Study On Application Technology Of Flexible Base Asphalt Pavement With Macadam In Nanchong City,Sichuan Province

Semi-rigid base asphalt pavement has many advantages,at the same time,there are some shortcomings,such as poor drainage,reflection cracks and so on,and the pavement is seriously damaged in use.Nanchong sand gravel is rich,the highway adopts graded gravel base asphalt pavement structure,which will improve the road performance of the pavement and reduce the project cost.Therefore,it is of great practical significance and theoretical value to study the flexible base asphalt pavement of southern charging and graded gravel.In this paper,through investigation and analysis,indoor test,indoor test tank test,theoretical analysis,combined with test road research,the asphalt pavement of Tibet graded crushed gravel flexible base has been studied systematically,the physical and mechanical properties of graded crushed stone materials have been analyzed,the bearing capacity characteristics of graded crushed gravel base have been analyzed,and the effect of the passing rate of graded crushed stone sieve holes on the mechanical properties has been put forward The recommended structure of graded crushed gravel flexible base asphalt pavement and the construction control technology of flexible base asphalt pavement are put forward.By comparing the mechanical characteristics and bearing capacity characteristics of graded crushed stone with different grading composition,the test results show that the formation of dense structure of graded crushed stone is not only related to the relative content of coarse and fine particles,but also has the largest size effect;the rebound modulus increases with the increase of unit pressure,and the coarse aggregate is helpful to the improvement of the strength of graded crushed stone.By measuring the resilient modulus of subbase and base,the results show that the equivalent modulus of base top and the vertical deformation increase with the increase of load,and the linear correlation is very good.In this paper,the structural characteristics of asphalt pavement with graded broken stone base are obtained through the indoor test of asphalt pavement with graded broken stone flexible base.The vertical stress caused by load decreases rapidly with the increase of depth.The application of the test road for more than three years shows that the graded crushed stone flexible base asphalt pavement proposed in this project has better road performance than the traditional semi-rigid base asphalt pavement,and the damage of the pavement is significantly reduced.Combined with indoor test tank test and test road paving,the construction and control technology of graded crushed gravel flexible base asphalt pavement is proposed.The results of this paper provide an important scientific basis for the application of flexible base asphalt pavement structure analysis,and have a certain reference value for the design,construction and analysis of pavement structure.