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In this study, four different sources of electric arc furnace oxidizing slag (EOS) were selected. The relationship between the composition of EOS and its expansibility was analyzed, and an autoclave pulverization rate test technique was developed to evaluate the expansibility of EOS. When the MgO/(FeO+MnO) in EOS is

In this study, a standard pH test procedure, based on the high alkalinity of electric arc furnace oxidizing slag, was developed for rapid content evaluation of potentially hazardous slag in the fine aggregate and recommended standards are further proposed. The advantages of the developed procedure include easy equipment acquisition, simple test method, short time, and high accuracy. This study found that sample size, water source, and filtrate process were the factors affecting the pH test accuracy. In the test, the pH increased with a decrease in the aggregate size when the proportion of electric arc furnace oxidizing slag in aggregate was fixed, especially when the aggregate size was less than 0.225 mm. Upon comparison of the results of autoclaved mortar bar expansion tests, a good logarithmic relationship was observed between pH and electric arc furnace oxidizing slag content. It is suggested that pH 9.0 could be used as the standard to determine excessive electric arc furnace oxidizing slag in fine aggregate. • Proposed a standardized process for rapidly assessing pH in fine aggregates, addressing hazards from electric arc furnace oxidizing slag (EAFOS). • Optimized pH testing factors: D100 particles, RO water, 10 % solid content, filtration through 5A + 5B paper before measurement. • Sample pH values consistently showed a logarithmic relationship with EAFOS content proportion. • pH values over 9.0 indicate excessive EAFOS content in fine aggregates, making them unsuitable for further application. [ABSTRACT FROM AUTHOR]

Electric arc furnace oxidizing slag (EAFS) is a by-product of the steelmaking industry, generated after the melting and the preliminary acid refining of liquid steel. It is a stony material that is easy to crush for use as aggregate in concrete mixes. This study examines the long-term aging reactions of EAFS and its volumetric stability, to gain further knowledge of this by-product, its behaviour as a construction material, and its inherent risk of swelling. Additionally, the good compressive strength of hydraulic mixes that incorporate this slag can be analyzed and explained on the basis of its steady and expansive compounds and its chemical evolution over time in the interfacial transition zone (ITZ); the appearance of calcium carbonate enhances the cohesiveness, stiffness and strength of this zone and, as a consequence, of the hydraulic concrete. [ABSTRACT FROM AUTHOR]

The article presents a study which predicts the concrete compressive strength of electric arc furnace (EAF) oxidizing slag. The study used artificial neural network (ANN) and the grey model (GM) to examine the concrete physical properties of EAF slags produced in Taiwan including water absorption rate (RA), dry-nodded unit weight (DNUW), and Los Angeles abrasion test. Results show that the physical characteristics of EAF slag can be used effectively to predict compressive strentgh.

The application of electric arc furnace oxidizing slag (EAS) in high strength concrete (HSC) as the cementitious material is investigated in this study. The microstructure and mechanical properties of HSC with four different replacement ratios of EAS were evaluated and HSC with two replacement ratios of ground granulated blast furnace slag (GBS) was used for performance comparison. The results show that the HSC with EAS replacement ratios smaller than 15% undergo similar hydration processes and result in a similar final product when compared with those of NC-NN. Increases in EAS replacement ratio cause a reduction in Ca(OH)2 content; this, in turn, leads to an increase in porosity and a reduction in compressive strength. In terms of shrinkage behavior under free conditions, mixtures with increasing replacement ratios of cementitious materials saw increasing shrinkage, with the HSC containing EAS being similar to the other specimens. The mixtures containing EAS saw a quite gradual decrease in their freezing and thawing resistance properties as the number of freeze–thaw cycles they underwent increased. However, the efficacy of HSC with less than 15% of EAS is similar to GBS; hence, EAS could replace cement in concrete for certain applications, which would lead to more environmental benefits. [ABSTRACT FROM AUTHOR]