Study On Durability Of Composite Modified HMAC With Calcium Sulfate Whisker And Polyester Fiber And Its Mixture

With the rapid development of the country,the number of uses and loads of roads are increasing day by day.In some developed regions,high-grade highways are overloaded and heavy-loaded,and the environment is getting worse and worse.Under such circumstances,fatigue damage to the pavement may occur,such as road surface cracking,rutting and other hazards.Starting with asphalt mixtures,studying its fatigue life is the current hot spot.This paper proposes to add calcium sulfate whisker and polyester fiber to the asphalt mixture to study the fatigue resistance of the composite modified asphalt and its asphalt mixtureIn the experiment,the three major indexes of the composite modified asphalt and the RTFOF aging test were studied by adding calcium sulfate whiskers and polyester fibers with different admixture admixtures.The comparison of the three indicators before and after aging revealed that under the same conditions,calcium sulfate whiskers The polyester fiber modified asphalt has the lowest penetration ratio,elongation and softening point increment,that is,the best fatigue resistance.Through the Marshall test to determine the best oil-stone ratio of asphalt mixture is 5.2%,the composite modified asphalt mixture test piece is produced.The test found that the asphalt mixture sample with the content of 6%calcium sulfate whisker and 0.3%polyester fiber The dynamic stability reached the maximum value and the high temperature stability was the best.The maximum load,compressive strain and stiffness modulus of the asphalt mixture with the highest amount were found by the low temperature bending test,indicating that the low temperature performance is more prominent;The water stability of 6%calcium sulfate whisker and 0.3%polyester fiber composite modified asphalt mixture was tested.In this paper,fatigue tests were carried out by adding different amounts of calcium sulfate whiskers and polyester fibers,and it was found that the cumulative dissipation energy value and the fatigue life number of 6%calcium sulfate whisker and 0.3%polyester fiber composite modified asphalt mixture were the largest.The largest,and by fitting equation analysis,the cumulative dissipative energy and fatigue life can be used to indicate the strength of the asphalt mixture anti-fatigue performance.Through the analysis of the amount and strain data,it is found that the fatigue properties of the asphalt mixture will be different according to the different dosages,and the data will be fitted by the three factors.The fitting result:admixture(calcium sulfate whisker,Polyester fiber has a positive correlation with the fatigue life of asphalt mixture.The tensile strain has a negative correlation with the fatigue life of asphalt mixture.The fatigue factor has a linear correlation with fatigue life.