Earthen construction, which has been used for a long time and involves many different methods, is currently re-emerging as a promising solution for revitalizing the building sector. In the Marrakech region (Morocco), the Toub or adobe technique remains a key component of the vernacular heritage and contributes to indoor thermal comfort. However, the long-term durability and mechanical performance of existing adobe structures are still not sufficiently documented. This study aims to provide an integrated characterization of earthen bricks taken from a traditional load-bearing building in the Marrakech region (Morocco), in order to assess their mechanical behavior, durability potential, and implications for sustainable construction and indoor comfort. The methodology combines in-situ sampling of adobe bricks from vertical load-bearing walls with laboratory investigations: macroscopic description, chemical analysis of major oxides, mineralogical characterization by X-ray diffraction (XRD), microstructural observations by scanning electron microscopy (SEM), and mechanical tests in compression and three-point bending. The results show a clay-rich and carbonate-rich soil, dominated by clay minerals, quartz and calcite, with an average density of about 1800 kg/m³. Compressive strengths between 0.98 MPa and 1.19 MPa and flexural strengths between 0.26 MPa and 0.44 MPa place the studied adobe within the typical range reported for traditional earthen constructions, with a relatively ductile post-peak behavior due to the presence of straw fibers. The high calcium content and balanced minerals give good cohesion and strength, while the porous structure helps stabilize indoor comfort; however, the high sulfate content can threaten durability in humid conditions.
Youssef et al. (Thu,) studied this question.