Structural characteristics of silane-modified ground tyre rubber and high-temperature creep property of asphalt rubber

In order to obtain a stronger asphalt rubber with better high-temperature creep property, ground tyre rubber was modified by a silane coupling agent. Structural characteristics and interaction mechanisms of this modified rubber and asphalt rubber were analysed by scanning electron microscopy with energy dispersive X-ray spectrometry, Fourier transform infrared spectroscopy, and gel permeation chromatography. In addition, influences on the high-temperature creep property of asphalt rubber were evaluated by dynamic shear rheometer at a single stress level. Results showed that (i) a layer of silane film grafted onto rubber surface changed the elemental composition; (ii) internal molecular cross-linking occurred and stable chemical bonds were formed within modified rubber, resulting in stronger reaction and adhesion state; (iii) modified rubber absorbed more oil and resin and the relative content of large molecules increased, thereby achieving better deformation resistance; (iv) modified rubber resulted in less creep deformation with increasing stress, indicating an improvement of stable property of asphalt under a certain high temperature. (C) 2019 Elsevier Ltd. All rights reserved.