Semnan University Press Journal of Transportation Infrastructure Engineering 2423-5350 11 2 2025 06 22 Examining the Impact of Steelmaking Slag on Stabilizing Materials in Road Sub-bases: A Case Study of Khuzestan Steel Slag and Soils from the Ghaizanieh and Suiseh Regions of Ahvaz Examining the Impact of Steelmaking Slag on Stabilizing Materials in Road Sub-bases: A Case Study of Khuzestan Steel Slag and Soils from the Ghaizanieh and Suiseh Regions of Ahvaz 105 116 9627 10.22075/jtie.2025.35680.1703 FA Rasoul Alipour Department of Civil Engineering, Faculty of Technology and Engineering, Shahrekord University, Shahrekord, Iran Hamed Javdanian Department of Civil Engineering, Faculty of Technology and Engineering, Shahrekord University, Shahrekord, Iran Sadegh Shokouhi Department of Civil Engineering, Faculty of Technology and Engineering, Shahrekord University, Shahrekord, Iran Journal Article 2024 11 29 Steel slag is widely used worldwide in various industries including civil engineering and executive projects. Steelmaking slag is a side product in the iron production process and constitutes about 10 to 15 percent of iron smelting output and is still considered as waste material. The use of this product has environmental value as well. This research examines the use of steelmaking slag from Khuzestan Steel Company for soil stabilization. Fine-grained soils from Ghaizaniyeh and Suiseh in Ahvaz were analyzed by mixing various weight percentages of the slag and conducting tests on soil grading, compaction, and California Bearing Ratio (CBR). Results indicated that the engineering properties of pure slag outperform those of the soil, enhancing both soil compaction and CBR values under saturated and dry conditions. Additionally, combining slag with clay soil significantly increases its bearing capacity, making it suitable for road embankments. The saturated CBR value for the Ghaizaniyeh soil (sandy clay) is 20, and a mix of 80% by weight of this soil with 20% coarse slag increases the saturated CBR value to 34. On the other hand, the saturated CBR value for the Suiseh soil (low-plasticity clay) is 7, and a mix of 80% by weight of this soil with 20% fine slag increases the saturated CBR value to 30. Using the slag by-product of steel factories (slag) is beneficial from an environmental point of view. Steel slag is widely used worldwide in various industries including civil engineering and executive projects. Steelmaking slag is a side product in the iron production process and constitutes about 10 to 15 percent of iron smelting output and is still considered as waste material. The use of this product has environmental value as well. This research examines the use of steelmaking slag from Khuzestan Steel Company for soil stabilization. Fine-grained soils from Ghaizaniyeh and Suiseh in Ahvaz were analyzed by mixing various weight percentages of the slag and conducting tests on soil grading, compaction, and California Bearing Ratio (CBR). Results indicated that the engineering properties of pure slag outperform those of the soil, enhancing both soil compaction and CBR values under saturated and dry conditions. Additionally, combining slag with clay soil significantly increases its bearing capacity, making it suitable for road embankments. The saturated CBR value for the Ghaizaniyeh soil (sandy clay) is 20, and a mix of 80% by weight of this soil with 20% coarse slag increases the saturated CBR value to 34. On the other hand, the saturated CBR value for the Suiseh soil (low-plasticity clay) is 7, and a mix of 80% by weight of this soil with 20% fine slag increases the saturated CBR value to 30. Using the slag by-product of steel factories (slag) is beneficial from an environmental point of view. https://jtie.semnan.ac.ir/article_9627_136424937671aaab85b9cf576ba646e6.pdf