Özet:

Steel slag and fly ash are particulate industrial by-products generated in steel plants and power plants, respectively. In this study, the properties of steel slag, fly ash and a steel slag-fly ash mixture that contain 20% fly ash (by weight) were investigated for their possible use as fill material. Fly ash and steel slag were characterized through specific gravity, sieve, hydrometer and Atterberg limits experiments. Compaction behavior of the industrial by-products and their mixture were evaluated through standard Proctor compaction, and their hydraulic conductivity were determined through falling-head permeability experiments. The shear strength parameters of the industrial by-products and their mixtures, prepared at 100% Proctor compaction, were evaluated based on direct shear experiments. pH and electrical resistivity measurements were taken, and leachate analysis were performed on fly ash and steel slag samples to determine the possible environmental risks that can arise from their use. The maximum dry unit weight (d) values recorded for the 80% steel slag - 20% fly ash mixture was higher, on the other hand, the optimum moisture content of the mixture was lower compared to that of steel slag sample. Based on direct shear experiments, the end-of-test friction angles (ds) are 40.1o and 28.9o for steel slag and fly ash, respectively. The end-of-test friction angle (ds) for the 80% steel slag-20% fly ash mixture is 37.8o. The peak shear strength of the mixture is close to that of steel slag and comparable to the higher end of the range obtained for natural sands that are used as fill material. The pH and electrical resistivity measurements indicate that these by-products may possess corrosive nature. The results of the leachate analysis point toward the need for further analysis of the mixture for the environmental effects.

Anahtar Kelimeler: