基于机制砂棱角性表征的级配测量修正方法及实验研究

Correction Method of Gradation Measurement Based on Characterization of Manufactured Sand Angularity and Experimental Study

机制砂的形状特征和级配对混凝土性能有着重要影响,图像法可以同时测量颗粒的形态和级配。在机制砂的级配测量中,需要考虑颗粒的形态特征对级配的影响。因此,提出利用图像分析技术实现机制砂棱角性的表征和级配测量修正,分别进行了机制砂的棱角性对比实验,级配重复性实验,图像法与筛分法级配测量对比实验以及修正前后的对比实验。实验结果表明,拟合椭圆棱角性算法可以独立地表征棱角性,不受粒径大小的影响。等效Feret椭圆短径作为等效粒径,粒度区间最大重复性误差出现在1.18~2.36 mm的尺寸区间,为1.26%。图像法测量的最大级配误差从修正前的6.29%减少到修正后的1.01%,细度模数的最大误差从0.17降低到0.04。相比传统的筛分方法,该测量系统具有良好的稳定性和功能性,满足测量的标准和要求。

The shape characteristics and gradation of manufactured sand have a significant impact on the performance of concrete.Image processing can simultaneously measure particle morphology and gradation.In the measurement of the gradation of manufactured sand,the influence of particle shape characteristics on the gradation needs to be considered.Therefore,a method utilizing image processing was proposed to characterize the angularity of manufactured sand and correct the measurement of gradation.Comparative experiments were conducted on the angularity of manufactured sand,repeatability of gradation,comparison of gradation measurements between image analysis and sieving methods,as well as before and after the correction experiments.The experimental results show that the fitted elliptical angularity algorithm can independently characterize the angularity and was not influenced by the particle size.The short diameter of the equivalent Feret ellipse,which represents the equivalent particle size,shows a maximum repeatability error of 1.26%within the particle size range of 1.18~2.36 mm.The maximum gradation error,as measured by the image processing method,decreases from 6.29%before correction to 1.01%after correction.Additionally,the maximum error of the fineness modulus is reduced from 0.17 to 0.04.Compared to traditional sieving methods,this measurement system demonstrates good stability and functionality,while also meeting the standards and requirements of measurement.