模型再生混凝土单轴受压应力分布特征

Stress Distribution Characteristics of Modeled Recycled Aggregate Concrete Under Uniaxial Compression

摘要:

根据再生混凝土各相材料的力学特性，对模型再生混凝土进行细观数值分析，获取模型再生混凝土单轴受压下内部应力分布特征.通过变参数分析，讨论不同天然骨料、界面过渡区和老硬化砂浆的力学参数对模型再生混凝土应力分布特征的影响.结果表明，模型再生混凝土天然骨料之间的新老界面过渡区处存在拉应力和剪应力集中现象；天然骨料弹性模量增大，应力集中现象愈加明显，界面过渡区弹性模量增大，应力集中现象则逐渐减弱，老砂浆弹性模量增大应力集中特征变化不大.

Abstract:

Based on the mechanical properties of each material phase in recycled aggregate concrete (RAC), a two dimensional modeled RAC was built, and the stress distribution characteristics of the modeled RAC under uniaxial compressive were obtained by meso level numerical analysis. A parametric analysis was conducted to investigate the sensitivity of the stress distribution of the modeled RAC, which focused on different mechanical parameters of natural aggregate, interfacial transition zone (ITZ) and old hardened mortar. Results show that a concentration of tensile stress and shear stress produces at new and old interfacial transition zones between the natural aggregates. The higher elastic modulus of natural aggregates are, the higher the magnitude of stress concentration is, and the higher elastic modulus of the interfacial transition are, the lower the magnitude of stress concentration is. Whereas the effects of the elastic modulus of old hardened mortar on stress concentration are not evident.