Preliminary Validation of Steel Slag-Aggregate Concrete for Rigid Pavements: A Full-Scale Study

Abstract

The high wear resistance and toughness of electric arc furnace slag (EAFS) means that this industrial by-product can successfully replace natural aggregate in hydraulic or bituminous concretes that withstand vehicle traffic. This article validates the use of concrete made with large amounts of EAFS for rigid pavements. Accordingly, three EAFS–concrete mixes made with metallic or synthetic fibers were designed. Their performance was studied through laboratory tests (compressive strength, modulus of elasticity, splitting tensile strength, and abrasion resistance) and field observations on full-scale slabs made with each of the studied mixes. All mechanical properties yielded adequate results for concrete for rigid pavements. The metallic fibers increased the strength and elastic stiffness by 7–10%, while the addition of synthetic fibers slowed the development of these properties over time. On the other hand, all the mixes allowed for a successful implementation of full-scale slabs, with none of them showing excessive deterioration after five years of exposure to the outdoor environment. Only minor cracking and some chips in the surface-treatment layer were detected. The strength development of the slabs and their slipperiness were adequate for use in high-speed pavements. The overall analysis of the results shows that concrete made with EAFS can be used in real rigid pavements.

Viability of Using High Amounts of Steel Slag Aggregates to Improve the Circularity and Performance of Asphalt Mixtures

“…In the last decades, the steel industry in Europe has transitioned towards the electric arc furnace steelmaking technology, being used for approximately 30% of European steel production [15]. In Portugal, there are two steelworks, one located in Seixal (SN Seixal), and the other in Maia (SN Maia), which belong to Siderurgia Nacional (SN) Empresa de Produtos Longos, SA.…”

“…It is a granular material with a high micro-porosity, very high density, around 3.5 Mg/m 3 , an angular shape, and excellent wear resistance. This slag has excellent properties for use in asphalt mixes, being especially suitable for surface courses where skid resistance and durability are critical functional requirements and for producing asphalt mixes subjected to heavy traffic [15,18,19]. Some previous research has shown that using this material improves the mechanical properties of the asphalt mixtures, such as durability, workability, stiffness, permeability, stability, resistance to fatigue, and permanent deformation [20][21][22][23][24][25].…”