Research On The Applications Of Electrical Resistance Tomography (ERT) Technology In Concrete

Concrete structure health monitoring technology is of great significance for ensuring structural safety and improving its durability.ERT(Electrical Resistance Tomography)is a new structural health detection technology.As an emerging structural health detection technology,ERT is widely used in the detection of damage to concrete structures due to its advantages of no radiation,simple structure,intuitive detection effect,and low cost.However,its application in practical engineering is limited due to a low conductivity of concrete material.In this way,this paper explores the related items of electrical resistance tomography applied in concrete.The results can be shown below.(1)Electrical resistance tomography system was built.Based on PXI platform,the data acquisition system was developed in LabVIEW.Combined with ‘COMSOL with MATLAB',it achieved rapid data acquisition.The electrical resistance tomography imaging system was also visualized through MATLAB,which realized the rapid reconstruction and evaluation of the image.(2)The image reconstruction algorithm used in this system was investigated.The image results under different simulation algorithms were compared.The simulation results show that the best imaging results are obtained by using the normalized conjugate gradient algorithm.(3)The electrical resistance tomography sensor characteristics were analyzed.Sensitive field characteristics of the ERT sensor were analyzed by the number of sensors and the arrangement of sensors respectively.Experiment results demonstrated that a 16-sensor model show a good performance.Besides,three kinds of concrete electrical resistance tomography imaging sensors were designed.The effect of three kinds of sensors in concrete was also studied and the results were obtained by major image quality evaluation indicators.(4)The performance of resistance tomography system to detect concrete damage was explored.Based on the established electrical resistance tomography system,the observation of prefabricated crack damage,reforcement corrosion and water penetration behavior was investigated in cementitious materials.The image results was also evaluated by image quality indicators.The results show that the image quality of the electrical resistance tomography imaging system for concrete penetration crack location and shape images is obviously higher than the imaging quality of concrete internal damage.Besides,it worked effectively in water penetration and bar corrosion tests.