Critical assessment of new polymer-modified bitumen for porous asphalt mixtures

Anik Gupta,Pedro Lastra-Gonzalez,Jorge Rodriguez-Hernandez,María González González,Daniel Castro-Fresno

doi:10.1016/j.conbuildmat.2021.124957

Anik Gupta, Pedro Lastra-Gonzalez + Show 3 more

Open Access

https://doi.org/10.1016/j.conbuildmat.2021.124957

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Abstract

New experimental polymer-modified bitumen with a high-vinyl content polymer was fabricated for porous asphalt (PA) mixtures. The bitumen with maximum stability was achieved using storage stability, gelation criteria and physical bitumen tests. A dynamic shear rheometer was used to compare the complex modulus, number of fatigue cycles, yield stress, and non-recoverable creep compliance of the experimental bitumen with a reference virgin bitumen 50/70 and a PMB 45/80-65 binder. PA mixtures were also designed to analyze the abrasion resistance and binder drainage characteristics. It was concluded that the experimental bitumen with 4.5% polymer content showed higher elastic response, better fatigue resistance, and improved rutting behavior than the reference PMB. PA mixtures with the new experimental bitumen exhibited higher abrasion resistance, but underwent higher binder drainage, which was addressed by the incorporation of aramid pulp and glass-hybrid fibers.

Highlights

Increasing traffic load has led to requirements of more durable asphalt mixtures
When polymer-modified bitumen is prepared by physical mixing, the polymer tends to separate during storage at high temperatures, giving rise to coarse phase dispersion on cooling, which results in the formation of a polymer-rich phase swollen by the aromatic compounds of the bitumen at the top, and asphaltene-rich phase with no polymer at the bottom
Dynamic Shear Rheometer The data obtained from temperature and frequency sweep tests was used for the calculating the complex modulus and phase angle of the three binders

Summary

Introduction

Adverse weather conditions reduce the serviceability of the pavement. These problems worsen in porous asphalt (PA) mixtures, due to their exposed structure that facil itates excessive oxidation of bitumen [1,2]. Due to combined effects of oxidation, climatic conditions, and vehicle loading, raveling constitutes the predominant distress in PA pavements [3,4,5]. Polymer-modified bitumen (PMB) can be used to enhance the interaction between binder and aggregates without causing segregation of material [6,7,8]. PA mixtures with PMB binder have more elasticity, which improves the low tem perature crack resistance [10,13]

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