Effects of quartz-based mine tailings on characteristics and leaching behavior of ultra-high performance concrete

High production cost and scarcity of raw materials may hinder the application and accessibility of ultra-high performance concrete (UHPC). In the present study, mine tailings, mineral waste products from mining sites, were applied to mitigate these problems. Two types of quartz-based mine tailings produced in South Korea were used to substitute silica powder and silica sand by half and fully in UHPC. The characteristics of UHPC with the tailings, including the compressive strength, workability, water absorption, and leachability of toxic elements, were experimentally evaluated. The effects of the tailings on the characteristics of UHPC varied according to the shape and size of particles of the tailings. The leaching of toxic trace elements from the tailings was highly controlled due to the chemical and physical capsulation of UHPC.