Eco-Friendly Basalt Fiber Reinforced Cement Composites (BFRC) Containing Waste Copper As Partial Replacement For Sand And Cement

Abstract

In this study, the use of copper slag and aggregate together with basalt fiber in cement-based composites was studied. It was aimed to contribute to the ecosystem by using copper waste, which is an environmental problem, in cement-based composites. In addition, the effect of basalt fiber on the strength and durability properties of composites was investigated. Taguchi optimization was carried out for cement-based composites. In this context, Taguchi L18 matrix was used. Copper slag was used at rates of 0, 7.5% and 15%, and copper aggregate at rates of 0, 25% and 50%. Basalt fibers of 6 and 12 mm length were used at the rates of 1%, 2% and 3%. The w/b ratios of the mixtures were chosen as 0.40, 0.50 and 0.60. Durability tests such as permeability, freeze-thaw and sulphate resistance with fresh and hardened mortar properties were performed on 18 different mixtures. In terms of the 7, 28 and 91-day flexural and compressive strength of the mixtures, the use of 1% of 6 mm long fiber in the mixtures with a w/b ratio of 0.40 provided more positive results. In terms of freeze-thaw resistance, it is necessary to use 3% of 6 mm long fiber in mixtures with 0.40 w/b. The use of 7.5% copper slag reduced the water penetration depth. The use of 15% copper slag in mixtures affected by sodium sulphate reduced the expansion values. Since the increase in the ratio of copper aggregate decreased the aggregate volume, it caused the drying shrinkage values to increase. As a result, it was observed that copper slag has a more positive effect than copper aggregate for the strength and durability of composites. However, by using 25% of copper aggregate by sacrificing some features, it can contribute to the environment and ecosystem. The use of basalt fiber with a length of 6 mm and a ratio of 1% increased the mechanical properties, while the use of 3% contributed significantly to the freeze-thaw resistance. It was determined that copper wastes contribute to the environment and ecosystem by using them instead of cement and aggregate.