Abstract
Aging changes the chemistry of bitumen and this adversely affects bitumen’s adhesion with aggregate. For this reason, the use of pull-off test was proposed to evaluate bitumen’s adhesion during different aging stages. In this study, the pull-off test method is used to evaluate the effects of aging on a 60/70 penetration grade bitumen and binders modified with 2 and 4% halloysite nano-tube (HNT). The short-term aging (STA) and long-term aging (LTA) of unmodified and modified bitumens were simulated using the rolling thin film oven (RTFO) and pressure aging vessel (PAV) tests respectively. The pull-off test was conducted using the universal testing machine (UTM). Stainless steel and granite substrates moulds were designed and fabricated for this purpose. Dry and wet conditions were simulated to evaluate the loss of bonding strength due to aging. Additionally, consistency tests, namely penetration test, softening