Surface Modification of Steel Slag Aggregate for Engineering Application in Asphalt Mixture

Abstract

The proper disposal of steel slag has always been a great challenge for the metallurgical industry in China and around the world. In this work, the steel slag aggregate (SSA) was surface pretreated (PSSA) and applied into asphalt mixture. The adhesive behavior between the bitumen and five different types of aggregates (i.e., limestone, diorite, diabase, SSA, PSSA) were evaluated based on the contact angle and binder bond strength tests. The pavement performance of three asphalt mixtures which contain normal aggregate, SSA and PSSA respectively, was analyzed by Marshall stability test, wheel-tracking rutting test, low-temperature bending creep test and water sensitivity test. The results showed that surface modification can improve the surface properties of SSA, reduce its contact angle with bitumen, and eventually lead to the improvement of adhesion between them. In addition to the satisfied low-temperature properties, PSSA was found to significantly improve the anti-rutting property and reduce the water sensitivity of asphalt mixture. This work is expected to promote an alternative application for recycling of SSA in pavement engineering.

Double Effects of Oxidative Aging on Carbon Nanotube–Asphalt Nanocomposite Interfaces: Enhancement and Deterioration

“…Currently, researchers are aware of the multiscale nature of asphalt interfacial aging and have used a variety of techniques to explore the phenomenon, including molecular dynamics (MD) simulations, , Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and property evaluation. , However, these studies tend to summarize information from multiscales and rarely involve coupling between different scales . In addition, the dual effect of macroscopic properties and the multifactorial nature of aging make it difficult to clarify the pathways and mechanisms of asphalt property change.…”