Changes in Composition and Molecular Structure of Asphalt in Mixing with Crumb Rubber Modifier
In the asphalt industry, interaction between crumb rubber modifier (CRM) and asphalt is conducted at different interaction conditions, which leads to various mechanisms of interactions and consequently different physical properties of final product. Several studies explained different mechanisms of interaction at macro level (changes in CRM particle size and morphology) and the exchange of components between CRM and asphalt. In this study, we are investigating the mechanism of interaction between the CRM and asphalt at molecular level using analytical techniques such as gel permeation chromatography (GPC) in combination with thermo-gravimetric analysis (TGA). The TGA shows the type of the material being released from CRM particles into the asphalt matrix. The GPC shows that the components of CRM released at certain mixing temperature (i.e. 190°C) have higher molecular weight than the ones released at higher mixing temperature (i.e. 220°C). Also, temperature sweep viscoelastic analysis on the CRM binder and its extracted liquid phase (CRM removed) indicates that the released components with high molecular weights are able to create internal network structure in the asphalt and consequently enhance its mechanical performance.
A. Ghavibazoo et al., "Changes in Composition and Molecular Structure of Asphalt in Mixing with Crumb Rubber Modifier," Road Materials and Pavement Design, vol. 17, no. 4, pp. 906-919, Taylor & Francis, Oct 2016.
The definitive version is available at http://dx.doi.org/10.1080/14680629.2016.1138878
Civil, Architectural and Environmental Engineering
National Science Foundation (U.S.)
Keywords and Phrases
Asphalt; GPC; Modification; Polymer; Rubber; TGA
International Standard Serial Number (ISSN)
Article - Journal
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