MULTI-TECHNOLOGY NDT INSPECTION AND MONITORING OF CORROSION IN STEEL BRIDGE MEMBERS

On-site evaluation of corrosion damage is posing challenges to maintenance engineering as corrosion damage is difficult to be evaluated accurately and it has significant spatial variation. When measures are not taken, corrosion could lead to reduction of load caring capacity, large repair costs and in some extreme cases could lead to collapse of the structure. The present study proposes a multi-technology approach for effective evaluation of corrosion progress rate and of the damage extent, combining monitoring with periodic inspections. The progress of corrosion is estimated by Atmospheric Corrosion Monitoring (ACM) technology, and by ultrasonic (UT) and electromagnetic (EM) inspection technology. Continuous monitoring by Atmospheric Corrosion Monitoring (ACM) technology is being used for determining the overall environment corrosivity. Also, ACM helps to pinpoint areas on the structure where more aggressive local corrosion inducing factors exists. Corrosion progress trends obtained from environmental corrosivity monitoring are presented. In addition to monitoring, on-site periodic inspections are used for measuring corrosion progress. Electromagnetic (EM) inspection is applied to measuring the corrosion scale thickness, eve