Development and Characterization of Nano-Engineered Cement Based Composites for Sustainable Construction

胶凝材料的耐久性在其作为建筑材料的使用过程中起着重要的作用。决定水泥基体系性能的参数与空穴网络、水化产物的稳定性以及水泥基体系中各相之间的界面结合密切相关。此外，各种专用混凝土的生产需要调整其新鲜和成熟的性能，包括流变性、渗透性和抗裂缝生长性。尽管外加剂和增强材料的发展，尝试主要集中在宏观工程的性质。鉴于水泥基体系的组成部分是在纳米尺度上，纳米技术的出现现在要求人们一致关注于定制胶凝体系的物理和化学性质，以适应每种应用。然而，虽然在胶凝体系中利用纳米材料的一些努力已经存在，但它们在很大程度上仍然局限于仅仅将它们作为外加剂。此外，这些尝试只集中在机械增强上。申请人最近的工作强调了使用可调纳米材料来设计胶凝体系的物理和化学特性的巨大潜力，从而适当地调整其新鲜特性和长期耐久性。因此，该提案将开发和表征纳米工程水泥基复合材料，以实现卓越的性能，特别是在加拿大的背景下。纤维素和其他纳米材料将首先被设计成在高pH环境中赋予精确的特性，然后被引入水泥基体系。通过一系列对新鲜和硬化性能的研究，该提案将开发和表征新一代可持续材料，并为建筑开发耐用的混合材料。

The durability during service of cementitious materials plays an important role in their operation as construction materials. The parameters that determine performance are related intimately to the air-void network, stability of hydration products and the interfacial bond between various phases in the cement-based system. In addition, the production of a wide variety of specialized concretes requires tailoring their fresh and mature properties including, the rheology, permeability and crack growth resistance. Notwithstanding the evolution of admixtures and reinforcing materials, attempts have largely focused at macro-engineering of properties. Given that the building block of cement-based systems is at the nanometric scale, the emergence of nanotechnology now warrants a concerted focus on tailoring the physical and chemical properties of the cementitious system to suit each application. However, while some efforts to utilize nanomaterials in cementitious systems exist, they remain largely restricted to merely incorporating them as admixtures. Further, these attempts have centred on mechanical enhancement only. Recent work by the applicants highlights a tremendous potential for the use of tunable nanomaterials to engineer the physical and chemical properties of cementitious systems and thereby suitably tailor their fresh properties as well as long-term durability. Therefore, this proposal will develop and characterize cement-based composites that are nano-engineered to achieve superior performance, specifically in the Canadian context. Cellulosic and other nanomaterials will be firstly designed to impart precise characteristics in a high pH environment and subsequently introduced into the cement-based system. Through a series of examination on fresh and hardened properties, this proposal will develop and characterize a new generation of sustainable materials and develop durable mixes for construction.