Abstract
Concrete is the most widely used construction material globally, and its production is a major contributor to global CO 2 emissions due to the energy-intensive processes involved in cement manufacturing. One the common strategies for reducing these CO 2 emissions of concrete production focus on partially replacing the Portland clinker with other binders made from waste by-products such as fly ash and blast furnace slag. However, as the global energy mix transitions away from coal power and the change in pig iron production, the availability of these by-products is declining, necessitating research into alternative low-emission or zero binders. The aim of the Norwegian research project Sustainable value chain and material use in road construction (BVM) is to find sustainable alternatives for materials used in construction. One such alternative with high potential for the Norwegian market is a product called Silica Greenstone (SiGS), which is a slag by-product from silico manganese production. Produced by Eramet, SiGS can be used as a partial replacement for cement in concrete. In the BVM project, laboratory testing was carried out using SiGS to replace 15-20% of the binder in B45/M40 Class A standard concrete. In this study, the material was applied in full scale pilot in parts of a concrete sound isolation wall in the E18 West corridor highway project in Oslo. The pilot demonstrated that SiGS exhibits comparable mechanical performance and durability to conventional concrete. It is also important to verify that the use of SiGS can reduce emissions in concrete. Therefore, this study used life cycle assessment to quantify the environmental impacts of concrete using SiGS compared to concrete with conventional binders. The results showed a notable reduction in CO2-emissions, reinforcing its potential as a sustainable binder alternative and can replace coal fly ash in an environmentally sound way. Furthermore, the results showed that SiGS represents a viable solution for infrastructure applications, reducing reliance on traditional cement-based materials and promoting sustainable construction practices.