Influence of ultrafine diatomite on cracking behavior of concrete: an acoustic emission analysis

Abstract The chief objective of this study is to investigate the cracking behavior of concrete with variable loadings of diatomite. Acoustic emission parameters during the compression testing such as the crack growth, the failure process, the crack pattern recognition, and the fracture modes are used to analyze the cracking behavior of concrete. The results demonstrate that the specimens containing diatomite can withstand higher crack initiation and crack damage, which is a stress threshold for the crack to change from stable to unstable. Moreover, the cumulative energy of the concrete specimens conforms to the Weibull distribution, which has important implications for developing a relation between the physical properties of concrete and the acoustic emission parameters. In addition, the variation of the b value shows that the formation of the main failure surface of the diatomite-treated concrete is delayed, which, through the pattern recognition, is attributed to the enhancement of the internal structure of the modified concrete. An attempt was also made to compare the fracture mode of the control specimen with that of the specimens containing diatomite through the analysis of the ratio of the rise time to the maximum amplitude and the average frequency. Finally, the density of the cracks was further investigated using the Gaussian mixture modeling.