Investigation of the Mechanical Behaviors of Sustainable Green Reactive Powder Concrete Produced Using Ferrochrome Slag and Waste Fiber

Reactive powder concrete (RPC) is a new generation concrete with high strength, used in special structures, and its use is increasing day by day. In this study, instead of using high-strength aggregates typically used in RPC, wastes released in ferrochrome production were used. In addition, the possibility of using fibers obtained from end-of-life automobile tires (ELT), instead of the micro steel fibers typically used in RPC, was investigated. Thus, sustainable green reactive powder concrete (GRPC), the material which is obtained from waste materials except the binder and chemical additive, has been developed. As ferrochrome wastes, olivine, serpentine, rum, slag, and pure waste were used as powder and aggregate in GRPC. Firstly, in GRPC without fiber, the physical and mechanical properties of ferrochrome wastes were examined by using different ratios. Then, the optimum mixture was selected, and different ratios of industrial steel and ELT fiber were added to this mixture. As a result, the compressive strength of GRPC using olivine and pure waste (ferrochrome slag) is close to the reference RPC. However, it is 28% more economical. The flexural strength of the samples with a 4% addition of industrial or ELT fiber increased by 182% and 213%, respectively, compared to the reference sample without fiber. With the use of 4% ELT fiber (by volume) in GRPC, the flexural strength increased by 11% compared to the use of industrial steel fiber. In terms of cost, with the use of ferrochrome waste and ELT fiber, GRPC was 48% more economical. When examined in terms of the flexural and compressive unit strength cost, GRPC was approximately 41% more economical. As a result of this study, high-performance concrete with high mechanical properties that is economical, sustainable, and environmentally friendly has been produced by evaluating the use of waste materials.