Multi-scale degradation of mechanical properties in limestone cultural relics under long-term acid rain leaching

The acid rain corrosion mechanism and apparent performance degradation of stone cultural relics are related to the safety of cultural relics, the complete preservation of historical information and the sustainable inheritance of cultural heritage. Limited by sampling, it is difficult to test and analyze limestone cultural relics under acid rain corrosion by traditional methods. In this study, nanoindentation technology suitable for micro-samples was adopted, combined with SEM, uniaxial compression testing, and image binarization analysis techniques. This approach enabled a cross-scale examination of morphological changes and mechanical property degradation patterns in limestone cultural relics. The results indicate that acid rain induces significant morphological damage to limestone artifacts. Furthermore, both their quality and macro-micro mechanical properties deteriorate as dissolution time increases, these changes stabilize after 1080 h. The deterioration law of macro-micro mechanical properties is consistent. These findings provide theoretical guidance for acid rain prevention measures in similar stone artifacts.