The Acoustic Emission Parameters Obtained during Three-point Bending Test on Thermal-stressed Concrete Specimens.

Fire response of concrete structural members depends on thermal, mechanical, and deformation properties of concrete. These properties vary significantly with temperature and also depend on the composition and characteristics of the concrete batch mix as well as heating rate and other environmental conditions. Concrete structures could be exposed to extreme temperature conditions. Examples of such conditions are concrete foundations for launching rockets carrying spaceships, concrete structures in nuclear power stations or those accidentally exposed to fire, for instance in the case of tunnel fires. This paper analyses acoustic emission signals captured during three-point bending test on thermal-stressed concrete specimens. The method of acoustic emission is an experimental tool suitable for monitoring the failure processes in materials. The typical parameters of acoustic emission signal were identified during the acoustic emission records for different concrete specimens to further describe the under-the-stress behaviour and failure development. The amount of crack growth was continuously monitored using four acoustic emission sensors mounted on the specimens. [ABSTRACT FROM AUTHOR]