**Acknowledgements**

*Microwave Heating - Electromagnetic Fields Causing Thermal and Non-Thermal Effects*

**Exposure time (s)** *σ3* **(MPa)** *σ1* **(MPa)** *c* **(MPa)** *φ* **(°)** 0 0 281.7 54.26 50.03 10 385.33 30 518 50 671 10 0 245.9 46.41 51.59 10 377.67 30 507.33 50 676.33 20 0 233.1 47.09 51.63 10 382 30 514.67 50 667 30 0 206.3 40.93 52.18 10 358.67 30 507.33 50 650.67

**160**

**Figure 12.**

**Table 1.**

**7. Summary and conclusions**

Microwave power level had a significant positive relationship with basalt heating

rate: the higher the applied power, the faster the basalt temperature rises. The surface temperature of the sample is not uniformly distributed, which is conducive to the generation of cracks. The higher the microwave power, the more serious the crack propagation. As the number of fractures increased, visible cracks were generated, leading to significant strength reduction. The Uniaxial compressive, Brazilian tensile, and point load strength all decreased after irradiation at each of the three

*Relationships between cohesion and internal friction angle of the basalts with microwave exposure time [45].*

*Conventional triaxial compressive strength test results of basalt samples at different exposure times [45].*

Financial support for this work by the National Natural Science Foundation of China (No: 42002281), by the Natural Science Foundation of Henan Province (No: 202300410002, 212300410325), by the Science and Technology Research and Development Plan of China Railway Group Limited (No: 2020-Zhongda-06) and the Science and Technology Innovation Plan of China Railway Tunnel Group (No: Suiyanhe 2020-11) are greatly appreciated.
