含缺陷混凝土的弹性模量预测

提出一种新的预测含缺陷混凝土弹性模量的估算方法。将混凝土看作是由砂浆、骨料、界面和缺陷(包括圆形孔隙和币状裂隙)等组成的四相复合材料,建立随机骨料数值模型,运用细观力学数值均匀化方法预测混凝土的有效弹性模量,并与无缺陷情况下的计算结果以及试验结果进行对比,在此基础上进行各影响参数的敏感性分析。结果表明,缺陷的存在会减小混凝土的有效弹性模量;混凝土的有效弹性模量随着骨料或砂浆弹性模量的增大而增大;界面特性参数和骨料最大粒径对混凝土有效弹性模量的影响有限;任意多边形骨料模型比圆形骨料模型对混凝土有效弹性模量的预测更接近试验值。

Predication of elastic modulus of concrete with defects

A new method to predict the elastic modulus of concrete with defects was proposed.The concrete was regarded as the four-phase composite composed of aggregate,mortar,interfaces and defects(including circular holes and penny cracks).A mathematical model for random aggregate was established.The effective elastic modulus of the concrete was predicted by use of the micromechanical numerical homogenization method,and the numerical results were compared with the calculated and test results for the cases without defects.On such a basis,the sensitivity of each parameter was analyzed.The results show that the existence of defects has a certain effect on the effective elastic modulus of the concrete.The effective elastic modulus of the concrete increases with the increase of the elastic modulus of aggregate or mortar.The interface properties and the maximum aggregate diameter have little influences on the effective modulus of the concrete.The predicted results of the effective modulus of the concrete for arbitrarily polygonal aggregate are closer to the test ones than those for circular aggregate.