Do regular- and nano-sized hydrated lime have different mechanisms in asphalt?

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© Chinese Society of Pavement Engineering. Currently, most highway agencies use hydrated lime, or specially referred as Regular-sized Hydrated Lime (RHL) as a multifunctional additive, especially to mitigate moisture damage of the asphalt mix. Previous physical studies by the authors have addressed the potential benefits of using the Nano-sized Hydrated Lime (NHL) over the RHL in the asphalt-aggregate system. However, the hydrated lime (RHL and NHL) mechanisms in asphalt-aggregate system, to be fully addressed, should be studied using physical and chemical investigations. One of the objectives this paper is to present a state-of-the-art of the mechanisms of hydrated lime in asphalt-aggregate system to highlight the aspects of such complex mechanisms based on previous studies performed on the RHL. Also, a developed methodology using the Fourier Transform Infrared Spectroscopy (FTIR) technique that was further supported by quantum chemical calculations was employed to quantify the hydrated lime reactive group (hydroxyl group, O-H) within the hydrated lime (RHL and NHL)-modified asphalt binder in an attempt to present a fundamental basis behind the effect of particle size on the chemistry of hydrated lime-asphalt system. In line with the physical results obtained from related studies, the hydrated lime particle size is a contributing factor to its functionality in the asphalt-aggregate system.

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International Journal of Pavement Research and Technology