Physical and Thermal Properties of Raw Earthern Bricks from Ksar Ait Benhaddou

Abstract

Abstract. The deterioration of historical earthen architecture in the Drâa-Tafilalet region of Morocco is becoming a significant concern. These structures are susceptible to various natural and human-induced factors, leading to their deterioration. Our research focuses on the recycling and valorization of debris from the deteriorated walls of Ksar Ait Benhaddou to potentially facilitate restoration. Various techniques were employed to characterize the debris from Ksar Ait Benhaddou, including geotechnical analysis (Atterberg limits, grain size), physicochemical assessment (X-ray diffraction, Infrared spectroscopy, X-ray fluorescence), and microscopic examination (Scanning electron microscopy). Standardized brick specimens were created from debris waste paste mixed with 22% water by mass. Additional specimens were prepared by incorporating stabilizers (portland cement or lime) or natural plant fibers (wheat straw) into the debris, with a water/solid ratio of 22%. The prepared specimens underwent aging for different periods (0 to 4 days). The study investigated the impact of aging duration and three additives on mechanical properties, material thermal conductivity, and hydrate formation. The debris exhibited medium plasticity, consisting of non-swelling clays and sand. The compressive strength of cement-stabilized samples yielded the best results, reaching 1.90 MPa for the DC5 sample. The thermal conductivity of samples stabilized with cement increased, contrasting with lime and straw, which had the opposite effect.