纤维增强水泥基复合材料（ECC）因其优异的抗拉应变硬化特征和裂纹宽度控制能力被广泛应用于各类建筑工程中，但其收缩变形大且在复杂荷载作用下易发生开裂已成为该领域的共性技术难题。本项目聚焦高强ECC材料经时变形特性和组合构件开裂响应，采用实验研究、数值模拟和理论分析相结合的方法，研究多种减缩方式对其经时变形性能的影响规律，确定高强ECC收缩调控的主要因素，获得收缩调控优化设计方案，同时建立基于水分迁移理论的一体化收缩预测模型；运用解析法逆推求解约束状态下高强ECC的抗拉徐变参数，构建约束作用下同时考虑材料收缩与徐变效应的内部应力计算模型；探索荷载耦合作用下材料收缩与构件开裂的内在联动关系，最终揭示荷载耦合作用下高强ECC-钢组合梁的开裂机制。研究结果不仅可为高强ECC材料的性能优化及推广应用打下坚实的基础，也为解决混凝土-钢组合桥面板等实际工程中普遍存在的开裂问题提供新方法和新思路。

Engineered Cementitious Composites (ECC) have been widely applied in multiple constructions thanks to its excellent strain-hardening characteristics and crack control ability. However, its large shrinkage deformation brings about common technical challenges that different levels of cracking occur under complex loads. Time-dependent performance of high strength ECC (HSECC) and cracking response of ECC-steel composite components became the focuses in related fileds. Based on the use of experimental technique, numerical simulation and theoretical analysis, present project aims at studying cracking mechanism of HSECC under coupling loads and its shrinkage control approach. Firstly, experiments on the influence of shrinkage reduction methods on the time-dependent deformation of HSECC is to be carried out to determine the main control parameter and an optimized shrinkage control approach will be obtained. Secondly, integrated shrinkage prediction model based on moisture movement theory will be established. Thirdly, tensile creep parameter under restrained condition will be calculated through backwards induction, shrinkage stress model regarding both shrinkage and creep will be established also. Then, internal relation between shrinkage performance and component cracking under coupling loads will be explored. Lastly, cracking mechanism of high strength-steel composite bridge deck will be analyzed and revealed. Research results provide not only strong basis for HSECC performance optimization and broader application, but also new ideas and strategies for cracking issues of practical concrete-steel composite bridge deck and other construction programs.