Study on the working performance of alkali-activated ultra-fine slag powder grouting material
XU Kai
DU Xiaoli
ZHANG Qingtao
Abstract：The workability of grouting materials critically governs their effectiveness in filling rock fractures and reinforcing rock masses.This study aimed to develop a high-performance grouting mate-rial utilizing ultra-fine slag powder.A systematic investigation was conducted through orthogonal ex-perimental design and range analysis,employing cement,ultra-fine slag powder,sodium silicate,and sodium hydroxide as raw materials.The variations in key performance indicators,including viscosity,fluidity,bleeding rate,and compressive strength of cement mortar,were quantitatively evaluated un-der different mix proportions.Complementary microstructural characterization via X-ray diffraction(XRD)and scanning electron microscopy(SEM)provided comparative insights into pure cement,optimized grout,and cement mortar.The experimental findings revealed that the synergistic incorporation of ultra-fine slag powder,sodium silicate,and sodium hydroxide substantially enhanced the grout's workability,achieving remarkable improvements:57.3%reduction in viscosity,25.6%increase in fluidity,and 96.7%suppression of bleeding rate.Microstructural analysis demonstrated that the hydration process modification-characterized by decreased portlandite(Ca(OH)2,CH)content and concurrent formation of limited ettringite(AFt)alongside abundant calcium silicate hy-drate(C—S—H)gel-contributed to a denser cement mortar matrix with enhanced durability.Both compressive and flexural strengths exhibited approximately linear growth with curing age,confirming the long-term stability of the optimized material.
Keywords：fractured rock massgrouting materialscement mortarultra-fine slag powdersodium sili-catemicrostructure
Publication Date：2026-02-28
Online Publishing Date：2026-01-31(First online date of this platform, not the publication date of the document)
Pages：9( 63-71 )