Research On Uniaxial Penetration Test Of Asphalt Mixture At High Temperature Stability Based On Marshall Specimens

So far, the national highway scholars have been proposed many test methods of theevaluation asphalt mixture at high temperature stability. These test methods have their owncharacteristics. This paper put forward uniaxial penetration test by using Marshall specimensto evaluate the shear resistance of asphalt mixture.This article selects different gradation asphalt mixture AC-13AC-16and SMA-16，Marshall specimens of different gradation with different asphalt aggregate ratio are tested byuniaxial penetration test method. The test results and the rutting test results are compared andanalyzed.The test instruments used in the article has mainly includes: uniaxial pressure headof Ф50mm,h:60mm; bottom board of Ф100mm，Center aperture70mm，ply10mm,the sleeveused in Loading confining pressure test of Outer diameter160mm, internal diameter140mm.Test temperature selects for40℃,50℃,60℃, load rate is4mm/s. Static pressure method ofuniaxial penetration test using a fixed load pressure above the specimen, with the passage oftime, studying the changes of displacement specimens.The results indicate that the uniaxial penetration test can be used to distinguish Marshallspecimens Uniaxial penetration failure loads of the same level with different the asphaltaggregate ratio. at Three different temperatures, the fitting curve of the test results showingthe convex parabolic shape, the maximum value is the optimum asphalt aggregate ratio testedvalue. As the temperature increases, the load confining pressure and unconfined test resultsappear more obvious differences, the load test results of confining pressure is always greaterthan the experimental values of unconfined. Static pressure method of uniaxial penetrationtest indicate that the displacement of the loading confining pressure is less than the value ofthe unconfined test. The gradation AC-13and AC-16under the different asphalt aggregateratio of Marshall specimens in the optimum asphalt aggregate ratio, decreased displacement isa minimum, the result of both sides ratio increased gradually.Analysis results indicate that test results of uniaxial penetration test and Static pressuremethod of uniaxial penetration test in the evaluation mixture on high temperature deformation is consistent. After correlation analysis,Uniaxial penetration test load confining pressure in the asphalt pavement design to evaluatethe high temperature stability of asphalt mixture.