复杂海洋环境下钢筋混凝土高耐久基础理论及关键技术

At present, it is urgent that the main challenge of key and mega marine projects is to be satisfied with the requirement from the long-life expectations (designed service life ≥ 120 years). In order to cope with the challenge, it is necessary to reveal the basic theory of high durability of reinforced concrete subjected to marine environment which is the key scientific puzzle of present research proposal. Based on the theory, the major technical bottlenecks of reinforced concrete with high durability can be break through. In this project, highly durable concrete, i.e., high toughness and permeability resistance, is to be designed by means of controlling the material gene (C-S-H gel) and even the multi-scale performance. Moreover, an initiative anti-cracking method is incorporated that assures a long life “matrix” (concrete). The high resistance "two interfaces” (steel-concrete interface, concrete-protective material interface) will be realized by the intelligent inhibition of steel corrosion and bionic reinforcement of concrete surface. Finally, during the whole service life, reinforced concrete is to be rehabilitated by dynamic enhancement of material performance. In this way, "high durability" of reinforced concrete in marine environment is then interpreted. The project will mainly address the following three key scientific issues: (1) modification of material gene and optimization of multi-scale performance; (2) release of corrosion inhibition molecules at the steel-concrete interface; and (3) diffusion of biomimetic components in protective material and interface strengthening. Meanwhile, it shall bring two technical breakthroughs, i.e., the novel control of micro-driving force and resistance for shrinkage on one hand, and large data based performance evaluation and dynamic enhancement for reinforced concrete on the other hand. The project shall enrich the concrete science and provide theoretical guidance and technical support for marine constructions.

面对当前重点、重大海洋工程120年以上的长寿命预期，亟需探明复杂海洋环境下钢筋混凝土的高耐久基础理论是亟需攻克的关键科学难题，突破钢筋混凝土高耐久的关键技术瓶颈。项目基于混凝土本源基因改性与多尺度优化实现其高韧、抗渗，并通过主动抗裂实现“一个基体”（混凝土）的长寿命；基于混凝土中钢筋表面智能阻锈与混凝土表层界面仿生强化实现“两个界面”（防护材料-混凝土-钢筋的双界面）的高耐蚀。最终，通过全寿命性能动态提升保障其长寿命，从而诠释海洋环境下钢筋混凝土“高耐久”内涵。项目将解决三个关键科学问题：1）胶凝基因改性与多尺度性能调控机制；2）阻锈分子智慧感应释放机制；3）防护材料仿生组分的渗透扩散及界面强化机制。与此同时，在混凝土收缩变形微观驱动力与抗力发展协同调控，基于大数据的混凝土全寿命性能评估与动态提升两个关键技术问题上形成突破。成果丰富了混凝土科学内涵，并为海洋工程建设提供理论指导与技术支撑。

项目针对当前严酷环境下重点、重大海洋工程混凝土结构的长寿命保障需求， 提出基于混凝土本源基因改性与多尺度优化实现其高抗渗，通过混凝土抗裂实现“一个基体”（混凝土）的长寿命，基于混凝土中钢筋表面智能阻锈与混凝土表层界面仿生强化实现“两个界面”（防护材料-混凝土-钢筋的双界面）的高耐蚀的创新思路。项目聚焦解决胶凝基因改性与多尺度性能调控、阻锈分子智慧感应释放、防护材料仿生组分的渗透扩散及界面强化的机制3个关键科学问题，开展了海洋工程混凝土基体胶凝基因改性与多尺度性能优化、多场耦合作用下混凝土主动抗裂机制与协同调控、钢筋-混凝土界面性能主动设计与智能调控、混凝土表层防护的界面仿生强化机制、钢筋混凝土全寿命性能评估与动态提升5个方面的系统研究。将材料-结构相结合，通过大数据分析技术建立了表面氯离子浓度和表观氯离子扩散系数时变概率预测模型，发展了考虑耐久性提升技术效果的海洋环境下混凝土耐久性设计方法，建立了胶凝基因改性、收缩裂缝控制、表层仿生强化、钢筋高效智能阻锈4项关键技术，研发了收缩裂缝控制与耐久性提升的系列功能材料，解决了寒区海洋环境下混凝土结构耐久性量化设计与多重保障难题，相关技术应用于青岛地铁13号线、胶州湾第二海底隧道等工程。