Adhesion Evaluation of Asphalt-Aggregate Interface Using Surface Free Energy Method

Abstract

Abstract:The influence of organic additives (Sasobit and RH) and water on the adhesion of the asphalt-aggregate interface was studied according to the surface free energy theory. Two asphalt binders (SK-70 and SK-90), and two aggregate types (limestone and basalt) were used in this study. The sessile drop method was employed to test surface free energy components of asphalt, organic additives and aggregates. The adhesion models of the asphalt-aggregate interface in dry and wet conditions were established, and the adhesion work was calculated subsequently. The energy ratios were built to evaluate the effect of organic additives and water on the adhesiveness of the asphalt-aggregate interface. The results indicate that the addition of organic additives can enhance the adhesion of the asphalt-aggregate interface in dry conditions, because organic additives reduced the surface free energy of asphalt. However, the organic additives have hydrophobic characteristics and are sensitive to water. As a result, the adhesiveness of the asphalt-aggregate interface of the asphalt containing organic additives in wet conditions sharply decreased due to water damage to asphalt and organic additives. Furthermore, the compatibility of asphalt, aggregate with organic additive was noted and discussed.

Effect of RAP content on flexural behavior and fracture toughness of flexible pavement

“…3. The bond strength of the interface depends on the compatibility between the bitumen and aggregate as mentioned by Ji et al (2017). As is already known, there are two different types of bond strength of the interface, i.e.…”

Fundamental Approaches to Predict Moisture Damage in Asphalt Mixtures: State-of-the-Art Review

“…Method to determine surface energies of bituminous binders [18,20,21,23,24,26,[28][29][30][34][35][36][37][38][39][40][41][42][43][44][45][46][47] Wilhelmy plate tests in probe liquids (VCG), ambient [20,39,[48][49][50][51] Sessile drops of probe liquids on bitumen surface (VCG) ambient [18,20,35] Inverse gas chromatography (CVS) [46,52] Pending drop (100-140 • C) combined with sessile drop on PTFE (OW) [53] Sessile drops on a microtome-cut bitumen surface 20 • C (OW) [39,54] Sessile drops of probe liquids on bitumen surface (OW) ambient [55] Dynamic sessile drop measurements of probe liquids on a bitumen surface (VCG) [56] Pending drops of bitumen (100-130 • C) (γ total) [53] Pending drops at equiviscous temperatures (γ total) [57] Pending drops of bitumen at a fixed G* 209 Pa (γ total) [39] Wilhelmy plate tests in probe liquids (OW) ambient [20] Atomic force microscopy (dispersive component)…”

“…Method to determine surface energies of aggregates used in asphalt applications [18,19,21,23,24,26,[28][29][30]35,36,38,40,41,45,46,[58][59][60] Universal sorption device (VCG) [49][50][51]55] Sessile drops of probe liquids on flat aggregate (VCG) [53,57,61] Sessile drops of probe liquids on flat aggregate (OW) [20,28] Micro calorimeter (VCG) [20] Inverse gas chromatography (VCG)…”

Incorporation of Additives and Fibers in Porous Asphalt Mixtures: A Review

“…The stripping phenomenon is a thermodynamically favorable condition as, in the presence of water, the adhesion of aggregate and bitumen is worse than that of aggregate and water [60,61,62]. In the absence of fillers, using additives may improve the adhesion between aggregates and bitumen [63]. Ye and Jian [64] mentioned that the adhesion of fiber and bitumen is better than bitumen and aggregates; thus, adding fiber leads to better resistance to moisture.…”