Advances using surface chemistry relations to quantify bitumen-aggregate stripping

The authors utilize data from electrophoretic experiments, reported in an accompanying paper, to quantitatively assess stripping in bitumen-aggregate systems. Modern surface energy theory has been applied in recent years to estimate adhesive bond strength between bitumen and aggregate. Through the application of the generalized form of the theory, inclusion of the free energy of electrostatic interaction (G EL-term) is evaluated and the potential quantification of the pH effect of interface water investigated. Results indicate that the electrostatic term relates to moisture sensitivity, but that its contribution to the total free energy of adhesion is negligible. Application of the theory in its current form (excluding G EL) is therefore appropriate. The authors propose that pH dependent change in donor-acceptor surface properties holds the key to quantification of the pH effect. This theory is supported by a relationship between the pH and donicity scales, paving the way to quantification of stripping at different pH levels. 2007 Taylor & Francis Group, London.

Advances using surface chemistry relations to quantify bitumen-aggregate stripping Conference Paper