Physicochemical and thermomechanical characterization of compressed earth blocks stabilized with cement or wood ash

• Identification, characterization, and optimization of soils from the Fès-Meknès basin (Morocco); • Comprehensive analysis of soil aggregates using XRF, FTIR, and EDX-SEM techniques; • Cement improves mechanical performance more effectively than wood ash in stabilized compressed earth blocks; • Optimal mechanical performance achieved with the addition of 10% cement and 12% water to the suitable soil; • Wood ash enhances thermal insulation properties more effectively than cement in stabilized compressed earth blocks. Amid current environmental challenges, raw earth materials offer a sustainable alternative. The energy efficiency and carbon footprint of compressed earth block constructions are influenced by the physicochemical properties of the soil and the stabilization technique employed. The main objectives of this work are to promote the production of stabilized compressed earth blocks while considering their targeted thermomechanical properties. To achieve this, the sandy-loamy raw material from the Sais basin, in the Meknes region of Morocco, was characterized and optimized through physical and chemical analyses to identify suitable soils for the construction of stabilized compressed earth blocks. Our study of soil samples collected from three different depths revealed the predominance of three minerals: quartz, calcite, and dolomite. The suitability of the soil and its stabilization using two binders (cement and wood ash) were subsequently investigated. Stabilized compressed earth blocks with different stabilizer contents were subjected to thermomechanical testing, and their performance was evaluated. Uniaxial compression testing revealed that higher cement content leads to substantial improvements in both Young’s modulus and compressive strength. The measured thermal properties indicate that wood ash exhibits notable thermal inertia, offering improved thermal comfort in buildings compared to cement.