超高强度高延性混凝土的微观力学设计与微结构调控

For matching the special design demands of higher security, high energy dissipation and durability, some ultra-high strength engineering structures in nuclear power, national defense, earthquake resistance and high pressure pipeline should be designed with multiple cracking and strain hardening properties under tensile stress. It means an ultra-high strength and high ductility concrete should be designed for them. Since the present Ultra-High Performance Concrete and the present High Ductility Cementitious Composites cannot simultaneously satisfy the requirement of ultra-high compressive strength, high energy dissipation and durability, therefore, it is necessary to design an Ultra-High Strength and High Ductility Concrete (UHSHDC) with compressive strength of 150MPa and ultimate tensile strain of 3%. The micro-mechanics design theory and mix design method for UHSHDC are proposed in this project after solving two core issues, i.e. (1) the synergistic effects between matrix, fiber and fiber-matrix interfacial zone as well as their regulation mechanism on the micro-structure of UHSHDC, (2)the micro-mechanics design guideline and theoretical criterion of UHSHDC. The sensitivity of this design theory will be investigated through the numerical simulation results and the text results. The research results have important theoretical significance and engineering application value for scientifically guiding the materials casting and applications of UHSHDC in special structures to match the special design demands of higher security, high energy dissipation and durability.

针对当前核电、国防、抗震和高压管道等超高强度等级特种工程结构在承受拉应力时需要超高强度和高延性以满足更高安全性、高耗能和耐久性的设计需要，亟待设计研制出超高强度高延性混凝土UHSHDC。面对现有超高性能混凝土和高延性水泥基复合材料二者均无法同时满足超高强度、高延性和应变硬化特性需求的现状，本项目借鉴现有超高性能混凝土基体设计理念和现有高延性水泥基复合材料微观力学设计理念，以抗压强度150MPa、极限拉伸应变超过3%为设计目标，围绕基体、纤维、纤维-基体界面区的三相协同效应及其微结构调控机制，以及UHSHDC微观力学设计准则及其理论判据，这两个关键科学问题开展系统研究，提出UHSHDC微观力学设计理论与配合比设计方法。将数值模拟与试验研究相结合，分析该设计理论的敏感性。研究成果对于科学指导UHSHDC材料制备以及在特殊结构中应用，具有重要的理论意义和工程应用价值。

针对当前核电、国防、抗震和高压管道等超高强度等级特种工程结构在承受拉应力时需要超高强度和高延性以满足安全性、高耗能和耐久性的设计需要，以及现有超高性能混凝土和高延性水泥基复合材料二者均无法同时满足超高强度、高延性和应变硬化特性需求的现状，本项目借鉴现有超高性能混凝土基体设计理念和现有高延性水泥基复合材料微观力学设计理念，以抗压强度150MPa、极限拉伸应变超过3%为设计目标，围绕基体、纤维、纤维-基体界面区的三相协同效应及其微结构更高调控机制，以及超高强度高延性混凝土（UHSHDC）的微观力学设计准则及其理论判据，这两个关键科学问题开展了系统深入研究，提出了UHSHDC微观力学设计理论与微结构调控机制，并通过理论计算和实验验证相结合，对关键参数进行了敏感性分析。研究成果对于科学指导UHSHDC 材料制备以及在特殊结构中应用，具有重要的理论意义和工程应用价值。. 本项目按研究方案和进度安排顺利完成了研究任务，达到了预定研究目标，并取得了丰硕预期成果。共发表高水平学术论文26篇，其中，JCR-1区SCI 14篇，Ei 12篇；授权国家发明专利6件；已培养毕业研究生5名，其中博士3名、硕士2名；培养在读博士生1名；江苏省 “333高层次人才培养工程”中青年学术技术带头人1名；晋升副高级职称1人、晋升中级职称1人；举办或参加国际学术会议共8次。相关研究成果荣获教育部科学技术进步二等奖1项（2019年，排名2/11）。