Nano-modified Concrete Incorporating Industrial Waste for Sustainable Infrastructure

耐久性混凝土对于恢复/升级加拿大老化的基础设施至关重要。用辅助胶凝材料（SCM）代替混凝土中的部分水泥，所述辅助胶凝材料通常是工业废料，例如粉煤灰和矿渣，通常提高混凝土的耐久性，具有显著的生态效益，例如保护自然资源和节约能源。然而，由于性能问题，包括凝固时间延迟，强度发展缓慢和表面结垢，大量的SCM并不常用于混凝土基础设施。在混凝土中应用纳米材料（尺寸范围为1- 1000亿分之一米）（纳米改性）有可能减轻与更高体积的SCM相关的限制，并创造具有上级性能的可持续混凝土。该研究计划将（i）开发创新的混凝土，将纳米颗粒与大量的粉煤灰或矿渣结合在一起，并在模拟现场条件下研究其早期和长期性能，（ii）建立基于智能的模型来预测其现场性能，以及（iii）启动现场研究，以展示/监测其实际性能。这项新颖的研究计划源于一种范式转变，它采用纳米技术来设计下一代混凝土。所提出的方法的意义在于捕捉纳米材料在移动水泥系统中的作用，并在恶劣的使用条件下测试其稳定性，从而提高评估和建模的可靠性，以适当地选择用于修复或新应用的材料。该计划将有效地促进在各种基础设施应用中更广泛地接受和使用具有更少水泥和更高工业废物量（即低碳足迹）的创新混凝土，预计将对混凝土标准和规范产生可衡量的影响，并将技术转移到建筑行业。如果精心设计，这种新型混凝土将延长使用寿命，而不会出现过早失效或昂贵的修复问题，从而有效地促进加拿大及其他地区基础设施的可持续发展。

Durable concrete is essential for restoring/upgrading Canada's aging infrastructure. Replacing part of the cement in concrete with supplementary cementitious materials (SCMs), which are typically industrial waste such as fly ash and slag, generally improves the durability of concrete with significant ecological benefits such as preservation of natural resources and conservation of energy. However, higher volumes of SCMs are not commonly used in concrete infrastructure due to performance issues including delayed setting time, slow strength development and surface scaling. Application of nano-materials (size scale of 1-100 billionth of a meter) in concrete (nano-modification) has the potential to mitigate limitations associated with higher volumes of SCMs and create sustainable concrete with superior performance. This research program will (i) develop innovative concretes incorporating nano-particles with high volumes of fly ash or slag and investigate their early-age and long-term properties under simulated field conditions, (ii) build intelligence-based models for predicting their field performance, and (iii) initiate field studies for demonstrating/monitoring their actual performance. This novel research program stems from a paradigm shift, which employs nanotechnology to engineer the next generation of concrete. The significance of the proposed methodology lies in capturing the role of nano-materials in shifting cementitious systems and testing their stability under harsh service conditions, thereby enhancing the reliability of assessment and modeling to appropriately select materials for repair or new applications. The program will effectively contribute to the wider acceptance and use of innovative concretes with less cement and higher volumes of industrial waste (i.e. low carbon footprint) in various infrastructural applications, with an anticipated measurable impact on standards and specifications for concrete and transfer of the technology to the construction industry. If engineered carefully, such novel concrete will have extended service life, without issues of premature failure or costly rehabilitation, thus effectively contributing to the sustainable development of infrastructure in Canada and beyond.