岩土力学2025，Vol.46Issue(6)：1667-1677,11.DOI:10.16285/j.rsm.2024.1082
磷石膏基团粒调控固化淤泥的物理力学性能
Physical and mechanical properties of solidified sludge regulation with phosphogypsum-based aggregate
摘要
Abstract
Sludge particles are fine and have a high water content.The strength of solidified sludge is predominantly provided by cementation strength,with insufficient frictional resistance.Phosphogypsum-based aggregates were synthesized using phosphogypsum,slag,and quicklime as raw materials.These aggregates were combined with cement for sludge solidification,and the physical and mechanical properties of the solidified sludge were assessed.Results show that the phosphogypsum-based aggregates have a water absorption rate of 13.4％,which locally separates free water in the sludge,enhancing cement solidification.After compaction,the leaching concentrations of soluble phosphorus(P)and fluorine(F)in the phosphogypsum are significantly reduced compared to the raw phosphogypsum.Both concentrations are below the discharge standards for class Ⅲ surface water(the leaching concentration of P is≤0.2 mg/L,the leaching concentration of F is≤1.0 mg/L),meeting environmental protection requirements.When the phosphogypsum aggregates are≤5 mm,their uniform distribution enhances the skeletal effect,significantly increasing the strength of solidified sludge by 22.3％,exceeding 1 MPa.This occurs because reactions among phosphogypsum,slag powder,and lime generate calcium silicate hydrate(C-S-H)gel and acicular ettringite.These products intertwine to form a spatial network structure,filling the pores inside the phosphogypsum-based aggregates and the transition zone.This immobilizes soluble phosphorus and fluorine and strengthens the bonding capacity of the aggregate-sludge interface transition zone.The research conclusions provide a reference for the comprehensive utilization of phosphogypsum and offer a novel approach to sludge solidification.关键词
固化淤泥/磷石膏基团粒/骨架效应/界面胶结Key words
solidified sludge/phosphogypsum-based aggregate/skeleton effect/interfacial cementation分类
建筑与水利引用本文复制引用
谈云志,吴仙桥,吴军,明华军,王冲,肖宇..磷石膏基团粒调控固化淤泥的物理力学性能[J].岩土力学,2025,46(6):1667-1677,11.基金项目
国家自然科学基金联合基金(No.U24A20183) （No.U24A20183）
国家大坝安全工程技术研究中心开放基金(No.CX2023B07) （No.CX2023B07）
宜昌市自然科学研究项目(No.A24-3-023).This work was supported by the Joint Fund of the National Natural Science Foundation of China(U24A20183),the Open Fund of National Dam Safety Research Center(CX2023B07)and the Natural Science Foundation of Yichang(A24-3-023). （No.A24-3-023）
