Mechanical Property Characterization of Warm-Mix Asphalt Prepared with Chemical Additives

This study experimentally characterized the mechanical properties of warm-mix asphalt (WMA) prepared with two chemical additives: Evotherm 3G and Rediset LQ-1106, using laboratory-mixed and laboratory-compacted (LMLC) specimens. A conventional stone matrix asphalt (SMA), widely used in expressway overlay projects in the Chicago area, was selected as the control mixture. Two warm SMA mixtures were prepared by adding 0.5% Evotherm 3G and 0.5% Rediset LQ-1106 by weight of binder, respectively. The performances of the control SMA, Evotherm SMA, and Rediset SMA were evaluated and compared through extensive laboratory testing, including complex modulus, loading wheel track, indirect tension, and semi-circular beam at various curing time periods after compaction. This study concluded that both warm SMA mixtures provided slightly lower tensile strengths and complex moduli than the control SMA. However, the rutting and fracture resistance potentials of the two warm SMA mixtures were relatively similar to that of the control SMA. The curing time effect on the performance of the two warm SMA mixtures varied depending on the material property measured as well as the additive type. A strong correlation between strength gaining and curing time for the two warm SMA mixtures could not be concluded. (C) 2014 American Society of Civil Engineers.