Study of the ancient masonry of historic mosques in Marrakesh (Morocco)

This study aims to examine the chemical, physical, and geometric properties of the components of ancient masonry used to build historic mosques in Marrakesh (Morocco). To this end, we conducted XRD and SEM analyses, as well as compressive strength tests on samples taken from historic mosques dating from the Almohad (1147–1269), Merinid (1472–1509), Wattasid (1472–1509), Saadian (1509–1649), and Alawite (1649-present) dynasties. The results of these analyses showed that these buildings were constructed using masonry composed of fired clay bricks, fixed with mortar composed of sand and air lime, with a lime content of approximately 57%. A geometric analysis of these bricks reveals a relative morphological homogeneity, characterized by a rectangular parallelepiped shape with average dimensions of approximately 273 mm × 134 mm × 45 mm (length × width × height). Nevertheless, certain variations are observed, reflecting differences related to historical periods, manufacturing techniques, and local construction contexts. Physical tests also revealed that these ancient bricks, some of which are over 500 years old, still retain acceptable compressive strengths of between 11 and 17 MPa, highlighting that this type of masonry has proven its durability and resistance to atmospheric agents over centuries. The conclusions of this study are an essential contribution to ensuring the sustainability of technical decisions in restoration, particularly in the choice of substitute materials for future projects to preserve Morocco’s built heritage.