Study of remobilization phenomena at reclaimed asphalt binder/virgin binder interphases for recycled asphalt mixtures using novel microscopic methodologies

Experimental investigation of blending phenomena in intergranular zones of recycled asphalt mixtures using customized infrared imaging and stage extraction methods

“…Thus, for asphalt mixtures incorporating high rates of RA, the degree of remobilization (or mixing) would be less complete. This interpretation of a low RA binder remobilization in warm-mix asphalt mixtures is in a good agreement with a previous study [53] performed at the microscopic binder scale which had highlighted that remobilization was lower with the aged binder temperature reduction.…”

“…An infrared microscope (Spotlight 400, Perkin Elmer) was used with an ATR (Attenuated Total Reflectance) accessory for which the crystal diameter equals to 600 µm. A complete apparatus description is available in [53], [55]. Briefly, the intimate contact is performed between the compacted asphalt mixture specimen surface and the ATR crystal tip.…”

“…As obtained results will enlarge the discussion about binder interactions, the degree of remobilization (or that of mixing) is also a term which is introduced here. As mixing is a process operation of two components in known amounts [35], [52], the degree of mixing corresponds here to the RA aged binder amount activated and available in the mix because only the manufacturing conditions and the RA binder properties allow the determination of the real activated amount of the aged binder [53].…”

On the degree of binder activity of reclaimed asphalt and degree of blending with recycling agents

“…These concepts seem to be widely recognised by the scientific community, however the results of a literature review (Table 1) highlighted that practitioners have not yet achieved a general consensus on the terms related to the blending phenomena and authors use concepts and terms interchangeably. Amongst these: blending efficiency (Bowers, Huang, Shu, & Miller, 2014;Bowers, Moore, Huang, & Shu, 2014;Xu, Hao, Zhang, & Yuan, 2018), blending status (Zhao, Huang, Shu, & Woods, 2016), blending ratio (Delfosse, Drouadaine, Largeaud, & Dumont, 2016), rate of intermixing (Oliver, 2001), binder transfer (Zhang, Wen, & Hobbs, 2015), mobilization rate (Bressi et al, 2015;Ding, Huang, & Shu, 2018;Vassaux et al, 2018;Zhao, Huang, Shu, & Woods, 2015), meso-blending (Gundla & Underwood, 2015) and the most used terminology by far degree of blending (DoB) (Abd, Al-Khalid, & Akhtar, 2018;Al-Qadi et al, 2009;Booshehrian, Mogawer, & Bonaquist, 2013;Castorena, Pape, & Mooney, 2016;Cavalli, Partl, & Poulikakos, 2017;Coffey, Dubois, Mehta, & Purdy, 2013;Gaitan et al, 2013;Kriz et al, 2014;Liphardt, Radziszewski, & Król, 2015;Mogawer, Booshehrian, Vahidi, & Austerman, 2013;Mogawer et al, 2012;Navaro et al, 2012;Norton et al, 2014;Rinaldini, Schuetz, Partl, Tebaldi, & Poulikakos, 2014;Shirodkar et al, 2013Shirodkar et al, , 2011Stephens, Mahoney, & Dippold, 2001). (Vassaux et al, 2019) "Blend" presents the ability of two components to create a homogenous product where the chemical composition is identical everywhere at the scale observation of the study.…”

On the Applicability of ATR-FTIR Microscopy to Evaluate the Blending between Neat Bitumen and Bituminous Coating of Reclaimed Asphalt

“…The analysis was applied on the bitumen level using markers to track the mobilization of artificially aged bitumen. The conclusion was that ATR imaging was the most successful technique [24]. Other studies have evaluated the blending of asphalt concrete enriched with titanium dioxide (TiO 2 ) as a tracer using Computer Tomography (CT), in macro-and micro-scale [25], and using environmental scanning electron microscopy (ESEM) [7,25].…”