Influence of de-icing agents on the viscoelastic properties of asphalt mastics

• Published in: Journal of materials science 2007-01, Vol.42 (2), p.676-685
• Main Authors: STARCK, P, LOFGREN, B
• Format: Article
• Language: English
• Subjects: Applied sciences; Asphalt; Biotite; Bitumen. Tars. Bituminous binders and bituminous concretes; Bitumens; Blends; Buildings. Public works; Chemical treatment; Deicing; Dynamic mechanical analysis; Exact sciences and technology; Formates; Formic acid; Glass transition temperature; Gneiss; Limestone; Materials; Materials science; Mica; Modulus of elasticity; Oscillating flow; Polymer blends; Potassium; Rheometry; Shear stress; Softening; Stiffness; Stone; Submerging; Temperature; Viscoelasticity
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-006-0316-0

A study using dynamic mechanical analysis (DMA) and stress rheometry was done on the viscoelastic properties of different bitumen-filler blends disposed to de-icing agents. The blends were mixtures of the same bitumen, B200 (B), and four different filler grades, limestone (L) filler, Oulu (O) stone (mica-gneiss with high biotite amount), Rovaniemi (R) stone (diabase) and Hietavaara (H) stone (diabase). The de-icing agents tested were water, formic acid, potassium acetate (KAc) and potassium formate (KFo). From the DMA measurements, the elastic modulus (stiffness) at −25 °C, the glass transition temperature (Tg) of the bitumen phase, and the softening temperature were measured. The stiffness data at −25 °C proposed that all agents seem to decrease the stiffness levels of the B-O blend with biotite to a larger extent. Formic acid and 50% potassium formates significantly decreased the stiffness level of the B-L blend. The stiffness of B-H blends was not affected by the chemical treatment. A plasticizing effect of water, formic acid, and 5% potassium acetate, was found for the B-L blend. From the changes in the softening temperatures in the temperature range 15–28 °C, it was concluded that chemical treatment may have an increasing effect on the softening temperatures of all blends, although the effect of hardening could not be omitted. Oscillatory flow measurements with a shear stress rheometer demonstrated that the viscosities of the blends increased significantly after the immersion in de-icing agents.