COMPARATIVE CARBON FOOTPRINT ASSESSMENT OF PALM KERNEL SHELL CONCRETE AND CONVENTIONAL GRANITE CONCRETE

ABSTRACT

The increasing demand for environmentally sustainable construction materials necessitates the evaluation of embodied carbon in conventional concrete systems. This study presents a cradle-to-gate life cycle assessment (LCA) comparing the carbon footprint of Palm Kernel Shell Concrete (PKSC) and Normal Weight Concrete (NWC). Palm kernel shell (PKS), an agricultural by-product, was used as a full replacement for granite coarse aggregate in a 1:2:4 mix with a water–cement ratio of 0.65. Embodied carbon emissions were quantified per cubic metre of concrete and further normalised against compressive and flexural strengths to evaluate performance-based environmental efficiency. Results indicate that PKSC achieved a carbon reduction of approximately 30–36% compared to NWC across curing ages. However, strength-normalised carbon intensity values revealed that PKSC exhibited higher emissions per MPa due to its lower compressive and flexural strengths. Material contribution analysis showed that cement accounted for over 85% of total embodied carbon, confirming that binder production remains the dominant emission source. Sensitivity analysis demonstrated that transport distance increases total emissions linearly, with lightweight PKSC maintaining environmental advantages due to reduced mass. The findings suggest that while PKS aggregate contributes to waste valorisation and moderate carbon reduction, substantial decarbonisation requires integrated strategies targeting cement replacement and mix optimisation.