Evaluation of strength and absorption behaviour of iron slag and recycled aggregates concrete and its comparative environmental estimation by life cycle assessment

Sustainable infrastructure is one of the fastest growing sectors and is concurrently producing huge amount of construction demolition waste (CDW). Correspondingly, industrial activities also result in generation of similar wastes, out of which slag from iron industries pose a serious threat to the environment. This study attempts to incorporate both of the above-mentioned wastes in concrete, thereby an attempt to encourage and contribute towards sustainability. The experimental program comprises the evaluation of strength and water absorption behaviour along with the prediction and validation of iron slag (IS) and recycled aggregate concrete (RAC). The replacement levels for IS range from 10 to 30% while those for recycled concrete aggregates (RCA) range from 0 to 50%. Based on the experimental outcomes, the predicted equations for strength and water absorption characteristics were established. Furthermore, the statistical analysis was performed, indicating the desired responses thereby validating the efficiency of the tested properties of IS–RAC concrete. The successful analysis indicates the optimum constituent mix of 24.8% IS and 26.9% RCA for maximum strength and water absorption behaviour. Finally, a comparative environmental estimation was performed by life cycle assessment, describing a reduction of nearly 12.28% and 22% in carbon dioxide emissions and eco-cost in optimized concrete respectively.