Abstract:
The issue of chloride induced corrosion of reinforced concrete is a serious problem affecting infrastructure globally and causing huge economic losses. As such this issue has gained a considerable attention in the scientific community in the recent past. Layered Double Hydroxides (LDHs) have recently emerged as a new class of concrete-additives with a potential to increase the chloride resistance of concrete and mitigate corrosion. LDHs are clay like structures consisting of positively charged layers of cations with associated hydroxides and exchangeable anions in between the layers. Due to this charge balanced structure, LDHs possess the property of encapsulating an anion from the environment and replacing it with an exchangeable anion present in its layers. Potential applications include chloride entrapment in concrete and delivery of corrosion inhibiting anions. However, many versatile compositions of LDHs can be easily synthesized and their application as cement additives reach far beyond corrosion mitigation in concrete. This review presents a summary of recent advances on the applications of LDH in concrete. An extensive set of recently published literature has been critically reviewed and trends have been identified.
摘要:
氯化物引起的钢筋混凝土腐蚀问题是影响全球基础设施并造成巨大经济损失的严重问题。因此,这个问题最近在科学界引起了相当大的关注。层状双氢氧化物(LDH)最近已成为一类新型的混凝土添加剂,具有增加混凝土抗氯化物性和减轻腐蚀的潜力。LDH是粘土状结构,由带正电的阳离子层以及层之间的缔合的氢氧化物和可交换的阴离子组成。由于这种电荷平衡结构,LDH具有从环境中包封阴离子并用存在于其层中的可交换阴离子代替它的性质。潜在的应用包括混凝土中的氯化物截留和腐蚀抑制阴离子的输送。然而,LDH的许多多功能成分可以很容易地合成,它们作为水泥添加剂的应用远远超出了混凝土中的缓蚀作用。本文综述了LDH在混凝土中应用的最新进展。对最近发表的大量文献进行了严格的审查,并确定了趋势。