Strength and durability assessment of stabilized Najd soil for usage as earth construction materials

For centuries, earth materials have been used in Saudi Arabia in building construction. Globally, these materials re-emerged as one of the possible solutions to the high energy consumption in residential buildings. Therefore, this research was intended to study the applicability of using the available earth materials as a potential solution and replacement for the current conventional materials in Najd area, Saudi Arabia. Four different soils from Najd area were collected and characterized to find out their physical and chemical properties. The soils were stabilized using different dosages of either cement or hydrated lime (mixed at 0%, 2.5%, 5%, 7.5%, 10%, 12.5% and 15% by the dry weight of the soil) and then assessed in terms of both their unconfined compressive strength and durability. The results indicated the superiority of cement stabilization in developing strong and durable soil mixtures that can be used as construction materials. Also, the durability of the soils was enhanced with the addition of different stabilizers. Comparing the results with the available standards, both the strength and durability of the soils proved the possibility of using the selected soils as construction materials. Finally, several correlations were developed through statistical analysis to address the mechanical properties of the stabilized soils, including the modulus of elasticity, density and stabilizer content. Such correlations could predict the mechanical properties of the stabilized soils and, hence, help in analysing the behaviour of earth materials.