Experimental study on the utilization of copper tailing as micronized sand to prepare high performance concrete

Abstract Preparing concrete with the copper tailing as micronized sand to modify manufactured sand (MS) contributes to both the utilization of copper tailing and improvement on the concrete performance. In this paper, experiments on preparing concrete with copper tailing as micronized sand were investigated. Parallel investigations on the properties, such as compressive strength, elastic modulus, chloride permeability coefficient, dry shrinkage and pore structure as well as heavy metal leachability test of concretes prepared with MS, RS, MR and MC were conducted. The results show that the gradation of MS is optimized by replacing it with 20% copper tailing. MC concrete has better anti-segregation ability and long-term strength development. It is found that MC increases elastic modulus and chloride permeation resistance of concrete, however, the dry shrinkage ratio of MC concrete is the higher than other groups. The ITZ between aggregates and paste of MC concrete become tighter. Although the porosity of concrete is increased in MC concrete, its pore size distribution is refined. Finally, the heavy metal leaching of copper tailing was significantly reduced when copper tailing was immobilized in MC concrete, which could eliminate the environmental impacts from copper tailing.