Acoustic Emission Behaviour of Prestressed Concrete Sleepers Under Quasi-static Homologation Testing

Prestressed concrete sleepers (PCS) play a key role in providing lateral,
longitudinal and vertical stability of railway track systems. Its capacity to fulfil these
tasks is principally examined through "homologation" tests based on crack initiation
and propagation. However, the current classical technique for crack detection by use
of a graduated microscope inspects only the surface while its accuracy is limited.
Additionally it does not offer insight on the cause of cracking in such a
heterogeneous medium as prestressed concrete. The present work aims at studying
the behaviour of PCS under quasi
emission (AE) parameters. The AE technique is used to determine the onset of
cracking, while indices like the calm and felicity ratios demonstrate the evolution of
damage for the successive loadin
in relation to the possible fracture mechanisms i.e. matrix cracking or interface
friction while AE activity is correlated to the crack width. It is demonstrated that AE
technique can substantially contribut
of PCS.