Analysis of the binder-aggregate interface of chip seal binders in different stages of ageing using the bitumen bond strength (BBS) test

This paper evaluates the binder-aggregate interface during the service life of binders used in chip seal treatments in Brazil based on the perspective of adhesion/cohesion and aggregate loss distress. For this purpose, three materials were selected: two rapid-setting emulsions (unmodified and polymeric) largely recommended for the construction of these coats and a conventional asphalt cement binder of 50–70 penetration, similar to the binder used in the manufacturing of these emulsions. Samples of the binder were aged in the laboratory using two methods: (i) ultraviolet (UV) induced ageing, in a weathering chamber; and (ii) conventional PAV ageing. The bitumen bond strength (BBS) test was used to evaluate adhesion/cohesion in the binder-aggregate interface. It was possible to conclude that ageing mechanisms considerably affect the binders' composition which is reflected in the increase of pull-off tensile strength necessary to break the bond between the binder and aggregate.