Synthesis and hydration characteristics of Ga-containing ye'elimite

The attractive properties of ye'elimite (C4A3$) are receiving particular attention in cement and repairing materials. The present paper aims to further explore the difference in hydration performance of different C4A3$ phases (o-C4A3$ and c-C4A3$) using the Ga-doping method. On this basis, C4A3-xGx$ specimens (noted as C4A3$, C4A2.3G0.7$, and C4A1.6G1.4$) were first synthesized and their hydration characteristics were systematically studied. Results showed that Ga-doping enhanced the hydration activity of ye'elimite. With increasing Ga3+ ions addition, the intensity of the initial peak gradually increased, but the duration of the induction period and the hydration heat development rate were gradually reduced. The conductivity and pore solution analysis also demonstrated a higher ion concentration precipitation at the early stage for cubic C4A1.6G1.4$ compared to pure C4A3$. The main hydration products of these specimens were AFt, AFm, and AH3 (gel). Moreover, the addition of Ga3+ ions improved the crystallinity of AFt and AFm with recorded a relatively higher decomposition temperature. Overall, this study demonstrated that the addition of Ga3+ ions can regulate the hydration characteristics of ye'elimite.