内约束条件下高强混凝土收缩开裂机理与裂缝控制方法研究

In recent years, the Steel concrete composite shear wall are widely used with the large-scale construction of high-rise building. However, the inherent shrinkage of high-strength concrete may result in serious cracks on the composite wall during construction under the high internal constraint of plates, studs etc, which bringing great threat to the safety of the structure and durability and becoming a hot subject on the problem of structural engineering. .The axial restraint test method for this project is proposed for steel plate-concrete composite shear wall. Carrying out shrinkage tests of high strength concrete under the constraint conditions to reveal the internal constraint of plates, studs etc and the complex system cracking mechanism caused by coupling constraints; carrying out fracture tests of high-strength concrete in early age to establish the relationship between its rules and internal humidity; basing on the experiment and combined with the fracture mechanics method to establish a time-varying model of fracture of high strength concrete based on double parameter model and put forward concrete cracking prediction method; considering concrete time-varying characteristics and construction features and built control methods of steel-concrete composite shear wall cracks..The research findings will enrich the design theory of steel-concrete composite shear wall system, improve the construction technology of steel concrete composite shear wall, which has great significance to ensure the safety of high-rise building steel-concrete composite shear wall.

近年来，随着高层建筑大规模建设，钢板-混凝土组合剪力墙体系得到广泛应用，但由于高强混凝土固有的收缩特性，形成钢板、栓钉等内部强约束作用，导致组合墙体在施工期间即严重开裂，给结构安全与耐久性带来极大威胁，因而成为结构工程学科热点研究问题。.本项目拟提出适用于钢板-混凝土组合剪力墙的轴向约束试验方法，开展高强混凝土内约束条件下收缩变形试验，揭示钢板、栓钉等内约束及其耦合形成的复杂体系开裂机理；开展高强混凝土早期断裂性能试验，建立其早期断裂性能规律及其与内部湿度的关系；在试验研究基础上，结合断裂力学方法，建立基于双参数模型的高强混凝土断裂时变模型，提出高强混凝土开裂预测方法；考虑混凝土时变特性及施工特点，建立钢板-混凝土组合剪力墙收缩裂缝控制方法。.研究成果将丰富钢板-混凝土组合剪力墙体系设计理论，完善钢板-混凝土组合剪力墙体系建造技术，对保证高层建筑钢板-混凝土组合剪力墙体系安全具有重要意义。

复杂约束条件下的混凝土结构开裂，是近年来工程施工阶段所面临的重要问题。 本项目以此为背景，对包含钢筋、钢板和栓钉等在内的内约束自身性能及其对混凝土、高强混凝土的收缩、开裂性能展开研究。通过理论分析、数值模拟和试验，阐明了内约束下混凝土、高强混凝土的收缩开裂机理，建立了复杂约束条件下混凝土收缩、收缩应力计算方法，形成了复杂约束条件下混凝土结构裂缝防治方法，研究对于避免由于裂缝导致的混凝土结构失效、使用性能降低具有重要作用。研究成果在国内多个重大工程中获得了成功应用，取得了良好的经济、社会效益。