Compatibility and Performance Assessment of Asphalt-Rubber Binder Activated with Waste Cooking Oil

Description

Compatibility and Performance Assessment of Asphalt-Rubber Binder Activated with Waste Cooking Oil

Vatsalya Gawande

Postgraduate Researcher, Department of Civil & Environmental Engineering, Indian Institute of Technology Tirupati, Andhra Pradesh 517 619, India, ce23m412@iittp.ac.in

Shobhit Jain

Postdoctoral Researcher, Department of Civil & Environmental Engineering, Indian Institute of Technology Tirupati, Andhra Pradesh 517 619, India, sj25@iittp.ac.in

Krishna Prapoorna Biligiri

Corresponding Author, Professor, Department of Civil & Environmental Engineering, Indian Institute of Technology Tirupati, Andhra Pradesh 517 619, India, Tel: +91-877-2503157; Fax: +91-877-2503004, bkp@iittp.ac.in

ABSTRACT. The adaptation of crumb rubber (CR) from discarded tires for asphalt modification has been popular due to its potential benefits in waste management along with durability. However, integrating CR into the asphalt binder (hereinafter, called asphalt-rubber or AR) presents environmental and performance challenges such as increased viscosity, stiffness, and production temperatures of the AR binder along with compatibility issues due to the differences in density and structure of the AR components. Thus, the major objective of this study was to enhance the compatibility between CR and the asphalt binder using waste cooking oil (WCO) as a compound activator. The scope of the study included: (a) preparation of modified binders using direct addition method as well as pretreatment method, (b) selection of optimum CR-WCO-modified binder formulation through advanced asphalt binder characterization tests, and (c) assessment of modified asphalt mixtures performance in terms of stiffness and cracking resistance. Utilization of WCO demonstrated significant reduction in viscosity of the modified AR binder and improvement in the workability of AR binder as well as CR-asphalt-WCO compatibility, thus, contributing to enhanced pavement durability and reduced environmental impacts. Further, pre-treating CR with WCO prior to incorporation into asphalt binder significantly improved rubber dispersion, reduced binder viscosity, and enhanced storage stability compared to conventional direct-addition methods. It is envisioned that the findings will contribute to the development of high-performance, waste-valorizing asphalt binder technologies that extend pavement life, reduce environmental impacts, and advance the principles of circular economy.

KEYWORDS: Crumb rubber, waste cooking oil, asphalt-rubber binder, activation, rheological properties, phase separation, storage stability.