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Dong Z.,Harbin Institute of Technology | Sun Z.,Harbin Institute of Technology | Gong X.,Harbin Institute of Technology | Liu H.,Beijing Municipal Road and Bridge Building Material Group Co.
Advanced Materials Research | Year: 2011

Frequent starting and braking of vehicles causes rutting of asphalt pavement at urban intersection. As a result, dynamic response of pavement subjected to these kinds of vehicle loadings can be used to analyze rutting mechanism. At first, vehicle loading at urban intersection was described by a vertical and horizontal combined moving pressure with variable speeds. Then, three-dimensional finite element model in transient dynamic mode is developed based on the practical pavement structure. And the moving load, boundary conditions and material parameters were briefly introduced. Finally, through the comparison of time histories and spatial distribution among accelerating, decelerating and uniform motion, mechanism of rutting of asphalt pavement at urban intersections was illustrated according to the finite element simulation. It shows that frequent starting and braking of vehicle at urban intersections, obviously change the stress distribution within pavement structure compared with uniform motion case. The distribution and amplitude of maximum shear stress and horizontal shear stress was observed during the passage of the loading, which will result in shear flow deformation. Pavement structure subjected to moving load exhibits an alternative characteristic which will accelerate the rutting damage of pavement. © (2011) Trans Tech Publications Switzerland.

Zhang J.-X.,Beijing University of Technology | Chen W.-L.,Beijing University of Technology | Yang R.-J.,Beijing Municipal Road and Bridge Building Material Group Co.
Jianzhu Cailiao Xuebao/Journal of Building Materials | Year: 2010

The physical and mechanical properties of coal gangue aggregate were investigated firstly, and then the microstructure characteristics of different kinds of coal gangue aggregate were analyzed. The mechanical property of concrete containing coal gangue aggregate was also measured. The results show that, the main composition of coal gangue is SiO2, which may result in ASR damage of concrete. The SEM experiments indicate that, pore-structure of coal gangues aggregate is different from that of natural aggregate, and the microstructure of natural aggregate is more homogenous than that of coal gangues aggregate. Coal gangue aggregate will not obviously affect the performance of concrete containing coal gangue aggregate when the content of coal gangue aggregate is limited to some extent.

Li Y.Y.,Beijing Municipal Road and Bridge Building Material Group Co. | Li Y.Y.,Harbin Institute of Technology | Yi Q.T.,Harbin Institute of Technology | Liu H.,Beijing Municipal Road and Bridge Building Material Group Co. | En G.L.,Beijing Municipal Road and Bridge Building Material Group Co.
Advanced Materials Research | Year: 2011

With the rapid development of highway construction and rehabilitation, more and more waste asphalt mixture is produced. The waste is under great environment pressure. The reuse of the waste is urgent. Foamed asphalt cold recycling is a solution. In this paper, the foaming abilities of different kinds of asphalts are tested and the best foaming asphalt is found out. Then, the RAP is evaluated. Finally, the properties of the cold recycling mixture are studied. As a comparison, two different gradations with different amount of RAP are designed and their performances are evaluated. By all these tests, it is illustrated that the cold recycled asphalt mixture with foamed asphalt can fulfill all the technical requirements. The foamed asphalt mixture began its first use in Beijing and exhibits well. © (2011) Trans Tech Publications, Switzerland.

Dong Y.,Harbin Institute of Technology | Tan Y.,Harbin Institute of Technology | Liu H.,Beijing Municipal Road and Bridge Building Material Group Co. | Yang L.,Beijing Municipal Road and Bridge Building Material Group Co.
International Journal of Pavement Research and Technology | Year: 2010

In this paper, the noise-reducing characteristics of open graded drainage asphalt mixture pavement were investigated. Based on the prevailing theory of the Pumping Effect between tire and pavement, tire-pavement noise was evaluated. The Standing Wave Tube (SWT) method and the Roadside Pass-by (RPB) method were used. The acoustic properties of the five types of asphalt mixtures typically used in the Beijing region were determined. Properties studied in the laboratory included the noise reduction coefficient and sound absorption coefficient. In situ noise levels and noise frequency spectrums were obtained and compared using these methods. Also, the relationships between the noise reducing coefficient and the percentage of air voids (Va), nominal maximum aggregate size (NMAS), and texture depth (TD) were also analyzed. Analysis of the frequency spectrum of the pavement noise indicated that the open graded drainage asphalt pavement mixture had outstanding performance in reducing the noise level compared with that of dense-grade mixtures. Its noise reducing coefficient was twice as large, and it reduced the pavement equivalent continuous sound level (Leq) by 3.4 to 6.7dB(A). © Chinese Society of Pavement Engineering.

Tan Y.-Q.,Harbin Institute of Technology | Chen F.-C.,Harbin Institute of Technology | Chen F.-C.,China Airport Construction Corporation of CAAC | Liu H.,Beijing Municipal Road and Bridge Building Material Group Co. | And 3 more authors.
Journal of Harbin Institute of Technology (New Series) | Year: 2010

A new approach using the Fiber Bragg Grating (FBG) sensor and viscoelastic model to monitor and analyze the internal strain and temperature of asphalt pavement is proposed. Some parameters including peak strain, temperature and loading time were calculated with the application of multi-dimensional sensors group. These parameters were incorporated with viscoelastic model of five units to evaluate the permanent deformation of pavement. An application example was conducted, and the results show that it is feasible to analyze and calculate the permanent deformation of pavement structures with FBG sensors.

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