Exploring the influence of calcined clay grade on the rheological dynamics of LC3 mortar

This study utilized a synthetic engineering limestone calcined clay (LC3) system to simulate the effects of different grades of calcined clay on the rheological, hydration, and mechanical properties of LC3 mortar. By finely grinding quartz to a particle size akin to that of calcined metakaolin and blending it in proportions ranging from 0% to 100%, it was able to explore the detailed relationships between metakaolin content and key properties of the mortar. The results show a nonlinear correlation between metakaolin content and rheological behavior, with 85 % metakaolin content identified as the optimal proportion. At this level, the compressive strength values closely approached those of the 100% group. The result also highlights the significant influence of water to binder ratio and the substitution of wollastonite for limestone on mortar flowability and mechanical strength. Notably, mixes with higher proportions of ground quartz exhibited delayed hydration and reduced early strength but increased long-term strength due to enhanced pozzolanic reactions. A significant contribution of this study is the modification of the traditional rheological formula specifically for LC3 materials, providing new insights for future research on the rheological properties of LC3 systems. These findings are crucial for the formulation of more efficient, sustainable LC3 systems tailored for specific engineering applications. The optimized rheological formula offers a robust foundation for further exploration and refinement of the balance between workability and mechanical performance in LC3 systems.