Research On The Experiment And Application Of Asphalt Pavement Structural Parameters

At present,asphalt pavement accounts for a large proportion of the total pavements in China,and its structural parameters can best express the performance of the pavement.Therefore,it is necessary to carry out the research on the structural parameters of the asphalt pavement.According to current design specifications in China,the structural parameters are recommended to be measured in the laboratory,while its specific conditions are quite different from the real scenario.In order to propose an analysis method that can reflect real parameters of the pavement to analyze the performance of asphalt pavement,the author studies the influence of the size,temperature and repeated load on asphalt concrete through experiments.Firstly,the typical pavement structure of Jiangsu Province is selected as the research object,and the dynamic modulus and creep curves of three different asphalt mixtures are tested.The size effect,temperature sensitivity and fatigue damage attenuation of dynamic modulus are investigated by changing the size of the specimen,the test temperature and the number of repeated load.After processing and analyzing the test data,mapping relationship about structural parameters from laboratory tests to practical pavement structure is established.Secondly,in order to study the development of the rut depth in asphalt pavements,the Burgers model is chosen to be the constitutive model of the asphalt concrete.The size effect and damage attenuation are taken into consideration in the model.With the UMAT subroutine in the finite element software,an analytical model reflecting the practical parameters of the pavement is obtained.After that,the strain hardening model and the self-made UMAT subroutine are applied to simulate the uniaxial creep test,verifying the feasibility of the model matched in single-layer materials.The MMLS3 is used to perform the accelerated pavement test on the test section cores.By comparing with the simulation results,it is confirmed that the model is also feasible to simulate multilayer composites.Consequently,the model of typical pavement structure in Jiangsu Province is established in the finite element software.The rut depth is simulated under the high temperature and the maintenance measure is evaluated.Some suggestions regarding the preservation of the practical pavement are proposed as well.