engleski

Acousto-ultrasonic approach for post-fire assessment of concrete structures

In this paper an experimental research work is presented which deals with non-destructive evaluation of properties of concrete that had been previously exposed to high fire temperatures. Investigation was conducted on specimens made of nine self-compacting concrete mixes of different compositions which were exposed to temperatures of 200, 400 and 600°C. Acousto-ultrasonic testing method is applied to and characteristics of stress waves transmitted through concrete specimens were analysed. Residual mechanical properties in terms of compressive strength and elasticity modulus were determined and correlated with parameters of ultrasonic waves obtained from acousto-ultrasonic testing. Results obtained on uniformly heated small-scale specimens showed that amplitude and attenuation of ultrasonic waves possessed strong correlations with residual mechanical properties of concrete and could be satisfactory used as an input for evaluation of residual loadbearing capacity of concrete element. These results presented a base for further research on real-scale fire damaged concrete elements.

self-compacting concrete; high temperature; acoustic emission; mechanical properties

nije evidentirano