Abstract
Steel slag has been used widely as an aggregate in road application, but it could pose a contamination risk for the environment due to considerable heavy metals (HMs). To explore the leaching behavior and contamination risk of HMs from steel slag and its asphalt mixture is of great significance. In this study, the physical-chemical features, batch leaching test and semi-dynamic test were conducted to determine the mobility capability and leaching characteristics of HMs. The results show that steel slag presents a low pollution risk in short-term leaching, whereas the cumulative release mass of Cd, Ni, As and Pb are more than or approach the limits, which indicates that steel slag exhibits environment impacts to a certain extent. Steel slag covered with asphalt binder results in As and Cu reduced by 3.64% and 4.83%. Diffusion is the main controlling mechanism of HMs in asphalt mixture and the mobility capability of most HMs were classed as “low mobility” (LI > 8). Asphalt stripping off can aggravate the release potential of HMs from asphalt mixture, but the pollution risk remains controllable.
Highlights
Waste solids are usually believed useless materials produced from all human industrial, commercial, building and demolition activities [1]
Some pores with different sizes are distributed on the surface of basic oxygen furnace slag (BOFS), which agrees with the fact that BOFS is a porous material
It was obvious that the morphology feature of the surface of BOFS is very rich, which is one reason to form the abundant microspores
Summary
Waste solids are usually believed useless materials produced from all human industrial, commercial, building and demolition activities [1]. Attributed to the above, significant attempts have been made to study the engineering properties of various waste solids as raw materials in the construction industry, which is beneficial to relieve dependence on virgin mineral and divert waste materials from landfills. Tugrul et al [2] studied waste marble as an ingredient in concrete, and indicated that the concrete which consists of waste marble instead of the coarse/fine aggregate, cement, and mixture material in certain rates exhibited higher strength. Steel slag, characterized by high basicity, rich geometric features and excellent mechanical properties [4], has been justified its feasibility to replace aggregate in road engineering [5,6]. E Masad et al [7] noted that the steel slag has the stronger bonding strength with asphalt binder in comparison to natural aggregates. The water damage resistance, as well as the stiffness and fatigue life of steel slag based asphalt mixture improved due to the vesicular and pitted structure of steel slag [8,9,10]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
