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，并继续在全球范围内发挥重要作用。无论以何种标准衡量，它们都相当于每年数十亿美元（欧洲GDP的10%用于建筑和基础设施;约50%用于维修; 2003年交付的水泥为2.7亿吨）。然而，尽管如此巨大的规模，详细了解水泥中的孔隙微观结构的演变，以及水泥孔隙内纳米/微米尺度的水动力学，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交叉研究问题。一方面，它抑制了水泥化学家和技术人员创造新材料的系统性进步，这些新材料提供更好的使用性能，更大的功能性和更好的耐久性。建模者面临着数字信息的缺乏。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 mm）的含水量和孔隙率-例如，见CIRIA报告C538（2000年）。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层水的存在和运动。关于昂贵的补救工作的决定需要了解孔隙结构和近表面和深度的水。在其他地方，在建造过程中，如果在基底适当固化之前铺设混凝土浇头，就会导致技术故障，如果延迟，就会造成经济损失。磁共振弛豫时间分析是表征充满液体的多孔介质的一种强有力的手段。例如，它被石油工业用于井下钻孔，以研究油藏岩石中的孔径分布和含油量。磁共振成像是一种可以获得空间分辨率相似信息的方法，二维相关弛豫技术的引入使弛豫时间分析得到了很大的发展。这为满足水泥行业的需求创造了新的令人兴奋的机会。二维相关弛豫法承诺在测量相关时间，描述水吸附到孔表面，水扩散通过孔表面，水交换率之间的孔隙和孔径分布在水泥水化过程中的重大进展。该项目将（i）提供水泥技术人员所需的水动力学的详细数值信息，用于一系列含和不含添加剂的水泥，以及（ii）在便携式磁共振成像系统上为顾问工程师实施2D相关弛豫测量，以便他们可以绘制新的和现有的地表水分布和动态图。非破坏性和现场施工。

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.