Study On Key Technology Of Low Temperature Crack Resistance Of Asphalt Pavement Based On Climate Characteristics In Cold Region

Semi-rigid base asphalt pavement has the characteristics of flexible and partial rigid structure,which is a typical high-grade pavement structure in China.In the northeast cold region of Inner Mongolia Autonomous Region,the asphalt surface is affected by temperature change in winter low temperature environment.The viscoelasticity of asphalt surface is greatly reduced,the fluidity of asphalt material is gradually reduced,and the deformation ability of pavement is getting worse.The temperature shrinkage of semi-rigid material leads to the formation of reflective cracks,and the cracking of pavement occurs,which reduces the overall strength of pavement structure.Simply improving the crack resistance of asphalt material not only improves the construction cost,but also has certain high temperature weather in the northeast of Inner Mongolia Autonomous Region in summer,which needs to take into account the high and low temperature performance of asphalt mixture.Therefore,changing the research ideas to carry out the composite structure crack resistance technology to explore the improvement of low temperature cracking of asphalt pavement in cold regions.In order to optimize the situation of insufficient low-temperature crack resistance of conventional asphalt pavement and respond to the current demand for social and economic development of green emission reduction,the rubber powder particles obtained from the current recycling of waste tires have good physical and chemical properties.Therefore,it is considered that rubber powder particles are used to replace part of fine aggregates,improve the internal composition layout of the mixture,and use the elastic resilience of rubber powder to form its own void adjustment system within a certain range,so as to better improve the mutual stress system between traditional mineral aggregates,so as to change the internal void structure of the mixture.In this paper,20-mesh and 40-mesh rubber powder are used to explore the use of rubber powder particles to change the internal structure of asphalt mixture at the physical level based on the principle of continuous density gradation design of mixture and the optimization structure of AC-13 rubber powder asphalt mixture,so as to improve the cracking status of winter asphalt pavement.In view of many factors affecting road cracking,the high temperature stability,low temperature stability,fatigue performance and water stability of asphalt road were studied.The content of 0 %,0.5 %,1.0 %,1.5 % and 2.0 % of 20 and 40 mesh rubber powder were selected.Through the analysis of test data,under the condition of rubber powder content increasing in turn,the test data of rubber powder asphalt mixture show the change of bell curve.And the optimal solution is obtained when the content is 1 %,the rubber powder asphalt mixture can maintain a good spatial structure,so that the internal density of the pavement layer can be improved.At the same time to avoid a large amount of rubber powder extrusion asphalt mixture internal structure,late asphalt road rolling difficulties and other issues.In order to further improve the asphalt road fatigue crack resistance and reflection crack ability.According to the characteristics of high strength,corrosion resistance and low density of carbon fiber,the carbon fiber surface felt is introduced to further improve the crack resistance of asphalt mixture.Through the composite crack resistance technology,not only the bearing capacity is improved,but also the structural compactness is enhanced,and the resistance to external water is improved.The occurrence of road surface cracking and other diseases caused by water erosion caused by natural rainfall and snow ablation in the northeast cold region of Inner Mongolia is reduced.In view of the low-temperature cracking status of asphalt pavement in cold regions,the composite anti-cracking technology studies the road performance of rubber powder asphalt mixture such as high temperature stability,water stability and fatigue resistance,so as to comprehensively improve the performance of asphalt pavement and prolong the service life of asphalt pavement.It provides a useful reference for the promotion of composite structural crack resistance technology in asphalt road construction in cold regions.