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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]

• Bricks made from AAC achieved a high superiority in compressive strength compared with conventional cement bricks. • Higher glass water decreases AAC setting time and leads to rapid flash setting. • High alkali-activated binder content increases compressive strength, density, and drying shrinkage. • Manufacturing compaction pressure has a significant effect in the enhancement of AAC bricks properties. • Fully green bricks could be made with wasted slag aggregates. Alkali-activated concrete (AAC) has shown high potential as a replacement for ordinary Portland cement concrete (OPCC). It has been found that fresh AAC is usually dry and difficult to control during the casting process, as well as having flash setting issues. In light of the lack of a final form for the use of AAC in construction, there is a need to discover applications that benefit from the advantages of AAC while also being able to deal with its drawbacks. This paper will focus on taking advantage of AAC's defects by using it in a nonstructural application that does not require high-workability concrete, such as producing bricks. Waste from the iron industry was used as the main component for producing the AAC bricks in order to reduce the environmental impact, reduce the cost, and save large quantities of cement and natural aggregates consumed by the brick industry. Ground granulated blast furnace slag (GGBFS) and electric arc furnace slag (EAFS) were substituted for cement and aggregates, mixed along with an alkaline solution and superplasticizer. AAC bricks were produced in the same way as normal concrete bricks. The physical and mechanical properties studied were compressive strength, water absorption, bulk density, efflorescence, and drying shrinkage. Six parameters were considered throughout this investigation. The effects of binder content, cement replacement ratio, alkaline-to-binder ratio, sodium silicate/sodium hydroxide mass ratio, sodium hydroxide molarity, and compaction pressure. The results showed that compared to ordinary bricks, AAC bricks provided high compressive strength up to 92 MPa, up to 54% less water absorption, a density of more than 2.8 t/m3, and a higher drying shrinkage up to 0.002 mm. Furthermore, no signs of efflorescence or salts appeared on the bricks. [ABSTRACT FROM AUTHOR]

• Solid waste-based magnetic response particles. • Active control of rheological properties. • Rheological properties are linearly related to additional energy. Interventions at the print head, such as magnetic fields, are expected to efficiently improve the buildability of 3D printed concrete (3DPC) without compromising flowability. A cement-based magneto-rheological (MR) fluid material has been developed using electric arc furnace slag powder (EAFSP). This paper found that the storage modulus and dynamic yield stress of cement-based MR fluids dramatically increased with the magnetic field strength and EAFSP concentration. According to the linear fitting results, the rheological properties correlate with the additional energy the magnetic moment obtains whenever a constant magnetic field is applied. Furthermore, after a time-limited magnetic sweep, the 3DPC buildability was improved, probably due to the presence of residual chain-like structures. This research assumes significance for the application of set-on-demand 3DPC. [ABSTRACT FROM AUTHOR]

[Display omitted] • Laboratory study of porous asphalt concrete made with electric arc furnace (EAF) steel slag and RAP. • With the use of 30% of RAP and/or 30% of artificial aggregates it is possible to obtain suitable porous asphalt materials. • The results showed the technical feasibility of the experimental porous mixtures. • The environmental assessment compared the porous asphalt mixture to enhance the use of artificial and recycled aggregates. • The LCA analysis proved that RAP and EAF steel slag improve the environmental performances of the porous asphalt mixtures. Porous asphalt mixtures play a remarkable role in road pavement thanks to their advantages to drain water and reduce noise. To meet the always-increasing environmental needs, new porous asphalt mixtures are being developed with the addition of recycled materials. The present paper investigates the physical, mechanical, and functional characteristics of two porous mixtures made with electric arc furnace (EAF) steel slag and reclaimed asphalt pavement (RAP). The properties of the two recycled mixtures are compared with conventional porous asphalt produced with natural aggregates. An LCA analysis is performed with a cradle-to-gate approach to evaluate and compare the possible environmental benefits connected to the production of the experimental porous asphalt. The results coming from the laboratory investigation demonstrated higher mechanical and functional performances related to the use of EAF steel slag and RAP aggregates. The environmental assessment established a reduction of up to 25% of potential impact for the mixture produced with both artificial and recycled aggregates. [ABSTRACT FROM AUTHOR]

• Experimental/numerical framework to design fiber-reinforced EAFS concrete elements. • Synthetic and steel fiber-reinforced EAFS concrete shows good mechanical performance. • Set of experiments is proposed to define the inputs required for the FE model. • Interface elements model synthetic and steel fibers bridging effect accurately. Over recent years, Electric Arc Furnace Slag (EAFS), a by-product of the steel-making industry, has been used as a replacement of natural aggregates to produce high-performance concrete. In EAFS concrete, fibers are normally added to improve post-cracking behavior, thereby prolonging the durability and range of applications of the composite. Despite the rise in its production, the mechanical performance of fiber-reinforced EAFS concrete is still poorly understood, posing important barriers to its daily use. This paper aims to study the effect of fiber materials (steel and synthetic) on EAFS concrete performance. To do so, the paper proposes, firstly, an experimental campaign and, secondly, a numerical simulation to model the effect of fibers both in the pre-cracking and post-cracking stages. Importantly, for the numerical study, an in-house Finite Element (FE) code is developed using interface elements to capture crack propagation. The FE code uses, as input, data obtained in the experimental campaign and is validated against previously unseen experimental results. The overall framework gives important insights on how fibers improve the post-cracking behavior of EAFS concrete and the relevance of fiber material in the overall performance. The validated numerical tool can be used in the future to design EAFS fiber-reinforced concrete structures and therefore increase the applicability of such composite material. [ABSTRACT FROM AUTHOR]

• Less dependence on PCE for 3DPC with EAFS fine aggregates. • 3DPC with EAFS possesses better flowability and buildability. • The spherical model of EAFS contributes to improved mechanical properties. • EAFS fine aggregates dense packing reduced the 3DPC pore volume. Polycarboxylate ether superplasticizer (PCE) is a popular option for improving the flowability of 3D printed concrete (3DPC). However, the side effects and high cost of PCE impede the development of 3DPC. In recent years, a spherical electric arc furnace slag (EAFS) was produced by a novel production method. It is, therefore, imperative to investigate the usage of EAFS's ball-rolling effect to improve 3DPC flowability. In this paper, the rheological properties, flowability, buildability, mechanical properties, and pore structure of superplasticizer-free 3DPC were determined with EAFS replacing 25%, 50%, 75%, and 100% of river sand (RS). The results were compared with the control sample which contains PCE and 100% RS. The rheological properties proved that both EAFS and PCE improved 3DPC flow initiation, but 3DPC with EAFS achieved a lower viscosity loss rate, which is beneficial to buildability. Under consistent printability conditions, the average flowability value of 3DPC with EAFS was 180 mm, which exceeded the control sample by 15 mm, and the optimum buildability was achieved when 50%–75% of RS was replaced. Furthermore, the EAFS spherical model allowed for significant improvements in 3DPC mechanical properties while also reducing the pore volume. Overall, utilizing EAFS to improve 3DPC flowability successfully eliminates dependence on PCE, while optimizing buildability and mechanical properties, among other benefits. [ABSTRACT FROM AUTHOR]

• Energy efficiency in MW heating is improved by increasing the loss factor ε″. • The incorporation of EAF slag in asphalt mortars increased its loss factor ε″. • Within the 0.1–6 GHz range, the frequency 5.8 GHz yielded the highest value of ε″. • Microwave radiation at a frequency of 5.8 GHz can penetrate the pavement 7 cm. Microwave (MW) heating could contribute to the sustainability of the construction and maintenance of asphalt pavements. The relationship between frequency and the dielectric properties (i.e. loss factor and penetration depth) is crucial for maximising the MW heating efficiency. The paper aims to study the dielectric properties of conventional and electric arc furnace (EAF) slag asphalt mortars. Results showed that the addition of EAF slag enhanced the dielectric response of asphalt mortars. Moreover, a frequency of 5.8 GHz seems to be the best choice for deicing application and assisted-healing of surface layers up to 7 cm. [ABSTRACT FROM AUTHOR]