Evaluation of the Nano-Hydrated Lime effect on Cohesion and Adhesion Failure Mechanisms against Moisture Susceptibility

Moisture damage of asphalt mixture is one of the key factors of asphalt cracking. The aim of this۱۴ study is to investigate the effect of aging on the performance of hot asphalt mixtures and examined۱۵ the improvement of moisture damage performance by using an anti-stripping additive via۱۶ mechanism and functional test. Two types of aggregates (limestone and granite) with different۱۷ degrees of moisture sensitivity, two types of bitumen (PG۶۴-۱۶ and PG۵۸-۲۲) with different۱۸ performances, and Nano-hydrated lime as bitumen modifiers were used. The Pull-Off test was۱۹ performed to investigate the effect of different failure mechanisms (cohesion and adhesion). The۲۰ Pull-Off test results showed that, in terms of hot asphalt mixture hardening in dry and wet conditions,۲۱ the additive relatively improved the yield modulus of the asphalt mixture, but the effect was greater۲۲ in the wet condition and as a result, the ratio of wet to dry modulus increased. A comparison of the۲۳ Pull-Off test results in two states of cohesion and adhesion failure demonstrated that Nano-hydrated۲۴ lime was more effective in enhancing bitumen and aggregate adhesion in the comparison with۲۵ cohesion between bitumen molecules.

Keywords:

hot-mix asphalt , moisture damage , Nano-hydrated lime , Pull-Off test