Article,
Aging of asphaltic binders investigated with atomic force microscopy
FUEL, 117 (A): 15-25 (2014)
DOI: 10.1016/j.fuel.2013.09.018
Abstract
We investigated the short and long term aging of asphalt cement (AC)
with different AFM techniques (topography, phase and friction imaging
and nano-indentation experiments). The aging process induces a growth
and nucleation of the asphaltene micelles with a concomitant reduction
of the maltene phase, whereas the short term aging induces the formation
of fractal-like micellar structures. The friction investigation shows
that the aging processes reduce the binder friction coefficient by 50%,
and this reduction occur predominantly during the short term aging,
while the growth of the micelles occur predominantly during the long
term aging. The micro-indentation experiments revealed that the aging
processes cause a stiffening of the AC film (half-order of magnitude for
short term aging, and one order of magnitude for long term aging). The
aging process also increased the apparent viscosity of the AC films by
half-order of magnitude. (C) 2013 Elsevier Ltd. All rights reserved.
