The complex modulus, G*, is the total resistance of the binder to deformation and
it has two components: the storage modulus, G', which reflects the elastic response and
the loss modulus, G", which reflects the viscous response. The relationship between G*,
G', and G" is shown below (1):
Viscous
Part
Viscous
Part
CG G* G*
/G"
GI S G' j
G' G'
s Elastic Part
Elastic Part
Asphalt A Asphalt B
Figure 3.5 Components of Complex modulus G*
The figure above also shows that the two asphalt binders with the same complex
modulus may have different phase angle and so the storage modulus and the loss modulus
are different.
The following equations are used to calculate the complex modulus, G*.
G*= Tmax (3.2)
Ymax
2T
rmz 3 (3.3)
Or
= (3.4)
Ymax h (34)
h
where
T = maximum applied torque