河南理工大学学报（自然科学版）2025，Vol.44Issue(4)：188-196,9.DOI:10.16186/j.cnki.1673-9787.2023120020
硅灰掺量对泡沫充填材料性能和微观结构的影响
Effect of silica fume content on the properties and microstructure of foam filling materials
摘要
Abstract
Objectives The high porosity of cement-based foam concrete used as a filling material signifi-cantly reduces its strength.Methods In this study,silica fume(SF)was used to partially replace ordinary Portland cement(OPC)to prepare a high-strength,low-density foam concrete(SF-OPC).The effects of dif-ferent SF replacement levels(0%,5%,10%,15%,and 20%,by weight)on the fluidity,setting time,compressive strength,and dry density of SF-OPC were systematacially investigated.Additionally,low-field nuclear magnetic resonance(LF-NMR)was employed to characterize pore structure,nanoindentation was used to evaluate the hardness of the hardened slurry skeleton,X-ray diffraction(XRD)was applied to ana-lyze hydration products,and scanning electron microscopy(SEM)was conducted to observe microstruc-tural morphology.Results The results showed that increasing SF content initially improved the fluidity of the slurry and then caused a decline,while the setting time decreased continuously.The compressive strength of the specimens first increased and then decreased.The maximum fluidity(223.1 mm)was ob-served at 5%SF content,whereas the highest compressive strength was achieved at 15%SF content,with 3-,7-,and 28-day strengths of 3.8 MPa,4.2 MPa,and 4.9 MPa,respectively—representing increases of 123.5%,100.0%,and 75.0%compared to the control group.The proportion of macropores decreased by 75.8%,while the proportion of nanopores increased by 208.4%.Conclusions The addition of silica fume promoted the formation of low calcium C—S—H gel,effectively optimizing the pore structure distribution,enhancing the structural hardness of the slurry skeleton,and resulting in a denser microstructure.Under the same foaming ratio,SF significantly improved the compressive strength of SF-OPC foam concrete.This makes it a promising material for high-strength,low-density backfilling applications in coal mine caving zones and offers a useful reference for fire prevention and control materials used in mine goafs.关键词
充填材料/泡沫混凝土/硅灰/孔隙结构/火山灰效应Key words
filling material/foam concrete/silica fume/pore structure/pozzolanic effect分类
建筑与水利引用本文复制引用
张海波,孙会婷,柴虎成,胡毅康,周运通,谢佰恩,田艳超..硅灰掺量对泡沫充填材料性能和微观结构的影响[J].河南理工大学学报（自然科学版）,2025,44(4):188-196,9.基金项目
国家自然科学基金资助项目(U1905216) （U1905216）
国家重点研发计划项目(2017YFC0603004) （2017YFC0603004）
