Laboratory research on rheological behavior and characterization of ultraviolet aged asphalt

Abstract

The influence of aging on the evolution of structural, morphological and rheological properties of neat asphalt was investigated by Fourier transform infrared (FTIR), atomic force microscopy (AFM) and dynamic shear rheometer (DSR), respectively. Asphalt was suffered under 20 W/m² of UV radiant intensity and under the condition of aging time (0, 48, 96 and 144 h) with film thickness of 100 μm and film thickness of 50, 100, 200 and 500 μm after aging for 120 h, respectively, at certain UV radiant intensity 20 W/m². Rheological results tested by DSR exhibit higher the complex shear (stiffness) modulus (G*) and lower phase angle (δ), compared to the virgin at the same test condition. The compositions analysis of asphalt before and after aging show an increase of carbonyl and sulfoxides, while a decrease of aromatic functional groups. With the increase of the component of asphaltene, obvious agglomerates of asphalten appear in neat asphalt surfaces after aging.

Keywords

ultraviolet (UV) aging asphalt / rheological behavior / chemical microstructure / morphology evolutions

References

[1] WuS.-p., PangL., MoL.-t., et al.. Ultraviolet and thermal aging of pure bitumen-comparison between laboratory simulation and natural exposure aging[J]. Road Materials and Pavement Design, 2008, 9: 103-113

[2] HveemF. N., ZubeE., SkogJ.. Proposed new tests and specifications for paving grade asphalts[J]. Proc Assn Asphalt Paving Technol, 1963, 32: 247-327

[3] AireyG. D.. State of the art report on aging test methods for bituminous pavement materials[J]. The International Journal of Pavement Engineering, 2003, 4(3): 165-176

[4] TraxlerR. N.. Durability of asphalt cements[J]. Proc Assn Asphalt Paving Technol, 1963, 32: 44-58

[5] Jime’nez-mateosJ. M., QuintroL. C., RialC.. Characterization of petroleum bitumens and their fractions by thermogravimetric analysis and differential scanning calorimetry[J]. Fuel, 1996, 75: 1691-1700

[6] Al-sammerraiF., Al-sammerraiD.. The use of thermogravimetry and NMR spectroscopy in the attempted identification of the source of babylonian building asphalt[J]. Thermochim Acta, 1987, 115: 181-188

[7] AireyG. D.. Rheological properties of styrene butadiene styrene polymer modified road bitumens[J]. J Fuel, 2003, 82(14): 1709-1719

[8] JTJ 052-2000, Standard test methods of bitumen and bituminous mixtures for highway engineering[S]. (in Chinese)

[9] AASHTO TP31-94, Standard test for determining the fatigue life of compacted hot-mix asphalt (HMA) subjected to repeated flexural bending T321-03[S].