水化响应疏水纳米前驱体构筑与混凝土抗介质传输机制研究

The durability of reinforced concrete structures is a worldwide problem and improving the overall hydrophobic performance of concrete is one of the most effective means to inhibit the accumulation and transmission of corrosive media in the alternating zone between dry-wet and spray. This project innovatively proposed that nano-precursor materials could improve the performance of concrete in situ response to hydrophobic and anti-medium transmission, and focused on the two key scientific issues of in situ response to hydrophobic and anti-medium transmission of nano-precursor materials. By preparation of different structures of nano-precursor materials, the interaction mechanism of release and hydration of nano-precursor under complex cement system was revealed, then the reaction degree of nanometer precursor can be controlled. Through the analysis of the pore micro-structure and surface properties of concrete, the growth of micro/nano particle in the pore and the mechanism of pore surface modification are revealed. At the same time, the inconsistency relationship between capillary hydrophobic and medium transmission including corrosion resistance of reinforced steel concrete structures influenced by nano precursor are studied, which can provide original results for the design, development and engineering application of more excellent hydrophobic and erosion medium transmission materials.

钢筋混凝土结构耐久性是世界性难题，提升混凝土整体疏水性能是抑制干湿交替、浪花飞溅区侵蚀性介质富集与传输的有效手段之一。本项目提出纳米前驱体材料实现混凝土原位响应疏水及抗介质传输性能提升，并重点围绕纳米前驱体材料原位响应疏水及抗介质传输的两个关键科学问题进行研究，通过构筑不同结构纳米前驱体材料，揭示不同胶凝材料体系下纳米前驱体活性基团释放与水化交互作用机制，实现纳米前驱体反应程度可控；通过混凝土孔隙微结构及表面特性的分析，揭示微/纳米颗粒在混凝土孔隙中的生长及孔隙表面改性机制；同时研究毛细疏水与介质传输非一致性关系以及对钢筋混凝土结构整体耐蚀性能的影响，为性能更优异的疏水和抗介质传输材料设计开发和工程应用提供原创成果。

钢筋混凝土结构耐久性是世界性难题，提升混凝土整体疏水性能是抑制干湿交替、浪花飞溅区侵蚀性介质富集与传输的有效手段之一。项目针对钢筋混凝土结构耐久性这一世界性难题，从混凝土整体疏水性提升角度开展了原位响应疏水纳米前驱体材料的设计与制备、原位响应疏水作用机制及抗介质传输性能提升的研究，实现了干湿交替、浪花飞溅等侵蚀介质富集与传输的有效抑制。完成的主要内容包括：（1）设计制备了20余种不同结构原位响应疏水纳米前驱体；（2）揭示了胶凝材料体系中纳米前驱体可控释放与水化交互作用机制；（3）明晰了胶凝体系纳米前驱体疏水及抗介质传输机制；（4）证实了纳米前驱体对混凝土抗氯离子、抗硫酸盐腐蚀以及钢筋耐蚀性能提升的效果，为严酷环境下钢筋混凝土整体耐蚀性能提升提供了全新的技术手段。.项目制备了羧酸胺盐、羧酸酯以及有机/无机硅等系列纳米前驱体材料，揭示不同材料结构与疏水抗介质性能的关系，通过混凝土孔隙密实度及孔隙表面能的优化与改善，实现混凝土的毛细吸水率比降低85%，混凝土抗介质传输系数降低40%，完成项目要求的吸水率比降低75%和介质传输系数降低30%的技术指标；建立了混凝土毛细孔疏水渗透抑制与介质传输的关系，阐明了新型疏水材料在水泥水化碱性孔隙液中响应刺激纳米前驱体功能基团水解，水解后的功能基团再与水化产物中钙离子等物质反应生成疏水性微纳颗粒的水化响应机理，揭示了前驱体对水泥材料微结构及孔隙表面特征的影响机制，明晰了疏水处理后对水泥基材料抗水分渗透、抗氯离子渗透、抗硫酸盐腐蚀及钢筋阻锈性能提升的效果。.项目共发表论文11篇，其中SCI/EI收录9篇，申请发明专利7项，相关材料实现产业化生产与工程示范应用，取得了良好的社会与经济效益。培养青年研究骨干2名，参与学术会议4次，通过大会报告及会议交流进一步提升了资助项目的研究深度和应用广度。研究成果获江苏省科技进步一等奖1项、中国公路学会科技进步一等奖1项，南京市优秀专利奖1项。已全面完成课题任务。