短龄期再生混凝土三轴受压力学性能及其本构关系

Mechanical Properties and Constitutive Relationship of Short Age Recycled Coarse Aggregate Concrete under Tri axial Compression

关键词:  短龄期  再生混凝土  三轴受压  强度计算  本构方程

Key words:  short age  recycled coarse aggregate concrete  tri axial compression  strength calculation  constitutive equation

摘要:

为研究短龄期再生混凝土的三轴受压力学性能，以龄期和围压值为变量，设计了14个圆柱体再生混凝土试件进行三轴受压试验，观察其破坏形态，获取应力应变曲线、峰值应力、峰值应变以及弹性模量等数据.基于试验数据分析了龄期和围压值对再生混凝土三轴受压力学性能的影响规律，建立了短龄期再生混凝土三轴受压的峰值应力、峰值应变和弹性模量的计算公式，并建立了再生混凝土三轴受压状态下的应力应变本构方程.结果表明：短龄期再生混凝土的峰值应变、弹性模量受龄期影响较大，随着龄期的延长，峰值应变减小，而弹性模量却显著增大；围压值对再生混凝土的峰值应力、峰值应变和弹性模量均有显著影响.采用CEB FIP（1990）规范中方法计算的再生混凝土三轴抗压强度值与实测值吻合较好.

Abstract:

In order to reveal the mechanical properties of short age recycled coarse aggregate concrete under tri axial compression, 14 cylinder specimens were designed for tri axial compression test. Aging time and lateral confinement were considered as variables in the test. Failure patterns of specimens were observed, peak stress, peak strain, elastic modulus and stress strain curves were obtained. Based on the experimental data, the influence of aging time and lateral confinement on the mechanical properties of short age recycled coarse aggregate concrete under tri axial compression were analyzed; the strength calculation methods were discussed; the formulas of elastic modulus, peak strain, peak stress and stress strain constitutive equation were put forward. Results show that: aging time has a great influence on peak strain and elastic modulus; on the other hand, peak stress, peak strain and elastic modulus of recycled coarse aggregate concrete are significantly influenced by lateral confinement. The calculated results by CEB FIP(1990) are in good agreement with experimental data.