Physicochemical properties of bitumens modified with bioflux

• Published in: Road materials and pavement design Vol. 14; no. 1; pp. 36 - 48
• Main Authors: Simonen, Markus, Blomberg, Timo, Pellinen, Terhi, Valtonen, Jarkko
• Format: Journal Article
• Language: English
• Published: Paris Taylor & Francis 01-03-2013; Lavoisier
• Subjects: Applied sciences; aromatics; asphaltenes; bioflux; Bitumen. Tars. Bituminous binders and bituminous concretes; Buildings. Public works; crystallisation; cut-back bitumen; Exact sciences and technology; fluxed bitumen; Materials; Molecular weight; Physical properties; Polymers; resins; Rheology; saturates; Solvents; Strength of materials (elasticity, plasticity, buckling, etc.); Structural analysis. Stresses; Studies; Temperature; VOCs; Volatile organic compounds; Asphaltene; Viscosity; aromatics; Rheology; Crystallization; Construction materials; Master curve; bioflux; Experimental study; Binders; Bitumen; cut-back bitumen; Polymer modified asphalt; crystallisation; saturates; fluxed bitumen; Resins; asphaltenes; Physicochemical properties
• ISSN: 1468-0629; 2164-7402
• DOI: 10.1080/14680629.2012.735798

Five laboratory-produced cut-back bitumens with same target viscosity of 600 mm
2
/s at 60°C were investigated to determine the effect of chemical composition on the rheological properties. Studied cut-back bitumens comprised four bioflux-modified bitumens and one traditional slow-curing cut-back bitumen as a reference. The generic fractions (saturates, aromatics, resins and asphaltenes) of base bitumens (viscosities of about 1500, 3000, 6000 and 37,000 mm
2
/s at 60°C) were quantified by thin-layer chromatographic method with flame-ionisation detection (IATROSCAN MK-6s) and the rheological properties of the base bitumens and cut-back bitumens were studied with a Physica 301 rheometer. The soft base bitumens (viscosity≤6000 mm
2
/s at 60°C) and their biofluxed solutions proved to be rheologically complex, which was witnessed by wax crystallisation and melting phenomena observed at temperatures between 10 and 30°C. The harder base bitumens with higher asphaltene content did not exhibit noticeable crystallisation. The low polarity and low molecular weight of the bioflux solvent reduced the stiffnesses of cut-back bitumens remarkably under 30°C. Thus, the composition of cut-back bitumens had a significant effect on the rheology of blends, although the target viscosities at 60°C were the same.