Fatigue characterisation of modified asphalt binders containing warm mix asphalt additives

Fatigue is one of the major distresses in asphalt pavements and is strongly influenced by the properties of asphalt binder. Use of warm mix asphalt (WMA) additives allows production of asphalt mixes at lower temperatures than conventional hot mix asphalt. Lower production temperatures reduce the oxidative ageing of binders and thus addition of WMA additives may significantly impact fatigue performance of the binders and the mixes. The existing Superpave specifications prescribe the parameter G*sin δ as an indicator for fatigue behaviour of asphalt binder. In view of critical weaknesses associated with G*sin δ, several test procedures have been proposed for evaluating the fatigue performance of asphalt binder. The current study investigated fatigue characteristics of two modified binders (polymer- and crumb rubber-modified, PMB and CRMB) containing different dosages of two WMA additives: an organic additive, and a chemical additive. A total of twelve binders including ten warm asphalt binders and two contr...