超高性能应变硬化水泥基复合材料多尺度交互设计及微观力学本构模型

现有的成熟高强混凝土和高延性水泥基材料均无法满足核电、国防、抗震、抗爆等工程对其同时具有超高抗压强度、大变形、高耗能、高安全性的特殊服役要求，亟需设计兼具超高抗压强度和超高延性的特种水泥基材料。本项目拟设计制备抗压强度超过160MPa、拉伸应变超过6%的超高性能应变硬化水泥基复合材料（UHP-SHCC），提出多尺度交互设计理论；研究纤维、基体、纤维-基体界面过渡区之间的复杂协同效应和科学调控机制，建立微-宏观性能之间的本构关系；建立应变硬化多缝开裂微观力学本构模型，确定关键微观力学参数取值范围，提出微观力学设计理论，并通过计算机模拟反演拉伸多裂缝应变硬化行为，分析关键微观力学参数离散程度对模拟结果影响程度。该研究将为UHP-SHCC的原材料和制备工艺优选、配合比优化设计、微观力学模型构建、数值模拟及工程应用提供理论依据和技术支持。

The engineering projects for nuclear power, national defense, earthquake resistance, explosion resistance require cementitious materials to have ultra-high compressive strength, large deformation, high energy consumption, and high safety. None of the existing high-strength concrete and high ductility cementitious composites meet these requirements. The special cementitious material with both ultra-high compressive strength and ultra-high ductility urgently need to be developed. This project intends to design and prepare an Ultra-High Performance Strain Hardening Cementitious Composites (UHP-SHCC) with a compressive strength exceeding 160 MPa and a tensile strain more than 6%, and proposes the multi-scale interaction design theory; investigate the synergy effect and regulation mechanism between fiber, matrix, and fiber-matrix interface transition zone, establish the constitutive relationship between micro and macro properties; establish a micromechanical constitutive model achieving the strain hardening multi-cracking behavior, determine the range of key micromechanical parameters, propose the micromechanical design theory, and simulate the tensile multi-cracking strain hardening behavior using the computer, analyze the influence of discrete degree of key micromechanical parameters on the simulation. This study will provide a theory basis and technical support for the optimization of raw materials and preparation process, design of mix proportion, micromechanical model construction, numerical simulation, and engineering application for UHP-SHCC.