Effect of slag composition on the hydration process of alkali-activated slag cement activated by composite weakly alkaline activator
WANG Jie
HE Juan
XI Mengfan
WU Yonghua
HE Junhong
Abstract：Alkali-Activated Slag(AAS)concrete prepared with weakly alkaline activator shows low shrinkage and good dura-bility.AAS cement was prepared by three kinds of slag and composite activator of Na2SO4,Na2CO3,Ca(OH)2 and R-MgO.The ef-fect of slag composition on hydration process of AAS cement was studied.The hydration kinetic characteristics of AAS cement were simulated by the Krstulovic-Dabic model.The results show that an increase in the CaO and glass phase content of slag is conducive to an increase in the alkalinity of the hydration environment of AAS cement,which in turn is conducive to the dissolu-tion of Si4+,Al3+,and Mg2+in the hydrated slurry.The concentration of Al3+is also affected by the content of MgO of slag.The higher the MgO content,the slower the increase in Al3+concentration.The hydration kinetic process of AAS cement activator goes through three NG,I and D stages.The finer the slag,the more rapid the AAS cement enters I stage from NG stage.The higher the CaO and glass phase content,the more rapid the hydration rate in I stage.The difference of slag composition does not affect the time from Stage I to Stage D and the reaction rate in Stage D.
Keywords：alkali-activated slag cementalkali compositionhydration kineticsionic concentrationhydrationpH value
Publication Date：2025-08-25
Online Publishing Date：2025-09-12(First online date of this platform, not the publication date of the document)
Pages：7( 34-40 )