Geotechnical Properties of Fresh and Aged Basic Oxygen Furnace Steel Slag

OpenAlex · İngilizce

The steelmaking industry in the United States generates 9–16 million metric tons of steel slag every year. The excess steel slag (∼15 to 40%) that is not reutilized is stockpiled in steel plants and eventually landfilled at slag disposal sites. Use of steel slag in civil engineering applications can help alleviate the steel slag disposal problem and help preserve natural resources. Understanding the in-service performance of steel slag is essential for its proper use as a geomaterial by the construction industry. In this paper, the results of a series of tests (grain-size analysis, X-ray diffraction, specific gravity, compaction, maximum and minimum dry unit weight, direct shear, consolidated-drained triaxial compression, and long-term swelling tests) performed on samples of both fresh and aged basic oxygen furnace (BOF) steel slag from a steel plant in Indiana are presented and analyzed. The test results indicated that both fresh and aged BOF steel slag exhibit superior strength and stiffness characteristics to conventional frictional materials. Based on toxicity characteristic leaching procedure (TCLP) test results, the BOF slag tested in this study was classified according to the Indiana Administrative Code (IAC). Long-term swelling test results showed that both fresh and aged BOF steel slag increase in volume when exposed to water due to the presence of free lime and magnesia in their chemical composition. Replacing 10% by weight of fresh or aged BOF steel slag with Class C fly ash was effective in suppressing the swelling behavior.