Glass transition measurements of asphalts by DSC
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The glass transition temperature (Tg), measured by Modulated Differential Scanning Calorimetry (MDSC), is related to the flow characteristics of asphalt at low temperatures as is the rate of change of the creep stiffnessm. This study compared the glass transition temperature of different asphalts (neat, chemically modified, and crumb rubber modified asphalts) with the creep stiffness, the rate of change of creep stiffness, and the low specification temperature of the continuous PG grading of those asphalts.
From the rheological data (BBR) and the thermal data (MDSC) for the virgin and the modified asphalts, the modified products had the same variations of values ofm, S, and Tg at lower temperatures as those of their corresponding virgin asphalts. A correlation between the Tg andm value was observed for both the modified and unmodified asphalts. Since DSC measurements for asphalt low temperature properties use less operator time, less sample, and have less measurement and operator error than rheological methods, Tg has promise to be considered as a fast and easy laboratory method to obtain the low temperature useful range of asphalts in pavements.
Keywordsasphalt creep stiffness glass transition rheology
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- 1.C. Such, A. Bernard and A. Poindefert, J. Calorim. Anal. Therm., Geneve, Suisse, 1992.Google Scholar
- 2.B. Brule, J. P. Planche, G. King, P. Claudy and J. M. Letoffe, Am. Chem. Soc., 35 (1990) 330.Google Scholar
- 4.H. U. Bahai and D. A. Anderdson, “Physical Hardening of Paving Grade Asphalts as related to Compositional Characteristics,” Div. of Fuel Chemistry, 204th ACS Meeting, 1992, p. 1397–1407.Google Scholar
- 5.P. Claudy, J. Letoffe, L. Germanaud, G. King and J. P. Planche, “A New Interpretation of Time dependent Physical Hardening in Asphalt Based on DSC and Optical Thermoanalysis,” Div. of Fuel Chemistry, 204th ACS Meeting, 1992, p. 1408–1426.Google Scholar
- 6.I. R. Harrison, G. Wang, T. C. Hsu, “A Differential Scanning Calorimetry Study of Asphalt Binder” SHRP Report # SHRP-A/UFR-92-612).Google Scholar
- 7.B. H. Chollar, G. M. Memon, N. Shashidhar, J. G. Boone and J. A. Zenewitz, “Characteristics of Furfural Modified asphalt,” Transportation Research Board Meeting Paper # 930913, Jan. 1993.Google Scholar
- 8.G. M. Memon and B. H. Chollar, “Thermal Characteristics of Crumb Rubber Modified Asphalt”, 24th NATAS, Sept. 10–13, 1995, pp. 27–32.Google Scholar
- 9.Strategic Highway Research Program (SHRP) report # A-308, “Binder Characterization and Evaluation” National Research Council, 1993, Vol. 2, p. 291.Google Scholar