# Application of Foundry Wastes in Eco-Efficient Construction Materials: A Review
## 5 Valorization of Foundry Waste in Construction Materials
### Foundry Slag
The potential of using imperial furnace slag (ImFS) as a replacement for aggregates in concrete was explored by [PERSON] and [PERSON] [88]. The study examined the durability and performance characteristics of concrete with different proportions of ImFS replacing natural sand. The study validated the feasibility of using ImFS, with a maximum replacement of 70% of natural sand, to improve the durability and sustainability of concrete. By incorporating this slag into concrete with lower water/cement ratios, several advantages were achieved, such as greater resistance to carbonation, lower initial shrinkage, and better resistance to steel corrosion. The study conducted by [PERSON] et al. [89] tested the feasibility and effectiveness of replacing natural fine aggregates with copper slag in concrete, evaluating its strength and durability. The concrete mixtures were formulated with 30% GGBFS as a substitute for cement, and the natural fine aggregate was replaced with copper slag in different proportions. The study concluded that the replacement of copper slag in up to 40% of natural fine aggregates resulted in improvements in mechanical behavior and durability. The mechanical performance of the concrete was destabilized when substitutions exceeding 40% were made, mainly due to the increase in porosity. Thus, the use of copper slag in structural applications was recommended, with a maximum limit of 40%. [PERSON] et al. [90] investigated the feasibility of incorporating cupola furnace slag (CFS) as a partial substitute for natural aggregates in concrete and evaluated its long-term properties for potential industrial-scale application. The study concluded that the replacement of 25.5% of natural fine aggregate with CFS in concrete exhibited properties equivalent to or very similar to the reference concrete. However, both the reference concrete and the concrete with CFS did not exhibit adequate freeze-thaw resistance. The authors indicated that this problem could be solved by increasing the air content from the current 2-2.4% to about 5-6% in the fresh concrete mix. Basic oxygen furnace steel slag (BOFSS) was studied by [PERSON] et al. [91] as a potential coarse and fine aggregate for concrete. The study aimed to propose the substitution of traditional aggregates with BOFSS in concrete production, determine the ideal substitution levels, and evaluate the mechanical properties and microstructure of the resulting concrete. The study concluded that the proportions that led to better performance were the replacement of 50% for coarse aggregates and 30% for fine aggregates, with significant improvements in compressive strength compared to conventional concrete. Moreover, the use of BOFSS resulted in a notable reduction in porosity, increasing the density and durability of the concrete. The use of induction furnace steel slag (IFSS) in concrete was studied by [PERSON] et al. [92] as a way to create a high-density composite material that effectively protects against gamma radiation. The objective of the study was to evaluate how the addition of IFSS to concrete affected its density, compressive strength, and radiation shielding capacity. The developed concrete replaced 40% of coarse aggregates with IFSS and 100% of fine aggregates with IFSS, demonstrating better density, compressive strength, and radiation protection properties. The study concluded as its main result that it is possible to completely replace the fine particles without compromising the strength of the concrete. The behavior of roller-compacted concrete (RCC) using various percentages of aggregate replacement with electric arc furnace steel slag (EAFSS) was studied by [PERSON] et al. [93] The study assessed the possibility of substituting EAFSS both as fine and coarse aggregates, to evaluate its influence on the mechanical properties and fracture properties of the concrete.