Rheological performance of modified binders with LDPE from municipal and consumer waste sources

Abstract

This research study evaluates the impact of five waste low-density polyethylene (LDPE) sources (LDP, LDF, LDPU, LDS, LDMS - directly from municipal solid waste) on the rheological and chemical properties of asphalt binders. Linear and nonlinear viscoelastic behaviour and chemical interactions were studied via DSR and Fourier Transform Infrared (FTIR) spectroscopy. FTIR spectroscopy identified that thermal degradation and oxidation during mixing enhance chemical interactions within a binder. Certain fillers and impurities present in municipal LDPE (LDMS) introduce reactive sites, improving dispersion, blending and binder stability. LDMS binder showed the highest stiffness, elasticity and reduced viscous behaviour at high temperatures and low frequencies. LDPE-modified binders (especially LDMS, LDS) showed improved resistance to permanent deformation, outperforming the base binder (VG 30), whereas higher stress sensitivity is observed in LDPU. However, upon long-term ageing LDMS showed brittle behaviour during the assessment of fatigue behaviour, especially at higher strains due to heterogeneity and impurities. © 2025 Informa UK Limited, trading as Taylor & Francis Group.