Research on preparation and performance of a powder alkali-free and fluorine-free accelerator
DENG Ni
LI Hanjian
SUN You
GAO Zonghong
LONG Xiao
WANG Yuanfu
FANG Shichang
Abstract：Aluminum sulfate is generated by reacting concentrated sulfuric acid with aluminum hydroxide,followed by the ad-dition of chelating agents and accelerators.After cooling,it solidifies into flakes and is crushed and dried to obtain a powder alka-li-free and fluoride-free accelerator.The influencing factors and laws of forming and solidification of reaction materials were inves-tigated.The stability and adaptability to different cements were also tested.The experimental results indicate that when using 25%aluminum hydroxide,2%pseudo-boehmite,30%concentrated sulfuric acid,6%diethanolamine,2%N,N,N',N'-tetrahydroxyethyl ethylenediaminealong with 0.3%silicon dioxide and 0.7%iron-free aluminum sulfate powder as setting accelerators,the prepared accelerator demonstrates the shortest solidification time and optimal stability.Both the setting time and strength performance meet the requirements specified in GB/T 35159-2017"Accelerators for Sprayed Concrete".And it has good adaptability to different brands of engineering cement.
Keywords：alkali-free fluorine-free acceleratorpowder acceleratoraccelerator
Publication Date：2025-07-25
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 98-101 )