Viscous-Elastic Characteristics of Plasma-Treated Rubberized Binders and Their Chemical Composition Influences

Abstract

The employment of cold plasma surface treatment on crumb rubber (CR) particles is expected to improve the performance of rubberized binders. In this study, the viscoelastic properties of plasma-treated rubberized binders were characterized by the multiple stress creep recovery (MSCR) test. The test results of two response parameters, namely, nonrecoverable creep compliance and percent recovery, indicated a positive effect of plasma treatment on the rutting resistance and stress sensitivity of rubberized binders. The rutting resistance of most rubberized binders met the criteria of the specification, and a nonlinear viscoelastic behavior of binders was observed during MSCR testing. Also, the modeling of the creep and recovery response was satisfactorily conducted using the Burgers model and modified power law model, respectively. However, the Burgers model lacked accuracy in predicting the strain response in the recovery phase, while the modified power model was indeed better with the consideration of nonlinearity. Further studies reported some pronounced correlations between the model parameters and response parameters. Finally, the creep and recovery behavior of the rubberized binder was fairly related to its large molecular size (LMS) fraction quantified by a gel permeation chromatography (GPC) test.