Freeze-thaw damage of architectural heritage grey brick materials based on fractal theory

This study focuses on the grey bricks from the Longshengzhuang architectural heritage site in Inner Mongolia and employs uniaxial compression testing to assess the materials before and after cycles of freezing and thawing. Using fractal theory, the compression fracture characteristics of grey bricks are studied from the perspectives of debris and cracks. Concurrently, the damage factor is used to characterize the uniaxial compression damage process of ancient building grey bricks, and the damage evolution model for grey bricks exposed to various cycles of freeze-thaw is formulated based on the damage factor. Architectural heritage constitutes a vital component of historical and cultural legacy, with grey brick being a prevalent material in its construction. The durability of grey bricks is subject to gradual degradation due to prolonged exposure to intricate natural environmental conditions and anthropogenic damages. This degradation is particularly pronounced in cold climates, where phenomena such as powdering, shedding, and cracking become prevalent. These processes can cause a significant deterioration in the mechanical properties of the materials and, consequently, compromise the structural integrity of architectural heritage sites ^1,2 . Consequently, investigating the damage patterns and degradation mechanisms of ancient grey bricks subjected to freeze-thaw cycles will furnish a scientific foundation for the assessment and preservation of architectural heritage.