Weakening rocks using microwave irradiation has been a major topic in research for the past 50 years. However, the thermal effect of microwaves on rocks is mostly studied with a multi-mode metal cavity, in which rocks absorb microwaves reflected from all directions, and this method cannot represent how the microwave pre-treatment affects the rock mass in the rock excavation process. To simulate microwave treatment before an excavation, we wrapped a sample of red sandstone in a copper foil to avoid microwave overheating and the thermal properties and structural deterioration of the sample were investigated. Collected temperature data showed that pore water not only elevated the heating rate significantly but also it related to the temperature distribution within the rock sample. With the continuous removal of moisture during the heating process, the temperature distribution changed from exponential to linear equation. Besides, increasing the microwave power was beneficial to improve the heating rate and energy concentration on the rock fragmentation. Combining the results from nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM), it was found that the porosity of macropores (T₂ greater than 100 ms) and mesopores (10 ms＜T₂＜100 ms) increased after microwave treatment, and change in porosity led to forming transgranular fracture and increasing the number of intergranular fracture. Furthermore, intragranular fractures decreased with microwave propagation, which indicated that the rock damage was a result of the development of intragranular fractures.

在过去的50年中，使用微波辐照弱化岩石一直是研究的主要课题。但是，微波对岩石的热效应主要是通过多模态金属腔研究的，其中岩石吸收了全方位反射的微波，这种方法不能代表微波预处理如何在岩石开挖过程中影响岩体。 。为了模拟开挖前的微波处理，我们将红砂岩样品包裹在铜箔中，以避免微波过热，并研究了样品的热性能和结构劣化。收集的温度数据表明，孔隙水不仅显着提高了加热速率，而且还与岩石样品内的温度分布有关。随着加热过程中水分的不断去除，温度分布从指数方程变为线性方程。另外，增加微波功率有利于提高碎石的升温速度和能量集中。结合核磁共振（NMR）和扫描电子显微镜（SEM）的结果，发现大孔的孔隙率（T₂ 大于100 ms）和中孔（10 ms ＜T ₂＜100 ms）在微波处理后增加，并且孔隙率的变化导致形成了跨晶断裂并增加了晶间断裂的数量。此外，随着微波的传播，晶内裂缝减少，这表明岩石破坏是晶内裂缝发展的结果。