1367856 - Generating Binder Inputs in Pavement ME for North Dakota’s Conditions

One of the challenges to implementing Pavement ME is the lack of comprehensive material input databases for bound layers. This study developed a database for binders used in typical HMA mixes in North Dakota by measuring their complex shear modulus (|G*|) and associated phase angle (δ) at unaged, short-term aged, and long-term aged conditions. Binder viscosity was also measured in these three aged states. Existing models were also used to estimate (|G*|) and δ. Results illustrated the aging effect led to an increase in binder viscosity; however, the values remained within the viscoelastic range. The |G*| and δ values for the unaged and short-term aged binders revealed that all the binders performed satisfactorily at high temperatures. For unaged binders, the PG 58H-34 for HWY 83 and HWY 32 displayed different |G*| and δ values indicating the importance of undertaking local binder characterization. For short-term aged binders, PG 58H-34-HWY 83 displayed high stiffness and high elasticity at high temperatures which means it is suitable for high traffic loads. For long-term aged binders, PG 58H-34-HWY 32 was the least susceptible to fatigue cracking since it had a |G*| sin(δ) value that was less than 5,000 kPa at 7⁰C; the rest of the binders were above the threshold at this temperature. The R2 values were above 0.9 for predicted and measured |G*| for all the binders, while for three binders the R2 values were above 0.9 for predicted and measured δ, and for two binders the R2 values were below 0.5.