Production of eco-friendly UHPC with high durability and resistance to harsh environmental conditions using copper mine tailings

In recent years, constructing environmentally friendly buildings, also known as green buildings, has become a crucial aspect of sustainable development principles. This experimental study investigates the partial replacement of Portland cement with Sungun copper mine tailings (SCMT) for the production of eco-friendly UHPC. The research includes resistance testing against sulfate attack at a 5% Na2SO4 concentration at 30, 90, and 180 days, with SCMT replacement ratios ranging from 5% to 30%. Furthermore, the mechanical properties of eco-friendly UHPC are examined. The study also assesses the mass loss and compressive resistance of UHPC after exposure to an HCl acid solution for 30 and 90 days. The resistance of UHPC to chloride penetration is evaluated using the rapid chloride migration test (RCMT). Additionally, capillary water absorption and microstructural properties of eco-friendly UHPC are studied through SEM analysis. The results indicate that UHPC with partial cement replacement by SCMT had improved mechanical properties, durability, and microstructure. The compressive strength reduction in ecofriendly UHPC mixtures due to acid attack was minimal when 10% SCMT was used as a replacement for cement after being immersed in HCl acid for 90 days. Furthermore, the mixture that contained 10% SCMT demonstrated lower penetration for chloride ions, Which referred to an improvement of 17.6%, compared to the control mixture. In addition, the results of the tests demonstrated that the incorporation of SCMT in UHPC at a rate of 5%-15% had a beneficial impact on the resistance of UHPC to sulfate attack when exposed to a 5% Na2SO4 concentration. This study demonstrates the potential of sustainable UHPC production with SCMT as a suitable alternative to cement in aggressive environments containing acids, sulfates, chlorides, and similar compounds.