Feasibility of silicomanganese slag as cementitious material and as aggregate for concrete

Abstract

The need to reduce environmental impact inevitably leads to research on new, more sustainable construction materials. In recent times, the use of the main slags from the steel industry has been vigorously investigated; however, the use of other industrial by-products should also be considered. This study aims to analyze the viability of the use of value-added silicomanganese slag (siderurgical aggregates from ferroalloy industries) in two ways. On the one hand, the potential of ground silicomanganese siderurgical aggregates as a binder or supplementary cementitious material (SCM) due to their high content of silica and alumina. On the other hand, the use of silicomanganese siderurgical aggregates for the manufacture of concrete. The hydraulicity of the ground material has been determined by designing mortars with 20 % replacement of cement and comparing the mechanical performance with Portland cement and fly ash at different ages. Its application as a granulometric skeleton of concrete has been analyzed by comparing the physical-mechanical performance and docility in the fresh state with a conventional limestone aggregate concrete. The results obtained guarantee the pozzolanicity of the material, obtaining resistances similar to Portland cement mortar at 90 days. Furthermore, the material as an aggregate meets the geometric, mechanical and leaching requirements imposed by current regulations, although its use with almost total replacement leads to mechanical losses of 25-30 %. For this reason, its use is only recommended in small replacement proportions or in concrete for non-structural use.