Analysis of creep properties using a flattened indirect tension test for asphalt concrete

The Indirect Tension Test (IDT) is frequently used for evaluation of asphalt material viscoelastic creep properties. With the increased use of finer aggregate gradations and polymer modified asphalt binders in asphalt materials, crushing can occur under the narrow loading heads. The new specimen configuration proposed has a trimmed area under the loading heads, creating a “flattened-IDT.” This integrated modeling and testing study shows that the flattened IDT reduces the crushing observed in the regular IDT. This study shows that the flattened configuration alters creep properties approximately 10-16% within typical experimental variability.