Improved comprehensive adhesion performance of aggregate- recycled asphalt interface via incorporating steel slag

Abstract

Steel slag, a typical industrial waste, reveals high alkalinity and abundant texture, endowing its excellent adhesion performance with asphalt and facilitating its implementation in recycled asphalt mixture. While few studies focused on the interaction mechanism and comprehensive adhesion performance of steel slag- recycled asphalt interface. Hence, this topic merits further exploration. In this study, the interface models of steel slag-asphalt were established and their interface parameters also were surveyed. And the comprehensive evaluation index of adhesion performance was explored by the improved radar chart. The experimental results elaborate that steel slag exhibits the larger surface energy of 46.69 mJ/m2 and higher percentage of dispersion component of 76.6 %. Recycled asphalt-steel slag demonstrates the greater adhesion work, the smaller exfoliated work and the larger adhesive destructive force than recycled asphalt-basalt, indicating its superior adhesion ability. Steel slag-asphalt molecule behaves the lower radial distribution function and larger interfacial bonding energy due to the dual provision of van der Waals force and electrostatic adsorption force. The exfoliated work in experiment and adhesion work in simulation presents a Pearson correlation coefficient of −0.683, resulting in their strong negative correlation. Steel slag-recycled asphalt interface with the higher comprehensive evaluation index of 0.9155 reveals the superior comprehensive adhesion performance than basalt- recycled asphalt.