| At present,With the implementation of the planning and design of a strong transportation country,rural revitalization and "One Belt,One Road" development strategy.In the Gobi Desert region,not only are more and more asphalt concrete pavements being planned and constructed,but there is also a trend toward heavy-duty vehicle transportation.These lead to serious constraints on the service life of asphalt concrete pavements in the Gobi desert area,This phenomenon has become a challenge for current road development.Therefore,the mechanical response of different pavement structures to this particular climate is research.Exploring the breakage mechanism and structural composition of pavement structures in this climate,this has important engineering implications for improving the service life of the road.In this paper,cement-stabilized crushed stone base asphalt pavement and crushed stone base asphalt pavement are used as research objects,The mechanical properties of asphalt mixtures,the temperature field of asphalt concrete pavement structures and the mechanical behavior of the temperature-load coupling field are studied.The relevant studies are as follows:(1)The research group conducted on-site research on the diseases and traffic volume of the G312 high platform section of the road,and determined that the main diseases of asphalt pavement in the Gobi Desert area include rutting,oil flashing,reflection cracks,fatigue cracks,and temperature shrinkage cracks.The mechanism of the diseases was analyzed;Among them,rutting,oil leakage and crack diseases are relatively widespread,which are not only related to the large-scale vehicles but also to the climate and environment of the region.(2)Vertical shear,flat shear and bending tests were done on six compound ratios of SMA-13,AC-13,AC-20(modified),AC-20(matrix),ATB-25(modified)and ATB-25(matrix).Finally,the pavement structure group was determined as SMA-13,AC-20(modified)and ATB-25(substrate)for the characteristics of large temperature in the Gobi desert area.Determine the gradation to do dynamic modulus test,calculate the viscosity and elasticity parameters of the mixture,provide material parameters for numerical simulations.Determine the base structure as asphalt stabilized crushed stone base,cement stabilized crushed stone base,and crushed stone stabilized base,and the subbase as cement stabilized crushed stone base.(3)Northwest cold and arid region road infrastructure long-term service performance of the transport industry field scientific observation research base as the support,investigation of meteorological parameters in the Gobi desert area.Research data for ABAQUS software simulation,analyze the effects of these factors,such as structure type,seasonal temperature,and structural layer thickness,on temperature and temperature stress fields.The results indicate that the temperature stress of asphalt stabilized crushed stone base is greater than that of cement stabilized crushed stone base,and the temperature stress of crushed stone stabilized base is greater than that of asphalt stabilized crushed stone base;Winter temperature stress<summer temperature stress;The thickness of the structural layer has a significant impact on the temperature stress of the upper and lower layers,followed by the middle surface layer.(4)Under the condition of considering the dynamic response of pavement structure under the coupling effect of high and low temperature season and load in Gobi desert area,the temperature field is coupled with the load model.Analysis of the effects of vehicle speed,axle weight,starting braking force and high and low temperatures on the dynamic response of road structures,prognostic modeling of power response indicators by multiple regression.Analysis found that various factors have an impact on the dynamic response,including changes in load ? Braking coefficient ? speed.The shear stress value at low temperature is greater than that at high temperature.The change in displacement response at high temperatures is greater than that at low temperatures.(5)Comparative analysis of dynamic response of pavement structure under different working conditions,analyze the influence and rationality of different working conditions on the dynamic response results of road structures.Establish fatigue life prediction model under different working conditions.Discovered that the fatigue life of structure 2 is lower than that of structure 1 under different working conditions,this establishes fatigue life prediction models to provide reference for proposing accurate relevant models under different working conditions. |
