钢筋高延性混凝土界面粘结滑移与退化机理研究

High ductile concrete (HDC)has good ductility and coordination deformation with steel bars, which can reduce interfacial shear stress and improve interface bonding performance.For this purpose, the effects of some parameters on bond strength will be researched in this project, such as bar shape and diameter, anchorage length, cover thickness of HDC, strength and ductility of HDC. Besides，this work comes up with the computing method of bond strength and then propose general anchorage length. The degradation of bond behavior between HDC and steel will be evaluated under low reserved cyclic load and degradation rate of bond strength can be build. After, the anchorage length considering the effect under earthquake can be recommended. Based on the bond stress-slip curves obtained from experiment, this paper puts forward the bond-slip constitutive model by taking position function into account. The excellent damage resistance ability and crack control ability of HDC can significantly reduce the width of crack. According to the experimental research and theoretical analysis, the calculation method of width of cracks will be proposed. Finally, the damage constitutive of HDC can reflect the practice engineering better. Therefore, this research will build the nonlinear analysis model of reinforced high ductile concrete structure by introducing the damage constitutive model and bond slip relationship. The research results have important theoretical significance and practical value for the popularization and application of high ductility concrete in structure.

高延性混凝土具有良好的变形能力，能与钢筋协调变形，减小界面剪切应力， 提高界面粘结性能。为此，本项目研究钢筋外形、钢筋直径、钢筋锚固长度、高延性混凝土保护层厚度、强度和延性对粘结强度的影响，提出极限粘结强度计算方法，进而提出合理的锚固长度；研究低周反复荷载作用下界面粘结性能的退化，提出粘结强度退化率，提出考虑地震作用下的锚固长度。通过测试粘结应力-滑移曲线，提出考虑位置函数的界面粘结滑移本构模型。高延性混凝土良好的耐损伤能力和裂缝控制能力，使得钢筋高延性混凝土构件的裂缝宽度减小，通过试验研究和理论分析，提出裂缝宽度计算方法。高延性混凝土损伤本构更符合工程实际，根据强度和延性提出损伤本构模型，并结合钢筋与高延性混凝土界面的粘结滑移本构关系，提出钢筋高延性混凝土结构的非线性分析模型。研究成果对于高延性混凝土在结构中的推广应用具有重要的理论意义和实用价值。

高延性混凝土具有良好的变形能力，能与钢筋协调变形，减小界面剪切应力，提高界面粘结性能。本项目研究了钢筋外形、钢筋直径、钢筋锚固长度、高延性混凝土保护层厚度、强度和延性对粘结强度的影响，提出极限粘结强度计算方法，进而提出基本锚固长度；研究了低周反复荷载作用下界面粘结性能的退化，提出粘结强度退化率，提出考虑地震作用下的锚固长度。通过测试粘结应力-滑移曲线，提出考虑位置函数的界面粘结滑移本构模型。高延性混凝土良好的耐损伤能力和裂缝控制能力，使得钢筋高延性混凝土构件的裂缝宽度减小，通过试验研究和理论分析，提出了裂缝宽度计算方法。研究成果对于高延性混凝土在结构中的推广应用具有重要的理论意义和实用价值。