Physical Properties of Cement Using Slag as Raw Mix of Clinker

The global cement industry emits approximately 2.9 billion tons of greenhouse gases, of which 1.74-1.89 billion tons are emitted from limestone, which is the main raw material for clinkers. Therefore, the feasibility of using slag, a non-carbonated CaO-based raw material, must be investigated, and the physical properties of cement must be considered. In this study, the mixing ratios of the raw mix and properties of cement were analyzed. The CaCO3 replacement ratio was limited when one type of slag was used; however, when the mixed slag was utilized, the CaCO3 replacement ratio increased by more than 12 %. The compressive strength of the slag-incorporated cement was lower than that of Ordinary Portland Cement (OPC). Therefore, the lime saturation factor (LSF) of the raw mix and fineness of the cement were increased to improve the compressive strength. The compressive strength of cement with improved fineness was similar to that of OPC for a CaCO3 replacement ratio of up to 6 %, and it decreased as the CaCO3 replacement ratio was increased to 9 %. When both fineness and LSF were increased, the compressive strength and flow value of the cement with a CaCO3 replacement ratio of 12 % were similar to that of OPC.