Rutting Potential of Warm Mix Asphalt and Possible Misleading Results due to Reheating: Warm mix asphalt, rutting resistance, reheating, modulus, tensile strength

The main objective of this study is to evaluate the rutting potential of warm mixesproduced with various warm mix additives (Evotherm, Sasobit, and foamed asphalt). To achievethis objective, an experimental matrix was developed to determine the mechanical properties ofwarm mixes and the control mix. Laboratory performance testing includes evaluation ofmodulus, strength, and rutting potential using dynamic modulus test, indirect tensile (IDT)strength test, flow number (FN) test, and loaded wheel track (LWT) test. The test results showthat the warm mix could have slightly greater or less rutting potential than the control mixdepending on the type of warm mix additive and the recycled material used in the mix. In thelaboratory tests, plant-produced mixes were compacted in the laboratory without and withreheating. It was found that the reheating process could significantly stiffen the mixture and thestiffening ratios varied from 1.2 to 2.0 depending on the performance characteristics and the typeof mixture. In addition, the rutting test results show different levels of correlation with thedynamic modulus and the tensile strength, depending on the stress state in the performance test.This suggests that attention should be paid to the measured characteristics of each performancetest based on the loading conditions.