Applied Mechanics and Materials Vols. 361-363

Abstract: Based on the multi-layer elastic system theory , a large general used finite element software is used to analysis in the paper. To the asphaltum concrete surface layer pavement structure, the basic layer shares more load for surface layer along with the basic layer rigidity increasing. To the cement concrete surface layer pavement structure, the basic layer shares less load for surface layer along with the surface layer rigidity increasing. Whichsoever, the soil ground equivalent stress below subgrade 2m deep is almost not affected from the pavement structure layer rigidity change, but it will increase with the load increasing.

Abstract: The ratio of asphalt mixture was designed with Superpave method. Through the test section, road performance of the asphalt mixture difference are expounded with Marshall design and Superpave method. Further validate asphalt mixture designed with Superpave has better performance.

Abstract: Crack is the common and important distress mode of Semi-Rigid Asphalt Pavement . To simulate the dynamic property of vehicle, three dimensional dynamic FEM is made use of and moving load is imposed on the surface of pavement model in this paper. Dynamic stress intensity factor of reflective crack in pavement structure layers is got by calculating the road model with crack , then comparing stress intensity factor of mode I and mode II under moving load with them under static load. It is discovered that the maximum of dynamic stress intensity factor is bigger evidently than static stress intensity factor when reflective crack extends in base layer and sub-base layer, but the results are very close when reflective crack expands into surface layer.

Abstract: Compaction parameters directly affected the performance of bituminous pavement, but the complex mechanism and factors brought difficulty to their reasonable selection. A DEM (Discrete Element Method) model was set up to simulate the pavement compaction with different compaction times, compaction velocities and roller tonnages. Then reasonable operation parameters for given pavement were concluded with VCA (the Void of Coarse Aggregates) as an index to evaluate compaction effect, and the results took on a good consistency with construction experience and the specification in PR China.

Abstract: Preparation of double layered specimen at laboratory scale is important in evaluating the performance of bond strength between pavement layers since it is normally less costly. It however involved single face compaction at wearing course layer during the specimen preparation which raised potential skepticism over the quality of the layer compacted at single face only. This paper presents the properties of single face compacted porous asphalt (SFCPA) specimen compared to conventional double face compacted porous asphalt (DFCPA) specimen. These specimens were of Grading A in accordance with the specification from Malaysia Public Works Department (PWD). The permeability and abrasive loss were investigated for specimens fabricated at 3 thicknesses of 35mm, 50mm and 65mm at an allowable limit of ±1mm. 50 blows compaction at each face according to PWD specification is adopted for DFCPA specimen, which resulted in compacting effort of 100 blows compaction for SFCPA specimen was applied for every thickness. For both tests, SFCPA possessed lower permeability and abrasive losses compared to DFCPA. This observation is the consequences of potential aggregate crushing in SFCPA which then partly filled up the voids within the specimen and reducing the permeability. Increased in density as a result of permeability reduction had increased the interlocking between coated aggregate particles, hence the abrasive loss in SFCPA is lessened.

Abstract: With China's high-speed railway are built in large quantities to a huge network, the new features of the high-speed railway present a severe challenge for train dispatching command. Therefore, development and design of high-speed railway train dispatching simulation training system is indispensable. This paper analyzes the requirement of the system, puts forward the overall structure of system, describes the data flow and designs the function modules. All work lays the foundation for the systems development and use. It has important significance in the cultivation of the high-speed railway transport professional talents and improves the railway transport information.

Abstract: A laboratory study was carried to investigate the recycled asphalt performance of recycled asphalt mixture. The recycled asphalt mixture is from the Guaxing road in Gansu Province. By extraction tests and combustion method test on recycled asphalt mixture, the content of recovery asphalt, penetration, softening point and ductility were measured. The chemical composition testing and rheological testing were conducted on the recovery asphalt and new asphalt. Results indicate that the recovery asphalt contain the high proportion of asphaltenes and the low proportion of aromatics and resins. With temperature increasing, the decrease in the complex shear modulus (G*) of the recovery asphalt is much larger than that of the new asphalt,the increase in the phase angle of the recovery asphalt is much larger than that of the new asphalt, too. All these lead to the recovery asphalt harden, poor liquidity and plasticity.

Abstract: A roads ecological environmental quality index data for years is a time-series, and accurate prediction by exploring the changing rule of the time series is significant for future environmental protection. For this end, based on time series analysis, this paper firstly carries out steady analysis and random test pretreatment for the eco-environment quality index (EQI) data collected. Next, an ARMA model is established by pattern recognition, established bands and parameter estimation, and then verified by the data collected in recent years. Finally, the ARMA model is used to predict the future EQI values. This research will provide effective guidance to the eco-environmental protection along the road.

Abstract: The traditional highway development even pays more attention to the technique index of the highway, emphasizing the service ability and the service quantities and to for national economy. Usually emphasized" technique" factor for the highway but neglected the peoples request of environmental protection, cultural, region, art and other comprehensive factor. This paper put forward the concept, contents and characteristics for the highway architecture and the highway architecture design, to leads into the public building design theories and methods, and to modify the idea of design and construction for highway. The highway architecture is to study the highway buildings structure, function, environments and pepoles activity etc. certainly also includes two aspects of technique and art. The highway architecture design is the space design for highway buldings to satisfy various basic functions of highway and moderates the foundation of various factors, such as the highway buildings and environment etc.

Abstract: Taking SBS and rubber powder as modifier, adopting the dosage of 4%, 5%, and 6% of SBS while 2%, 4%, 6% of rubber powder to prepare composite modified asphalt, studied the preparation technology of composite modified asphalt, analyzed the trend of ductility, penetration, softening point and elastic recovery. The results show a certain SBS dosage, with the increase of the rubber powder, ductility decrease while softening point and elastic recovery increase, penetration decrease first and then rise. It can provide reference for the preparation technology and performance study of composite modified asphalt.