摘要
国内的高速公路绝大部分采用沥青混凝土路面。沥青混合料是由多种材料组成的多相复合材料,其中占混合料质量90%以上的集料是沥青混合料的工程特性的重要影响因素,尤其是集料的形态特征。传统的集料形状测试方法繁琐,耗时多,工作量大,受测试者主观影响较大,不易得到客观及时的结果。近年来,随着计算机图像处理技术越来越多地应用到工程材料领域,采用图像处理技术采集并分析集料的形态特征的研究越来越受到重视。本文在归纳总结国内外研究的基础上主要利用数字图像技术来分析粗集料的二维形状特征。
试验方案是通过将集料均匀平铺,在自然光下采集集料图像。使用matlab处理分割图像。根据研究集料本身的特性,分割方式不采用常用的灰度阀值分割,而是直接对真彩图分三个通道分别分割处理,成功得到各个颗粒的轮廓投影图。计算提取轮廓的相应指标,具体指标有长轴、短轴、长轴/短轴、矩形度、形状指数和棱角性。根据样本的概率分布特征进行统计分析,最终计算得集料各指标的形状特征值统计值。
进行单档集料捣实密度试验,发现同一个料场的各档集料的VCADRC随着粒径的增大而减小;另外,针对本文研究的集料,对岩性不同的粗集料,辉绿岩的VCADRC普遍要高于玄武岩的。
研究集料形状特征指标同VCADRC相关性,VCADRC对同一粒径集料的大小指标并不是很敏感,比较敏感的形状特征指标是棱角性。利用二维指标推导一个“伪”三维指标高度;VCADRC对高度和针片状含量指标都比较敏感。同时高度h正好为针片状的相反指标,即h值越大对应集料的针片状含量应该越小,这与VCADRC随h的增大而减小、随针片状含量增大而增大的趋势是吻合的。
Domestic highways mainly used asphalt concrete pavement. Asphalt mixture is multi-phase composite materials composed by various materials. The aggregate which account for more than 90% of mixture quality is an important factor of the engineering properties of asphalt, especially in the morphological characteristics of aggregates. The traditional aggregate shape test methods are tedious, time-consuming and big workload, influenced by subjective testers, cannot easily get objective timely results. In recent years, with the increasing number of digital image processing technology applied to engineering materials, more and more attention the use of image processing technology to collect and analyze the morphology of aggregates. This paper based on summarizes the domestic and international research on digital imaging technology, mainly to analyze the two-dimensional shape characteristics of coarse aggregate.
Testing scheme is acquisition aggregate image in natural light, with aggregate evenly spread. Using matlab processing segmentation images. Because of the aggregate itself characteristics, segmentation methods don’t adopt commonly gray threshold segmentation, but directly to segmentation the true color pictures of three-channel respectively, successfully obtained the outlines of each particle projection. Calculated the corresponding outlines indexes, specific indexes are major-axis, minor-axis, major-axis / minor-axis, rectangular, shape index and angularity. Finally calculated the statistics value of aggregate shape feature index, which according to statistical analysis of the probability distribution of the samples.
Take single-file aggregate tamping density test, find that the VCADRC from the same set of yard materials decreases as the particle size increasing; In addition, for the aggregate with different rock character of this study, the VCADRC of diabase generally higher than the basalt.
Research the relationship of aggregate shape feature index with VCADRC, the VCADRC is not sensitive of size index for the same size aggregate, more sensitive shape characteristic index is Angularity. The "pseudo" three-dimensional index height is derived by two-dimensional; the VCADRC have high sensitive with height and flakiness content. While the height is exactly the opposite index of flakiness, that is, the greater height corresponding of the aggregate flakiness content should be smaller, which is consistent with the trend that VCADRC decreases as height increases and increases as flakiness content increases.
引文
[1]林辉.基于数字图像处理技术的粗集料形状特征量化研究[D].湖南大学.2007.11~14.
[2]李智,徐伟,王绍怀,张肖宁.沥青混合料压实状态的数字图像分析[J].岩土工程学报.2002,24(4):451~455.
[3]李芬,沈成武,吴少鹏.基于CT图像的沥青混合料分形特征的研究[J].华中科技大学学报(城市科学版).2006,23(2):35~36.
[4]颜强,黄彭,沥青混合料空隙的分形特性.同济大学学报.2004,32(1):43~48.
[5]张肖宁,李智,虞将苗.沥青混合料的体积组成及其数字图像处理技术.华南理工大学学报(自然科学版).2002,30(11):113~118.
[6]彭勇,孙立军,杨宇亮,董瑞琨.一种基于数字图像处理技术的沥青混合料均匀性研究新方法[J].公路交通科技.2004,21(11):10~12.
[7]杨新华,王习武,陈传尧,蒙培生.用图像处理技术实现沥青混合料有限元建模[J].中南公路工程.2005,30(3):5~7.
[8]孙朝云,姚秋玲,沙爱民,张惠玲.沥青混合料数字图像特征提取边缘跟踪算法[J].计算机应用与软件.2007,24(3):156~158.
[9]汪海年,郝培文,肖庆一,刘丽.粗集料棱角性的图像评价方法[J].东南大学学报.2008,38(4):637~641.
[10]李嘉,林辉.基于数字图像处理的粗集料棱角性量化研究[J].公路交通科技.2008,25(7).
[11]肖源杰,蒯海东.粗集料形状特征对沥青混合料抗剪性能的影响[J].材料与应用. 2006,3 :10~12.
[12]黄碧霞,陆阳.基于数字图像处理的粗集料颗粒分布分析[J].路基工程.2008,1:23~25.
[13]汪海年,郝培文,胡世通.粗集料形态特征研究与应用[J].公路.2008,10:180~184.
[14]满臣.基于图像灰度的三维重构递推算法的研究[D].大连理工大学.2005:2~5.
[15]L.Wang,D.S.Lane,Y.Lu,C.Druta.Portable image analysis system for characterizing aggregate morphology[C].TRB 2009 Annual Meeting.88:1~13.
[16] L.Wang,C.Druta,Y.Zhou,and C.Harris.Three-Dimensional Aggregate Evaluation Using Laser and X-ray Scanning[C].TRB 2008 Annual Meeting.87:1~14.
[17]Y.P.Wang,L.B.Wang,T.Harman.Noninvasive measurement of 3D permanent strains asphalt concrete using X-ray tomography imaging[C].TRB.2007:1~25.
[18] L.B.Wang,J.D.Frost,and J.S.Lai.Three-Dimensional Digital Representation of Granular Material Microstructure from X-Ray Tomography Imaging[J]. JOURNAL OF COMPUTING IN CIVIL ENGINEERING.ASCE,2004:28~34.
[19]L.B.Wang,J.D.Frost,L.Mohammad,T.Y.Pang.Three-Dimensional Aggregate Evaluation Using X-ray Tomography Imaging[C].TRB.2002 Annual Meeting:1~10.
[20]L.B.Wang,Jin-Young Park and Louay Mohammad.Quantification of Morphology Characteristics of Aggregate from Profile Images[C].TRB2003 Annual Meeting:1~10.
[21]E.Masad,A.M.ASCE,V.K.Jandhyala,N.Dasgupta,N.Somadevan,S.M.ASCE, and N.Shashidhar,Aff.ASCE.Characterization of Air Void Distribution in Asphalt Mixes using X-ray Computed Tomography[J]. JOURNAL OF MATERIALS IN CIVIL ENGINEERING.2002:123~128.
[22]Hyoungkwan Kim,Carl T.Haas,Alan F.Rauchand Craig Browne.Dimensional Ratios for Stone Aggregates from Three-Dimensional Laser Scans[J]. JOURNAL OF COMPUTING IN CIVIL ENGINEERING.2002:175~183.
[23]Richard A.Ketcham,Naga Shashidhar.Quantitative Analysis of 3-D images of Asphalt Concrete[C]. Annual Meeting of the Transportation Board.2001.
[24]E.Masad,B.Muhunthan,N.Shashidhar,and T.Harman.Internal structure characterization of asphalt concrete using image analysis[J]. JOURNAL OF COMPUTING IN CIVIL ENGINEERING.1999:88~94.
[25]裴建中.沥青路面细观结构特性与衰变行为[M].科学出版社:66~73.
[26]张德丰.matlab数字图像处理[M].机械工业出版社.2009:276~301.
[27]FLETCHER T,CHANDAN C,MASAD E,eta1.Aggregate Imaging System(AIMS)for Characteirzing the Shape of Fine and Coarse Aggregates[J].Transportation Research Record 2003,1832:67~77.
[28] KUO Chun-yi. Correlating Permanent Deformation Characteris-tics of Hot Mix Asphalt with Aggregate Geometric Irregularities [J].Journal of Testing and Evaluation,2002,30(2):13~14.
[29] WILSONJD,KLOTZLD.Quantitative Analysis of Aggregate Based on Hough Transform [J].Transportation Research Record,1996,1530:111~115.
[30]英红.数字图像在沥青混合料中的应用及研究[D].2008:39~41.
[31]周品,赵新芬.MATLAB数理统计分析[M].2009:188.
[32]茆诗松,周纪芗.概率论与数理统计[M].2007:226~250.
[33]中华人民共和国国家标准.数据的统计处理和解释正态性检验[S].2001:6~10.
[34]沈金安,改性沥青与SMA路面[M].1999年第一版:161~165.
[35]中华人民共和国交通部发布.公路工程集料试验规程[S].2005年3月:31~33.