PSI - Issue 68

4

Koji Uenishi et al. / Procedia Structural Integrity 68 (2025) 547–553 Uenishi et al. / Structural Integrity Procedia 00 (2025) 000–000

550

a

Reinforcing steel bars Box drawing

Cartridge

b

e

Screw holes

1,500 mm

c

d

Blast holes

Desired vertical exposure of the reinforcing steel bars

Fig. 2. Vertical cutoff of the front section of a RC block by EDI-induced waves. (a) Typical concrete block with rebars (diameter 19 mm), prepared for the new series of the field fracture experiments using EDI. The positions of the EDI sources (cartridges) and the rebars are indicated [unit: mm]. The RC block (b) before and (c, d) after the application of EDI. Due to the vertical “virtual interface” effect, only the concrete in the specific region in front of the virtual interface composed of the foremost rebars has been fragmented as desired. (e) This vertical cutoff phenomenon is well reproduced in this series of field fracture experiments. 3.2. Numerical speculations In the above section, it has been indicated that the vertical “virtual interface” effect can be induced even without the existence of empty dummy holes. Indeed, the mechanics behind the vertical “virtual interface” effect is much