Preparation and Mechanism of Fluorine-Free,Chlorine-Free and Alkali-Free Liquid Accelerator
LIU Yan
SUN Zhenping
YANG Haijing
LI Huanhuan
LI Zhilin
Abstract：The effects of two early-strength components,MgSO4 and triethanolamine(TEA),on the storage stability of Al2(SO4)3 solutions containing diethanolamine(DEA)were investigated,and the influences of DEA-Al2(SO4)3 solution(herein after referred to as Al2(SO4)3 solution)incorporating different early-strength components on the setting time of cement paste and the strength of cement mortar were also studied.A fluorine-free,chlorine-free,and alkali-free liquid accelerator(LA)was prepared by combining Al2(SO4)3 solution with MgSO4 and TEA,and its comprehensive performance was tested.Hydration heat analysis,hydrogen proton low-field nuclear magnetic resonance analysis,X-ray diffraction,thermogravimetric analysis,and scanning electron microscopy were employed to elucidate the mechanism of LA.The results show that at low LA content,both MgSO4 and TEA can enhance the early-strength effect of Al2(SO4)3 solution.The incorporation of LA significantly shortens the setting time of cement paste and improves the early compressive strength of cement mortar.LA promotes the formation of early ettringite crystals in hardened paste,accelerates the development of a skeletal framework in the liquid phase,and thereby achieves rapid setting,hardening,and early strength development of the cementitious system.
Keywords：fluorine-freechlorine-free and alkali-free liquid acceleratorearly strength componentsetting timecompressive strengthhydration productmechanism
Publication Date：2025-09-30
Online Publishing Date：2025-10-17(First online date of this platform, not the publication date of the document)
Pages：9( 869-877 )