Zheng Yuanxun, Xie Yuxiao, Zhang Yu, Wan Cong, Miao Li, Zhang Peng
School of Water Conservancy and Transportation, Zhengzhou University, Zhengzhou 450001, China.
State Key Laboratory of Tunnel Boring Machine and Intelligent Operations, Zhengzhou 450001, China.
Gels. 2025 Sep 18;11(9):755. doi: 10.3390/gels11090755.
River sediments have attracted increasing attention as alternative raw materials for sustainable cementitious materials due to their abundant availability and silica-alumina-rich composition. In this study, a systematic literature search was conducted in Web of Science and Google Scholar using combinations of the keywords "river sediment," "cementitious materials," "activation," and "pozzolanic activity," covering publications up to July 2025. In addition, a citation network tool (Connected Papers) was employed to trace related works and ensure comprehensive coverage of emerging studies. This review systematically examines the properties of river sediments from diverse regions, along with activation and modification techniques such as alkali/acid activation, thermal calcination, and mechanical milling. Their applications in various cementitious systems are analyzed, with mix design models compared to elucidate the effects of replacing fine aggregates, coarse aggregates, and cement on workability, strength, and durability. Multi-scale characterization via XRD, FTIR, and TG-DSC reveals the mechanisms of C-S-H and C-A-S-H gel formation, pore refinement, and interfacial transition zone densification. The review highlights three key findings: (1) moderate sediment replacement (20-30%) improves strength without compromising flowability; (2) alkali-water glass activation and calcination at 600-850 °C effectively enhance pozzolanic activity; and (3) combining the minimum paste thickness theory with additives such as water reducers, fibers, or biochar enables high-performance and low-carbon concrete design. This review provides a comprehensive theoretical foundation and technical pathway for the high-value utilization of river sediments, carbon reduction in concrete, and sustainable resource recycling.
由于河砂资源丰富且富含硅铝成分，作为可持续胶凝材料的替代原料，其已引起越来越多的关注。在本研究中，利用“河砂”“胶凝材料”“活化”和“火山灰活性”等关键词组合，在Web of Science和谷歌学术上进行了系统的文献检索，涵盖截至2025年7月的出版物。此外，还使用了一种引文网络工具（Connected Papers）来追踪相关研究，并确保全面涵盖新兴研究。本综述系统地研究了不同地区河砂的特性，以及碱/酸活化、热煅烧和机械研磨等活化和改性技术。分析了它们在各种胶凝体系中的应用，比较了配合比设计模型，以阐明替代细骨料、粗骨料和水泥对工作性、强度和耐久性的影响。通过XRD、FTIR和TG-DSC进行的多尺度表征揭示了C-S-H和C-A-S-H凝胶形成、孔隙细化和界面过渡区致密化的机制。该综述突出了三个关键发现：（1）适度替代河砂（20-30%）可提高强度而不影响流动性；（2）碱-水玻璃活化和600-850°C煅烧可有效提高火山灰活性；（3）将最小浆体厚度理论与减水剂、纤维或生物炭等添加剂相结合，可实现高性能和低碳混凝土设计。本综述为河砂的高价值利用、混凝土的碳减排和可持续资源循环提供了全面的理论基础和技术途径。
