Preparation of β‐cyclodextrin / SBS modified asphalts for the improvement of anti‐aging, rheological property, and storage stability

Styrene‐butadiene‐styrene (SBS) modified asphalt (SMA) has been widely used in road engineering for decade. However, the phase separation of SMA was obvious during the transport and SBS degraded after aging. To resolve these problems, β‐cyclodextrin (β‐CD) was used to modify SMA in this work. Conventional properties, storage stability, the effect of short‐term aging on the morphology, and rheological property for SMA and β‐CD/SMA were investigated. The softening point of modified asphalt reached to the maximum of 66.7°C when 1 wt% β‐CD was added to SMA, where the penetration had shown the minimum of 80.8 dmm. In addition, the ductility of β‐CD/SMA increased to the maximum of 797 mm when the content of β‐CD was increased to 5 wt%. Furthermore, incorporation of β‐CD improved the storage stability of SMA. Importantly, the aggregation of SBS was observed in β‐CD/SMA, but modifiers distributed uniformly after a short‐term aging. The rutting resistance and antiaging performances of SMA were also improved by the addition of β‐CD. Considering the comprehensive properties of modified asphalt, the optimum content of β‐CD was found to be 2 wt%.