Life cycle assessment (LCA) is a methodology that has been widely used to evaluate the environmental impact of products and processes throughout entire life cycles. In this context, the reuse of waste in paved road construction is a practice that has received increasing attention as a sustainable alternative to solid waste disposal. This article presents a systematic review of existing studies on the LCA of paved roads that incorporate waste reuse and proposes a guideline for LCA in this context. Several criteria were analyzed in the articles, and the results showed that only 5% of the articles followed all the recommendations set out in ISO 14040. The proposed guideline aims to provide guidance for future research and includes recommendations for each of the steps involved in LCA, from defining the objectives and scope of the study to interpreting the results.

This study aims to systematically synthesize and critically evaluate the characteristics of electric arc furnace slag (EAFS) and ladle furnace slag (LFS) when applied as an alternative paving material. A systematic literature review was conducted following the PRISMA methodology, with research published between 2000 and 2024. Three major databases were searched, considering only Q1–Q2 and English articles. After independent, blinded screening by two reviewers, a total of 177 papers met the selection criteria. The results were qualitatively synthesized through bibliometric analysis, slag characteristics, and application type. Results show that asphalt concrete (AC) is the most common application of EAFS, representing 61% of studies, with many studies exploring 100% substitution of natural aggregates. Overall, EAFS and LFS demonstrate favorable mechanical properties, including high toughness, hardness, and adequate soundness, largely attributed to their iron-rich composition, supporting their use in base layers, AC, and Portland cement concrete (PCC). However, significant chemical and mineralogical variability influences swelling potential and reactivity, highlighting the need for case-specific characterization. While swelling concerns limit its use as an unbound base material, these issues are reduced when EAFS and LFS are used as a soil binder or encapsulated within AC or PCC matrices. Environmental assessments show that most EAFS and LFS samples meet the regulatory thresholds for their respective local leaching limits, though behavior varies with steel type (low-alloy vs. stainless), particle size and pH. Significant gaps remain in long-term performance and testing standards. This review proposes guidelines for selecting appropriate tests according to the intended pavement application, aiming to facilitate the safe and effective use of EAFS and LFS in road infrastructure.

Soil stabilization using chemical additives is a proven technique for enhancing the strength and performance of weak subgrade soils. Electric arc furnace (EAF) slag has shown significant potential to improve the geotechnical and mechanical properties of soils because of its unique chemical and physical characteristics. However, the heterogeneous nature of EAF slag makes it challenging to determine whether a specific source is suitable for stabilization purposes. This study aimed to identify key EAF micro- and mesoscale properties that contribute to the development of effective soil stabilization mechanisms. To achieve this, a comprehensive characterization program was established to evaluate the slag’s chemical, physical, mechanical, morphological, and mineralogical characteristics. Fully graded EAF samples and slag fines were considered for soil stabilization. A silty clay soil considered poor for pavement applications according to the AASHTO classification system was stabilized with different additives (fly ash, cement, and EAF) to assess the effectiveness of the steel coproduct as a stabilizing agent. Chemical analyses confirmed the presence of key oxides (CaO, SiO ₂ , and Al ₂ O ₃ ) in the EAF samples, although limited reactivity was observed because of dominant crystalline phases. In the soil mixtures, the swelling potential was reduced from 0.92% to 0.29%, and strength significantly improved with slag fines, indicating pozzolanic activity. When combined with 2.5% cement, EAF slag produced synergistic effects, outperforming cement alone with an increase of 17% for 7 days of curing. The findings highlight the importance of slag composition and confirm its viability as a sustainable, performance-enhancing alternative for soil stabilization.

The use of industrial co-products as components for civil construction has been a good way to promote a circular economy in the sector. However, this material must be analyzed so it avoids offering future risks. Life cycle assessment is an essential tool to quantify the environmental impact of replacing or integrating new components. Thus, this study aims to compare the potential environmental impacts between a crushed embankment designed with crushed natural aggregate (gravel and clay) and an embankment designed with steel aggregate to replace gravel on the OpenLCA software, which is an open life cycle assessment tool. The carried-out assessment considered the impact of materials and the construction of the embankment (cradle to construction site). Results indicate that using steel aggregates to replace natural aggregates offers environmental advantages for the evaluated proposition as the steel plant lies within up to 243 km from the work site.