Dynamic master curves from the stretched exponential relaxation modulus

The stretched exponential relaxation modulus of regular and polymer modified asphalts is studied. It is shown that this relaxation function can generate the dynamic functions of these materials very well on any finite interval of the reduced frequencies (master curves). By continuation one can, in principle, cover the whole region of master curves of G' and G ''. The dispersive defect diffusion mechanism, which leads to the stretched exponential law, points to the stronger three-dimensional structure of modified asphalt at low temperatures. The method of calculating G' and G '' from the stretched exponential relaxation modulus is proposed and tested on one regular and one modified asphalt. (C) 1997 John Wiley & Sons, Inc.