Early Hydration Characteristics of Magnesium-Doped C3A in the Absence of Gypsum
SONG Qiang
YANG Jiahui
ZHANG Tongsheng
HU Yaru
PAN Zhigang
Abstract：To investigate the early hydration characteristics of magnesium-doped tricalcium aluminate(C3A)in the absence of gypsum,C3A samples incorporating 16.67%and 28.57%MgO were prepared by calcination,and the evolution of phase composition and hydration degree during hydration were analyzed.The results demonstrate that MgO significantly promotes the hydration of C3A,with magnesium-aluminum layered double hydroxides(Mg-Al LDH)forming within 1 h of hydration.The content of Mg-Al LDH increases markedly with higher MgO incorporation in the samples.The sample with 28.57%MgO achieves a C3A hydration degree of 95%after 2 days,representing a 20%-30%improvement compared to the sample with 16.67%MgO.Mg(OH)2 cannot be observed during the formation process of Mg-Al LDH,indicating that the formation of Mg-Al LDH does not transfer from an intermediate product of Mg(OH)2 but rather through direct reaction between Mg2+(from MgO hydrolysis)and Al3+(from C3A hydrolysis)under alkaline conditions.Consequently,the formation of Mg-Al LDH also accelerates the hydrolysis of MgO.
Keywords：MgOC3AhydrationMg-Al LDHC3AH6
Publication Date：2025-12-30
Online Publishing Date：2026-01-08(First online date of this platform, not the publication date of the document)
Pages：9( 1190-1198 )