Marble dust as a sustainable cementitious material: investigating the synergistic effects of curing conditions

Abstract

This study examines the effect of seven different curing regimes (normal water, marine environment, ambient, jute bag, polythene bag, accelerated water, and carbonation curing) on the mechanical properties and durability of concrete that incorporates marble dust as partial replacement of cement at 0%, 2.5%, 5%, 7.5%, 10%, 12.5%, and 15% replacement rates. The curing regime considerably impacted minimizing the compressive, flexural, and split tensile strength losses induced by increased marble dust content. Under normal water curing, an optimum 7.5% marble dust dosage resulted in a 9.5% increase in 28-day compressive strength over the control mix. Carbonation curing resulted in higher 28-day flexural strengths (up to 12.5% marble dust) than normal water curing. Marine environment curing reduced strength significantly (up to a 30.1% decrease at 7-day compressive strength at 15% marble dust) due to chloride ion interference. Water absorption dropped by up to 15.7% at the optimal 7.5% marble dust dosage under normal water curing but increased by up to 3.9% under ambient curing, highlighting the importance of adequate curing for pozzolanic reactions. Rapid chloride permeability testing revealed up to 53.9% lower charge passing values under normal water curing at 15% marble dust, demonstrating better chloride resistance when compared to other curing regimes. Continuous hydration and pozzolanic reaction facilitation through appropriate curing procedures, such as conventional and accelerated water curing, significantly increased performance at optimal marble dust dosages. The study emphasizes the importance of adjusting curing regimens to optimize the use of marble dust as a sustainable SCM in concrete production.