2D-Correlation NMR relaxation analysis of pore-water interactions in cement materials: laboratory and in-situ analysis.

水泥和混凝土已经使用了数千年，并继续在全球发挥重要作用。无论以何种标准衡量，它们每年都转化为数十亿美元（欧洲GDP的10%花在建筑和基础设施上；大约50%花在维修上；2003年交付了2.7亿吨水泥）。然而，尽管规模如此之大，但对水泥孔隙微观结构演变的详细了解，以及水泥孔隙中纳米/微观尺度的水动力学，仍然是非常难以捉摸的。根据欧洲主要工业/学术联盟NANOCEM的说法，缺乏定量理解是水泥行业面临的一个关键的跨领域研究问题。一方面，它阻碍了水泥化学家和技术专家创造新材料的系统进展，这些新材料提供了更好的使用性能、更大的功能和更高的耐久性。建模者面临着数值信息的缺乏。另一方面，最终用户顾问工程师需要改进的定量方法来绘制混凝土外层（顶部50毫米）的含水量和孔隙率-参见例如CIRIA报告C538（2000）。工程结构的破坏是由几个过程驱动的，所有这些过程都取决于表面层中水的存在和运动。决定昂贵的补救工作需要了解孔隙结构和近地表和深层的水。在其他地方，在建造过程中，如果在基材正确固化之前铺设混凝土浇头，则会导致技术故障，如果延迟浇头，则会造成经济损失。同样，需要绘制水图。磁共振弛豫时间分析是表征充液多孔介质的有力手段。例如，它被石油工业用于井下研究油藏岩石的孔隙大小分布和含油量。磁共振成像是一种以空间分辨率获取相似信息的手段。随着二维相关弛豫法的引入，弛豫时间分析得到了长足的发展。这为满足水泥行业的需求创造了令人兴奋的新机遇。2d相关松弛法有望在测量相关时间方面取得重大进展，相关时间描述水泥水化过程中孔隙表面的水吸附、孔隙表面的水扩散、孔隙之间的水交换率和孔径分布。这项建议的目的是实现这些机会。该项目将(i)为水泥技术人员提供一系列有添加剂和不含添加剂的水泥所需的水动力学的详细数值信息，以及（ii）为顾问工程师在便携式磁共振成像系统上实施二维相关松弛测量，以便他们可以无损地就地绘制新建筑和现有建筑表层的水分布和动力学。

Cements and concretes have been used for millennia and continue to be globally important. By any measure, they translate to billions of dollars per year (10% of European GDP is spent on buildings and infrastructure; circa 50% is spent on repairs; 270 million tonnes of cement delivered in 2003). However, and notwithstanding this vast scale, a detailed understanding of the evolution of pore micro-structure in cements, and of water dynamics at the nano / micro scale within cement-pores, remains singularly elusive. According to a major European industrial / academic consortium, NANOCEM, this lack of quantitative understanding is a key, cross-cutting, research problem facing the cement industry. On the one hand, it inhibits systematic progress by cement chemists and technologists creating new materials that offer better in-use performance, greater functionality and improved durability. Modellers face a dearth of numerical information. On the other hand, end-user consultant engineers require improved, quantitative methods to map water content and porosity in the outer layers (top 50 mm) of concrete - see e.g. CIRIA report C538 (2000). Failure of engineering structures is driven by several processes all of which depend on the presence and movement of water in surface layers. Decisions about expensive remedial work require knowledge of the pore structure and water near surface and at depth. Elsewhere, during build, technological failure results if concrete toppings are laid before substrates are properly cured , economic loss results if they are delayed. Again water mapping is needed.Magnetic resonance relaxation time analysis is a powerful means of characterising liquid filled porous media. It is used, for instance, by the oil industry down-bore-hole to investigate pore size distributions and oil content in oil-reservoirs rocks. Magnetic resonance imaging is the means by which similar information can be got with spatial resolution.Relaxation time analysis has recently been advanced considerably by the introduction of 2D-correlation-relaxometry. This has created new and exciting opportunities to address the needs of the cement community. The 2D-correlation-relaxometry promises major advances in measuring the correlation times which describe water adsorption to pore surfaces, water diffusion across pore surfaces, water exchange rates between pores and pore size distributions during the hydration of cement. The aim of this proposal is to realise these opportunities.The project will (i) provide the detailed numerical information on water dynamics required by cement technologists for a range of cements with and without additives, and (ii) the implementation of 2D correlation relaxometry on a portable magnetic resonance imaging system for consultant engineers so that thay can map water distributions and dynamics in the surface layers of new and existing construction non-destructively and in-situ.