Research On Value Of Modulus Of Asphalt Mixture In Surface Layer

The bending stiffness modulus and compressive modulus of resilience of asphalt mixture are important to the design of asphalt pavement and temperature performance evaluation, especially for the surface layer of asphalt mixture, the size of the modulus is closely related to the material mechanics performance, directly affects the road performance of asphalt mixture. However, at present, there is lack of the study on the relationship between the modulus and the parameter of mixture materials, the understanding of the reasonable value of modulus in pavement structure design and analysis is unclear. This paper established the database of modulus by collecting the existed module data, used the comparative analysis method to seek the variation between modulus, temperature parameter and material parameter. Gave the modulus prediction equation under different conditions by fitting regression method, through these methods, this paper provided the reference of modulus value to pavement design and performance evaluation.The comparative analysis results show that the changes of temperature, nominal maximum aggregate size, asphalt content, asphalt type and asphalt grade have different effects on the modulus. The effect of temperature on the modulus of the mixture was the most notable. The relationship between asphalt content and modulus is very complicated, reasonable amount of asphalt is helpful to improve the ability to resist deformation and cracking. The modified asphalt mixture, such as SBS and SBR, can acquire better mechanical properties, and also can effectively reduce the temperature sensitivity of asphalt mixture. Established the regression equation between modulus and temperature in different conditions, use the correction factor to revise the modulus forecast results, the comparison between the calculated value and measured values shows that the polynomial curve built has high fitting accuracy and reproducibility, which can provide reference for the value of modulus in asphalt pavement structure design and analysis.