In order to establish a new method for measuring the dimensions of coarse aggregates, five different-size flat and elongated (F&E) coarse aggregates were glued into two specimens by epoxy resin, respectively, and ...In order to establish a new method for measuring the dimensions of coarse aggregates, five different-size flat and elongated (F&E) coarse aggregates were glued into two specimens by epoxy resin, respectively, and slice images were obtained by X-ray CT, then the aggregates were extracted by the fuzzy c-means clustering algorithm. Attributions of the particle on different cross-sections were determined by the ‘overlap area method’. And unified three-dimensional Cartesian coordinate system was established based on continuous slice images. The coefficient values of spherical harmonics descriptor representing particles surface profile were gained, then each scanned particle was represented by 60×120 discrete points conformably with spherical harmonics descriptor. The chord length and direction angles were determined by the calculation. With the major axis (L) and orthogonal axis (W and T), the calculated results were compared with those measured by caliper. It is concluded that the new L, W, and T dimension measuring method is able to take the place of the present manual measurement.展开更多
In this paper a series of digital image processing methods were adopted for getting separated coarse aggregates from asphalt mixture specimen using high-resolution X-ray Computed Tomography (CT) images.The existing th...In this paper a series of digital image processing methods were adopted for getting separated coarse aggregates from asphalt mixture specimen using high-resolution X-ray Computed Tomography (CT) images.The existing three dimensional (3D) particles matching methods based on two dimensional (2D) continuous cross-sections were analyzed and a new 'overlap area method' was presented.After the 3D particles were extracted one by one successfully,the basic parameters of each aggregate:perimeter,area,surface area,and volume were calculated by chain code method.Finally,the 3D mass center coordinates and the sphericity index were introduced.展开更多
In order to study the damage mechanism of asphalt mixture,it is important to obtain the distribution of displacement and strain of its sample in the indirect tension mode.As a result,the digital image correlation meth...In order to study the damage mechanism of asphalt mixture,it is important to obtain the distribution of displacement and strain of its sample in the indirect tension mode.As a result,the digital image correlation method (DICM) was used to evaluate the displacement field and strain field of asphalt mixture.The results showed that the displacement fields under DICM and ABAQUS are similarly;the strain fields are different due to the different modulus of mastic and aggregate;and DICM is an practical method to study the indirect tension displacement and stain.展开更多
基金Project(51038004) supported by the National Natural Science Foundation of ChinaProject(2009318000078) supported by the Western China Communications Construction and Technology Program, China
文摘In order to establish a new method for measuring the dimensions of coarse aggregates, five different-size flat and elongated (F&E) coarse aggregates were glued into two specimens by epoxy resin, respectively, and slice images were obtained by X-ray CT, then the aggregates were extracted by the fuzzy c-means clustering algorithm. Attributions of the particle on different cross-sections were determined by the ‘overlap area method’. And unified three-dimensional Cartesian coordinate system was established based on continuous slice images. The coefficient values of spherical harmonics descriptor representing particles surface profile were gained, then each scanned particle was represented by 60×120 discrete points conformably with spherical harmonics descriptor. The chord length and direction angles were determined by the calculation. With the major axis (L) and orthogonal axis (W and T), the calculated results were compared with those measured by caliper. It is concluded that the new L, W, and T dimension measuring method is able to take the place of the present manual measurement.
基金Sponsored by the Key Projects of National Natural Science Foundation of China (Grant No.51038004)the Western China Communications Construction and Technology Project (Grant No.2009318000078)
文摘In this paper a series of digital image processing methods were adopted for getting separated coarse aggregates from asphalt mixture specimen using high-resolution X-ray Computed Tomography (CT) images.The existing three dimensional (3D) particles matching methods based on two dimensional (2D) continuous cross-sections were analyzed and a new 'overlap area method' was presented.After the 3D particles were extracted one by one successfully,the basic parameters of each aggregate:perimeter,area,surface area,and volume were calculated by chain code method.Finally,the 3D mass center coordinates and the sphericity index were introduced.
基金Sponsored by the National Science and Technology Infrastructure Program (Grant No. 2006BAJ18B05)the National Natural Science Foundation of China(Grant No.50778057)+1 种基金Program for New Century Excellent Talents in University (Grant No. NCET-06-0340)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20060213002)
文摘In order to study the damage mechanism of asphalt mixture,it is important to obtain the distribution of displacement and strain of its sample in the indirect tension mode.As a result,the digital image correlation method (DICM) was used to evaluate the displacement field and strain field of asphalt mixture.The results showed that the displacement fields under DICM and ABAQUS are similarly;the strain fields are different due to the different modulus of mastic and aggregate;and DICM is an practical method to study the indirect tension displacement and stain.
