基于随机骨料的混凝土边界效应影响研究

Boundary Effect of Concrete Based on Random Aggregate

为了研究混凝土构件内的骨料边界效应,分别采用图像识别技术和随机骨料建模技术分析了真实的骨料分布、形状、长径比、粒径及表面棱角数量等因素对骨料密度分布曲线及边界效应的影响规律。研究结果表明:骨料密度分布曲线呈现先上升、随后下降、最终趋于稳定或略有震荡的规律,且不受骨料几何形态影响,稳定时对应的密度分数略高于平均骨料密度分数;骨料密度曲线峰值厚度约为骨料最小粒径,边界效应层厚度约为骨料平均粒径,且这二者均随着骨料粒径及长径比的增加逐渐增大;在骨料的几何形态特征因素中,骨料粒径对密度分布曲线、峰值厚度及效应层厚度影响较为显著,影响程度强于其他的几何形态特征。

In order to study the aggregate boundary effect inside concrete components,the influence rule of real aggregate distribution,shape,length to diameter ratio,particle size,and number of surface edges and corners on the density distribution curve and boundary effects of aggregate was analyzed by image recognition technology and random aggregate modeling technology respectively.The research results show that the aggregate density distribution curve shows a pattern of first rising,then falling,and finally stabilizing or slightly oscillating,and is not affected by the geometric shape of the aggregate.When stable,the corresponding density fraction is slightly higher than the average aggregate density fraction.The peak thickness of aggregate density curve is approximately the minimum particle size of the aggregate,the thickness of the boundary effect layer is about the average particle size of the aggregate,and both gradually increase with the increase of aggregate particle size and length to diameter ratio.Among the geometric characteristic factors of the aggregate,the particle size of aggregate has a significant impact on the density distribution curve,peak thickness,and effect layer thickness,with a stronger degree of influence than other geometric characteristics.