摘要
【目的】研究复合激发剂各因素间交互作用对碱活化钢渣基胶凝材料(alkali-activated steel slag-based cementitious material,ASCM)强度性能的影响,揭示其强度提升机制。【方法】以硅灰、生石灰和Na2SO4掺量(质量分数,下同)为自变量,以ASCM胶结体龄期为3、7、28 d的抗压强度为响应值,采用Box-Behnken响应面法设计17组试验,建立二次多项式回归模型,结合数值优化方法优化模型自变量参数,并分析ASCM试样水化产物组成及微观结构形貌。【结果】生石灰和硅灰掺量、Na2SO4和硅灰掺量的交互作用是影响ASCM胶结体强度性能的关键因素,复合活化剂最优配比为硅灰掺量为1.1%,生石灰掺量为4%,Na2SO4掺量为1.3%,该条件下ASCM胶结体龄期为3、7、28 d的抗压强度分别为26.33、38.14、46.73 MPa,与预测值相对误差均小于5%。【结论】优化复合激发剂配比能有效促进ASCM胶凝产物生成与微观结构改善,使其表现出良好的力学强度,该模型精度较高,可靠性较强。
Objective This study aims to investigate the effects of various types,concentrations,and proportions of composite activators on the strength properties of alkali-activated steel slag-based cementitious materials(ASCM).By analyzing the synergistic effects of composite activators,the study examines their influence on the microstructure,chemical composition,and hydration products of ASCM.It aims to reveal the underlying mechanisms of strength enhancement in ASCM,thereby providing a theoretical foun-dation and technical support for the efficient preparation of these materials in engineering applications.Methods A systematic experimental approach was employed using Box-Behnken response surface methodoligy(RSM).Seven-teen experimental groups were designed with silica fume,quicklime,and Na₂SO₄contents as independent variables.The com-pressive strength of ASCM specimens at 3,7,and 28 days was selected as the response variable.A quadratic polynomial regres-sion model was developed to identify the relationship between activator variables and strength performance.To optimize theactiva-tor formulation,model parameters were analyzed using the Numencial optimization function.This enabled the identification ofthe optimal activator proportions.Advanced characterization techniques,including scanning electron microscopy(SEM),X-ray diffraction(XRD),and Fourier-transform infrared spectroscopy(FTIR),were used to analyze hydration products and micro-structural morphology,revealing the mechanisms driving strength enhancement.Results and Discussion The results demonstrated that the interactions between quicklime and silica fume,as well as between Na₂SO₄and silica fume,significantly influenced ASCM strength.The optimal composite activator composition was identified as 1.1%silica fume,4%quicklime,and 1.3%Na2SO4.Under these conditions,the compressive strength of ASCM reached 27.51 MPa,36.76 MPa,and 45.24 MPa at 3,7,and 28 days,respectively.Notably,the relative error between experimental results and model predictions was less than 5%,indicating high accuracy and reliability of the regression model.The interactions among activator components promoted the formation of calcium silicate hydrate(C-S-H)gel sand ettringite(AFt),which are crucial for improving the strength of cementitious materials.The dense reticulate structure formed by these hydration products improved microstructural integrity of ASCM.Furthermore,silica fume particles,which did not directly participate in the activa-tion reaction,served as a filler,further enhancing packing density of the matrix.This combination of chemical and physical enhancements resulted in a significant improvement in the macroscopic mechanical strength of ASCM.The analysis of hydration products confirmed the formation of a robust microstructure,which contributed to the enhanced strength properties of ASCM.The composite activators worked synergistically to optimize the development of hydration products and address potential micro-structural weaknesses.This synergy ensured that ASCM exhibited excellent strength and durability,making it a viable material for a wide range of engineering applications.Conclusion This study highlights the role of composite activators and silica fume in enhancing ASCM mechanical properties and durability by improving microstructure and packing density,offering valuable insights for optimizing formulations tailored to engineering needs.By utilizing industrial byproducts like steel slag,ASCM serves as a sustainable alternative to Portland cement,reducing environmental impact and promoting waste management.These findings lay a foundation for developing next-generation construction materials,with future research focusing on ASCM's long-term durability and large-scale application performance.
作者
张轩硕
朱一丁
兰永军
王红雨
李宏波
ZHANG Xuanshuo;ZHU Yiding;LAN Yongjun;WANG Hongyu;LI Hongbo(School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,China;Ningxia Water-saving Irrigation and Water Resources Regulation Engineering Technology Research Center,Ningxia University,Yinchuan 750021,China;Engineering Research Center of Ministry of Education for Efficient Utilization of Modern Agricultural Water Resources in Arid Regions,Ningxia University,Yinchuan 750021,China)
出处
《中国粉体技术》
2025年第3期179-194,共16页
China Powder Science and Technology
基金
国家自然科学基金项目,编号:52069025
宁夏自然科学基金项目,编号:2024AAC03064。
关键词
响应面法
钢渣
碱活化
胶凝材料
微观结构
response surface methodology
steel slag
alkaliactivation
cementitious material
microscopic structure
