaging Method To Detect The Corrosion Rate Of Steel Bars In The State Of Swelling And Cracking

The engineering environment in which some hydraulic structures are located is complex and the reinforced concrete structures are easily damaged.Therefore,the study of the durability of reinforced concrete structures is very important.Steel corrosion is one of the important factors that affect the durability of reinforced concrete.In the actual project,the corrosion of reinforced concrete is very serious,which leads to the decline of the durability of the building and many safety problems.Therefore,the durability evaluation of the structure is very necessary.Therefore,it has important practical significance to study the corrosion detection of steel bars.At present,there are many methods used to detect the corrosion rate of reinforced concrete,but most of the detection methods have problems such as insufficient technical conditions,small application scope,and low accuracy.In this paper,infrared thermal imaging method is used to detect the corrosion rate of steel bars.The main research is to investigate the change of the surface temperature field of corrosion protection of reinforced concrete and the corrosion of steel bars after forced heating of steel bars under the condition of corrosion and cracking of reinforced concrete specimens.The relationship between depth.In order to eliminate the non-uniform heat transfer in the longitudinal direction of the steel bar caused by electromagnetic induction heating in this study,a steel bar that can be forced to heat evenly was fabricated.The sample can be directly heated to force heating of the rusted steel bar,which can eliminate the influence of the longitudinal heat transfer of the steel bar.After the test specimens were made,electrochemical corrosion tests on the specimens were carried out and different specimens with different corrosion cracks were obtained.Finally,infrared thermal image method was used to detect the change of the surface temperature of the protective layer after the reinforcement heating.According to the analysis of the test data,the relationship between the surface temperature field of the concrete protection layer and the corrosion depth of the steel bar was determined under the condition of corroded cracking.The temperature difference decreases with the increase of the rust depth,decreases to a value close to the rust depth of about 2.8 mm,and then starts to increase with the increase of the rust depth,and the rust depth reaches 2.8.Prior to mm,there was a linear relationship between the temperature difference and the rust depth.This conclusion can be used in the actual project.The temperature difference is obtained by heating the steel bar and then the corrosion depth of the steel bar is calculated.It is of practical significance for the non-destructive testing of reinforced concrete using infrared thermal imaging.