高强不锈钢绞线网增强ECC力学特性及其加固RC梁抗弯性能研究

Both Engineered Cementitious Composites (ECC) and high strength stainless steel wire mesh have excellent material performance. Combining their advantages to develop a new type of composite materials, namely, high strength stainless steel wire mesh reinforced ECC, will provide a new technical way to solve the problems of the engineering structure and its reinforcement. This project takes the newly developed composite material as the research object, and conduct theoretical and experimental investigations on its mechanical properties and flexural behavior of RC beams strengthened with it. The specific content includes experimental study on uniaxial tensile and compressive properties of ECC and tensile property of high strength stainless steel wire to explore their mechanical behaviors. In addition, experimental researches will be conducted on the tension behavior and the thin plate bending performance of high strength stainless steel wire mesh reinforced ECC, as well as on the mechanical behaviors including anchor, connection and so on of high strength stainless steel wire mesh in ECC. Based on test results, the tensile constitutive model, calculation method of bending behavior and structural requirements will be established for high strength stainless steel wire mesh reinforced ECC. Moreover, experimental study will be performed on flexural property of RC beams strengthened with high strength stainless steel wire mesh reinforced ECC considering the factors such as reinforcement quantity, interface anchoring conditions and so on. According to the finite element simulation analysis and the test results, the influence laws of these factors, reasonable interface anchorage method and design method will be proposed for the RC beams strengthened with high strength stainless steel wire mesh reinforced ECC. The implementation of this research will provide theoretical and technical supports for application of high strength stainless steel wire mesh reinforced ECC in engineering structure and reinforcement.

ECC和高强不锈钢绞线网均具有优异的材料性能，结合二者优点研制而成的新型复合材料（高强不锈钢绞线网增强ECC）将为解决工程结构及其加固难题提供新的技术手段。本项目以所研制的新型复合材料为研究对象，对其力学特性及用于RC梁抗弯加固性能进行理论和试验研究。具体内容包括：试验研究ECC单轴受拉、受压及高强不锈钢绞线受拉性能，探究其力学行为；试验研究高强不锈钢绞线网增强ECC受拉和薄板受弯性能以及高强不锈钢绞线网在ECC中锚固、搭接等受力特性，基于试验结果探究该复合材料的拉伸本构关系、受弯计算方法及构造措施；试验研究加固量、界面锚固情况等因素对高强不锈钢绞线网增强ECC加固RC梁抗弯性能影响，结合有限元模拟分析，研究各因素影响规律，提出合理的界面锚固方法及高强不锈钢绞线网增强ECC加固RC梁抗弯设计方法。课题的实施将为高强不锈钢绞线网增强ECC在工程结构及加固中的应用提供理论和技术支持。

针对既有工程中已产生损伤以及不满足现行规范要求的结构及构件，虽然已有多种加固方法，但要使既有结构或构件在加固后的抗裂、延性、韧性、耐久性及抗震能力等整体性能大幅度提升，还需从加固材料层面深入研究。ECC和高强不锈钢绞线网均具有优异的材料性能，结合二者优点研制而成的新型复合材料（高强不锈钢绞线网增强ECC）将为工程结构及其加固材料提供更多的选择。本项目以所研制的新型复合材料为研究对象，对其力学特性进行理论和试验研究。具体研究内容和研究成果包括：考虑ECC配合比、高强不锈钢绞线种类的影响，对ECC单轴受拉、受压性能以及高强不锈钢绞线的受拉性能进行了力学试验，研究了其具体力学行为，构建了能准确描述其力学行为的ECC单轴受拉、受压及高强不锈钢绞线受拉本构模型；以高强不锈钢绞线的种类、ECC强度、高强不锈钢绞线网的锚固长度、横向钢绞线间距为试验参数，进行了单边拉拔试验，分析了以上参数对高强不锈钢绞线网在ECC薄板中粘结性能的影响，根据试验结果，给出高强不锈钢绞线网在ECC中的锚固构造要求及粘结滑移特性；试验研究了ECC强度、钢绞线网配筋率等因素对高强不锈钢绞线网增强ECC薄板受拉和受弯性能的影响，研究了以上参数对高强不锈钢绞线网增强ECC复合材料受拉及受弯破坏形态、承载能力、抗裂、延性等性能的影响规律，探明了该复合材料的单轴拉伸本构关系、裂缝分布机理及受弯分析计算方法；进行了高强不锈钢绞线网增强ECC加固RC梁抗弯性能的探索性研究，考虑加固量、界面锚固情况等因素影响，进行了加固梁受弯试验，并结合有限元模拟分析，揭示了高强不锈钢绞线网增强ECC加固RC梁受弯性能的影响因素及影响规律。课题的研究成果为高强不锈钢绞线网增强ECC在工程结构及加固中的应用提供理论和技术支持，具有重要的科学意义。