Impact mechanism of fabric changes in different classes of redbeds under static water on their degradation of physical properties

Deterioration of the physical properties of redbeds is one of the leading causes of geological disasters, engineering problems, and ecological damage. Fabric changes are internal factors leading to the deterioration of physical properties. Existing research on fabric changes in redbeds is qualitative and fuzzy, and their impact on the decline of physical properties needs to be revealed urgently, making the efficient control of redbeds disasters challenging. Therefore, this study focuses on 22 types of redbeds samples and divides them into five classes based on their fabric (composition and structure). Physical property degradation experiments were conducted on different classifications of redbeds during water–rock interaction, and the impact of fabric changes on the degradation of physical properties was analyzed. The results indicate that a linear correlation exists between the internal changes in composition, structure, and physical properties under the action of static water. Moreover, the trend of changes between composition and structure, composition–physical properties, and structure–physical properties shows an exponential regression relationship. Based on this, an action mechanism between compositions such as redbeds, catastrophic minerals, elements, and oxides, as well as the void structure, was proposed, revealing the multifield degradation mechanism of the chemical reactions of the compositions, physical response of the structure, and mechanical reaction of the rock block under the influence of the fabric. The research results can provide a foundation for theoretical research and engineering practice of disaster modes, disaster mechanisms, and prevention and control principles of redbeds disasters.