This study evaluated the standard consistency, setting time, hydration heat, and compressive strength of binary blended cement concrete (general and high strength) using air cooled ladle furnace slag (LFS) of 3, 5, 7, 10wt.% as an admixture for ordinary portland cement (OPC). Results showed that binary blended cements using the LFS of lower than 5wt.% shortened the setting time and reinforced the compressive strength of concrete (general and high-strength) compared to OPC concretes although binary blended cements needed more water to achieve the standard consistency. This indicated that LFS could be used as a useful admixture for manufacturing binary blended cement. Thus, we expected that the upcycling of LFS would be contributed to save energy consumption and reduce the greenhouse gas emission from the field of cement industry.

In this study, “Recycling of ladle furnace slag (LFS) in the electric furnace process to produce ultra rapid harding cement” is the target technology. Environmental and economic efficiencies of target technology are analyzed and ecoefficiency is assessed based on these results. The methodologies to analyze environmental and economic efficiencies are LCA (Life Cycle Assessment) and market price which is calculated based on LCC (Life Cycle Costing), respectively. Global warming potential (GWP) and abiotic resource depletion (ARD) are selected as indicator of environmental analysis. The reference flow of this study is considered 1kg of ultra rapid harding cement which made from the LFS. As a result of that, target process has environmental efficiency of 13.1 for global warming and 5.93 for abiotic resource depletion and has economic efficiency of 4.86. Eco-efficiencies are derived from this study can be applied to slag recycling policy formulation and effect analysis in the future. This can be also applied to improve process’s environmental and economic performances.