罗杰波^1a，彭晓彤^1a，刘兆磊²，王忠清²，张秀芝^1b

1.济南大学 a. 土木建筑学院，b. 材料科学与工程学院，山东 济南 250022；2.中铁十局集团城建工程有限公司，山东 烟台 264001

引用格式：

罗杰波，彭晓彤，刘兆磊，等.硅灰和水泥对免蒸压加气混凝土的性能影响与微观分析［J］.中国粉体技术，2025，31（2）：1-9.

LUO Jiebo，PENG Xiaotong，LIU Zhaolei，et al.Effect of silica fume and cement on the properties of non⁃autoclaved aerated concrete and   microanalysis ［J］.China Powder Science and Technology，2025，31（2）：1−9.

DOI：10.13732/j.issn.1008-5548.2025.02.014

收稿日期：2024-10-22，修回日期：2024-11-23，上线日期：2025-01-20。

基金项目：国家自然科学基金项目，编号：52178211。

第一作者简介：罗杰波（2000—），男，硕士生，研究方向为新材料结构。E-mail：1151579328@qq. com。

通信作者简介：彭晓彤（1973—），男，教授，博士，硕士生导师，研究方向为新材料结构。E-mail：pengxito@163. com。

摘要：【目的】研发一种采用免蒸压工艺的新型加气混凝土。在不显著增加导热系数的基础上，通过优化硅灰掺量和水泥标号，确定提高强度的最佳试验配比。【方法】设计不同硅灰替代率的单因素试验，在此基础上复掺水泥，对比分析各试件的干密度和抗压强度，同时通过扫描电子显微镜（SEM）分析最优免蒸压加气混凝土的微观形貌与孔隙特征。【结果】随着硅灰掺量增加和水泥强度提高，免蒸压加气混凝土的干密度和抗压强度均增大，而导热系数没有明显变化。免蒸压加气混凝土硅灰的最佳掺量（质量分数）为4%，用P.O52.5硅酸盐水泥制得的免蒸压加气混凝土性能更优，相应试件的干密度为798 kg/m³ ，抗压强度为3. 9 MPa，导热系数为0.095 53 W/（m·K），符合《蒸压加气混凝土制品应用技术标准》中A2.5 B06级加气混凝土的性能要求。【结论】在保持自保温墙板理想导热系数的前提下，优化硅灰掺量与水泥强度是提高材料强度的有效途径。

关键词： 免蒸压加气混凝土； 干密度； 抗压强度； 硅灰； 微观结构

Abstract

Objective　An innovative non-autoclaved aerated concrete （NAAC）is developed to achieve an optimal balance between thermal insulation and mechanical properties，addressing the demand for energy efficiency and environmental sustainability in construction.Traditionally，the production of aerated concrete relies on autoclaving to enhance material strength，which is highly energy-consuming and has stringent re-quirements on equipment.To overcome these limitations，the study focuses on the non-autoclaved process，systematically optimizingraw mat-erials ratios to enhance material performance.By refining silica fume dosing and cement grade，the optimal test ratios for strength enha-ncement are determined without significantly increasing thermal conductivity.

Methods　This study used a single-factor test method to optimize the composition in aerated concrete.By designing tests with varying si-lica fume substitution rates，the dry density and compressive strength of each specimen were analyzed. Based on these results，the cement grade was varied to determine the optimal silica fume admixture and cement grade.Firstly，a small amount of silica fume was used to addr-ess the insufficient strength of traditional autoclaved aerated concrete while ensuring minimal impact on thermal conductivity.The effec-ts of silica fume content on material performance were assessed to determine the optimal substitution rate.Subsequently，the effects of  different cement grades on NAAC performance were explored through additional tests. Finally，the microstructure of the optimal NAAC was analyzed using a scanning electron microscope （SEM）.

Results and Discussion　Optimizing silica fume content and cement grade proved effective in improving the strength of NAAC，while mai-ntaining the ideal thermal conductivity for self-insulated wall panels.Increasing silica fume content improved the dry density and compr-essive strength of the material.At a silica fume substitution rate of 2%，the dry density was the smallest，while at a substitution rate of 10%，the compressive strength was the highest.A 4% substitution rate was proved to strike the best balance：the dry density increased minimally by 0.92%，and compressive strength increased significantly by 4.17%，with an increase of only 7% in thermal conductivity compa-red to the benchmark group.These findings demonstrated that the material is both lightweight and high-strength.The addition of silica fu- me，which had a lower density and higher reactive silica content compared to fly ash，resulted in lighter wall panels.Changing the cement grade also influenced material properties.Specimens made with P.O 52.5 silicate cement exhibited higher compressive strength and lower   dry density than those made with P.O 42.5 silicate cement. However，the thermal conductivity of the P.O 52.5 specimens increased by 5.43% at the same mix ratio.Microstructural analysis revealed that silica fume’s pore structure did not significantly change thermal conductivity，and the fibres could be pulled out from the matrix，enhancing compressive strength. Moreover，the use of silica fume and P.O 52.5

cement promoted the distribution of the acicular hydrated calcium silicate（C-S-H）and hexagonal flake or plate calcium hydroxide（CH）  along the inner side of the pore walls.These hydration products intertwined to form a mesh-like structure，which enhanced the overall st-rength and stability of the material.

Conclusion　The optimal silica fume content for non-autoclaved self-insulating aerated concrete is determined to be 4%（mass fraction）. Compared to fly ash，silica fume’s lower density and higher reactive silica content effectively reduce the weight of the wall panel mat-erials when used as an admixture.As self-insulated wall panels are mainly self-supporting，their compressive strength requirements are   relatively low.Specimens prepared with P.O 52.5 silicate cement demonstrate superior performance in engineering practice，achieving a   dry density of 798 kg/m³ ，a compressive strength of 3.9 MPa，and a thermal conductivity coefficient of 0.095 53 W/（m·K）.These values meet the A2.5 B06 grade specifications for aerated concrete，ensuring both performance and compliance.

Keywords： non-autoclavedaeratedconcrete； dry density； compressive strength； silica fume； microstructure

参考文献（References）

［1］BUKHARIS A，PATIL D，GOGATEN G，et al.Utilization of waste materials in non-autoclaved aerated concrete blocks：state of art review［J］.Materials Today：Proceedings，2023.

［2］ILINA L，RAKOV M，VELICHKO B，et al.Technology and automation of non-autoclaved aerated concrete production［C］//IOP Conference Se-ries：Materials Science and Engineering.IOP Publishing，2020，953（1）：012050.

［3］KUNCHARIYAKUN K，ASAVAPISIT S，SOMBATSOMPOP K.Properties of autoclaved aerated concrete incorporating rice husk ash as partial repl-acement for fine aggregate［J］.Cement and Concrete Composites，2015，55：11-16.

［4］EBEAD U A，SHRESTHA K C，SAEED H.Development of high-strength lightweight non-autoclaved aerated concrete［J］.Proceedings of the   Institution of Civil Engineers-Structures and Buildings，2020，173（10）：705-714.

［5］FABIEN A，SEBAIBI N，BOUTOUIL M.Effect of several parameters on non-autoclaved aerated concrete：use of recycling waste perlite［J］.European Journal of Environmental and Civil Engineering，2022，26（1）：58-75.

［6］TARIQ S，SCOTT A N，MACKECHNIE J R，et al.Glass powder replacement in self-compacting concrete and its effect on rheological and mechanical properties［J］.Journal of Sustainable Cement-based Materials，2022，11（3）：210-221.

［7］XUAN D X，TANG P，POON C S.MSWIBA-based cellular alkali-activated concrete incorporating waste glass powder［J］.Cement and Concrete Composites，2019，95：128-136.

［8］HE T S，XU R S，DA Y Q，et al.Experimental study of high-performance autoclaved aerated concrete produced with recycled wood fiber  and rubber powder［J］.Journal of Cleaner Production，2019，234：559-567.

［9］RAJ I S，SOMASUNDARAM K.An optimized mix for the manufacture of sustainable aerated concrete blocks using waste rubber powder［J］. Clean Technologies and Environmental Policy，2023，25（4）：1273-1289.

［10］KERIENE J，KLIGYS M，LAUKAITIS A，et al.The influence of multi-walled carbon nanotubes additive on properties of non-autoclaved and autoclaved aerated concretes［J］.Construction and Building Materials，2013，49：527-535.

［11］BISWAL B K，CHEN Z，YANG E H.Hydrothermal process reduced Pseudomonas aeruginosa PAO1-driven bioleaching of heavy metals in a novel aerated concrete synthesized using municipal solid waste incineration bottom ash［J］.Chemical Engineering Journal，2019，360：1082-1091.

［12］STEL’MAKH S A，SHCHERBAN E M，BESKOPYLNY A N，et al.Influence of recipe factors on the structure and properties of non-autoclaved aerated concrete of increased strength［J］.Applied Sciences，2022，12（14）：6984.

［13］SEKER B Ş，GOKCE M，TOKLU K.Investigation of the effect of silica fume and synthetic foam additive on cell structure in ultra-low  density foam concrete［J］.Case Studies in Construction Materials，2022，16：e01062.

［14］LASHARI A R，KUMARA，KUMAR R，et al.Combined effect of silica fume and fly ash as cementitious material on strength characteristi- cs，embodied carbon，and cost of autoclave aerated concrete［J］.Environmental Science and Pollution Research，2023，30（10）：27875-27883.

［15］MEHTA A，ASHISH D K.Silica fume and waste glass in cement concrete production：a review［J］.Journal of Building Engineering，2020，29：100888.

［16］LUO T，HUA C，SUN Q，et al.Early-age hydration reaction and strength formation mechanism of solid waste silica fume modified concr-ete［J］.Molecules，2021，26（18）：5663.

［17］REIS D C，ABRAO P C R A，SUI T，et al.Influence of cement strength class on environmental impact of concrete［J］.Resources，Conservation and Recycling，2020，163：105075.

［18］WANG C Q，MEI X D，ZHANG C，et al.Mechanism study on co-processing of water-based drilling cuttings and phosphogypsum in non-autoc-laved aerated concrete［J］.Environmental Science and Pollution Research，2020，27（18）：23364-23368.

［19］孙小巍，张雯琪，杨林，等.石墨尾矿蒸压加气混凝土性能研究［J］.非金属矿，2022，45（5）：92-96.

SUN X W，ZHANG W Q，YANG L，et al.Study on properties of graphite tailings autoclaved aerated concrete［J］.Non-metallic Mines，2022，45（5）： 92-96.

［20］陈鳌聪.利用金尾矿生产砂加气混凝土的性能优化试验研究［J］.建材世界，2021，42（6）：24-27.

CHEN A C.Experimental study on performance optimization of aerated concrete made by gold tailings［J］.The World of Building Materials， 2021， 42（6）： 24-27.

［21］英志刚，雷一鸣，乔林，等.正交分析免蒸压粉煤灰加气混凝土性能［J］. 中国粉体技术， 2021， 27（6）： 105-111.

YING Z G，LEI Y M，QIAO L，et al.Orthogonal analysis on performance of non-autoclaved fly ash aerated concrete［J］.China Powder Science and Technology，2021，27（6）：105-111.

［22］SHON C S，MIUKANGALI I，ZHANG D，et al.Evaluation of non-autoclaved aerated concrete for energy behaviors of a residential house in Nur-Sultan， Kazakhstan［J］.Buildings，2021，11（12）：610.

［23］NARATTHA C，THONGSANITGARN P，CHAIPANICH A.Thermogravimetry analysis，compressive strength and thermal conductivity tests of non-autoclaved aerated Portland cement−fly ash−silica fume concrete［J］.Journal of Thermal Analysis and Calorimetry，2015，122（1）：11-20.

［24］HE T S，XU R S，DA Y Q，et al.Experimental study of high-performance autoclaved aerated concrete produced with recycled wood fiber and rubber powder［J］.Journal of Cleaner Production，2019，234：559-567.