Paper Contents
Abstract
The transformation of industrial steel waste into value-added construction materials represents a vital strategy for advancing sustainable development, promoting resource efficiency, and supporting the principles of a circular economy. Among various industrial by-products, steel slag has drawn significant attention due to its abundant availability, high specific gravity, and potential pozzolanic activity. Rather than being landfilled, which poses environmental and land use challenges, steel slag can be incorporated into concrete as a partial replacement for natural aggregates, thereby reducing reliance on virgin materials while enhancing performance. Complementing this approach, the addition of polypropylene fibers (PPF) offers a secondary benefit by addressing the issue of microcracking, which is a primary cause of water ingress and reduced durability in conventional concrete. This study investigates the synergistic contribution of steel slag and PPF in the development of waterproof concrete with superior mechanical and durability characteristics. Experimental investigations included the partial replacement of natural coarse aggregates with steel slag at varying proportions, coupled with the introduction of PPF as a crack-control additive. The concrete specimens were subjected to a comprehensive series of durability tests including water absorption (ASTM C642), sorptivity (ASTM C1585), depth of water penetration (EN 12390-8), and rapid chloride permeability (ASTM C1202), alongside compressive strength evaluations. The results revealed that the optimum mix configuration occurred at 30% slag replacement combined with 0.250.50% PPF. At this dosage, compressive strength increased by approximately 20%, water absorption reduced by 35%, and chloride permeability decreased by nearly 40% compared to the control mix, indicating a substantial improvement in both strength and impermeability. Microstructural characterization through SEM and XRD provided further insights, showing a denser microstructure, refinement of pores, reduced portlandite content, and enhanced formation of calcium silicate hydrate (CSH) gel. These findings suggest that the combined use of steel slag and PPF not only enhances mechanical properties but also imparts superior resistance against aggressive environmental conditions. Therefore, this dual approach offers a practical pathway for extending the service life of reinforced concrete structures, while simultaneously valorizing industrial waste for sustainable construction practices.
Copyright
Copyright © 2025 SHUBHAM RAI. This is an open access article distributed under the Creative Commons Attribution License.
