Understanding Acoustic Emission Testing- Reading 1 Part B-A

16.7.8 Thermal Cracking
Relatively little work has been carried out on acoustic activity when concrete
is subjected to high temperatures, such as those that may be encountered in
fires. However, Hinrichsmeyher et al. carried out tests up to temperatures of
900°C. They claimed that acoustic emission analysis during heating enabled
them to distinguish the different types of thermally induced cracking that
occurred. They noted a thermal Kaiser effect in the temperature range 300 to
600°C, which might help in determining the maximum temperature reached
in a previous heating cycle. The technique was even sensitive enough to
record the acoustic emissions from the quartz inversion at 573°C.
Charlie Chong/ Fion Zhang