engleski

Evaluation of Ageing Properties of SBS Polymer Modified Bitumens

The blends of bitumen, BIT, and thermoplastics SBS block copolymer are very important as materials for road, roofs and bridges. SBS is used as modifier of BIT rheological properties. The ageing properties of SBS polymer modified bitumen have the main role in quality of BIT/SBS blends. In the preparation of the blends and in the service conditions the temperature influences on polymer bitumen rheological properties. From this reason it is very important to determine intensity of thermooxidative degradation of pure components of BIT/SBS blends as well as blends. In the paper the bitumen and BIT/SBS blends were aged by means of Rolling Thin Film Oven Test, RTFOT, at temperature 163 oC. The changes of rheological properties of SBS polymer modified bitumen were evaluated using Dynamic Mechanical Analyzer, DMA, and rotational viscosimetar. The oxidative degradation of BIT, SBS and BIT/SBS blends were followed by IR spectras. The thermooxidative stability of polymer bitumen were evaluated on the base of the following results obtained: the changes of viscoelastic functions in relaxation spectras, viscosity in rheograms and changes in IR spectras. The changes in rheological properties of aged polymer bitumen, and the changes in chemical and physical structures dependent on a combine effect of SBS and bitumen oxidation and degradation processes, which varied with the content of polymer. The relationships between viscoelastic measurements, chemical and morphological characteristics

polymer modified bitumens; SBS; rolling thin film oven test; dynamic mechanical analysis; rotational viscosimetar; evaluation of ageing

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