Evaluation of Reinforcing Bars Using the Magnetic Flux Leakage Method

Reinforcement bars in concrete are exposed to several actions, such as overloading, fatigue, and corrosion. These actions can lead to a deterioration of the reinforcement bars. However, only advanced stages of damage in the reinforcement will be visible at the surface. Since no suitable commercial nondestructive methods are available yet, the concrete cover must be removed if damage is suspected. The magnetic flux leakage method is a promising approach to solving this problem. A measuring device was developed that enables the simultaneous magnetization of the reinforcement and measurement over a width of 20 cm. To support the user, a software is in development that allows for immediate evaluation and interpretation of the results. The present project aims at demonstrating the value of the magnetic flux leakage method in particular for bridge evaluation. (C) 2016 American Society of Civil Engineers.