再生混凝土与钢筋粘结滑移性能的试验研究及力学分析

EXPERIMENTAL AND MECHANICAL ANALYSIS OF BOND-SLIP PERFORMANCE BETWEEN RECYCLED CONCRETE AND REBAR

  • 摘要: 良好的粘结性能是确保再生混凝土与钢筋能够共同工作的前提条件。通过120个试件的拉拔试验,并结合非平衡态热力学与损伤力学的相关理论分析再生混凝土与钢筋间的粘结滑移性能。提出三段式的粘结滑移本构模型,对比表明该模型对实测粘结滑移曲线具有较好的模拟效果。分析了粘结破坏过程中的能量守恒与能量耗散特性,给出了耗散能与弹性变形能代表值的计算公式,探讨了初始弹性变形能与极限弹性变形能的关系,并基于本构破坏能,对影响粘结性能的因素进行了分析。提出相对损伤变量的概念,定义了界面相对损伤变量,推导出相对损伤滑移方程,分析了界面初始损伤、界面损伤发展阶段以及界面损伤的发展速度。研究结果可为推广应用钢筋再生混凝土结构提供基础研究资料。

     

    Abstract: Good bond performance is a prerequisite to ensure that the recycled concrete and the rebar can work together. According to the pull-out test with 120 test specimens, the bond-slip performance between the recycled concrete and the rebar is investigated using the theory of non-equilibrium thermodynamics and damage mechanics. The bond-slip constitutive model is proposed and the analysis result shows that the model has better simulation effect. The characteristics of the energy conservation and dissipation during the bond failure process are analyzed, and then the formula to represent the dissipated energy and elastic deformation energy are proposed. The relationship between the initial elastic deformation energy and the limit elastic deformation energy is studied. The main factors affecting the bond performance are analyzed based on the constitutive energy. Then, this paper proposes the concept of relative damage variation which defines the interface relative damage variation, and proposes the equation of relative damage to slip. Besides, the initial damage, the stages of interface damage development and the growth rate of interface damage are analyzed. The results of the present study could provide fundamental research data to promote the application of reinforced recycled concrete structure.

     

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