Optimizing nutmeg shell biochar production temperature for enhanced cement composite performance

The growing focus on sustainability has driven research into converting agricultural waste into biochar (BC) for concrete applications. As cement manufacturing contributes significantly to global CO₂ emissions, BC offers a promising replacement solution. This study investigates nutmeg shell BC as a sustainable cement alternative produced through pyrolysis at temperatures of 400 °C, 500 °C, and 600 °C, and incorporates it at concentrations of 1%, 2%, and 3% by weight. The main findings reveal that 2% BC prepared at 500 °C achieved optimal performance, with 23% and 27.57% increase in compressive strength and electrical resistivity, respectively, at 28 days. Additional benefits included enhanced water absorption resistance, reduced chloride permeability. Hydration analysis confirms BC’s porous structure provides nucleation sites for cluster formation during early hydration, representing a novel mechanism for accelerated strength development. This research demonstrates BC as a sustainable alternative to cement, offering environmental benefits through CO₂ reduction and the valorization of agricultural waste.