"Interlaminar properties of stress absorbing layer with styrene-butadiene-styrene/crumb rubber co-modified asphalt based on warm mix asphalt technology"

Abstract

Three warm-mixed agents were added into the styrene-butadiene-styrene block polymer (SBS)/crumb rubber (CR) composite modified asphalt, and the composite specimen was made of stress absorbing layer mixture with the resulting modified asphalt. The viscosity reduction effect of different warm-mixed agents on SBS/CR composite modified asphalt was evaluated by the viscosity test and the variation characteristics of interlaminar properties of stress absorbing layer with SBS/CR composite modified asphalt were studied by the pull-out test, shear test and interlaminar shear fatigue test. The results showed that the viscosity reduction effect of warm mixing agent on SBS/CR composite modified asphalt from good to bad was followed by Evotherm-3 G, Sasobit-LM and Aspha-min. The bonding property and shear resistance of stress absorbing layer of composite modified asphalt under normal condition was not affected by warm mix asphalt technology, and the interlaminar properties of different stress absorbing layer were evidently descended under high temperature condition and bath environment. The interlaminar pull strength and shear strength of stress absorbing layer of composite modified asphalt modified by different warm mixing agents had some differences, and the addition of Evotherm-3 G and Sasobit-LM could strengthen the interlaminar mechanical strength of stress absorbing layer. Compared with stress absorbing layer of SBS/CR composite modified asphalt, the interlaminar shear fatigue of stress absorbing layers of composite modified asphalts modified by Evotherm-3 G, Sasobitt-LM and Aspha-min decreased by 10.0%, 17.4% and 2.7%, respectively.

Keywords

• composite pavement
• warm mixing agent
• warm mixing asphalt technology
• stress absorbing layer
• styrene-butadiene-styrene block polymer
• crumb rubber
• co-modified asphalt