Geotechnical Assessment of Sabkha Soil Treated with Steel Slag for Sustainable Infrastructure in Saudi Arabia

In the hot and arid regions of Saudi Arabia, sabkha soils are widely recognized for their poor engineering characteristics, including surface salinity, weak strength, and unpredictable behavior under loads. Their spatial variability and sensitivity to moisture make them unsuitable for direct use in infrastructure without modification. This study investigates the potential use of steel slag, an industrial byproduct, as a practical material for improving the performance of sabkha soil. Soil samples were treated with steel slag at rates of 10, 20, 30, 40, and 50% by dry weight. The effect of steel slag on sabkha soil compaction behavior and strength was examined through laboratory testing, including Proctor compaction, direct shear, and California Bearing Ratio (CBR). The results revealed that the incorporation of steel slag significantly enhanced the compaction characteristics, shear strength parameters, and CBR values. These results show that steel slag is not only an effective additive for stabilizing sabkha soil but also a step towards more sustainable and long-lasting geotechnical solutions.