Quantitative evaluation and enhancement of adhesion between bitumen and aggregates

Jiusu Li, Wenbo Zhang, Wenke J

Abstract

Stripping of asphalt-binder (bitumen) from the aggregate surface can undesirably contribute to various distresses in hot-mix asphalt (HMA) pavements such as ravelling (aggregate loss), cracking, pot-holing, etc. As a means to minimize this phenomenon, a quantitative adhesion test and evaluation method (QATE) was proposed and investigated in this study to characterize the bitumen-aggregate bond strength and adhesion properties. Concurrently, an innovative anti-stripping additive was developed in the laboratory through appropriate combination of the following chemical agents: Polyamide (PA), anti-moisture polymer (AMP), epoxy resin (EP), and dioctyl phthalate (DOP). The optimum anti-stripping mix proportions were determined and proved effective with an adherence percentage of 97.3% after 10 minutes boiling in water.