Mechanical and Microstructural Analysis of Jarosite-Enhanced Concrete for Sustainable Construction

¹ Department of Civil Engineering, Babu Banarasi Das University, Uttar Pradesh, Lucknow, India
² Department of Civil Engineering, Z.H College of Engg.& Tech., AMU, Aligarh, Uttar Pradesh, India

Abstract

This research explores the effects of incorporating jarosite, a byproduct from the zinc industry, as a partial substitute for cement in concrete on its mechanical performance, durability, and microstructural characteristics. Four concrete mixes, including a control mix (M45) and mixes with jarosite replacing 10%, 15%, and 20% of the cement, were prepared and tested. The results show that jarosite reduces workability but maintains stable density. Compressive strength was highest at 15% jarosite replacement, exceeding the control mix at 28 and 56 days. A similar pattern was observed in split tensile strength, though the control mix still demonstrated the greatest tensile strength. Water absorption increased with jarosite content but remained comparable to the control mix at 15% and 20% replacements. Electrical resistivity tests indicated low to moderate corrosion risk, with the 20% jarosite mix showing the best resistance. Microstructural analysis via SEM revealed denser calcium silicate hydrate (CSH) gel structures in the 15% jarosite mix, enhancing strength, while the 20% mix exhibited voids, potentially affecting durability. Overall, 15% jarosite proved to be the optimal replacement level, offering improved mechanical performance and durability, with potential benefits for sustainable concrete production.