Performance-driven validation of a vegetable-oil-based asphalt binder in experimental pavement sections

Abstract

Decarbonizing road infrastructure has intensified interest in renewable substitutes for petroleum-derived diluents in asphalt binders. This study presents a full-chain evaluation of a bio-based binder (SDR-VO) in which a vegetable-oil derivative replaces the aromatic extract as diluent of a pre-salt deasphalting residue, benchmarked against the conventional counterpart (SDR-AE) sharing the same base and 50/70 penetration grade. Both binders were characterized through Multiple Stress Creep Recovery (MSCR), Linear Amplitude Sweep (LAS), and aging-resistance testing. The bio-based formulation reproduced the high-temperature response of SDR-AE (true Performance Grade, PG ≈ 64 ^∘C) and delivered a modest improvement in rutting-relevant rheology, a lower MSCR J_nr3.2 that brings SDR-VO into the Standard traffic class (PG 64S-22), unlike SDR-AE, while matching its fatigue, aging, and low-temperature indicators, including an equivalent continuous low-temperature PG (\({\approx }{-}23\) ^∘C). A three-point Balanced Mix Design supported by FlexPAVE BR simulations identified the optimal volumetric envelope. Two experimental sections (400 and 340 m) were built in Rio de Janeiro under identical conditions; as-built mixtures showed equivalent fatigue and marginally better rutting for SDR-VO (Flow Number 428 vs. 319 cycles), and FlexPAVE BR projected a marked fatigue advantage of SDR-VO (2.3% vs. 15.6% cracked area at \(10^{7}\) equivalent single axle loads, ESALs) with equivalent rutting. Field surveys yielded maximum Falling Weight Deflectometer (FWD) deflection reductions of 35% (SDR-AE) and 38% (SDR-VO), rut depth below 1 mm, International Roughness Index (IRI) of 3.9 and 2.6 m/km, and equivalent macrotexture. The results substantiate the viability of vegetable-oil derivatives as renewable diluents in pre-salt-based binders.