Pomegranate peel extract slows bitumen oxidation in laboratory tests
A peer-reviewed laboratory study tests pomegranate peel extract as an antioxidant additive in bitumen, the binder used in asphalt. Modified samples showed smaller chemical changes associated with oxidation and improved high-temperature behaviour. A balanced result came at a 1.5 percent dose by weight. The experiment concerns binder samples; it does not establish longer pavement life under road conditions.
Science··Midday
Fruit-processing waste becomes a binder additive
Pomegranate peel extract reduced oxidation-related changes in bitumen samples during a single peer-reviewed laboratory experiment. In asphalt, bitumen acts as the binder between stone particles. Its flexibility can fall as exposure to oxygen and heat stiffens the material over time. Polyphenols in the extract were investigated for their antioxidant contribution. The preparation used an extracted additive, rather than loose pieces of peel added to a road surface.[1]
Laboratory ageing tests chemistry and flow together
The test set compared unmodified bitumen with several extract concentrations, before and after short- and long-term laboratory ageing. Physical measurements, tests of flow behaviour and chemical analyses were combined. An ageing-related rise in the asphaltene fraction was smaller with the additive. Infrared measurements also tracked oxidation: carbonyl and sulfoxide indicators increased less in modified samples. Stiffness and softening temperature supplied additional measures of binder behaviour.[1]
The balanced dose still needs road validation
The 1.5 percent formulation was the most balanced choice across tests of workability, stiffness and behaviour at high temperatures. Its rotational viscosity at 110 degrees Celsius rose by approximately 77 percent, so processing conditions remain relevant alongside oxidation resistance. These are binder measurements under laboratory conditions. Long-term pavement durability in traffic was not measured, and the precise molecular interactions between extract and bitumen require further chemical investigation.[1]
