Control of the internal network structure of crumb rubber-modified asphalt (CRMA) was investigated for its effect on property development in the study presented in this paper. The investigation included evaluation by rheological and interrupted shear tests. Rheological testing involved the monitoring of the changes of the produced complex modulus (G*) and phase angle (δ) for CRMA. In the interrupted shear tests, the shear stress profile for the produced CRMA was investigated. It was found that triggering the critical conditions of the combined interaction of speed, temperature, and time was essential to inducing the formation of the three-dimensional network structure within CRMA. Such triggering conditions played an important role in the swelling, dissolution, and release of crumb rubber modifier components into the asphalt liquid phase. Gel permeation chromatography was used to characterize the nature of modifications that led to the occurrence of a three-dimensional network structure within the produced CRMA. The formation of a three-dimensional network structure for CRMA played a major role in the enhancement of its rheological properties in terms of its stiffness and elasticity. Superior improvements in the stiffness and elasticity indicated improved rutting resistance as well as alleviated permanent deformation problems.


Civil, Architectural and Environmental Engineering

Keywords and Phrases

Asphalt; Elasticity; Gel Permeation Chromatography; Rubber; Stiffness; Stress Analysis

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version

Final Version

File Type





© 2013 National Research Council (U.S.), All rights reserved.

Publication Date

01 Jan 2013