Durability of Mg-Si-hydrate-based cements from brucite

水镁石水合镁硅水泥的耐久性

• 批准号: 2295449
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2295449
• 关键词: Durability; Mg; Si; hydrate; based

Magnesium silicate hydrate cements are a new type of cement that exploits the strength generated when magnesium oxide is made to react with a soluble silica source to form a mostly amorphous hydrated gel of magnesium silicate (M-S-H gel). It is a perfect candidate for reducing the volume of waste from the fuel ponds in Sellafield as the solids in those ponds are mostly magnesium hydroxide, which can also be converted in M-S-H gel under the right circumstances, i.e. the waste would effectively be a large component of the binder in which it is immobilised. However, while hydrated magnesium silicate gels have been known for a long time as a by-product of magnesium sulphate attack on normal Portland cement, much less is known about its durability and long term behaviour. Therefore the project would explore (i) how sludges should be pre-treated to enable the production of a suitable wasteform as too much water will reduce the mechanical properties substantially and (ii) the durability, i.e. long term stability of such cements, to ascertain whether this new type of cement is likely to remain stable especially during the initial above ground storage of the waste.

水合硅酸镁水泥是一种新型水泥，它利用氧化镁与可溶性二氧化硅源反应形成大部分无定形的硅酸镁水合凝胶（M-S-H 凝胶）时产生的强度。它是减少塞拉菲尔德燃料池废物量的完美候选者，因为这些燃料池中的固体主要是氢氧化镁，在适当的情况下也可以转化为 M-S-H 凝胶，即废物实际上是一个大的组成部分它被固定在粘合剂中。然而，虽然水合硅酸镁凝胶长期以来一直被认为是硫酸镁侵蚀普通波特兰水泥的副产品，但对其耐久性和长期行为知之甚少。因此，该项目将探索（i）如何对污泥进行预处理，以生产出合适的废物，因为过多的水会大大降低机械性能，以及（ii）耐久性，即此类水泥的长期稳定性，以确定这种新型水泥是否可能保持稳定，特别是在废物的最初地上储存期间。