Sustainable Use of Imperial Smelting Furnace Slag in Cement Concrete Pavements: Mechanical Performance, Economic Viability and Environmental Impact

This study investigates the use of imperial smelting furnace (ISF) slag, a zinc industry by-product, as a sustainable replacement for natural fine aggregate (FA) in concrete pavements. Laboratory specimens were prepared by substituting natural FA with ISF slag from 0-100%. Laboratory specimens were prepared by substituting natural FA with ISF slag from 0 to 100% on volume basis. Results showed that incorporating ISF slag enhances compressive and flexural strength up to 60% replacement at 7 and 28 days, after which strength declines. Additionally, the compressive strength of dry lean concrete (DLC) mixes prepared with an aggregate-to-cement ratio of 10:1 and results indicated that the compressive strength increased with an increase in ISF slag content. Split tensile strength increased from 3MPa at 0% to a peak of 4.54MPa at 80%, before decreasing to 4.16MPa at 100% at 28 days. Thus, ISF slag offers economic and environmental benefits for sustainable pavement construction.