Investigating the potential of using dry battery waste powders (DBWPs) as a modifier for asphalt binders

Abstract

This study aims at investigating the potential of using dry battery waste powders (DBWPs) as modifiers in asphalt binder. A 60/70 penetration grade asphalt binder was used in this study. DBWPs, which were extracted from spent batteries, were mixed with the asphalt binder at seven different percentages [0% (control sample), 2%, 4%, 6%, 8%, 10%, 15%, and 20% by weight of asphalt binder]. The mixing process was performed at 175 °C for 30 min using a high-speed mechanical mixer. To study the effect of DBWPs on asphalt binder properties, both traditional and Superpave binder tests were carried out. Consistency tests included penetration, softening point, and ductility, while Superpave tests included Rotational Viscometer (RV), Dynamic Shear Rheometer (DSR), and Bending Beam Rheometer (BBR). Flash and fire point tests were also conducted. The test results indicated that the addition of DBWP to the asphalt binder decreased ductility and penetration values and increased the softening and the flash and fire points of the asphalt binder. High-temperature rutting performance of asphalt binder, as presented by DSR rutting parameter (G*/sinδ), was improved by adding DBWP. The high-temperature performance grade of asphalt binder was raised by one grade by adding DBWP up to 10%, two grades at 15%, and three grades at 20%. On the other hand, fatigue and low-temperature performance of asphalt binder were adversely affected by adding DBWP. The Superpave fatigue parameter (G*.sinδ) was negatively increased by increasing the content of DBWP but remained less than the Superpave limit (≤ 5000 kPa). The low-temperature asphalt binder grade was decreased from − 22 °C (for control asphalt binder) to − 16 °C at 15% DBWP and then to − 10 °C at 20% DBWP. Therefore, it is recommended to use DBWP modifier in high-temperature regions to resist rutting distresses.