6533b853fe1ef96bd12ac2ff

RESEARCH PRODUCT

Microstructure and rheological response of laboratory-aged SBS-modified bitumens

Pietro LeandriGiovanni PolaccoMassimo LosaD. Lo PrestiD. Lo PrestiSara FilippiGordon AireyGiacomo Cuciniello

subject

chemistry.chemical_classification050210 logistics & transportationPolymer-modified bitumen SBS ageing GPC percent recovery sulphur MSCR.Materials sciencePercent recovery05 social sciences0211 other engineering and technologiesMSCRmacromolecular substances02 engineering and technologyPolymerMicrostructureAgeingSulphurchemistryRheologyGPC021105 building & construction0502 economics and businessHardening (metallurgy)Polymer-modified bitumenComposite materialageing; GPC; MSCR; percent recovery; polymer-modified bitumen; SBS; sulphurSBSCivil and Structural Engineering

description

Polymer additives are widely used to improve the performance of road bitumens including their resistance to hardening during oxidation, although their oxidative inhibitor effect has not been well documented. This study aims to investigate the effect of laboratory-simulated ageing on the microstructure, and rheological properties of Polymer Modified Bitumens (PMBs) prepared with a Styrene-Butadiene-Styrene (SBS) copolymer and sulphur as a cross-linker. The laboratory ageing was conducted through the Rolling Thin Film Oven (RTFO) and the Pressure Aging Vessel (PAV) procedures. The unaged and aged binders were characterised using the Multiple Stress Creep and Recovery (MSCR) test, Gel Permeation Chromatography (GPC) and fluorescence microscopy. The MSCR test showed that the cross-linked polymer had a higher capability of mitigating the effect of bitumen hardening on the rheological response, while for the PMBs without cross-linking, the polymer effects decreased significantly after RTFOT ageing. The GPC results showed that the aromatics, resins and asphaltenes fractions of the unmodified bitumens shifted towards heavier molecules after one cycle of PAV ageing but showed limited variation with further ageing. Similar behaviour was observed for the uncross-linked polymer binders, while for the cross-linked polymer binder, the behaviour depended on the polymer concentration.

yearjournalcountryeditionlanguage
2019-05-27
10.1080/14680629.2019.1621771http://hdl.handle.net/10447/383110