Hydromechanical Characterization of Raw Earth Mortar – Stabilizing Cement and Lime

Abstract Earth-based mortars are again taking their place as building materials for plastering, rendering and repairing earth walls, not only in a sustainable context but also in terms of efficiency. Nevertheless, scientific understanding of these mortars is still scarce. This present paper reports on an experimental study, conducted at the laboratory of the university center of El-Bayadh, concerning the study of the hydro-mechanical characteristics of mortars based raw and stabilized earth. In doing so, mortars prepared with clay-sand soil, treated with cement (C) (6%, 8% and 10%), lime (L) (4%, 6% and 8%) and mortars treated with both binders (4% C+2% L, 5% C +4% L, 8% C+6% L) taking into account control mortars of raw earth, are investigated. Compressive and tensile percentage strengths, total absorption, and swelling are determined. Therefore, the obtained results in the case of total absorption test, showed significant erosion in the mortars specimens weakly stabilized with cement and those without added stabilizer. Indeed, it was observed during the swelling test that the mortars specimens weakly stabilized with cement were fragile to the erosive water and showed deterioration, especially at the edges. Furthermore, increasing the cement content from 6% to 10%, the water absorption percentage was reduced by 30%. It appears that the composition that led to a better behavior towards water is the mixed combination (8% cement + 6% lime). However, stabilization with cement confers a higher strength compared to lime powder. In fact, the maximum resistances were obtained for high cement dosages (8 and 10% respectively) and the 4% lime dosage.