effectiveness of reusing steel slag powder and polypropylene fiber on the enhanced mechanical characteristics of cement-stabilized sand

Waste generated by steel industry cases environmental and economic problems. therefore, it becomes very important to utilize steel industrial waste material in a proper manner. one promising use for this huge amount of industrial waste is soil improvement. in this work, unconfined compressive strength (ucs) tests were conducted to study the influence of steel slag on the mechanical characteristics of cementstabilized sand. the ucs tests were conducted on the compacted specimens which prepared in the laboratory at their optimum moisture content (omc) and modified proctor maximum dry density (mdd). the results indicate that use of steel slag powder as a partial replacement of chemical stabilizer such as cement in soil stabilization has advantages from economic, environmental and technical points of view. the highest value of ucs was observed in the sample containing 7.2% cement and 0.8% steel slag powder. beyond optimum steel slag powder dosage, the ucs value decreased. the addition of polypropylene fiber into the specimens treated with cement or steel slag powder improves significantly the mechanical behavior of specimens and significantly increases the ucs and strain corresponding to the maximum compressive strength. the specimen containing 0.2% of polypropylene fiber, 6.4% of cement and 1.6% steel slag exhibits the highest ucs value when the sum of the amounts of cement and steel slag was 8%. the failure pattern of specimen indicates a transition from ductile to brittle behavior with addition of cement and steel slag. however, the addition of polypropylene fiber changes the brittle response of treated specimens to a more ductile behavior.