This article reports on importance of acoustic emission (AE) based b-value in the study of fracture process in reinforced concrete (RC) structures. The significance of amplitude- distribution and b-value (slope of the line plotted using log-linear frequency-amplitude relation) of acoustic…
This article reports on importance of acoustic emission (AE) based b-value in the study of fracture process in reinforced concrete (RC) structures. The significance of amplitude- distribution and b-value (slope of the line plotted using log-linear frequency-amplitude relation) of acoustic emissions released ahead of the failure of reinforced concrete beams of 2.6 m span are presented. The experiments were conducted in incremental cyclic loading under load control and simultaneously the released AE, strain in tensile steel, displacement at midspan were recorded. The effect of loading rate, compressive strength of concrete on variation in AE based b-values with the development of cracks in RC structures were studied. The average b-values are lower as a few but larger amplitudes of AE events occurred in contrast to more number of low amplitude AE events observed at low loading rates (or at low strain rates). Moreover, the b-values are compared to the strain in steel and the evolution of cracks on the specimen to assess the damage state. It is observed that when the loading rate is higher, quick cracking development lead to rapid fluctuations and drops in the b-values.