Sustainable applications for utilizing molybdenum tailings in concrete

This paper provides a cleaner production solution for the potential usage of molybdenum tailings as a replacement of fine aggregates in structural concrete. The influence of Molybdenum tailings on the concrete properties, reinforced concrete columns and concrete-filled steel tubular columns was investigated. The environmental impact of these structural concrete products with molybdenum tailings was also assessed. The results show that the molybdenum tailings, whose radionuclides satisfy the requirement in the standard, are suitable for the preparation of structural concrete under proper replacement ratio. The workability, mechanical and duration properties of molybdenum tailing concrete are reduced by increasing the molybdenum tailings replacement ratio. The rise of replacement ratio results in a linear reduction trend on the axial strength of the reinforced concrete and concrete-filled steel tubular columns using molybdenum tailing concrete. The results of the axial compressive tests for stub columns verify the fact that molybdenum tailing concrete could be used as cleaner productions in the construction industry. The cost and environmental impact assessment indicate that concrete filled steel tube is a more preferable solution for the usage of molybdenum tailings in structural concrete, especially with higher molybdenum tailing replacement ratio. It is feasible to replace natural sand with molybdenum tailings to prepare structural concrete members along with environmental benefits. The successful application of molybdenum tailing concrete in cleaner production may further promote the sustainable development of concrete structures. (C) 2020 Elsevier Ltd. All rights reserved.