摘要
粗骨料形态特征直接影响了其堆积状态,从而影响混凝土性能。为了更准确地描述骨料形态,量化特征差异,揭示骨料形态特征与空隙率的关系,本研究采用数字图像技术分析计算了粗骨料形态参数,结合二维与三维形态特征对粗骨料形态进行了准确的评价与分类,同时采用主成分分析(PCA)方法去除了形态特征之间的重叠性,探明了多个形态特征对空隙率的综合影响。结果表明,利用棱角度(An)、圆度(Rd)、球度(Sp)能够很好地区分粗骨料形态差异。结合扁平度(FR)与伸长率(ER)可将粗骨料进一步细分为类球状、盘状、条状、针片状四种粒形。PCA分析表明粗骨料形态特征参数与空隙率具有显著的相关性,且紧密堆积削弱了形态特征对空隙率的影响程度。Sp、An是影响空隙率的关键形态特征,粗骨料空隙率随Sp增大或An减小而减小,在粗骨料生产和选型时应重点控制。
The morphology of coarse aggregate directly affects its packing state,thus affecting the performance of concrete.In order to accurately describe the morphology of aggregate,quantify its characteristic difference,and reveal the relationship between aggregate morphology and voidage,digital image technology was used to analyze and calculate the coarse aggregate morphological parameters in this study.The morphology of coarse aggregate was accurately evaluated and classified by combining 2D and 3D morphological parameters.Meanwhile,the principal component analysis(PCA)was used to remove the overlap between morphological parameters,and the comprehensive influence of multiple morphological parameters on voidage was found out.The results show angularity(An),roundness(Rd)and sphericity(Sp)can well distinguish the morphology differences of coarse aggregate.Combined with flatness ratio(FR)and elongation ratio(ER),coarse aggregate can be further subdivided into four particle shapes:spherical,disc-like,strip-like and needle-like.The PCA results show that there is a significant correlation between the morphology characteristic parameters of coarse aggregate and the voidage,and the close packing weakens the influence of morphology characteristics on voidage.The Sp and An are the key morphology characteristics that affect the voidage.With the increase of Sp or the decrease of An,the voidage of coarse aggregate decrease,which should be controlled in the production and selection of coarse aggregate.
作者
李长志
周新斌
魏世恭
马昆林
于连山
邹卫东
LI Changzhi;ZHOU Xinbin;WEI Shigong;MA Kunlin;YU Lianshan;ZOU Weidong(School of Civil Engineering,Central South University,Changsha 410075,China;Hunan Zhitong Expressway Construction and Development Co.,Ltd.,Huaihua 418000,Hunan,China;China Railway First Group No.5 Engineering Co.,Ltd.,Baoji 721004,Shaanxi,China;China Railway 21st Bureau Group No.6 Engineering Co.,Ltd.,Beijing 100000,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2024年第17期127-135,共9页
Materials Reports
基金
湖南省自然科学基金(2022JJ30732)。
关键词
粗骨料
形态特征
空隙率
T检验
主成分分析
coarse aggregate
morphology
voidage
t-test
principal component analysis
