Synthesis and hydration characteristics of Ga-containing ye'elimite

Abstract

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$) using the Ga-doping method. On this basis, C₄A_3-xG_x$ specimens (noted as C₄A₃$, C₄A_2.3G_0.7$, and C₄A_1.6G_1.4$) were first synthesized and their hydration characteristics were systematically studied. Results showed that Ga-doping enhanced the hydration activity of ye'elimite. With increasing Ga³⁺ ions addition, the intensity of the initial peak gradually increased, but the duration of the induction period and the hydration heat development rate were gradually reduced. The conductivity and pore solution analysis also demonstrated a higher ion concentration precipitation at the early stage for cubic C₄A_1.6G_1.4$ 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.