The following equation was used to calculate the Energy Ratio (ER):
aE x DCSEf
ER =
m298 xD1
(2.36)
where:
a = 0.0299c 3(6.36 S,) + 2.46 x 108
o = tensile stress of asphalt layer ,assumed 230 psi
St= tensile strength, MPa
DCSEf = Dissipated Creep Strain Energy, KJ/m3
D1= creep parameter, 1/psi
m = creep parameter
St and DCSEf were obtained from IDT test. D1 and m were obtained from the
following procedure:
5. Lock-in Do = 0.048 (1/GPa)
6. Determine D1 and m at 20 C from regression
7. Fix m = m at 20C ( assuming m is a constant at three temperatures for the same
mixture)
8. Calculate D1 at 0C and 10C using the following relationship:
1
D(0) = D(20) x
(4.4)