Utilizing agricultural turmeric bulbs as an alternative to traditional coarse aggregates in geopolymer concrete to explore its engineering properties

Abstract

Extensive infrastructure development has led to the overexploitation of traditional virgin materials. To preserve the ecosystem, it's crucial to find alternatives. This study explores the viability of using turmeric bulb (TB) as a substitute for virgin coarse aggregate in geopolymer concrete (GPC). With 36 trial mixes varying in activator concentration and curing methods, the aim is to assess TB as a filler material replacement. Experimental trials revealed that replacing up to 20% of the coarse aggregate with TB maintained 28-day compressive strength at 35–38 MPa under ambient curing. However, with oven curing, strength was sustained only up to a 30% TB replacement, beyond which it declined. The UPV value for concrete with 50% TB was 3.79–3.9 km/s. Increasing the activator concentration from 8 M to 16 M significantly enhanced GPC strength, ranging between 24 and 36 MPa. GPC blended with TB showed a higher rate of water absorption, ranging from 24% to 26% for 50% replacement of conventional coarse aggregate. Sustainability analysis revealed that lower activator concentrations (e.g., 8 M) offered a more sustainable alternative to traditional cement concrete. In conclusion, this study underscores the potential of replacing coarse aggregate in GPC, promoting eco-friendly concrete production through sustainable practices and optimized activator concentration.