Magnetic-Based NDE of Prestressed and Post-Tensioned Concrete Members: The MFLSystem

摘要

This report describes all aspects of a study to develop a nondestructiveevaluation (NDE) system based on the concept of magnetic flux leakage (MFL) to detect corrosion and fracture of prestressing steel in pretensioned and post-tensioned concrete bridge members. The basic methodology is based on introducing a direct-current magnetic field in close proximity of the prestressing or post-tensioning steel and monitoring the variations of the field due to loss of cross-sectional area of steel from corrosion or fracture.