Issue 50

V. Saltas et alii, Frattura ed Integrità Strutturale, 50 (2019) 505-516; DOI: 10.3221/IGF-ESIS.50.42 505 Focused on the research activities of the Greek Society of Experimental Mechanics of Materials The use of acoustic emissions technique in the monitoring of fracturing in concrete using soundless chemical demolition agent Vassilios Saltas, Despoina Peraki Laboratory of Geophysics and Seismology – UNESCO Chair in Solid Earth Physics and Geohazards Risk Reduction, Technological Educational Institute of Crete, Greece vsaltas@chania.teicrete.gr, http://orcid.org/0000-0003-4958-2876 desnikper@gmail.com Filippos Vallianatos Laboratory of Geophysics and Seismology – UNESCO Chair in Solid Earth Physics and Geohazards Risk Reduction, Technological Educational Institute of Crete, Greece Dept of Geophysics–Geothermics, Faculty of Geology and Geoenvironment, National and Kapodistrian University of Athens, Greece fvallian@geol.uoi.gr A BSTRACT . Soundless chemical demolition agents (SCDAs) have been used during the last decades in the demolition of boulders and concrete structures as well as in open-surface and sub-surface rock excavation, as an alternative to the use of explosives posing safety risks. However, the knowledge of the governing fracture mechanisms in brittle materials is rather limited. In the present work, we thoroughly investigate the use of the acoustic emission technique to study the SCDA-induced fracture process in concrete blocks. Energy-related features and waveform parameters of the recorded AE activity are correlated to the fracture mode of the concrete where a quasi-static behavior is observed. Monitoring of the progressive fracture is also achieved by the 3D localization of the AE sources. The distribution of the inter-event times of the recorded hits is further analyzed in the context of non-extensive statistical physics. K EYWORDS . Acoustic emissions; Fracture; Soundless chemical demolition agent; Concrete; Non-extensive statistical physics; Tsallis entropy. Citation: Saltas, V., Peraki, D., Vallianatos, F., The use of acoustic emissions technique in the monitoring of fracturing in concrete using soundless chemical demolition agent, Frattura ed Integrità Strutturale, 50 (2019) 505-516. Received: 29.01.2019 Accepted: 27.05.2019 Published: 01.10.2019 Copyright: © 2019 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION oundless chemical demolition agents (SCDAs) have been used during the last decades in the demolition of boulders and concrete structures as well as in open-surface and sub-surface rock excavation, as an effective alternative to the use of explosives posing safety risks [1-5]. Recently, the potential application of SCDA fracking in unconventional oil and gas recovery as well as in mineral processing applications has been under investigation [5,6]. The effect of the non- S