## 2 Materials and Methods
### Experimental Methods  
The experimental procedure is divided into three stages: preparation, discharge process, and data collection and analysis. The flow diagram of the experimental procedure is shown in Figure 2. By comparing the discharge characteristics, shock wave intensity, and concrete sample fragmentation under different dielectric conditions, this study provides a reference for selecting suitable environmentally friendly dielectrics for engineering applications. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Density/(g/cm\({}^{3}\))** & **Elastic** & **Poisson’s Ratio** & **Tensile** & **Compressive** \\  & **Modulus/GPa** & **Poisson’s Ratio** & **Strength/MPa** & **Strength/MPa** \\ \hline
2.21 & 26 & 0.2 & 3.45 & 35 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Mechanical parameters of the concrete blocks. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Number** & **Dielectric Types** & **Particle Size/\(\mu\)m** & **Concentration/** & **Electrical** \\  & & **(mg/cm\({}^{3}\))** & **Conductivity/(\(\mu\)S/cm)** \\ \hline
1 & Aluminum powder suspension & 53 & 48 & 790 \\
2 & Iron powder suspension & 53 & 48 & 802 \\
3 & Copper (II) oxide suspension & 53 & 48 & 873 \\
4 & Iron (III) oxide powder suspension & 53 & 48 & 4.91 \(\times\) 10\({}^{3}\) \\
5 & Potassium chloride solution & / & 48 & 61.8 \(\times\) 10\({}^{3}\) \\
6 & Sodium chloride solution & / & 48 & 59.9 \(\times\) 10\({}^{3}\) \\
7 & CO\({}_{2}\)-dissolved liquid & / & 10 & 711 \\
8 & Water & / & / & 908 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Parameters of dielectric materials. During the preparation phase, the dielectric materials were first prepared, and their electrical conductivity was measured and recorded using a DDS-307 (LEICI, Shanghai, China) conductivity meter. Meanwhile, concrete samples were fabricated, and their mechanical parameters were determined. Subsequently, the high-pressure pulsed experimental platform was assembled, and the prepared dielectric materials were injected into the pre-drilled holes in the concrete samples. The discharge electrodes were then integrated into the experimental setup, with a compression rod used to secure the electrodes, ensuring a sealing effect. Finally, the overall assembly and debugging of the experimental system were completed (Figure 3). During the discharge phase, the adjusted initial parameters were applied to conduct single metallic wire explosion experiments. The discharge device charged the energy storage capacitor through the control unit, and once fully charged, the discharge gap was triggered to break down, forming a closed circuit. This caused the copper wire to undergo rapid electrical explosion in different dielectrics, generating shock waves that acted on the  
Figure 3: Physical diagram of the concrete block and discharge electrode assembly. Figure 2: Flowchart of the experimental procedure. surrounding concrete block (Figure 4a). The experiment utilized a pulse capacitor (C) with a capacitance of 500 \(\upmu\)F, charged to a voltage of 5 kV. This configuration generated pulse currents of several tens of kiloamperes, with a total stored energy of approximately 6.25 kJ. During the data collection and analysis phase, the measurement system was designed to monitor the electrical parameters of the discharge process and the intensity of the shock wave. A high-voltage differential probe ((PINTECH PT-5240, Guangzhou, China) and a custom-made Rogowski coil were used to measure the discharge voltage (\(U\)) and circuit current (\(I\)), respectively. A digital oscilloscope (Tektronix MDO 3014, Beaverton, OR, USA) recorded the electrical signals, allowing for the calculation of load impedance and deposited energy. The resistive voltage of the load (\(U_{R}\)), energy deposited in the load circuit (\(E\)), deposited power (\(P\)), and energy deposition efficiency (\(\eta\)) were calculated using Equations (2)-(5) [9].