PSI - Issue 46

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2021) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 46 (2023) 136–142

5th International Conference on Structural Integrity and Durability Precisely controlled dynamic disintegration of steel-concrete composite structures Koji Uenishi a *, Kota Wada a , Hiroshi Yamachi b , Junichiro Nakamori b a Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8561, Japan b Sumitomo Mitsui Construction Co., Ltd., 518-1 Komagi, Nagareyama 270-0132, Japan

© 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSID 2021 Organizers Abstract In place of explosives, by using safer and more controllable electric energy and based on the theory of wave and fracture dynamics, we have been investigating more reliable technique for precisely controlled dynamic disintegration of structures with/without reinforcements. So far, by applying electric discharge impulses, we have successfully, i.e. as desired, disintegrated rectangular and cylindrical concrete specimens with/without reinforcing steel bars in the field. In order to find optimal geometrical and loading conditions that can control the three-dimensional propagation and interaction of waves and cracks as well as the structural disintegration pattern, we have traced, for instance, with a high-speed digital video camera, the fracture development induced by electric discharge at multiple blast holes in each specimen. We have found that specific combinations of blast holes, empty dummy holes as well as free surfaces and pre-existing planes of weakness can really govern the dynamic behavior of the waves and the main crack, and thus the disintegration pattern in given structures. In this study, we continue conducting our field experiments and numerical simulations of dynamic disintegration by electric discharge impulses and try to optimize fracture development in a steel concrete composite structure consisting of a reinforced concrete slab on top of a steel girder and headed stud shear connectors that strengthen the link between the slab and the girder. Our aim is to dynamically control wave interaction and crush only concrete material while the headed stud shear connectors and the steel girder remain undeformed for later renovation. © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSID 2021 Organizers. Keywords: Controlled fracture; wave dynamics; fracture dynamics; finite difference method

* Corresponding author. Tel.: +81-4-7136-3824; fax: +81-4-7136-3824. E-mail address: uenishi@k.u-tokyo.ac.jp

2452-3216 © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSID 2021 Organizers

2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSID 2021 Organizers 10.1016/j.prostr.2023.06.023