GFRP增强水泥模板-混凝土复合剪力墙的受力机理与设计方法研究

The permanent formwork, a type of composite thin plate reinforced by FRP, is formed into compound components of "formwork and concrete" by means of concrete pouring, which not only can save the traditional formwork materials and default the processes of formwork removal and transportation, but can take full advantages of FRP and concrete, improve structure performance and restrain the occurrence and development of cracks. However, at home and broad, only a few researches have been done until in recent years. So there are still many problems need to be studied further..Through the low-cycle cyclic loading test, the purpose of this project is to study the comprehensive performances of "formwork-concrete-formwork" sandwich type hybrid shear wall with permanent cement formwork reinforced by GFRP mesh, such as strength, cooperative deformation, ductility, energy dissipation capacity, etc. The damage theory will be applied to analyze composite shear wall's damage evolution process from the occurrence and development of cracks to failure, then associated with the results of experimental investigation and numerical analysis, the stress transfer and failure mechanism of the hybrid shear wall will be clarified, the damage constitutive model of "formwork-concrete-formwork" sandwich type shear wall will be founded, and the appropriate correlation mode between formwork and concrete will also be determined. Finally, a performance-based simplified design method on hybrid shear wall with GFRP reinforced cement formwork and concrete will be put forward, which will be convenient to use in the practical engineering applications. The research production of this project will promote the engineering applications of this new type of structure in our country.

使用由FRP材料增强的复合薄板作为永久性模板，与混凝土浇筑成一体形成模板与混凝土的复合构件，既可节约传统模板材料、省却拆除和倒运模板等工序，还可以充分发挥FRP和混凝土各自的材料优势，改善结构性能、抑制裂缝的发生和开展。但直到近年来国内外才进行了少量的试验研究，有很多问题尚待进一步深入。.本项目将通过低周反复荷载试验，研究以GFRP网格布增强水泥薄板作为永久性模板的"模板-混凝土-模板"夹芯式复合剪力墙的强度、协同变形、延性和耗能能力等综合工作性能；采用损伤理论分析复合剪力墙从裂缝发生、开展至失效的损伤演化过程，结合试验研究和数值分析，明确此类复合剪力墙的传力机理和破坏机制，建立"模板-混凝土-模板"夹芯式复合剪力墙的损伤本构模型；确定模板与混凝土间的合理关联方式，给出基于性能的便于实际工程应用的GFRP增强水泥模板-混凝土复合剪力墙的简化设计计算方法，促进此类新型结构在我国的工程应用。

本项目针对玻璃纤维网格布增强水泥基复合模板与混凝土组成的夹芯式复合剪力墙的受力性能展开了如下研究：（1）通过14榀水泥基模板与混凝土复合剪力墙的单调静载试验和低周反复荷载试验，对其协同工作性能、承载能力、破坏模式、传力机制、变形性能、滞回特性等进行了研究，结果证明了此类复合剪力墙的良好工作性能，确定了水泥模板对主体混凝土的复合增强作用；（2）通过9榀水泥基模板附带保温层的夹芯复合剪力墙的单调静载试验和低周反复荷载试验，对其协同变形、破坏形态、耗能能力等基本受力性能和构造措施进行了研究，证明了自保温复合剪力墙这一结构形式的可行性，确定了合理界面关联方式；（3）针对水泥基模板平面刚度小、抗弯折性能差的特点，研制了专用于此类复合剪力墙混凝土施工的配套支护体系，可在施工中为水泥基模板提供足够的抗侧向压力、对墙体厚度控制准确、安装/拆卸方便、节约空间，还可以重复使用；（4）通过近400个复合试件的双剪推出试验，分别对常规环境下和常见侵蚀环境下水泥基模板与混凝土的界面粘结性能、保温层与混凝土的界面粘结性能进行了研究，研究结果对了解界面在不同因素影响下的粘结滑移状况以及更有针对性地建立界面本构关系模型具有重要作用；（5）基于有限元软件ABAQUS，针对此类复合剪力墙中不同材料特点及界面形式，引入损伤因子，建立了较为合理的几何模型、材料本构关系及边界条件，得到了具有一定可信度的数值计算方法，可以用于此类复合剪力墙的近似计算；（6）在试验研究和数值分析的基础上，依据规范计算公式，结合解析推导和试验结果，分别建立了此类复合剪力墙在静力荷载和反复荷载作用下的开裂荷载计算公式和极限荷载计算公式；还结合以往试验数据，针对水泥基模板与混凝土复合板进行了受力分析，并分别建立了相应的开裂荷载、屈服荷载和极限荷载计算公式；可用于此类复合剪力墙及复合受弯构件的近似计算和研究分析。