碱-硫酸根激发淤泥流态固化土强度与微观结构分析OA

Compared to traditional cement solidification technology,alkali-sulfate composite activation solidification offers advantages such as low energy consumption and high resource recycling rates.However,its practical solidification effects and environmental adaptability in sludge solidification applications require further investigation.In this study,alkali-sulfate composite activation technology was employed to prepare sludge fluid-solidified soil,using ground granulated blast furnace slag as the alkali-activated material and flue gas desulfurization gypsum as the sulfate source.Tests,including unconfined compressive strength,direct shear,splitting,and wet-dry cycles,were conducted.Additionally,scanning electron microscopy(SEM)and X-ray diffraction(XRD)analyses were performed to examine the macro-mechanical properties,microstructural evolution,and solidification mechanisms.The results show that composite fluid-solidified soil significantly outperforms cement-based fluid-solidified soil in key indicators such as compressive strength,shear strength,wet-dry cycle resistance,and splitting tensile strength.It also exhibits lower porosity,average pore area,and probability entropy,along with a higher area probability distribution index,indicating a denser and more uniform pore structure.The alkali-sulfate composite activation technology accelerates the conversion of calcium hydroxide(CH)to calcium silicate hydrate(C-S-H)and calcium aluminate hydrate(C-A-H)through the synergistic action of alkali and sulfate ions.This forms a dense cementation network,improving the soil's density and mechanical strength.This study provides both theoretical and practical insights for the application of alkali-sulfate composite activation solidification in sludge treatment.