In-situ investigation of earthen building materials in the Ksour of the Ziban region, Algeria: A comparative study between Chetma and Lichana

Earth is one of the primary building materials utilized in the Saharan region of Algeria. This study seeks to characterise, diagnose, and compare the earthen materials employed in constructing two (2) ksour in southern Algeria: the ksar of Chetma and the ksar of Lichana in the Ziban region. The research methodology combined in-situ observations, analysis of traditional construction techniques, and applying three (3) fundamental tests developed by CRAterre in 1979 and 1989: sedimentation in a bottle, the cigar test, and the pellet test. The investigation into the conservation state of the ksour of Lichana and Chetma revealed their highly precarious condition. Furthermore, the tests revealed that the earth used for construction at the two sites shows similarities, with the earth from Chetma containing slightly more clay than that from Lichana. This difference is more apparent in the composition of the mud bricks (40x20x10 cm), as those from Chetma incorporate a natural fibre, wheat straw. In contrast, the bricks from Lichana do not contain straw, resulting in distinct properties. In addition, the investigation into the conservation state of the ksour of Lichana and Chetma revealed their highly precarious condition. The article’s findings contribute to the characterisation of the mud bricks, offering valuable insights for documentation purposes and informing future conservation and restoration efforts requiring compatible construction materials.