Quantitative determination for effective rubber content in aged modified asphalt binder

Abstract

During the aging process, the desulfurization and degradation process of crumb rubber modified asphalt binders (CRMA) consistently occurs. In this paper, a toluene insoluble test, an electrochemical titration method, viscosity, FTIR and GPC were developed to determine the effective crumb rubber content of CRMA after exposure to various aging conditions. Centering on efficiency and accuracy, these five methods were compared with the Pearson coefficient method. The results show that when the degree of aging was severe, the desulfurization and degradation of rubber were aggravated, causing the CC bond in the rubber to break and an increase in the large molecular weight of the asphalt binder. The effective rubber content in the aged CRMA was 7.7–14.2% less than the unaged CRMA. At the same time, the correlation coefficients among the five methods were all above 0.90, but the electrochemical titration and FTIR had priority over the other methods.