Monitoring Structural Degradation Using Magnetostrictive Sensors. ResourceMaterials

摘要

This report describes the results of an experimental investigation fordetermining the feasibility of detecting and locating wire fractures in steel strands in prestressed concrete beams using embedded magnetostrictive sensors (MsS's). Experimental data aquired from several concrete beam specimens containing seven-wire prestressing steel strands showed that the MsS can be embedded in concrete and used for long-term monitoring of prestressed concrete beams. The sensors were especially good for detecting impacts over a long range. The sensors could also detect wire fractures in prestressing strands; but, in concrete-encased strands, the range of wire fracture detection was limited to no more than 1.5 m because of weak and highly attenuative fracture signals in concrete. Although the above detection range may be extended by improving sensor design and instrumentation, the applicability of the MsS for wire fracture monitoring in prestressing concrete structures may be limited to only localized areas.