Frequency analysis of stress relaxation dynamics in model asphalts

摘要: Asphalt is an amorphous or semi-crystalline material whose mechanical performance relies on viscoelastic responses to applied strain stress. Chemical composition and its effect the properties of model asphalts have been investigated here by computing complex modulus from molecular dynamics simulation results for two different compositions each resemble Strategic Highway Research Program AAA-1 asphalt in ways. For a system that contains smaller molecules, storage loss at 443 K reach both low high frequency scaling limits Maxwell model. Results composed larger molecules (molecular weights 300–900 g/mol) with longer branches show quantitatively higher decreases significantly as temperature increases over 400–533 K. Simulation approach limit only highest simulated...