Applied Mechanics and Materials Vols. 587-589

Abstract: Through the freeze-thaw splitting test, rutting test, low temperature bending test, comprehensive analysis the affect of coarse and fine ratio on ATB asphalt mixture performance. The results showed that: the ratio of change have a significant effect on water stability, high temperature stability, low temperature stability. Reasonable coarse and fine ratio have a higher degree of stability; Smaller coarse and fine ratio can effectively improve the asphalt mixture water stable performance, with coarse and fine ratio increased, freeze-thaw splitting strength ratio decreases; Larger coarse and fine ratio have an adverse effect on the high temperature stability, dynamic stability after the first increase and then decrease with increasing coarse and fine ratio; Smaller coarse and fine ratio can significantly improve the low temperature stability.

Abstract: Research shows that rheological property of asphalt relates directly to pavement property. To get a grip on the influence of different factors on rheological property of high modulus asphalt, this paper makes a systematic study of different temperatures, loading frequency, strain 70# base asphalt and rheological property of high modulus asphalt by the method of DSR measurement, and compared their anti-fatigue performance. The experiment’s results shows that high-modules asphalt has a low sensitivity of temperature. Compare with the base asphalt, the high-modules modified asphalt’s G*/sinδ will have a slower decrease rapid under the condition of temperature increase. Both asphalt’s G*/sinδ would decrease with the decrease of load frequency, high-modules asphalt has a higher G*/sinδ than base asphalt especially at the high temperature and low frequency.

Abstract: This paper describes the importance of CBR test in the highway construction control. According to theoretical and practical experiments for many years, we put forward own opinions for technical problems occurring in the CBR test.

Abstract: In order to study the anti-cracking performance for high viscoelastic asphalt sand, the semicircle flexural Semi-Circular Bending (SCB) Test is carried out for measuring the maximum load and fracture energy of high viscoelastic asphalt sand. High viscoelastic asphalt sand are subjected to three loading rate (5,20,50mm/min) at three temperature conditions (5,15,25°C).When the temperature is constant ,the maximum load and fracture energy of specimen are increased with the loading rate increased. But, when the loading rate is constant, the maximum load of the specimens is decreased and fracture energy is increased with the temperature increased.

Abstract: Taking the meteorological data in Fuzhou area in 2011 as an example, this paper investigate the seasonal change of the temperature and humidity field of embankment in moist heat areas based on the finite difference technology programmed Moisture-heat coupled procedure. The results show that the highest temperature in the soil surface of embankment is near 40°C and the highest temperature gradient is up to 0.22°C/cm in summer. The lowest temperature is near 10°C and the highest temperature gradient is up to-0.21°C/cm in winter. Fluctuation range of the water content in the surface of the embankment (0cm~10cm) is between 3% and 20%, and fluctuation range of the water content of the shallow soil layer of embankment (10cm~50cm) is between 10% and 20%, and the water content in the deep layer of embankment (50cm~250cm) changes not apparently with season. If the temperature gradient of soil is 0°C/cm and the yearly fluctuation range of the water content of the embankment is 2%, the temperature and humidity of the embankment that can be affected by the climate of the Fuzhou area is in the depth of about 4.0m and 2.5m respectively.

Abstract: At present, the widening highway retaining wall is often used in engineering practice, but compare to the new highway retaining wall, there is not any highlight differences on design method to the widening highway retaining wall. The paper lays on a widening highway retaining wall in an engineer, based on the analysis of the differences between the widening highway retaining wall and the new highway retaining wall, using the finite element method for modeling and analysis of the widening highway retaining wall and the new highway retaining wall, then conclude that the soil displacements and earth pressures between the two models are significantly different, finally point out the considerations in design.

Abstract: The basic physical and mechanical properties of Libyan soil are analyzed through some experiments, including direct shear test, grading analysis test and compression test. According to the test results, the soil is named as low liquid limit silt featured by weak strength, high compressibility and permeability, which directly influences sub-grade stability, durability and pavement’s usability. In order to solve these problems, measures are discussed from two aspects, namely, soil improvement and construction method. The strength of the soil is apparently increased by the cement and lime adding, and the compressibility is decreased at the same time. And the rising height of capillary water reducing and protection forms for silt soil slope are also proved to be effective in the subgrade construction.

Abstract: Granite is a kind of acid stone which has the advantages of high strength, high wear resistance, etc. However, the poor adhesion between the granite and asphalt often fail to meet the corresponding design requirements, and the application of granite asphalt mixture is often affected. Based on the analysis of the comparative tests of common treatment methods in projects, the paper tried to explore the best countermeasures to improve the water stability of granite asphalt mixture, and provide guidance for engineering practice.

Abstract: The rail fastener assemblies under alternating load for a long time , in addition to the vibration and strength,fatigue also is the main reason for damage .So effective fatigue test and life assessment is one of the important means to ensure the safety of railway operation .This paper introduces the routine fatigue test method of railway track fastener assembly which adopts the European Railway Standard EN13146-4,by using 33° test platform which conform to the actual operation stress conditions of the railway track can more effective test the rail fastening assembly.

Abstract: WJ-8 fasteners are widely used in passenger dedicated line in China. Ballastless track structure is required due to the special line for passenger transport. Fasteners for fixed rail, adjust orbit deformation, etc. Therefore, study the changing rule of the fastener performance especially fastener torque for the design and maintenance of track structure has important theoretical and practical significance. Combined with the force of the track structure, this article through the fatigue test was carried out on the track structure. A simulated train bogie of loading. Research WJ-8 fastener torque as the change of fatigue loading two million times. To provide reference for design and maintenance of Ballastless track.