Avaliação Mecânica e de Durabilidade de Compósitos Cimentícios de Alto Desempenho Contendo Escória de Ferroníquel como Adição Mineral

Abstract

The manufacture of ferronickel alloys results in the significant production of byproducts, such as granulated ferronickel slag (EFN), generated in the pyrometallurgy process to produce the ferronickel alloy. In order to propose a destination for this by-product, the use of EFN as a supplementary cementitious material in high-performance concrete was studied. For this study, concretes containing 10%, 20% and 30% replacement, by mass, of Portland cement with EFN were dosed, for a w/c ratio of 0.35. The following tests were carried out: consistency, fresh specific mass, chemical reactivity (R³). absorption by immersion and capillarity, penetration of chloride ions, compression resistance and calorimetry. Based on the results, it is observed that up to 10% of cement replacement with EFN does not affect mechanical resistance at 91 days. With other replacement levels, they showed a drop in compressive strength, but required lower consumption of Portland cement per MPa. The presence of EFN led to increases in the induction period, between 14 and 22% higher than the reference mixture. Electrical conductivity decreased by up to 26.82% for concrete containing 30% EFN, when compared to references. Finally, it can also be observed that EFN presents chemical reactivity according to the accelerated test prescribed by ASTM C1897:2020, reaching a total released value of 144 J/g.