Study on the preparation and mechanism of fluorine-free and alkali-free liquid accelerator at room temperature
CHEN Ronghui
LI Shunkai
DOU Huakang
SUN Fengpin
Abstract：Using aluminum sulfate,pseudo boehmite and nano titanium dioxide as main raw materials,a fluorine-free and alka-li-free liquid accelerator(AS)for shotcrete was prepared through high-speed shear action under normal temperature conditions.Its properties and mechanism were studied through setting time,compressive strength,hydration heat testing,as well as XRD and SEM analysis.The test results show that the initial and final setting time can be shortened to 2.5 min and 5.8 min,the strength of 1 d and 28 d can be increased to 14.0 MPa and 51.3 MPa,and the compressive strength ratio of 28 d can reach 110.5%when the con-tent of AS is 7%.The addition of AS made the cement slurry produce more AFt and C-S-H gels and fill the pores between the cement particles in the early stage,which can effectively improve the internal structure of the cement slurry,thus promoting the so-lidification and hardening of the cement slurry and the development of mortar strength in the early stage.
Keywords：fluorine-free and alkali-free liquid acceleratorsetting timecompressive strengthaccelerating mechanism
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( 94-97 )