【摘要】 为研究球体率作为粗骨料形状特征的定量评价指标的可行性,基于图像处理技术,应用Image-Pro Plus软件测定了四组形状特征不同的粗骨料球体率,在粗骨料级配不变的前提下,研究了球体率对粗骨料堆积空隙率与自密实混凝土工作性的影响。结果表明,不规则粗骨料颗粒的含量与粗骨料球体率呈正相关关系;当粗骨料球体率从0.5240增大到0.5922时,粗骨料堆积空隙率呈先减小后增大的趋势,自密实混凝土的坍落扩展度逐渐增大,T₅₀₀逐渐减小,间隙通过性能与抗离析性能逐渐提高。通过建立粗骨料球体率与自密实混凝土工作性的定量关系式,能够确定满足一定工作性要求的球体率,进而达到控制粗骨料质量的目的。更多还原

【Abstract】 The feasibility of spherical rate as a quantitative evaluation index of coarse aggregate shape characteristics was researched. Based on image processing technology, four groups of coarse aggregates with different shape characteristics were measured by Image-Pro Plus software,the effects of spherical rate on the voidage of coarse aggregate and the workability of self-compacting concrete were investigated under the premise of the invariable particle distribution. The results show that irregular coarse aggregate particles content is positively correlated with the spherical rate of coarse aggregate,with the increase of spherical rate from 0.5240 to 0.5922, the voidage of coarse aggregate decreases first and then increases, the slump flow of self-compacting concrete increases gradually, the time of T₅₀₀ decreases gradually, the passing ability and segregation resistance improve gradually. By establishing quantitative relationship between the spherical rate of coarse aggregate and workability of self-compacting concrete, the spherical rate meeting certain workability requirements can be determined, and then the quality of coarse aggregate can be controlled.更多还原