Page 43 - MODELING OF ASPHALT CONCRETE
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Modeling of Asphalt Binder Rheology and Its Application to Modified Binders 21
11 100
AC-40 (G∗) AC-40 (Delta)
10 AC-5 (G∗) AC-5 (Delta) 80
Complex Modulus at 25°C, log Pa 7 60 Phase Angle at 25°C
9
8
6
40
5
4
3
2 20
1 0
−5 −3 −1 1 3 5 7 9 11 13 15
Loading frequency, log rod/s
(a) Frequency master curves
11 100
AC-40 (G∗) AC-40 (Delta)
10 AC-5 (G∗) AC-5 (Delta) 80
Complex Modulus at 10 rad/s, log Pa 7 60 Phase Angle, °
9
8
6
40
5
4
3
2 20
1 0
−50 −30 −10 10 30 50 70 90
Temperature, °C
(b) Isochronal curves
FIGURE 2-1 Typical rheological spectra for two asphalt binders.
on the composition of the asphalt. Some will show a rapid decline with
temperature and frequency; others will show a gradual change. Asphalts within
∗
this range may show significantly different combinations of G and d.
• At high temperatures, the d values approach 90° for all asphalts, which reflects
the approach to complete viscous behavior or complete dissipation of energy in
∗
viscous flow. The G values, however, vary significantly, reflecting the different
consistency properties (viscosity) of the asphalts.
