长沙理工大学学报（自然科学版）2025，Vol.22Issue(3)：23-36,14.DOI:10.19951/j.cnki.1672-9331.20250221002
基于全固废固化剂固化/稳定化赤泥的路基施工工艺研究
Research on subgrade construction process based on solidified/stabilized red mud by all-solid-waste binder
摘要
Abstract
[Purposes]Red mud is a kind of solid waste produced in the production process of aluminum industry.Long-term stockpiling of red mud not only occupies a large amount of land but also causes environmental pollution.In order to realize the large-scale utilization of red mud in subgrade filling engineering,it requires solidified/stabilized.[Methods]In this paper,red mud solidified/stabilized by all-solid-waste binder(CGFPA)with calcium carbide residue(C)as alkali activator,ground granulated blast furnace slag(G)and fly ash(F)as pozzolanic materials,phosphogypsum(P)as supplementary material,and graphene(A)as additive was prepared.A compaction-type construction process featuring two-times of water addition that reduced the toxicity of red mud and was easy to construct was proposed.Through infiltration,water ratio distribution,unconfined compressive strength,pH value,and toxicity leaching tests,the changing rules of water absorption,strength characteristics,pH value,and toxicity leaching of the solidified/stabilized red mud as a subgrade filling material were studied,and the parameters of the construction process,such as the amount and duration of water addition were determined.Moreover,the reaction productions and microstructure of solidified/stabilized red mud were obtained by scanning electron microscopy-X-ray energy dispersive spectrum(SEM-EDS)test,thereby the micro-mechanism was analyzed.[Findings]Utilizing the Kostiakov infiltration model which is satisfied by water infiltration in fill material,the relationship equation between infiltration rate,infiltration height and infiltration time was obtained.Under the construction condition of four mixing ratios(15%,20%,25%,and 30%),the first addition of water was 0.78wL,0.79wL,0.82wL,and 0.85wL(wL is the liquid limit of soil,%),and the second addition of water was 0.22wL,0.41wL,0.48wL,and 0.55wL,respectively.The paving time for the next layer of filling material was 300 min,720 min,2 160 min,and 3 600 min,respectively.The hydration products of red mud solidified/stabilized by CGFPA mainly included hydrated calcium silicate,hydrated calcium silicoaluminate,monosulphur-type hydrated calcium sulphoaluminate,and magnesium aluminium hydrotalcite.These hydration products solidified/stabilized the red mud through adsorption,cementation,etc.,hence increase the strength and reduce the concentration of pollutants.Furthermore,the unconfined compressive strength and pollutant concentrations of filling materials met the specification requirements.[Conclusions]The feasibility of compaction-type construction process featuring two-times of water addition was verified by comparing the properties of CGFPA solidified/stabilized red mud with those of conventional construction process,and the findings can provide a theoretical basis for the application of red mud in subgrade engineering.关键词
赤泥/固化/稳定化/施工工艺/固废/入渗/路基施工Key words
red mud/solidification/stabilization/construction process/solid waste/infiltration/subgrade construction分类
建筑与水利引用本文复制引用
严立俊,杨俊杰,武亚磊,李锋民..基于全固废固化剂固化/稳定化赤泥的路基施工工艺研究[J].长沙理工大学学报（自然科学版）,2025,22(3):23-36,14.基金项目
国家自然科学基金资助项目(52378380、52078474、51779235) Projects(52378380,52078474,51779235)supported by the National Natural Science Foundation of China （52378380、52078474、51779235）
