Selecting And Optimizing Of Test Method Performance Based On Low Temperature Performance Of Asphalt Crack Propagation Test Method Performance

Since1950s, there has been an increase in the proportion of the asphalt pavementsconstructed worldwide, and our country, over the past20years, has built a large quantityof asphalt pavements that have been widely used in the highways and city roads. As thepavement condition is influenced directly or indirectly by vehicle load and naturalconditions, low temperature cracking has become one of the general forms of roaddestruction. One of the main damages to semi-rigid base in our country is reflectivecracking, the cracking mechanism of which is related to many factors such as load,temperature, humidity, pavement structure, structural combination and materialproperties. Nevertheless, as long as the cracking does not extend to the top and therainwater does not enter into the inside of the road, the damage would not increase, andthe reflective cracking would not be a big problem. Therefore, how to develop a bettertest method to evaluate the reflective-cracking resistance of asphalt mixture, whichwould make guidance to pavement structure design and material design, is of greatsignificance in improving crack resistance of asphalt pavement of our country.At present, there are many test methods to evaluate the cryogenic property ofasphalt mixture, for example, Indirect Tensile Test (i.e. Splitting Test), Direct Tensile Test,Cryogenic Bending Creep Test, Semi-circular Bending Test (SCB), Stress RelaxationTest, Overlay Tester and others. However, on the cryogenic property of asphalt mixture,no unified or generally accepted approach has been generated to make a reasonablejudgment both at home and abroad. Resulting from the difference in loading methods,specimen shape and dimensions, test and constraint conditions, the mechanical propertiesand the deformation characteristics reflected or simulated in each test would not be thesame.This paper, in the first place, makes some comparative analyses on the existing testmethods of cryogenic property of asphalt mixture within and without China, and then, through the numerical finite element modeling, it calculates and analyzes the formationand extension situation of the asphalt pavement cracking in real situation. After that, atest method that could better simulate the actual behavior of the pavement cracking canbe selected. In the next step, this paper also conducts a reliability demonstration on thetest equipment of this method, and studies the reflective-cracking resistance of theasphalt mixture in the meantime. After a series of comparisons and experimentalverifications, this paper selects a test method that is not only stable in the result,repeatable in process, but also time-consuming and maneuverable to stimulate thereflective-cracking resistance.