S. Nahar, A. Schmets, A. Scarpas, G. Schitter:
"Microstructural changes in bitumen at the onset of crack formation";
European Polymer Journal, 56 (2014), S. 17 - 25.

Kurzfassung englisch:
For the first time the initiation and early stages of damage and microcrack growth in
bitumen under mechanical loading conditions have been observed on the micrometer
length scale by atomic force microscopy (AFM). Bitumen films have been applied on
flexible substrates. Tensile loading of the substrate leads to straining of the substrate itself
as well as the bitumen film that has been attached to it. The surface microstructure of the
bitumen film has been studied with AFM for three loading levels: no loading, moderate (5%
strain) and high loading (10% strain) conditions. The initiation and onset of propagation of
microcracks have been observed for the moderately loaded specimen. It is found that
damage in the shape of crazes and cracks does only occur in one of the two microstructural
phases of bitumen, i.e. in the ellipse-shaped domains. Subsequent application of higher
loading levels leads to complete embrittlement and fragmentation of the elliptical domains
into lamellar structures which tend to align and orient in a direction perpendicular to the
direction of loading.

Bitumen, Microstructure, Onset of microscale damage, Microcrack morphology, Crack propagation, Atomic force microscopy

Erstellt aus der Publikationsdatenbank der Technischen Universitšt Wien.