Influence Of Water On Warm-Modified Asphalt: Views From Adhesion, Morphology And Chemical Characteristics

It has been proven that warm mix asphalt (WMA) has great potential for reducing the fuel consumption and polluting emissions during the construction of asphalt pavement. However, the moisture susceptibility of WMA is one of the main concerns associated with this material, and it limits the wide application of this technology. In this study, a styrene-butadienestyrene (SBS) modified asphalt was selected as a control binder, and two types of WMA additives with different dosages were used to prepare warm modified asphalt binders. Atomic force microscopy (AFM), dynamic shear rheometer (DSR), and fourier transform infrared spectroscopy (FTIR) tests were carried out to evaluate the influence of water immersion on the nano-adhesion properties, morphological characteristics, stiffness, and chemical constituents of asphalt with and without the WMA additives. The results showed that several changes in the asphalt resulted from water immersion, including a decline in the adhesion performance, the appearance of small bumps on the surface of the asphalt, an increase in asphalt stiffness, and the amount of oxygen-containing functional groups and polar components in the asphalt. In addition, the SBS modifier in the asphalt remained stable during water immersion. Considering the effects of the WMA additives, it was found in this study that the water-induced adhesion degradation, oxidative aging, and increase of the polar components in asphalt could be delayed with the use of Sasobit. (C) 2020 Elsevier Ltd. All rights reserved.