Estimation of rutting characteristics of waste tire rubber-modified asphalt binder using GPC

Abstract

The asphalt binder is modified using the crumb rubber from scrap tires to improve its performance in the pavement on street and highways in an urban area setting. In this study, the rutting resistance index (G*/sin δ) and chemical composition of rubber-modified binders (RMB) were evaluated using a dynamic shear rheometer and a gel-permeation chromatography system respectively. A source of PG 64-22 asphalt was used for preparing a total of 12 RMB binders. Routine Superpave binder testing was carried out; RMB as the original binder and then RTFO-aged binder as RTFO in DSR test at high temperatures. From chromatogram data, the correlation of large molecular size (LMS) with G*/sin δ was evaluated by service temperatures, 70 and 76°C. A significant correlation was found between LMS and G*/sin δ. The size and type of CRM were significant factors affecting the rheology of the binders. The values of G*/sin δ could be estimated using LMS and CRM size by temperature with R2 of over 0.92 by the developed prediction model.