在细观层次上将轻骨料混凝土看成是砂浆基体、骨料夹杂和界面层组成的三相复合材料,在此基础上,运用细观力学均质化理论,对混凝土的抗压强度进行了数值模拟,分别探讨了骨料和水泥砂浆的杨氏模量比和轻骨料的体积百分比对混凝土和骨料的抗压强度比的影响。研究发现:骨料与基体的杨氏模量比存在一个临界值,当小于临界值时,混凝土的强度由界面层的抗压强度控制;当大于临界值时,混凝土的强度由骨料的抗压强度控制。

Lightweight aggregate concrete is considered as a three-phase composite material composed of matrix cement mortar, intercalated aggregate and interface layer. In line with the homogenization theory in mesoscopic mechanics, the compressive strength of light aggregate concrete is analyzed via numerical simulation. The influences of ratio of aggregate's Young's modulus and mortar matrix's Young's modulus and aggregate's volume fraction on the ratio of concrete's compressive strength to aggregate's compressive strength are examined. Result reveals that there exists a critical value of Young's modulus ratio, below which the compression strength of concrete is dominated by the compressive strength of interface, and above this value the compression strength of concrete is controlled by the compressive strength of aggregate.