Smart, Bio-Inspired, Nano-Engineered Fiber Reinforced Cementitious Composites for Sustainable Infrastructure Rehabilitation and Maintenance

修复和加强我们迅速恶化的混凝土基础设施是加拿大面临的一项重大挑战，迫切需要耐用、可持续和高性能的修复材料以及有效的应用程序。本文提出的研究计划的主要目标是开发可喷涂、低碳的高性能纤维增强水泥基复合材料(LC-HPFRCC)，用于维修和加固应用。进一步探讨了其中一些复合材料作为智能材料和传感器应用于结构健康监测的潜力。建议在以下四个方面进行研究：--应变能力接近3%的应变硬化LC-HPFRCC的开发。这些复合材料将以低碳基质为基础，如土地聚合物，并携带回收骨料和回收纤维。对于回收产品，将研究包括纳米涂层在内的表面处理以及超声波振动和微波等接枝和清洁方法。--优化LC-HPFRCC作为修补材料的性能，包括它们的剪切/拉伸粘结能力、与旧基层混凝土的尺寸、物理化学和电化学兼容性，以及它们控制修复结构中钢筋腐蚀的能力。-开发携带碳纤维和碳纳米管的智能、压阻纤维增强水泥复合材料(PFRCC)，不仅用于传感应变和温度，还用于传感化学环境的变化、氯化物前沿的进展、钢材腐蚀和破裂的开始。最后，建议对LC-HPFRCC作为修复材料在BC省的一座桥、一个停车场、一座大坝和一所学校等四个需要抗震加固的示范工程中的性能进行评估。在未来五年内，拟议的研究计划预计将提供总计30个研究生年的HQP培训。

Repair and strengthening of our rapidly deteriorating concrete infrastructure is a major challenge for Canada, and durable, sustainable and high performance repair materials along with effective processes for their application are critically needed. The primary objective of the research program proposed here is to develop Sprayable, Low-Carbon High Performance Fiber Reinforced Cementitious Composites (LC-HPFRCC) for repair and strengthening applications. It is further proposed to explore the potential of some of these composites as smart materials and sensors for Structural Health Monitoring (SHM). Research is proposed in the following FOUR areas:--Development of strain-hardening LC-HPFRCC with a strain capacity approaching 3%. These composites will be based on low carbon matrices such as geopolymers and carry recycled aggregates and recycled fibers. For recycled products, surface treatments including nano-coatings and grafting and cleaning methods such as ultrasonic vibrations and microwaving will be investigated. --Optimization of LC-HPFRCC properties as repair materials including their shear/tensile bond capacity, dimensional, physico-chemical and electro-chemical compatibility with old substrate concrete, and their ability to control rebar corrosion in repaired structures. ---Development of Smart, Piezo-resistive Fiber Reinforced Cementitious Composites (PFRCC) carrying carbon fibers and carbon nanotubes for sensing not only strains and temperatures, but also for sensing changes in the chemical environment, progression of chloride front, onset of steel corrosion and cracking. Finally, it is proposed to evaluate the performance of LC-HPFRCC as rehabilitation materials in four demonstration projects including a bridge, a parking garage, a dam and a school in BC requiring seismic strengthening. Over the next five years, the proposed program of research is expected to provide a total HQP training of 30 graduate student-years.