Rheological and aging behaviors of base and SBS modified asphalt with thermochromic microcapsule

Abstract

Thermochromic microcapsule is an innovative and promising asphalt modifier which can dynamically adjust its reflectivity to solar radiation in accordance with temperature. However, thermochromic microcapsule may exhibit different effects on base and modified asphalt binders due to the existence of modifiers. In this paper, the effects of thermochromic microcapsule on rheological and aging behaviors of base and styrene-butadiene-styrene copolymer (SBS) modified asphalt binders were compared. Pavement performance-related rheological tests such as continuous performance grade (PG) grading, multiple stress creep recovery (MSCR), linear amplitude sweep (LAS), shear stress relaxation (SSR) and temperature sweep (TS) were conducted by dynamic shear rheometer (DSR) or bending beam rheometer (BBR) to evaluate rutting, fatigue, cracking and aging resistances of base and SBS modified asphalt binders influenced by thermochromic microcapsule. In addition, aging susceptibilities of asphalt binders were further analyzed by tracking the carbonyl increment after aging. The results indicated that thermochromic microcapsule improved fatigue resistances of both base and SBS modified asphalt binders while improving effect on base asphalt was more obvious than SBS modified asphalt binder. Different from base asphalt binder, SBS modified asphalt binder was almost not influenced by thermochromic microcapsule in terms of rutting and cracking performances. Like base asphalt binder, aging resistance of SBS modified asphalt binder was improved due to the introduction of thermochromic microcapsule. However, the influence of thermochromic microcapsule on anti-aging behaviors of SBS modified asphalt binder was more complex in comparison with base asphalt due to the existence of SBS modifier.