Experimental-based assessment of physical, mechanical and chemical characteristics of ancient and new clay bricks of Babylon city: A comparative study

In Babylon city's historical structures, mud bricks are vital for constructing and restoring masonry walls. Understanding clay bricks characteristics is essential, where they are influenced by various factors, including the raw materials used, construction methods, and the local climate conditions. This study compared clay bricks from the temple of Ninmah with new clay used in its restoration. The physical, mechanical, and chemical compositions of both were investigated. Ancient bricks showed lower porosity (32%), leading to less water absorption (23%) and higher compressive strength (1.7 N/mm²). Field emission scanning electron microscopy showed nanostructure accumulation and rough surfaces in ancient bricks. X-ray diffraction results are closely matched with energy dispersed X-ray fluorescence examinations concerning oxide element proportions. The mineral composition was similar between old and new bricks, with slight variations in silica, alumina, hematite, and magnesia proportions. This study proposes criteria for producing new mud bricks for the Ninmah temple's restoration, using the conventional sun-drying process and varying soil, straw, and water ratios. KEY WORDS: Ancient clay bricks, New clay bricks, Physical properties, Mechanical properties, Chemical composition, Comparative study Bull. Chem. Soc. Ethiop. 2025, 39(10), 2027-2038. DOI: https://dx.doi.org/10.4314/bcse.v39i10.17