The synergic impacts of salt mixture and frost damage on rock decay: implications for the deterioration of rock-hewn heritages

Rock-hewn heritages, such as those found in the West Lake Cultural Landscape of Hangzhou (WLCL), are vulnerable to combined salt weathering and freeze–thaw cycles, leading to significant deterioration. A study revealed that stones with moderate porosity (~5%) and a higher proportion of micropores, like flint, were particularly susceptible to these synergistic effects, exhibiting surface deformation and strength decline. Porous tuff developed a hard crust and pore fill, while compact carbonate rock showed minimal damage. The research used laboratory ageing tests on five stone types from the WLCL area, simulating 25 cycles of salt impregnation (Na₂SO₄–MgSO₄ mixture), freezing-thaw, and evaporation. Findings indicate that inherent rock properties significantly influence vulnerability to weathering, emphasizing their role in developing preventive conservation strategies for UNESCO World Heritage Sites.

Wang, Y., & Zhang, H. (2023). The synergic impacts of salt mixture and frost damage on rock decay: implications for the deterioration of rock-hewn heritages. Heritage Science, 11(1). https://doi.org/10.1186/s40494-023-01054-8