Enhancing Ye’elimite-Gypsum Hydration and Microstructure in Cementitious Systems Using Layered Double Hydroxides

This study evaluates the effect of nano-CaAlNO₃ layered double hydroxide (CAN LDH) on the early-age hydration of ye’elimite–gypsum systems. CAN LDH was synthesized via co-precipitation and added at 0%, 2%, and 5% dosages to ye’elimite–gypsum pastes. Isothermal calorimetry showed that LDH addition accelerated hydration, while XRD analysis confirmed increased ettringite formation, particularly at 5 wt%. The improvements are attributed to the LDH’s high surface area, ion release, and nucleation capabilities. Results suggest that CAN LDH enhances hydration kinetics and microstructure development, making it a promising additive for CSA-based low-carbon binders.