Time filter

Source Type

Tan Y.-Q.,Harbin Institute of Technology | Xu H.-N.,Harbin Institute of Technology | Zhou C.-X.,Dalian Maritime University | Zhang K.,Guangdong Hualu Communications Technology Co. | Chen F.-C.,China Airport Construction Group Corporation of CAAC
Harbin Gongye Daxue Xuebao/Journal of Harbin Institute of Technology | Year: 2011

Based on the field data collected from a medium-scale experimental pavement system, temperature distribution characteristic of subgrade in seasonally frozen regions was studied in detail, and the prediction model for subgrade temperature distribution was proposed with regression analysis. Test data illustrated that: The temperature of subgrade changed with time, and it followed cosine distribution; Energy was stored with the heat transfer in subgrade, and it transferred nonlinear with depth. Based on the collected data, the prediction model for subgrade temperature distribution in this area was proposed. The comparison between measured and predicted temperatures indicated that this model had good applicability and accuracy for this area.


Li J.,South China University of Technology | Zhang X.N.,South China University of Technology | Liu Y.,Guangxi JinMeng Engineering Co | Wu C.H.,Guangdong Hualu Communications Technology Co
Advanced Materials Research | Year: 2013

The surface free energy of the asphalt was determined using the Owen-Wendt method by determining the contact angles between asphalt and different probe liquids. The effect of rock asphalt on the surface free energy of asphalt was measured. The results indicate that the rock asphalt increase the surface free energy of asphalt, which enhances the moisture damage resistance of asphalt. © (2013) Trans Tech Publications, Switzerland.


Li S.-Q.,Chang'an University | Li H.,Research and Development Center on Road Transport Safety and Emergency Support Technology & Equipment | Li H.,Guangdong Hualu Communications Technology Co.
Wuhan Ligong Daxue Xuebao/Journal of Wuhan University of Technology | Year: 2015

Based on oil corrosion degree, oil corrosion text method was put forward. Oil corrosion degrees of matrix asphalt and modified asphalt at both high and ambient temperatures were evaluated qualitatively and quantitatively through oil corrosion text method to express the oil mechanism. Marshall stability test, Immersion Marshall stability test, Cantabro test and rutting test were carried out under oil corrosion, and tracked the development of disease in the oil corrosion sections at the same time. The experimental results were fitted, and were used to distinguish asphalt oil corrosion resistance. According to the theory that similarities can be solvable easily in each other, cohesive force of asphalt fell as the similarity in composition. It was suggested that Cantabro test and rutting test were used as the right method to evaluate high temperature performance and moisture susceptibility in high temperatures and rainy regions, which will provide the important base for the emergency detection and rapid diagnosis. © 2015, Wuhan University of Technology. All right reserved.


Duan Y.-H.,South China University of Technology | Duan Y.-H.,Guangdong Hualu Communications Technology Co. | Zhang X.-N.,South China University of Technology | Wu C.-H.,Guangdong Hualu Communications Technology Co.
Journal of Central South University of Technology (English Edition) | Year: 2011

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. © 2011 Central South University Press and Springer-Verlag Berlin Heidelberg.


Duan Y.-H.,South China University of Technology | Duan Y.-H.,Guangdong Hualu Communications Technology Co. | Zhang X.-N.,South China University of Technology | Zhang S.-X.,South China University of Technology | Yuan M.-M.,South China University of Technology
Journal of Harbin Institute of Technology (New Series) | Year: 2011

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.


Duan Y.-H.,South China University of Technology | Duan Y.-H.,Guangdong Hualu Communications Technology Co. | Zhang X.-N.,South China University of Technology | Li Z.,South China University of Technology | And 2 more authors.
Zhongguo Gonglu Xuebao/China Journal of Highway and Transport | Year: 2011

X-ray computed tomography (CT) was used to get the cross section images of asphalt concrete specimen. Two-dimensional profiles of aggregates were extracted by a series of digital image processing methods. The Fourier descriptors were used to represent the particle profile. Combined with the concept of equivalent diameter, the reasonable sampling intervals were determined, the value of n was qualitatively analyzed, the goodness and degradation of fit were described by coefficient of determination R 2 and graphs, the possible failure case was analyzed. The spherical harmonics transformation was used to represent the 3-D surface profile of particles, the 3-D visualization results of different spherical harmonics transformation values n ' and different sampling points were compared, changing rule of R 2 with n and sampling points was discovered. Results show that the value of n ' is more appropriate to take 25 to 30. The spherical harmonics transformation can describe the 3-D surface profile and local meso-scale characteristic of aggregate particles more accurately, and representing the aggregates by this way is beneficial to the need of computer modeling, and it is beneficial to future virtual experiment work on concrete.


Xu X.,Research and Development Center on Road Transport Safety and Emergency Support Technology & Equipment | Xu X.,Guangdong Hualu Communications Technology Co. | Wu C.,Research and Development Center on Road Transport Safety and Emergency Support Technology & Equipment | Wu C.,Guangdong Hualu Communications Technology Co. | And 2 more authors.
Wuhan Ligong Daxue Xuebao (Jiaotong Kexue Yu Gongcheng Ban)/Journal of Wuhan University of Technology (Transportation Science and Engineering) | Year: 2016

In order to improve the service life of the asphalt pavement of Expressway in Guangdong Province, the asphalt pavement structure risks caused by the inappropriate selection are reduced, In this paper, the structural types, maintenance measures and performance of the asphalt pavement of 13 Highway in Guangdong province are investigated and analyzed. In order to ensure the excellent usage performance, the average service life of typical semi-rigid base asphalt pavement of heavy traffic highway is 10 years. The middle and upper layers are not used to modify asphalt and the asphalt pavement is prone to serious rutting disease. The combined base asphalt pavement is more suitable for use in hot humid area of special heavy duty highway. © 2016, Editorial Department of Journal of Wuhan University of Technology. All right reserved.


Duan Y.-H.,South China University of Technology | Duan Y.-H.,Guangdong Hualu Communications Technology Co. | Zhang X.-N.,South China University of Technology | Li H.-J.,South China University of Technology | And 3 more authors.
Jianzhu Cailiao Xuebao/Journal of Building Materials | Year: 2011

The industrial CT was used for getting the cross-section images of asphalt mixture. Based on digital image processing methods, the coarse aggregates were extracted from the images, and the adhesion problem of coarse aggregates particles was resolved successfully. The judgment criterion of contact between particles was established, and a 5 pixel × 5 pixel size window was designed for contact searching along the particle boundary. After total 640 images were searched by these procedures, the data were analyzed qualitatively, and a contact degree indicator(C) was tried to establish. Four different probability density distribution functions were used to fit C data, and the validity of fit was tested by Kolmogorov-Smirnov and Chi-square methods. Finally, the lognormal distribution was determined for describing the contact characteristics of coarse aggregates particles.


Duan Y.,South China University of Technology | Duan Y.,Guangdong Hualu Communications Technology Co. | Zhang X.,South China University of Technology | Li Z.,South China University of Technology | Wang D.,South China University of Technology
International Journal of Pavement Research and Technology | Year: 2011

Until now, voids in the Coarse Aggregate (VCA) parameter were used to judge whether the coarse aggregate skeleton is formed in asphalt mixtures. However, this method has several shortcomings and deficiencies. In this paper, the X-ray Computed Tomography (CT) is used to obtain two-dimensional (2D) images through a series of digital image processing methods to separate the aggregates successfully. A contact searching method was established to find all the contacting pixels surrounding each particle. All pixels found were stored and analyzed. The contact degree changes, along with the different depths of the specimen, and the contacting pixel values calculated by the algorithm concentrate to approximately 0-20 pixels, which equals about 0-2 mm. Three quantitative indicators, Cl, C2, and C3, were established. Their input data were fitted by 4 different probability density functions (PDFs): Normal distribution, Lognormal distribution, Gamma distribution, and Weibull distribution. The goodness of the fit was simultaneously tested through two different formal statistical tests (Kolmogorov-Smirnov and Chi-square) to provide mathematical support. Finally, the Lognormal PDF was found to be the most suitable for describing the input data distributions, and Cl was recommended as the quantitative indicator for the assessment of stone-stone contact degree. © Chinese Society of Pavement Engineering.

Loading Guangdong Hualu Communications Technology Co collaborators
Loading Guangdong Hualu Communications Technology Co collaborators