The Effect of Polymer Blends on Fatigue of Asphalt Mixtures

Damage in asphalt pavements due to repetitive stresses and strains caused by both traffic loading and environmental factors can manifest itself as fatigue and thermal cracking, respectively. Cracking is considered as a primary distress mechanism in asphalt pavements. Many studies have been carried out on resolving these distresses. One of these ways is the use of polymer modifiers to improve the properties of asphalt binder and asphalt mixtures. Therefore, this research was conducted to study the effects of domestic polymers (with trade names of SBR and PP) in equal proportions on the fatigue properties of asphalt mixtures compared to expensive imported polymer (called SBS). Accordingly, four-point beam fatigue and indirect resilient modulus tests were carried out. It was found that combination of PP and SBR leads to better preservation of fatigue performance of modifed mixes and increases the fatigue life up to 50% compared to SBS-modified mix. Consequently, such polymers combination can be more beneficial than using SBS polymer