含碎红砖再生混凝土基本力学性能及其应力-应变关系

来源于拆迁工程的废弃混凝土中，不可避免地会混入废弃红砖，碎红砖对再生混凝土力学性能影响显著。为研究含碎红砖再生混凝土的基本力学性能及其受压应力-应变本构关系，以碎红砖掺量为主要试验参数，进行了再生混凝土立方体抗压强度、弹性模量及棱柱体轴心受压应力 应变全曲线试验，量化了红砖掺量对再生混凝土力学性能的影响。基于试验结果，引入红砖取代率这一关键参数，对现有再生混凝土应力-应变关系表达式进行修正，提出了含碎红砖再生混凝土应力-应变关系表达式，并将现有试验结果与公式预测结果进行对比，验证了公式的可靠性。研究表明，碎红砖的掺入会降低再生混凝土的抗压强度，显著增大混凝土峰值应变与泊松比，使混凝土横向变形系数在更低的荷载等级下即迅速增大。

Basic mechanical properties and stress-strain relationship for recycled concrete including crushed clay bricks

It is almost impossible to exclude the waste brick from the waste concrete in the production of recycled coarse aggregates. The crushed clay bricks (CCB) has significant influence on the mechanical behavior of the RAC. Taking the CCB replacement ratio as the main test parameter, this paper quantified the influence of the CCB on the compressive strength, the elastic modulus, and other mechanical behaviours (e.g. the peak strain, the ductility, the dilation ratio, etc.) of the RAC based on the cubic and prism test results. Introducing the CCB replacement ratio as a key parameter, the available stress-strain equation for RAC had been modified to account for the influence of CCB. The model equations were benchmarked against available experimental results. It is found that the CCB would significantly increase the peak strain and the Poisson’s ratio, decrease the strength, and cause significant increase of dilation ratio at a relatively lower load level.