Evaluation of new aspect of styrene-butadiene-styrene modified bitumens: Damping property and mechanism

Abstract

Damping is essential to bearing dynamic loads of construction structures, such as bridges, pavements, and high-speed rails. This paper presents a novel and preliminary understanding of the damping property and mechanism of styrene-butadienestyrene modified (SBS-modified) bitumens. The damping property was evaluated based on the temperature spectra of the loss factor (LF) by a dynamic shear rheometer and the damping mechanism was interpreted from molecular structure, morphology, and thermal analysis, respectively. The results first demonstrated that the SBS-modified bitumens appeared to maintain good damping property with a wide effective damping temperature range, low damping temperature susceptibility, and relatively high LF in normal working temperature range of pavement. In addition, the damping property seemed to be further improved separately by the crosslinker and plasticizer and the synthetic role on improving damping capacity was also observed by the combination of these two additives. Furthermore, the damping property of the SBS-modified bitumens appeared to be considerably influenced by temperature and the integrity of the hybrid via polymers blending and the use of additives. It was noted that the plasticizer promoted the swelling process of SBS polymers, by which improved the dispersion and chain movement ability. Moreover, the crosslinker increased the internal friction by forming denser polymer network. The findings in this paper will facilitate the development and application of the SBS-modified bitumen based damping materials in noise and vibration reducing and controlling to some extent.