

Type of Document Master's Thesis Author Sellers, Brent Harper Author's Email Address bselle4@tigers.lsu.edu URN etd-06082009-115927 Title Characterization and Transitions of Asphalt Cement Composite Materials Degree Master of Science (M.S.) Department Chemistry Advisory Committee
Advisor Name Title William H. Daly Committee Chair Ioan I. Negulescu Committee Member Louay N. Mohammad Committee Member William E. Crowe Committee Member Huangen Ding Dean's Representative Keywords
- asphalt cement
Date of Defense 2009-04-07 Availability unrestricted Abstract Blends of a PG 64-22 asphalt with a range of load levels (0.2 — 20 wt %) ofSasobit® wax and a single loading of 2 wt % Elvaloy AM® were prepared and
characterized. Sasobit® wax is a high molecular weight paraffinic wax produced
commercially through the Fischer-Tropsch process. Elvaloy AM® is a reactive elastic
terpolymer, comprised of ethylene, butyl acrylate and glycidyl methacrylate monomeric
units. The blends were analyzed by gel permeation chromatography (GPC), differential
scanning calorimetry (DSC), x-ray diffraction, epifluorescence microscopy, scanning
laser confocal microscopy, and dynamic shear rheology. Sasobit (1 wt %) composite
material showed little difference in aging characteristics with respect to the aging
chromatograms of the un-modified asphalt cement. Aging of Elvaloy (2 wt %) composite
material leads to increased concentrations of asphaltene and asphaltene aggregate
components at a greater rate than that observed with the Sasobit composites and
unmodified asphalt cement. Analysis of DSC heating curve enthalpies revealed that
Sasobit composites at loadings above 4% that the Sasobit was completely crystalline.
X-ray diffraction confirmed that ambient temperature Sasobit composite samples
maintained their crystalline form down to the level of 0.2 wt % loading. Evidence for the
additives presence could be seen within the asphalt matrix through epifluorescence and
scanning laser confocal microscopy imaging of each of the composite systems
investigated. Bright point-sources of fluorescence, most easily picked out in the Elvaloy
(2 wt %) composite images, are believed to be asphaltene micelles. Evidence of
improved G* performance in both Sasobit and Elvaloy composite master curves with
respect to the neat asphalt cement master curves is presented. The dynamic viscosity
data at 1 Hz shows that original and TFOT data doesn’t clearly differentiate between
Sasobit composites and neat asphalt cement until after PAV aging. At that stage the
Sasobit composite shows truly linear dynamic viscosity response suggesting that
Sasobit inclusion leads to better dispersion of the viscosity building asphaltene
component throughout the asphalt cement. It is believed that the Elvaloy AM composite
experienced some degree of crosslinking during aging and this is most evident following
the PAV aging in the rheological data.
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