Research On Meso-characteristics Of Mechanical Properties Of Asphalt Mastics

As an important part of the asphalt mixture,the asphalt mortar has an important effect on the pavement performance of the asphalt mixture.The interaction between the mineral filler and the asphalt in the asphalt mastics affects the performance of the asphalt mastics.At the same time,the ratio of the mineral filler to the asphalt also determines the mechanical properties of the asphalt mastics.Especially in low temperature conditions,the influence of asphalt mastics performance on the overall performance of the pavement is more significant.The current research on the low-temperature performance of asphalt mastics does not have a unified viewpoint,and the influence of the composition and the ratio of mineral filler to asphalt in asphalt mastics has been widely concerned by pavement researchers.This study took asphalt mastics as the research object,and used the cold climate of Jilin as the background to explore the influence of the interaction between mineral filler and asphalt,the ratio of the amount of mineral filler to asphalt and the low temperature environment on the pavement performance of asphalt mastics.The asphalt mastics trabecular bending test was used to study the low-temperature performance of asphalt mastics.And taking fixed asphalt and free asphalt as the starting point,a reasonable explanation of the change of asphalt mastics performance with the filler-to-asphalt ratio was given,and a reasonable selection of the best filler-to-asphalt ratio was given.The meso-characteristics of the mineral filler were analyzed first in the research.The aspect ratio,circularity and particle size distribution of the mineral filler,and the Rigden porosity were tested to lay the foundation for the subsequent research on the performance of the asphalt mastics.The asphalt mastics trabecular bending test was used to obtain the ultimate bending failure stress and ultimate bending failure strain under three low-temperature conditions and eight filler-to-asphalt ratio conditions.The influences of different influencing factors on the asphalt mastics performance were analyzed.Numerical simulation of trabecular bending test was performed using PFC simulation software.The results of numerical simulation analysis were used to obtain the change trend of the mechanical properties of the asphalt mastics with the filler-to-asphalt ratio,which were fitted with actual relevant experiments and the corresponding theoretical calculations were given.It is proved that the actual trabecular bending test is a reasonable method to verify the low temperature performance of asphalt mastics.Finally,the strength and strain properties of the fixed asphalt and free asphalt were quantitatively calculated through the calculation formulas for the strength and deformation properties of the structural asphalt and free asphalt.The influence of low temperature conditions on the strength and strain of fixed asphalt and free asphalt was analyzed,and the performance of asphalt mastics with filler-to-asphalt ratio was analyzed from the angle of fixed asphalt and free asphalt.Finally,based on the actual test and simulation test of asphalt mastics trabecular bending,and the strength and strain properties of structural asphalt and free asphalt,the optimal filler-to-asphalt ratio in asphalt mastics was reasonably recommended.