Li Haizhou, Zhang Lu, Liu Jianping, Chu Daozhong, Ren Jiaolong
School of Resources and Environmental Engineering, Shandong University of Technology, Zibo 255000, China.
Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials of Ministry of Education, Shandong University, Jinan 250061, China.
Materials (Basel). 2025 May 30;18(11):2569. doi: 10.3390/ma18112569.
To address the low resource utilization of copper tailings and high environmental impact of conventional river sand, this study innovatively integrates Box-Behnken design (BBD) with fractal theory to systematically investigate the performance optimization mechanisms of cement mortar incorporating copper tailings sand. A three-factor interaction model was developed through BBD experimental design, considering water-cement ratio (0.38-0.48), replacement ratio (10-30%), and binder-sand ratio (0.3-0.4), to elucidate the macroscopic performance evolution under multiparameter coupling effects. Fractal dimension analysis was employed to quantitatively characterize microstructural evolution. Experimental results demonstrate that the optimal parameters (water-cement ratio: 0.43, replacement ratio: 20%, binder-sand ratio: 0.35) yield superior performance, with 28-day compressive/flexural strengths reaching 61.88/7.14 MPa (12.3%/9.8% enhancement over the control group), and sulfate attack resistance showing 0.74% mass loss after 30 cycles. Microstructural analysis reveals reduced fractal dimension (D = 2.31) in copper tailings-modified specimens, indicating improved pore structure homogeneity. The enhanced performance is attributed to synergistic effects of micro-aggregate filling and pozzolanic reaction-driven C-S-H gel densification. This research establishes a novel multiscale methodology overcoming the limitations of conventional single-factor analysis, providing theoretical and technical support for high-value utilization of industrial solid wastes in construction materials.
为了解决铜尾矿资源利用率低以及传统河砂对环境影响大的问题，本研究创新性地将Box-Behnken设计（BBD）与分形理论相结合，系统地研究了掺入铜尾矿砂的水泥砂浆的性能优化机制。通过BBD实验设计建立了一个三因素相互作用模型，考虑水灰比（0.38 - 0.48）、替代率（10 - 30%）和胶凝材料与砂比（0.3 - 0.4），以阐明多参数耦合效应下的宏观性能演变。采用分形维数分析对微观结构演变进行定量表征。实验结果表明，最佳参数（水灰比：0.43，替代率：20%，胶凝材料与砂比：0.35）产生了优异的性能，28天抗压强度/抗折强度达到61.88/7.14 MPa（比对照组提高12.3%/9.8%），30次循环后的抗硫酸盐侵蚀性能质量损失为0.74%。微观结构分析表明，铜尾矿改性试件的分形维数降低（D = 2.31），表明孔隙结构均匀性得到改善。性能的提高归因于微集料填充和火山灰反应驱动的C-S-H凝胶致密化的协同效应。本研究建立了一种新颖的多尺度方法，克服了传统单因素分析的局限性，为建筑材料中工业固体废物的高值利用提供了理论和技术支持。
