Several high rise buildings in the world are made of reinforced concrete shear walls. This type of structures performed very well during the past earthquakes better than reinforced concrete frame buildings.Concrete wall structures are well known for their excellent performance during earthquakes. Since 1963, no concrete building with shear walls has collapsed during an earthquake [19]. In some cases, buildings with concrete structural walls showed little or no damage when neighbouring reinforced concrete frame buildings were severely damaged or destroyed.One type of seismic force resisting structure used in high-rise wall buildings is a centrally located core without supplemental moment resisting frames.Effect of some parameters on the behavior and performance of reinforced concrete shear walls was carried out in the past. However, these studies were conducted on rectangular reinforced concrete shear walls. Frequently, designers are using other configurations beside the rectangular cross sections, such as T-shaped, H shaped and U shaped cross sections, in order to reach higher levels of strength and stiffness.In many cases, these complex members show completely different behaviors than rectangular walls, and particular consideration is needed when these shapes are used in structures. Among all types of flanged shear walls, the ones with T-, H-, and U-shaped cross sections have been those most studied by researchers [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Research has been more focused on walls with symmetric cross sections, and few studies in the literature report the behavior of flanged shear walls with asymmetric cross sections, such as L-shaped walls. The stiffness, strength, and

This research objective is to propose a co-valorization of powdered tuff, containing a slight amount of clay and dune sand, by mixing the two substances at different rates such as 0%, 5%, 15%, 25% and 35% of sand. The adapted criteria formulas are those recommended by the technical Saharan road. The results of the proposed study showed that "tuff-sand" mixtures are denser with a lower optimum water content modified proctor, the fine rate decreases together with the plasticity index, whereas the bearing index (CBR: California bearing ratio test) increases. The intrinsic characteristics, cohesion and sensitivity of mixtures with respect to compactness are almost identical to those of tuff without addition. The optimal adapted sand incorporation rate is estimated at 25% at 96% of compactness. Under these conditions, the amount of fines decreases from 40% to an acceptable level of 25% and the plasticity index from 16.2 to 12. The compaction water content decreases by 36% and the CBR (bearing index) increases by 30% and the compressive strength and sensitivity, according to compactness, of the elaborated material are almost identical to those of tuff without addition.