Characterization of Bricks from Baroque Monuments in Northeastern Poland: A Comparative Study of Hygric Behavior and Microstructural Properties for Restoration Applications.

This study presents a comprehensive material characterization, including physical, hygric, and mechanical properties, of historical ceramic bricks to enhance the understanding of heritage masonry structures and support the effective planning of conservation interventions. The primary objective is to systematize the knowledge of constituent materials in brick walls from different historical periods and to evaluate the compatibility of modern repair materials with the original fabric. To this end, a comprehensive experimental protocol was employed, which included the determination of fundamental physical properties such as density, water absorption, and sorptivity. Additionally, chemical and thermogravimetric analyses were performed, followed by freeze-thaw resistance testing and compressive strength measurements. Microstructural analysis was conducted using mercury intrusion porosimetry. The results identified the pore size ranges most susceptible to frost-induced degradation and revealed correlations between the physical, hygric, and mechanical properties of the tested ceramic materials. These findings provide essential data on the physico-mechanical characteristics of historical bricks, establishing a basis for the informed selection of compatible materials in conservation practice.