Investigation into the Preparation Process and Properties of High-Ferrite Cement-Composite Cementitious Materials

Abstract

In this study, ordinary Portland cement (OPC) clinker, high-ferrite cement (HFC) clinker, desulfurization gypsum, and limestone powder were utilized as raw materials. The effects of two processes, separate grinding followed by blending and co-grinding, on the particle size distribution, water requirement for normal consistency, and setting time of the OPC-HFC composite cementitious system were compared. On this basis, a strengthening agent was introduced to systematically investigate the rheological properties, early hydration heat evolution, and mortar strength development of the co-ground cementitious system. The results indicate that compared to separate grinding, the co-grinding process exploits the difference in the grindability of the two clinkers to produce a “self-widening” effect, thereby effectively optimizing the particle size distribution of the composite system. Among the three compositions examined, the co-ground CG2 system exhibited the lowest water requirement for normal consistency and relatively low yield stress, particularly at low w/b ratios. Furthermore, a relationship can be observed between the time-dependent rheological behavior of the paste and the staged characteristics of the early-age hydration heat evolution. The addition of the strengthening agent improved the 28 d compressive strength of the co-ground cementitious systems. These findings provide laboratory-scale experimental evidence regarding the performance feasibility of OPC–HFC composite cementitious materials and a reference for further composition and process optimization.