层状双氢氧化物对混凝土力学及耐久性能影响研究进展

Research Progress of Mechanical and Durability Performance of Concrete with Layered Double Hydroxides

  • 摘要: 钢筋锈蚀是钢筋混凝土结构耐久性退化的主导因素之一,是长期困扰实际工程难以处理的难题。近年来,层状双氢氧化物(Layered double hydroxides,LDHs)因其优异的离子交换性及记忆结构效应在混凝土防腐蚀等领域展现出巨大潜力。现有研究表明,掺入适量的LDHs(<5wt%)有助于缩短混凝土凝结时间(4.6%~69.1%)、提升抗压强度(13.6%~31%)与抗折强度(0%~55.2%),并增强耐久性能。然而,关于不同LDHs体系对不同水泥混凝土的差异化效果及作用机制缺乏系统性总结。为充分了解LHDs在混凝土中所能发挥的独特优势,明确LDHs改善混凝土性能的方式和机制,本文首先简述了LDHs的物理化学性质与制备方式,其次归纳了近年来LDHs在建筑领域中的研究应用进展,围绕其工作性、力学性能与耐久性能进行对比评述,并深入探究其作用机制和影响因素。最后,针对目前研究中LDHs规模化制备困难、力学性能研究单一和缺乏长期性研究等不足提出展望,以期待为LDHs在混凝土中的研究与运用提供参考。

     

    Abstract: Corrosion of reinforcing steel is one of the dominant factors in the durability degradation of reinforced concrete structures, posing a long-standing challenge in practical engineering. In recent years, Layered Double Hydroxides (LDHs) have shown great potential in concrete corrosion protection and other related fields due to their excellent ion-exchange properties and structural memory effect. Existing studies had indicated that the incorporation of an appropriate amount of LDHs (<5wt%) could significantly shorten the concrete setting time (by 5%~69%), enhance compressive strength (by 10%~46%) and flexural strength (by 18.1%~62%), as well as improve durability. However, there is a lack of systematic summaries on the differentiated effects and mechanisms of various LDH systems on different cement concretes. To fully understand the unique advantages that LDHs can offer in concrete,and to clarify the ways and mechanisms through which LDHs improve concrete properties, this paper first birefly described the physical and chemical properties and preparation methods of LDHs. Secondly, it summarized the recent research progress on the application of LDHs in cement-based materials, providing a comparative review of their effects on workability, mechanical properties, and durability, while also exploring their mechanisms of action and influencing factors. Finally, it offered an outlook on the current challenges in LDHs research, including difficulties in large-scale preparation, limited studies on mechanical properties, and a lack of long-term research, aiming to provide valuable insights for the future research and application of LDHs in concrete.

     

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