Performance based evaluation of ISF slag as a substitute of natural sand in concrete

Abstract

ISF (Imperial Smelting Furnace) slag is generated during refining of lead and zinc. This slag contains heavy metals and requires safe disposal options for a healthy environment. In this study, ISF slag has been used as sand in concrete to address cleaner production and sustainability of natural materials. The suitability of the slag as sand has been established by comparing the performance of slag concrete with control concrete.Up to 70% volumetric proportion of sand was replaced with ISF slag and concrete mixes at different water to cement ratios were prepared. Durability was ascertained by comparing the transport properties, chloride induced corrosion of embedded steel, shrinkage, and microstructure of control and slag concrete. Slag concrete demonstrated increased resistance to carbonation, reduced initial shrinkage, and improvement in resistance to steel corrosion in comparison with control. Sorptivity and chloride diffusion of slag concrete was comparable with control for up to 70% replacement of sand. The microscopic studies highlighted that the morphology of slag particles govern the differences observed in various characteristics of slag concrete. The results ensured that it is possible to produce durable concrete using ISF slag as partial substitute of natural sand.