and 80.7 C). Similarly, table 4-5 shows the results of viscosity test results obtained from
the Dynamic Shear Rheometer. The viscosity is reported in centiPoise (cP).
Table 4-5. Dynamic shear rheometer results on unaged and RTFO aged binder
Testing Temperature Unaged Binder Viscosity RTFO Aged Binder Viscosity
(0C) (cP) (cP)
30 2.46E+06 5.08E+06
40 1.99E+05 1.20E+06
Based on the results shown in Tables 4-4 and 4-5, the viscosity for each complex
modulus test temperature was obtained using the equation (4-4).
Log(log(r) = A + VTSlog(T) (Eq. 4-4)
in which qr is bitumen viscosity in centipoises, T is test temperature in Rankine, and A
and VTS are regression constants reflecting the specific type of asphalt cement and aging
conditions of the material. Table 4-6 summarizes the calculated A and VTS values for
the unaged binder, and the RTFO aged binder results from the Brookfield Rotational
Viscometer test and the Dynamic Shear Rheometer test. Similarly, Table 4-7 lists typical
A and VTS values for PG 67-22 (AC- 30), recommended by Witzcak and Fonseca
(1996), for two conditions: (a) original, and (b) short-term (mix/laydown). A comparison
of Tables 4-6 and 4-7 shows that the parameters obtained from the Brookfield Rotational
Viscometer test for RTFO aged asphalt are close in values to the A and VTS values
recommended by Witzcak and Fonseca (1996) for Mix/Laydown conditions. The A and
VTS values obtained from the Dynamic Shear Rheometer are slightly lower.
Based on the results presented in Tables 4-6 and 4-7, the viscosity (in Poise) was
finally calculated for the complex modulus testing temperatures used. The viscosities of