Time filter

Source Type

Li Y.-W.,Tongji University | Mu K.,The First Highway Survey and Design Institute Co. | Mu K.,Chang'an University | Shi X.,Bureau of Transportation in Shijiazhuang | Wang X.-C.,Chang'an University
Chang'an Daxue Xuebao (Ziran Kexue Ban)/Journal of Chang'an University (Natural Science Edition) | Year: 2014

In order to study the impact of the base-surface contact conditions on pavement performance, the mechanical response of pavement under different bonding conditions between base and surface layer was analyzed. A numerical model based on delamination failure theory was established. Substructure analysis was used to study the bonding state influence on pavement with fine milling, rubber, SBS and conventional asphalt. Direct shear test was used to verify the prediction model. The results show that compared with traditional methods, delamination failure theory can reflect mechanical properties of interlayer with different materials and thicknesses; loss of stiffness in interlayer material can be considered with the increasing wheel load; fine milling and other measures can improve the interlayer stress state under following condition, thin pavement, large horizontal load coefficient and heavy traffic.


Wang C.-H.,Chang'an University | Mu K.,The First Highway Survey and Design Institute Co Ltd | Zhao J.-J.,Chang'an University | Wang X.-C.,Chang'an University
Chang'an Daxue Xuebao (Ziran Kexue Ban)/Journal of Chang'an University (Natural Science Edition) | Year: 2013

In order to obtain the effective compacting time and the temperature, a mixture heat losing finite element model was established based on the heat conduction theory, and the actual experiment was conducted to confirm the model. The mixture heat losing law was systematically researched when the outside temperature was between 0°C and 40°C, then the effective compacting time was presented, and a test road was taken to verify the actual effect. The results show that the mixture heat losing law got by the model of double layer spreading and the observed temperature have the similar losing trend, which shows its high precision. The effective compacting time is from 28 to 48 min and 22 to 37 min when the paving temperature is 150°C and 170°C respectively, which meets the engineering requirement. The test road indicates that when the finite element model is taken to predict the effective compacting time, the smoothness can be improved, the pavement can be compacted fully, and the quality of the road can be guaranteed.


Li J.-p.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute | Li J.-p.,The First Highway Survey and Design Institute Co. | Sheng Y.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute | Zhang J.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute | Zhang J.,The First Highway Survey and Design Institute Co.
Cold Regions Science and Technology | Year: 2010

Because the study on cement concrete pavement in permafrost regions is not enough, we have made an exploration on it along G214 of China. After that the diseases of pavement along the typical road of G214 in permafrost regions were firstly analyzed based on field investigations. The results indicated that the distribution, reasons and mechanism of diseases of cement concrete pavement were different from that of the adjacent asphalt pavement and the general regions. Moreover, the results indicated that longitudinal fracture and broken slabs were the major types of diseases of cement concrete pavement in permafrost regions. Finally, based on the field measurements of settlement along the G214, a possible critical settlement value of fracture failure was calculated under specific conditions. Analysis of the reasons showed that the diseases of cement concrete pavement in permafrost regions were related to the thermal stability of embankment and thaw deformation of embankment etc. © 2009 Elsevier B.V. All rights reserved.


Mu K.,The First Highway Survey and Design Institute Co Ltd | Wang X.-C.,Chang'an University | Zhang J.-Z.,The First Highway Survey and Design Institute Co Ltd
Chang'an Daxue Xuebao (Ziran Kexue Ban)/Journal of Chang'an University (Natural Science Edition) | Year: 2014

In order to study the distribution of free asphalt in double-layer paving technology and to propose reasonable asphalt-aggregate ratio, a temperature losing FE model was established with cold interface considered. The heat influence ranges in upper and lower cold interface were contrasted and analyzed and the factors for free asphalt content reducing were analyzed. Asphalt-aggregate ratio cutting formula was presented under different paving thick messes (8-12 cm). The formula was verified by actual projects. The results show that double-layer paving reduces two cold interface, so the structure layer contains more free asphalt than traditional crafts. By traditional asphalt-aggregate ratio designing, flushing and slippage disease will have more chance for occurring. Layer thickness between 8 cm and 10 cm, asphalt-aggregate ratio should be cut down by 0.10-0.15, and between 10 cm and 12 cm, asphalt-aggregate ratio should be cut down by 0.15-0.20.


Huo M.,The First Highway Survey and Design Institute Co. | Chen J.-B.,The First Highway Survey and Design Institute Co. | Zhu D.-P.,The First Highway Survey and Design Institute Co. | Zhang J.-Z.,The First Highway Survey and Design Institute Co.
Yantu Lixue/Rock and Soil Mechanics | Year: 2010

With the development of the global warming and human activities, the geology along the Qinghai-Tibet highway in permafrost regions appeared new changes. In order to inspect the influences of the changes on the stability of roadbed and take a long-term monitoring system study of early warning on roadbed diseases, the fuzzy math theory was introduced. In the warning system, some key factors including the annual average ground temperature, frozen soil type (ice content), the change of permafrost table, and drainage condition of the roadbed and the method of special adjustment were selected. Then linguistic variables and fuzzy membership function for describing the diseases and their intensity were installed. At last, 37 items of the logic rules for describing influencing factors of the diseases and their relationship with the disease intensity were put forward, combining the disease investigations and experience from experts. Matlab Fuzzy Logic Toolbox was adopted for building the early warning system on roadbed diseases of Qinghai-Tibet highway in permafrost regions.

Loading The First Highway Survey and Design Institute Co. collaborators
Loading The First Highway Survey and Design Institute Co. collaborators