Research On Shape Characteristics And Distribution Characteristics Of Aggregate Based On Image Analysis

Set of geometric characteristics of material can be divided into three aspects: shape,angularity and surface texture,which reflect the aggregate piece,highlighting the degree of contour angular,aggregate surface roughness.The aggregate shape of traditional experimental method is indirect measurement,heavy workload,tedious and subjective method.In this paper,digital image processing technology is used to select the commonly used kinds of river sand and mechanism sand,granite and limestone in the coarse and fine aggregate,and the 2D and 3D shape characteristics of the aggregate are systematically studied and analyzed.The main contents include four aspects: the extraction and quantification of coarse and fine aggregate shape parameters,analyze the horizontal and vertical distribution,and explores the relationship between fractal and aggregate shape parameters;for the first time put forward two kinds of imaging device for sand image acquisition and proposes a new method of measuring the fineness modulus of sand the validation of image analysis;the aggregate shape parameters for aggregate mechanics experiment;this paper proposes a CT three-dimensional reconstruction and extraction of 3D shape parameters of aggregate.The experimental results show that the particle size range of 9.5-13.2mm and16.0-19.0mm is easy to exist in the shape of needle like and sharp edges and corners,but the shape parameter of river sand with different grain sizes has little change.Between different aggregates,granite in the rectangular flat degree,degree,the mean shape index of three parameters should be smaller than the limestone in the two parameter evaluation of angularity on more than limestone,also found that the parameters of the discrete nature of granite is less than limestone;shape parameters of river sand are less than artificial sand,discrete are less than artificial sand.Linear fitting of the characteristic parameters and the fractal dimension of aggregate shape index,found in coarse aggregate,there is a good linear relationship between shape index,angularity AC ?AP of coarse aggregate,overall profile coefficient and edge angle in fine aggregate and fractal dimension,indicating that these parameters affect the particle fractal changes.It is found that there is a good correlation between shape index,rectangle degree,flatness,edge AC of coarse aggregate,overall profile coefficient,flat degree,degree of roundness and crushing index of fine aggregate and crushing index.In this paper,the design of two kinds of coarse,fine aggregate imaging device can solve the error caused by external factors in the imaging process and the situation of sand particles taking pictures difficult separation.A method for the determination of sand fineness modulus is proposed,to achieve the precise determination of fineness modulus of sand,and obtained better reflect the average thickness of the sand Feret minimum diameter.The grinding machine is put forward for the first time slice technology to obtain image sequence of concrete,with the help of the coarse aggregate in concrete was extracted from image processing technology and Mimics software,3D reconstruction,and extract the 3D size model library is established.