Hydrogen embrittlement of prestressing cables

In this study, hydrogen embrittlement is simulated in an accelerated way with an ammonium thiocyanate media test. Damage evolution of prestressing strand is monitored with electrochemical measurements and with acoustic emission (AE). Three stages of the damage mechanism are identified with different acoustic activities. For each stage, three pattern parameters coming from AE analyse are highlighted to distinguish each emitting stage. To have a precise description of damage evolution of prestressing cables during the hydrogen embrittlement test, some interrupted tests have been used. For each interruption, metallographic observations enable to characterize degradation mechanisms. Finally, each acoustic stage has been correlated to a degradation mechanism.