Journal Published Online: 01 March 1973
Volume 1, Issue 2

A Microscopic Approach to the Microstructure of Paving Asphalts



Asphalts are colloidal solutions consisting of micelles (asphaltene plus adsorbed resins) of the dispersed phase and petrolenes (resins plus oils) of the continuous phase. Depending on the type of asphalt the micelles may flocculate to form a network of small or large structures measuring about 0.005 and 0.050 mm respectively. In the case of an oxidized roofing asphalt the microstructure observed measured about 0.150 mm. Thus, the microstructure can be conveniently observed with a suitable microscope utilizing high intensity reflected light. It is possible in this way to measure the size of individual micellar clusters and thus distinguish between various sol-gel and gel type asphalts.

The small microstructure is the result of good peptizing power of the resins and good solvency power of the petrolene fraction. The large microstructure on the other hand results from poor peptizing power of the resins and poor solvency power of petrolene phase.

Author Information

Sontowski, DP
British Columbia Department of Highways, Geotechnical and Materials Branch, Victoria, B. C., Canada
Pages: 3
Price: $25.00
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Stock #: JTE10891J
ISSN: 0090-3973
DOI: 10.1520/JTE10891J