Life Cycle Assessment of Concrete Products for Special Applications Containing EAF Slag

Electric Arc Furnace (EAF) slags are steel slags that derive from the steel manufacturing process and are produced in large volumes (∼10% of the steel produced) worldwide, which pose an environmental threat when disposed in landfills. Their physicochemical characteristics (high density, roughness and resistance to fragmentation) favor their use in concrete products for special applications, especially where high resistance to abrasion is required and the increase concrete density is not a problem. The special concrete applications considered in this paper were industrial pavements, heavyweight concrete and pervious concrete paving blocks and all proposed products were designed in order to perform in a similar way as reference products with ordinary concrete. Then, in order to quantify the benefits arising from the utilization of an -otherwise useless- industrial by-product, a Life Cycle Assessment was carried out for each of the concrete products. One m3 or one m2 of concrete was selected as functional unit and a cradle-to-gate approach was followed for the LCA, including material extraction, transport and production and placement, stating the limitations and system boundaries used. Cost estimation for each of the products was also performed in order to assess their commercial viability. The results show that for industrial pavement construction, concrete with EAF slag aggregates has similar environmental load and cost with the reference concrete, while in the case of pervious paving blocks the use of EAF slag aggregates reduces the environmental load by 14% at a reduced cost, and for heavyweight concrete the environmental load is reduced by 44% at a significantly lower cost.