Asphalt Pavement Of Guizhou Expressway Study On The Variation Of Construction Quality And Improvement Measures

Because the asphalt pavement has better mechanical performance,comfortable driving and convenient construction and maintenance,it occupies a large proportion in Expressway in China.But with the increasing traffic volume and increasing axle load,asphalt pavement structure design and construction itself also has some limitations and shortcomings.These factors lead to some early diseases such as cracking,lapse,oil generalization,exfoliation,rutting,and other early diseases and durability,which seriously affect the safety and comfort of the vehicle.Therefore,how to effectively improve the quality of asphalt pavement,prolong the service life and reduce the maintenance cost to the maximum extent is when it is used.The main problems need to be solved before asphalt pavement engineering.The research shows that the variation of the properties of raw materials and asphalt mixtures and the violent fluctuation of the quality control parameters during the construction will seriously affect the quality of the asphalt pavement,and are the main factors that cause the early diseases of the asphalt pavement.Therefore,controlling the variation of the influencing factors of asphalt pavement quality is the main content of the current quality control of asphalt pavement construction.Based on the survey,test and test data of Guizhou expressway,the main technical parameters(such as penetration,softening point,ductility,grading of bitumen mixture,asphalt content,construction temperature,compaction,evenness and thick Ness)affecting the quality of asphalt pavement construction and variability are introduced in this paper.We studied the variation level,distribution rule and its influence on pavement performance,and put forward some measures to reduce the variability of construction.The paper mainly includes the following four aspects:(1)road condition investigation and cause analysis of asphalt pavement of existing expressway in Guizhou.The survey results show that the main diseases of Guizhou highway pavement are vertical and horizontal cracks,pit grooves,subsidence and so on.These diseases are related to heavy rain in Guizhou area,many roads with long and steep slopes and serious overloading of heavy vehicles.(2)the influence of asphalt binder quality index variation on asphalt mixture pavement performance and control variation measures.The quality of asphalt affects the high temperature stability,low temperature crack resistance and water stability of the mixture.(3)the influence of gradation,asphalt dosage and temperature on the quality of asphalt mixture and the control and variation measures.(4)the variation level and influence factors of the degree of compaction,flatness and thick Ness of asphalt pavement are analyzed,and the measures for improving the degree of compaction,flatness and thick Ness are put forward.It is found that the early diseases of the asphalt pavement in Guizhou expressway are mainly related to the variation of the variation factors that affect the quality of the construction.The variation of asphalt performance will affect the performance of the asphalt mixture,and the performance of the asphalt mixture is directly related to the road performance of the asphalt pavement.The compaction degree,smoothness and thick Ness of asphalt pavement are important control indicators in construction.Controlling their variability is conducive to improving the quality of asphalt pavement.