Asphalt Modified by Styrene-Butadiene-Styrene Triblock Copolymer: Morphology and Model
Publication: Journal of Materials in Civil Engineering
Volume 14, Issue 3
Abstract
The styrene-butadiene-styrene (SBS) triblock copolymer was used to modify the asphalt binder. The morphology and engineering properties of the binders were investigated using transmission electron microscopy (TEM), rotational viscometer, and dynamic shear rheometer. The morphology of polymer-modified asphalt was described by the SBS concentration and the presence of microstructure of the copolymer. When the SBS concentration increased, the copolymer gradually became the dominant phase, and the transition was followed by a change in engineering properties of SBS-modified asphalt. Results from TEM showed that depending on the asphalt and copolymer source, a variety of morphology can be found. The SBS-modified binders might show a continuous asphalt phase with dispersed SBS particles, a continuous polymer phase with dispersed asphalt globules, or two interlocked continuous phases. The optimum SBS content was determined based on the formation of the critical network between asphalt and polymer. Because of this network formation, the binders showed a large increase in the complex modulus that indicates resistance to rutting. At low SBS concentrations, the Kerner model was found to be appropriate to estimate the rheological properties of SBS-modified asphalt. An adapted Kerner equation was proposed in this study to predict the complex modulus of modified asphalt at high SBS concentrations.
Get full access to this article
View all available purchase options and get full access to this article.
References
Bahia, H. U., Hislop, W. P., and Zhai, H.(1998). “Classification of asphalt binders into simple and complex binders.” J. Asphalt Paving Technol., 67, 1–41.
Bandyopadhyay, G. G., Bhagawan, S. S., Ninan, K. N., and Thomas, S.(1997). “Viscoelastic behavior of NBR/EVA polymer blends: Application of models.” Rubber Chem. Technol., 70, 650–662.
Blanco, R., Rodriguez, R., Garcia-Garduno, M., and Castano, V. M.(1995). “Morphology and tensile properties of styrene-butadiene copolymer reinforced asphalt.” J. Appl. Polym. Sci., 56, 57–64.
Blanco, R., Rodriguez, R., Garcia-Garduno, M., and Castano, V. M.(1996). “Rheological properties of styrene-butadiene copolymer reinforced asphalt.” J. Appl. Polym. Sci., 61, 1493–1501.
Brule, B. (1996). “Polymer-modified asphalt contents used in the road construction industry: Basic principles.” Transportation Research Record 1535, Transportation Research Board, Washington, D.C., 48–53.
Buttlar, W. G., Bozkurt, D., Al-Khateeb, G. G., and Waldhoff, A. S. (1999). “Understanding asphalt mastic behavior through micromechanics.” Transportation Research Record 1681, Transportation Research Board, Washington, D.C., 157–169.
Christensen, R. M. (1979). Mechanics of composite materials, Wiley, New York.
Gahvari, F.(1997). “Effects of thermoplastic block copolymers on rheology of asphalt.” J. Mater. Civ. Eng., 9, 111–116.
Isacsson, U., and Lu, X.(1999). “Laboratory investigation of polymer modified bitumens.” J. Assoc. Asphalt Paving Technol., 68, 35–63.
Kerner, E. H.(1956). “The elastic and thermoplastic properties of composite media.” Proc., Physics Society, 69, 808–813.
King, G. N., King, H. W., Harders, O., Arand, W., Chaverot, P., and Planche, J. P.(1992). “Influence of asphalt grade and polymer concentration on the high temperature performance of polymer modified asphalt.” J. Assoc. Asphalt Paving Technol., 61, 29–61.
Kraus, G.(1982). “Modification of asphalt by block polymers of butadiene and styrene.” Rubber Chem. Technol., 55, 1389–1402.
Lee, D. Y., and Demirel, T. (1987). “Beneficial effects of selected additives on asphalt cement mixtures.” Final, Rep. Project HR-278, Iowa Dept. of Transportation, Ames, Iowa.
Lee, Y. J., France, L. M., and Hawley, M. C.(1997). “The effect of network formation on the rheological properties of SBR modified asphalt binder.” Rubber Chem. Technol., 70, 256–263.
Lesueur, D., Gerard, J. F., Claudy, P., Letoffe, J. M., Martin, D., and Planche, J. P.(1998). “Polymer modified asphalts as viscoelastic emulsions.” J. Rheol., 42, 1059–1074.
Lewandowski, L. H.(1994). “Polymer modification of paving asphalt binders.” Rubber Chem. Technol., 67, 447–480.
Little, D. N., Button, J. W., White, R. M., Ensley, E. K., Kim, Y., and Ahmed, S. (1987). “Investigation of asphalt additive.” FHWA-RD-87-001, Federal Highway Administration, McLean, Va.
Michler, G. H.(1996). “Electron microscopic investigations of morphology and structure formation of polymers.” J. Macromol. Sci., B35, 329–355.
Nielsen, L. E. (1978). Mechanical properties of polymers and composites, Marcel Dekker, New York.
Shuler, T. S., Hanson, D. L., and McKeen, R. G. (1992). “Design and construction of asphalt concrete using polymer modified asphalt binders.” ASTM Special Tech. Publication 1108, Philadelphia, 97–128.
Information & Authors
Information
Published In
Copyright
Copyright © 2002 American Society of Civil Engineers.
History
Received: Sep 21, 2000
Accepted: May 2, 2001
Published online: May 15, 2002
Published in print: Jun 2002
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.