型钢再生混凝土界面劣化机理及本构关系研究

The steel reinforced concrete (SRC) structure has a good seismic performance and high bearing capacity. On the other hand, the recycled concrete has the characteristics of green environmental protection and saving resources. Combining with the above respective advantages, a green and energy-efficient structure which is called‘steel reinforced recycled concrete structure(SRRC)’is put forward in this project. The bond behavior and deterioration mechanism as well as constitutive equation of this new structure will be focused on research. Through the experimental study and theoretical analysis, the influencing factors of bond strength between shaped-steel and recycled concrete are studied,and the calculation formula of interfacial bond strength of SRRC is confirmed.In order to establish the basic theory of bond-slip, the bond anchorage mechanism and deterioration mechanism of interfacial transition zone between shaped-steel and recycled concrete are studied.The finite element simulation analysis of SRRC considering bond-slip is presented.Based on the above research,the reliable design method of anchorage measures and shear connectors will be also put forward. The project has important theoretical significance and practical value to drive the development of the basic theory of SRRC structure, and to promote its engineering application.

本项目将具有承载能力高、抗震性能好的型钢混凝土结构与绿色环保、节约资源的再生混凝土相结合，重点研究型钢与再生混凝土界面间的黏结滑移性能、劣化机理及黏结-滑移本构关系。通过试验及理论分析，研究影响型钢与再生混凝土黏结力分布的因素，提出型钢再生混凝土界面黏结强度计算公式；探讨型钢与再生混凝土之间的黏结锚固机理及性能退化规律，建立型钢再生混凝土黏结-滑移本构关系，并提出考虑黏结滑移的型钢再生混凝土组合构件有限元仿真分析技术；在此基础上，提出可靠的黏结锚固措施和剪切连接设计方法。本项目的研究对推动型钢再生混凝土组合结构基本理论的发展，促进其工程应用具有重要理论意义和实用价值。

型钢与再生混凝土界面黏结作用是两种材料可以共同工作的基础。本项目围绕型钢与再生混凝土界面间的黏结滑移性能、劣化机理及黏结-滑移本构关系等方面开展研究。.为研究循环往复荷载作用下型钢再生混凝土界面黏结滑移性能，设计了20个型钢再生混凝土试件并进行低周反复推拉试验。分析了再生混凝土取代率、型钢保护层厚度、体积配箍率及再生混凝土强度对型钢再生混凝土界面黏结性能的影响，建立了特征黏结强度计算公式，对计算公式的合理性进行分析，将特征黏结强度的试验值和计算值对比分析，满足计算精度，表明计算公式可以用于循环往复荷载作用下型钢再生混凝土特征黏结强度的计算。分析结果表明：循环往复荷载作用下试件的极限黏结荷载较单调推出荷载作用下的极限黏结荷载有较大程度的降低，极限黏结荷载约为单调推出试件的59.0%左右。型钢再生混凝土的黏结应力随着再生混凝土取代率的增加而降低，随着型钢保护层厚度、体积配箍率及再生混凝土强度的提高而增加。.为研究型钢与掺钢纤维的再生混凝土界面黏结滑移性能，设计了20个型钢钢纤维再生混凝土试件并进行了压力推出试验。分析了钢纤维体积率、钢纤维长径比、再生混凝土保护层厚度和型钢锚固长度对界面黏结强度的影响，建立了黏结强度的计算公式，分析了影响型钢与钢纤维再生混凝土粘结滑移性能的影响因素。结果表明：钢纤维体积率在0.4-1.6和钢纤维长径比在60-100范围内，钢纤维对型钢与再生混凝土黏结滑移性能提高程度都先增后减；钢纤维的加入起到了阻裂增韧的作用，裂缝发展变缓，产生更多分支裂缝；型钢表面应变在荷载上升段和荷载下降段分别呈指数分布和线性分布，型钢与钢纤维再生混凝土连接界面滑移曲线在荷载上升段和荷载下降段分别为下凹曲线和斜直线；建立的基于型钢应变分布规律的平均粘结强度计算公式与试验拟合公式结果相符；界面粘结抗剪刚度和断裂能两个角度都可有效评估钢纤维的增强效果。