Effect of the physical properties of aggregates on aggregate-asphalt bond measured using the UCL method

One of the main properties required for the asphalt binder to ensure a good durability in pavements is the bonding ability to hold aggregates. In this context, this paper shows the results of a research study aimed at evaluating the bonding ability of different types of asphalt binders in the aggregate-asphalt matrix, depending on the geometric pattern of the aggregates. According to the UCL method, bitumen performance curves have been evaluated for each studied matrix, and the effect of temperature, water and ageing has been analysed. The most important conclusion is that geometric characteristics of aggregates significantly influence the adhesive properties that can be provided by the asphalt binder, especially at low temperatures and when exposed to ageing.